tag:blogger.com,1999:blog-28965528082744551962024-03-05T21:02:38.921+00:00A Walker's RamblingsThoughts on the state of the world from David Cotton.
Might also include some walking.David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.comBlogger530125tag:blogger.com,1999:blog-2896552808274455196.post-89839767577494391862021-02-11T20:18:00.004+00:002021-02-11T20:18:40.228+00:00System safety<p> A couple of decades ago, a company was working on a new transport system that was *the future*. It offered fast, silent, and comfortable transport that had the potential to replace both rail and air.</p><p>They got millions in funding, and developed a fully-functioning record-breaking prototype.</p><p>A publicity document (1) mentioned 'safety' several times. It claimed:</p><p></p><blockquote>"Collisions between (the) vehicles are also ruled out due to the technical layout of the system and the section-wise switching of the ”guideway motor“. The vehicle and the traveling field of the guideway motor move synchronously, i.e. with the same speed and in the same direction. Additionally, the section of the longstator linear motor in which the vehicle is moving is only switched on as the vehicle passes."</blockquote><p></p><p>In other words, you can only have one vehicle on a track at once. This sounds brilliant, as you can only have a collision if two vehicles are on the same track, and the system does not allow two vehicles on the same section of track.</p><p>The system was the German Transrapid Maglev system. </p><p>In September 2006 (2), a Transrapid Maglev vehicle was in a collision at Lathen (3), killing 23 people. It collided with a maintenance vehicle on the track; a maintenance vehicle that did not depend on power from the track, and therefore 'defeated' the inherent safety systems mentioned in the paragraph above. Add in an earlier-than-usual Maglev test run, and multiple staff errors, and you had a tragedy. </p><p>No-one wanted the crash to occur; it was an accident, and yet it was totally caused by Human error, not an act of nature. The systems were not in place to prevent it.</p><p>What can we learn from this? Simply, safety is difficult. Human and technical errors compound safety issues, and therefore you require safety in depth with many fail-safes. These lessons have been learnt the hard way over a couple of centuries on the 'traditional' railway; they should not be forgotten by new systems, as the lessons are often paid for in human blood.</p><p>Most of all, safety has to be built-in to the system, not an afterthought. No system can be made safe by liberal applications of handwavium. And I fear this is a major issue with the proposed Hyperloop systems.</p><p>(1): <a href="https://www.ncl.ac.uk/media/wwwnclacuk/pressoffice/files/pressreleaseslegacy/TRI_Flug_Hoehe_e_5_021.pdf">TRI_Flug_Hoehe_e_5_021.pdf</a></p><p>(2): Sadly, the document is undated. However, it obviously dayes from before the crash.</p><p>(3): https://en.wikipedia.org/wiki/Lathen_train_collision</p>David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com1tag:blogger.com,1999:blog-2896552808274455196.post-37411377070800580252020-10-30T06:12:00.002+00:002020-10-30T06:12:15.493+00:00Pity the policymakers<div class="kvgmc6g5 cxmmr5t8 oygrvhab hcukyx3x c1et5uql ii04i59q" style="background-color: white; color: #050505; font-family: "Segoe UI Historic", "Segoe UI", Helvetica, Arial, sans-serif; font-size: 15px; margin: 0px; overflow-wrap: break-word; white-space: pre-wrap;"><div dir="auto" style="font-family: inherit;">Imagine you are a UK politician with power during this Covid crisis. It doesn't matter which party, or whether your power is national or local, whether you are PM or a mayor. Imagine yourself as a politician you like, or one you hate.</div></div><div class="o9v6fnle cxmmr5t8 oygrvhab hcukyx3x c1et5uql ii04i59q" style="background-color: white; color: #050505; font-family: "Segoe UI Historic", "Segoe UI", Helvetica, Arial, sans-serif; font-size: 15px; margin: 0.5em 0px 0px; overflow-wrap: break-word; white-space: pre-wrap;"><div dir="auto" style="font-family: inherit;">You need to make policy, and you need data to base that policy on. This week, two large studies have delivered some interesting and contradictory results.</div></div><div class="o9v6fnle cxmmr5t8 oygrvhab hcukyx3x c1et5uql ii04i59q" style="background-color: white; color: #050505; font-family: "Segoe UI Historic", "Segoe UI", Helvetica, Arial, sans-serif; font-size: 15px; margin: 0.5em 0px 0px; overflow-wrap: break-word; white-space: pre-wrap;"><div dir="auto" style="font-family: inherit;">According to Imperial College, there are ~96,000 cases a day in England alone. The R-rate is 1.56, and the number of cases are doubling every 9 days.</div></div><div class="o9v6fnle cxmmr5t8 oygrvhab hcukyx3x c1et5uql ii04i59q" style="background-color: white; color: #050505; font-family: "Segoe UI Historic", "Segoe UI", Helvetica, Arial, sans-serif; font-size: 15px; margin: 0.5em 0px 0px; overflow-wrap: break-word; white-space: pre-wrap;"><div dir="auto" style="font-family: inherit;">This may point to a hard lockdown - probably national - being required immediately.</div></div><div class="o9v6fnle cxmmr5t8 oygrvhab hcukyx3x c1et5uql ii04i59q" style="background-color: white; color: #050505; font-family: "Segoe UI Historic", "Segoe UI", Helvetica, Arial, sans-serif; font-size: 15px; margin: 0.5em 0px 0px; overflow-wrap: break-word; white-space: pre-wrap;"><div dir="auto" style="font-family: inherit;">Another study from Kings / ZOE points at ~44,000 cases a day in the UK as a whole (not just England). The R-rate is 1.1, and the cases are doubling every 29 days.</div></div><div class="o9v6fnle cxmmr5t8 oygrvhab hcukyx3x c1et5uql ii04i59q" style="background-color: white; color: #050505; font-family: "Segoe UI Historic", "Segoe UI", Helvetica, Arial, sans-serif; font-size: 15px; margin: 0.5em 0px 0px; overflow-wrap: break-word; white-space: pre-wrap;"><div dir="auto" style="font-family: inherit;">In this scenario, just a few changes - perhaps even targeted local ones - could push the R-value below 1. It is still not a good situation, but it paints a very different picture from the Imperial study.</div></div><div class="o9v6fnle cxmmr5t8 oygrvhab hcukyx3x c1et5uql ii04i59q" style="background-color: white; color: #050505; font-family: "Segoe UI Historic", "Segoe UI", Helvetica, Arial, sans-serif; font-size: 15px; margin: 0.5em 0px 0px; overflow-wrap: break-word; white-space: pre-wrap;"><div dir="auto" style="font-family: inherit;">The national test figures, which only pick up symptomatic cases that have been tested, point at ~23,000 new cases a day. This will be a low figure.</div></div><div class="o9v6fnle cxmmr5t8 oygrvhab hcukyx3x c1et5uql ii04i59q" style="background-color: white; color: #050505; font-family: "Segoe UI Historic", "Segoe UI", Helvetica, Arial, sans-serif; font-size: 15px; margin: 0.5em 0px 0px; overflow-wrap: break-word; white-space: pre-wrap;"><div dir="auto" style="font-family: inherit;">So you are that politician. You need to make a decision in the next few days, and cannot afford to wait for more data. What do you do?</div></div><div class="o9v6fnle cxmmr5t8 oygrvhab hcukyx3x c1et5uql ii04i59q" style="background-color: white; color: #050505; font-family: "Segoe UI Historic", "Segoe UI", Helvetica, Arial, sans-serif; font-size: 15px; margin: 0.5em 0px 0px; overflow-wrap: break-word; white-space: pre-wrap;"><div dir="auto" style="font-family: inherit;">Not easy, is it? </div></div><div class="o9v6fnle cxmmr5t8 oygrvhab hcukyx3x c1et5uql ii04i59q" style="background-color: white; color: #050505; font-family: "Segoe UI Historic", "Segoe UI", Helvetica, Arial, sans-serif; font-size: 15px; margin: 0.5em 0px 0px; overflow-wrap: break-word; white-space: pre-wrap;"><div dir="auto" style="font-family: inherit;">Pity the politicians who have to make decisions based on such contradictory data - especially where those decisions are a balance of life, death, health, wealth and happiness. I wouldn't want to do it.</div></div><div class="o9v6fnle cxmmr5t8 oygrvhab hcukyx3x c1et5uql ii04i59q" style="background-color: white; margin: 0.5em 0px 0px; overflow-wrap: break-word;"><div dir="auto" style="color: #050505; font-family: inherit; font-size: 15px; white-space: pre-wrap;">And the linkies:</div><div dir="auto" style="color: #050505; font-family: inherit; font-size: 15px; white-space: pre-wrap;"><span style="font-family: inherit;"><a class="oajrlxb2 g5ia77u1 qu0x051f esr5mh6w e9989ue4 r7d6kgcz rq0escxv nhd2j8a9 nc684nl6 p7hjln8o kvgmc6g5 cxmmr5t8 oygrvhab hcukyx3x jb3vyjys rz4wbd8a qt6c0cv9 a8nywdso i1ao9s8h esuyzwwr f1sip0of lzcic4wl py34i1dx gpro0wi8" href="http://www.imperial.ac.uk/news/207534/coronavirus-infections-rising-rapidly-england-react/?fbclid=IwAR3b11f9p7YpUSsmPHSe2KWdqGkTohbRoF1RXdLCNY_G4M_r8Ofh77Aa8FQ" rel="nofollow noopener" role="link" style="-webkit-tap-highlight-color: transparent; background-color: transparent; border-color: initial; border-style: initial; border-width: 0px; box-sizing: border-box; cursor: pointer; display: inline; font-family: inherit; list-style: none; margin: 0px; outline: none; padding: 0px; text-align: inherit; text-decoration-line: none; touch-action: manipulation;" tabindex="0" target="_blank">http://www.imperial.ac.uk/.../coronavirus-infections.../</a></span></div><div dir="auto" style="color: #050505; font-family: inherit; font-size: 15px; white-space: pre-wrap;"><span style="font-family: inherit;"><a class="oajrlxb2 g5ia77u1 qu0x051f esr5mh6w e9989ue4 r7d6kgcz rq0escxv nhd2j8a9 nc684nl6 p7hjln8o kvgmc6g5 cxmmr5t8 oygrvhab hcukyx3x jb3vyjys rz4wbd8a qt6c0cv9 a8nywdso i1ao9s8h esuyzwwr f1sip0of lzcic4wl py34i1dx gpro0wi8" href="https://covid.joinzoe.com/data?fbclid=IwAR1PEMtvPeW8czbw63AostwfdiPU77dlv3yqn1q9SAYdQQRJTSlBuobFkac#interactive-map" rel="nofollow noopener" role="link" style="-webkit-tap-highlight-color: transparent; background-color: transparent; border-color: initial; border-style: initial; border-width: 0px; box-sizing: border-box; cursor: pointer; display: inline; font-family: inherit; list-style: none; margin: 0px; outline: none; padding: 0px; text-align: inherit; text-decoration-line: none; touch-action: manipulation;" tabindex="0" target="_blank">https://covid.joinzoe.com/data#interactive-map</a></span></div><div dir="auto"><span style="color: #050505; font-family: Segoe UI Historic, Segoe UI, Helvetica, Arial, sans-serif;"><span style="font-size: 15px; white-space: pre-wrap;"><a href="https://coronavirus.data.gov.uk/">https://coronavirus.data.gov.uk/</a></span></span></div></div>David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com0tag:blogger.com,1999:blog-2896552808274455196.post-87037858407409827812020-05-08T17:05:00.001+01:002020-05-08T17:05:46.263+01:00Why V.E. Day?In another place, someone asked why we commemorate V.E. Day. After all, we have Remembrance Sunday every year, so why do we need another martial commemoration?<br />
<br />
I think they are very different events. Remembrance Sunday is to remember those who fell in service of the country. This means not just the Second World War, but wars before and after, including somewhat politically-controversial conflicts such as the Falklands or the Gulf Wars. The rights and wrongs of those wars are irrelevant: we remember and honour those who served.<br />
<br />
V.E. day is different. It commemorates the whole country, an entire generation who suffered to help free half of Europe from tyranny. An entire country who worked together in the face of evil. Not just the soldiers, sailors and airmen, but everyone. The evacuee, the ARP warden, the land girl and the codebreaker. Even the anonymous housewife who had to make do and mend and feed their families with limited rationing.<br />
<br />
I cannot think of anything more worthy of commemoration.David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com1tag:blogger.com,1999:blog-2896552808274455196.post-13221097626222619712020-04-08T16:15:00.001+01:002020-04-08T16:15:48.020+01:00Covid-19: death stats - announced deaths versus reality.The Department of Health release daily statistics on the Covid-19 crisis, including the number of deaths and the number of tests. These headline figures are then splashed over the media ("UK records highest daily death toll from coronavirus at 854").<br />
<br />
Reporting-wise, the announced statistics on tests have recently improved, with both the number of tests performed and the number of people tested released. The number of people tested is always lower than the number of tests performed, for many reasons: the accuracy of the test is low, a negative result might need confirming, someone might have developed new symptoms after a test, test failures, etc, etc.<br />
<br />
However, the deaths data released is oddly lumpy. For instance, over the last few weeks, there have generally been fewer reported deaths on Sunday and Monday, and then new highs on Tuesdays. Why is this? Is there a medical reason?<br />
<br />
Probably not. Instead, it is much more likely to be administrative, with fewer staff on-hand to report deaths on weekends, and the unreported deaths being reported in bulk on Monday. These are then shown in Tuesday's figures, producing a slump in deaths followed by a spike.<br />
<br />
The deaths announced are only those that occur in hospital; figures for deaths from Covid-19 in the community are harder to compile in the absence of copious numbers of tests. However, even the reduced number relating to hospital deaths can be massively useful for planning purposes, as long as it is consistently compiled.<br />
<br />
A major issue is that deaths are not immediately reported. For instance, doctors and nurses have other things to do, autopsies may be required, relatives may have to be informed before the figures are compiled, and there might be a general lag in the system. This essentially makes the charts of deaths shown on the media useless for planning, as deaths announced today may have occurred up to a week ago.<br />
<br />
Fortunately, the Department of Health have produced oodles of lovely data that highlight this, split down to trust level:<br />
<br />
<a href="https://www.england.nhs.uk/statistics/statistical-work-areas/covid-19-daily-deaths/">https://www.england.nhs.uk/statistics/statistical-work-areas/covid-19-daily-deaths/</a><br />
<br />
The figures look very different to those published in the media, and are a lot less noisy. For instance, the 'announced' number of deaths on the first of April was 569; the 'real' number of patients who died on that day was 495. Those 74 patients still died, but they died on previous days.<br />
<br />
This is the data we should be making informed decisions from, not the charts from 'announced' deaths shown so frequently on Twitter, Facebook and the media.<br />
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It's a shame the media can't be bothered to report this correctly and actually inform the public. Heck, an educational program on the statistics would be brilliant (a TV version of 'more or less').<br />
<br />
The media are having a very poor war.<br />
<br />
(Apologies; I'm sounding a little tin-foil hatty here).David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com1tag:blogger.com,1999:blog-2896552808274455196.post-15444903545414538172020-04-02T17:28:00.000+01:002020-04-02T17:28:16.169+01:00Who should we test for Covid-19?In an ideal world (or country...) we would be testing everyone for Covid-19 at regular intervals. We would get a pack by post, we would do a swab or pinprick test, and get an immediate result, like a pregnancy test or breathalyser. Then, if it is a positive result, you have another, official test done and isolate yourself and others in your household.<br />
<br />
There would be many problems with this: people may not bother to do the tests; they may not perform them correctly or frequently enough, or they may just fake the results, especially if there is a compelling reason for them to do so (e.g. being allowed to go out of the house). However, such a routine should produce enough data to massively restrict the spread of the virus (a reproduction rate of less than one, where each ill person infects less than one other person) and keep the economy and country going.<br />
<br />
There is one problem: the technology to do this does not exist, and the technology we do have is much more complex to administer. I covered <a href="https://walkerramblings.blogspot.com/2020/03/how-do-we-test-for-covid-19.html">this previously</a>.<br />
<br />
It is not just a case of producing / obtaining enough kits at a time when virtually every country in the world is screaming out for them (and in some cases, like in Spain, obtaining worthless ones (1)). The current test requires a swab to be taken, the swab to be sent to a lab, and a complex polymerase chain reaction (PCR) test performed on it (2).<br />
<br />
This all means we do not have the ability to perform enough tests, and we have to ration them. This is where critical choices need to be made. We do not have enough tests to do everyone, so who do we choose?<br />
<br />
<b>Patients</b><br />
An obvious one is patients. Sadly, the telltale symptoms of Covid-19 are coughing and an elevated temperature, which can all be symptoms of common-or-garden influenza or other illnesses. If someone has bacterial pneumonia, they need treating with antibiotics, and not the same treatment as Covid-19 patients - even if the symptoms appear the same. Knowing who has Covid-19 allows doctors to prioritise and tune their treatment, which is vital with a disease that sadly seems to linger in the critically ill: even when a patient is in intensive care, the road back to health is long and arduous. But this symptoms of this illness are not specific enough, and there are too many people who are potentially symptomatic for them all to be tested: we are already having a very high negative rate (i.e. testing people who turn out not to have it).<br />
<br />
<b>NHS Staff and other frontline workers</b><br />
Another obvious one is any front-line NHS staff who are symptomatic. Currently, doctors and nurses exhibiting symptoms are having to self-isolate for at least a week. If they are clear of Covid-19, then they could be helping patients. However what if testing a nurse means a patient remains untested, and gets incorrect treatment as a result? What if asymptomatic doctors continue to spread the illness? Do you test all of the nearly million-strong NHS frontline staff?<br />
<br />
There are other issues. *If* the false negatives are too high, then it would cause front-line NHS workers to go back to work whilst infectious, and infect other people - especially other front-line workers. If the false negative values is that high, then it would be safer to keep any such worker who shows symptoms away from patients, the vulnerable and fellow key workers. This would depend on the false negative values of the tests - and that is generally somewhat of an unknown at the moment, and small value changes could have large consequences. A way around this is to perform two separate tests on such key workers, with two separately-taken swabs sent to two different labs. But even this does not mean perfection with a low enough false-negative value, and uses up more of the required tests.<br />
<br />
<b>Contacts</b><br />
Yet another is to test contacts of people who have already tested positive, to inform and influence personal behaviour and national policy. This 'contact tracing' is said to have worked well in South Korea.<br />
<b><br /></b>
<b>High-risk groups</b><br />
Another priority might be people in very high-risk groups: for instance care homes and prisons, where an infection could rapidly spread through a closely-congregated population.<br />
<br />
<b>Other uses</b><br />
There are other requirements to add into this: for instance, it might be very useful from a data point of view to do a randomised sampling to see how many people have currently got Covid-19, but are asymptomatic (the current tests do not highlight if you have had it and have recovered; for that we are awaiting a reliable antibody test or similar). This data might be very useful in modelling the spread of the disease, but would use up many kits we do not have. A study in the small Italian village of Vò performed in early March indicated that many people are infected but asymptomatic. (4) The asymptomatic people can still spread the disease, even if they are perfectly healthy.<br />
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Also, a certain number of the kits should be tested (preferably randomised samples of batches) to ensure that each batch of kits is performing correctly. Laboratory technicians also need to be tested as part of the process, to ensure they are performing the tests correctly. Confirmatory samples should perhaps be sent between labs, to validate their work. Such tests may require small numbers of kits, but the small numbers add up.<br />
<br />
<b>And hence the problem</b><br />
There are not enough kits for even a small part of all this. And so we get into a classic situation of a constrained critical resource.<br />
<br />
To make matters worse, it's perfectly possible that the hurried tests that are being done are so inaccurate that they are essentially pointless: the higher the proportion of false negatives there are, the more worthless (and indeed dangerous) the test. I don't feel that's the case, but it's possible.<br />
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So who to test? I don't know, and I fear there is no clear or easy answer: and worse, the answer may change as we gain knowledge of this disease, and both our ability to test and test accuracy increase.<br />
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The good answer, obviously, is to massively increase the number of tests that can be performed: although that is much easier said than done with the existing PCR test, and has massive logisitical and practical issues.<br />
<br />
Therefore we await newer, faster tests - especially ones that do not require a lab to analyse them.<br />
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But until such tests are widely available, I'm glad I'm not the one trying to make policy on this.<br />
<br />
<b>In other news:</b><br />
<br />
One of the problem with this story is that it moves rapidly. Since the last couple of posts, I have come across new stories and angles.<br />
<br />
There is hope for such tests, for instance from the US (5) and here in Cambridge (6), amongst others. As an aside, an interesting thing about the UK-made Samba-II machines is their price: £2.4 million for 100 machines means each costs £24,000 - incredibly cheap. I can only hope that the consumables such as reagents are easily available.<br />
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(1): <a href="https://www.businessinsider.com/coronavirus-spain-says-rapid-tests-sent-from-china-missing-cases-2020-3?r=US&IR=T">h</a><a href="https://www.voanews.com/science-health/coronavirus-outbreak/chinese-firm-offers-replace-faulty-test-kits-sold-spain">https://www.voanews.com/science-health/coronavirus-outbreak/chinese-firm-offers-replace-faulty-test-kits-sold-spain</a><br />
(2): <a href="https://www.medicalnewstoday.com/articles/coronavirus-testing#how-does-it-work">https://www.medicalnewstoday.com/articles/coronavirus-testing#how-does-it-work</a><br />
(3): <a href="https://www.fda.gov/media/136151/download">https://www.fda.gov/media/136151/download</a><br />
(4): <a href="https://www.bmj.com/content/368/bmj.m1165">https://www.bmj.com/content/368/bmj.m1165</a><br />
(5): <a href="https://www.vox.com/science-and-health/2020/3/28/21198021/coronavirus-test-abbott-fda-covid-19-5-minutes">https://www.vox.com/science-and-health/2020/3/28/21198021/coronavirus-test-abbott-fda-covid-19-5-minutes</a><br />
(6): <a href="https://www.cam.ac.uk/research/news/rapid-covid-19-diagnostic-test-developed-by-cambridge-team-to-be-deployed-in-hospitals">https://www.cam.ac.uk/research/news/rapid-covid-19-diagnostic-test-developed-by-cambridge-team-to-be-deployed-in-hospitals</a>David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com0tag:blogger.com,1999:blog-2896552808274455196.post-51744242664070308542020-04-01T18:14:00.002+01:002020-04-01T18:14:48.852+01:00Covid-19: what tests do we need?My <a href="https://walkerramblings.blogspot.com/2020/03/how-do-we-test-for-covid-19.html">previous post</a> summarised (*) the currently-used test for Covid-19, the PCR test, including its various limitations.<br />
<br />
So what would improve it? Any new test would have to be:<br />
<br />
*) Accurate. This means it would have as few false negatives and false positives as possible. Greater than 85% accuracy would be good. Chasing higher values (e.g. >95%) might delay the availability of tests, and allow the best to be the enemy of the good.<br />
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*) Sensitive. Sensitivity is the percentage of people with the disease that test positive. A patient may only have low amounts of virus in their system, especially early on, and therefore a test needs to be able to detect these low levels.<br />
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*) Selective. Selectivity is how well the test can separate the target disease (in this case Covid-19) from other, similar diseases.<br />
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*) Timely. Ideally, a patient or doctor would take a swab, and the result would come immediately, as it does with a pregnancy test or breathalyser. Any positives could then be taken through the existing PCR process for validation. Ideally, it would err towards false positives over false negatives.<br />
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*) Portable. Ideally it would be portable; the test can be conducted in hospitals, doctor's surgeries, or even in the home.<br />
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Various companies claim to be near this holy grail, and I hope they are correct. Ideally it would be multiple companies, allowing countries and organisations to choose which test - or tests - they believe are the best. South Korea have a rapid test that appears to be based on a speedier PCR process, but details on it appear to be sparse. However any PCR-based test will, by its very nature, be complex to administer.<br />
<br />
<b>Serological tests</b><br />
<br />
Whilst PCR-style tests are useful, we also need other tests. The current PCR test only indicates if you have the disease; if you have had it, been symptomatic and beaten it, it will show up as a negative. Therefore we also need a serological test as well. This would show whether an individual has developed antibodies against this virus. Such a test could give us information on how prevalent Covid-19 has become in the community.<br />
<br />
Serological tests are being developed by various groups. It appears that most will require a pinprick sample of blood, and the tests will be able to be performed in larger batches than PCR tests, easing restraints on laboratories. However the tests only work seven to fourteen days after the onset of symptoms, so there is still a need for PCR tests.<br />
<br />
Many of the requirements for a PCR test are also required for a serological test: it will need to be sensitive, selective and timely.<br />
<br />
For this reason, care needs taking that any newly-developed tests are actually fit for purpose, particularly in relation to false positives (in the case of antibody tests, false positives are more dangerous than false negatives. This is the opposite to PCR tests, where false negatives are the bigger problem).<br />
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There are other tests that might be useful, but the big two are the 'have-you-got-it-now' and the 'have-you-had-it' tests. Once we have these available in massive volumes, then we can start planning how to get back to normality. Without them, normality is a much rockier road.<br />
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<b>Beware, the hustlers</b><br />
<br />
Vast amounts of money will be available to anyone who manages to make a 'Holy Grail' test, and this will attract not only genuine actors, but charlatans. Some of these will be unknowing charlatans - people who genuinely believe 'their' solution is the Holy Grail when it isn't, whilst there will be genuine charlatans - snake-oil salesmen looking to make a quick buck. They will get discovered, but they could do massive damage in the meantime.<br />
<br />
And before anyone thinks this doesn't happen, just remember James McCormick and the hideous ADE bomb-sniffer scandal (2). If people want something badly enough, others will sell them it - even if the item sold is worthless.<br />
<br />
In addition, newly-developed tests would usually be run through trials to try to gauge accuracy, sensitivity and other values. The understandable hurry to get new tests out and used may lead to less understanding of the test itself, its limitations, and how it is to be administered.<br />
<br />
<b>A happier thought</b><br />
<br />
It feels somewhat wrong - frivolous, perhaps - to say so, but this hideous disease has struck us at the best time in our history. We are not prepared, but we have the science and technology to fight it. We have a few decades of experience with genetic assaying as an invaluable tool in the battle, and we have had a few near misses in which we have developed basic tools. It can - and will be - argued that we should have done more after those near misses, but we're closer to winning the battle then we were.<br />
<br />
Then there is another aspect: the Internet. Fifty years ago, the idea of essentially quarantining the entire country would have been unthinkable, from both an economic and social point of view. Now, the Internet allows us to communicate, order food, and in many cases even work from home. The Internet provides us with an invaluable tool in the battle - both economic and social.<br />
<br />
(*) hopefully with a modicum of accuracy.<br />
<br />
(1): <a href="https://wellcome.ac.uk/news/can-chloroquine-prevent-coronavirus-disease-only-research-will-give-us-answer">https://wellcome.ac.uk/news/can-chloroquine-prevent-coronavirus-disease-only-research-will-give-us-answer</a><br />
(2): <a href="https://en.wikipedia.org/wiki/ADE_651">https://en.wikipedia.org/wiki/ADE_651</a><br />
(3): <a href="https://www.amazon.co.uk/gp/product/000728487X/">https://www.amazon.co.uk/gp/product/000728487X/</a>David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com0tag:blogger.com,1999:blog-2896552808274455196.post-9281417137466429442020-03-31T13:15:00.001+01:002020-03-31T13:15:45.929+01:00How do we test for Covid-19 ?(Yet again, IANAE. Below is information I have gleaned from various sources for my own interest. Any mistakes are my own.)<br />
<br />
In all the information being written about Covid-19, there seem to be few resources that highlight the test's methodology and its limitations. It has become a black box 'the test', and many - sadly including journalists - seem to be treating it as an all-conquering miracle.<br />
<br />
In reality, whilst it's the best we've got, it's awkward.<br />
<br />
The current Covid-19 tests have been produced very rapidly, and is a tribute to the companies and organisations that have developed them. They were aided by the fact there have been several close calls over the last couple of decades - for instance SARS in 2002 and MERS from 2012. These earlier diseases proved to be less susceptible to spreading between humans, and gave investigators a target to concentrate on. The Covid-19 tests are built on that earlier work, which is why we got test for Covid-19 within a couple of weeks of the outbreak starting.<br />
<br />
The current commonly-used Covid-19 test are variants of a PCR test.<br />
<br />
So (deep breath), what is a PCR test?<br />
<br />
A polymerase chain reaction (PCR) test detects viral particles in bodily fluids, such as blood. It is essentially molecular photocopying: small amounts of a pathogen's DNA or RNA are copied many times (amplified) to a level where they can be detected. Without a PCR test, the virus's RNA would be at too low a level for detection. I like to think of it as a gigantic magnifying glass, although perhaps not wielded by Sherlock Holmes.<br />
<br />
PCR's inventor, Kary B. Mullis, won a Nobel Prize for Chemistry it in 1993, and it initially proved useful for the Human Genone Mapping Project, although is also used for purposes such as DNA fingerprinting and genetic research (1).<br />
<br />
So, what is the testing procedure?<br />
<br />
<ol>
<li>A swab is taken from the patient, or a sample taken from the back of the throat.</li>
<li>The sample is sealed into a tube and sent to a lab for processing.</li>
<li>In the lab, the sample's RNA is extracted.</li>
<li>Chemicals are mixed with the sample in different combinations.</li>
<li>These mixtures are tested in a PCR machine.</li>
<li>The result is given as positive, negative, or uncertain (a catch-all for various errors and problems, for instance the presence of similar viruses).</li>
</ol>
<br />
There are many issues with the test:<br />
<br />
<ul>
<li>The PCR tests can only tell if you currently have the disease; not if you have had it and have recovered. For that, we need an antibody test.</li>
<li>The test is not instant; samples have to be sent to labs (often distant) for testing.</li>
<li>It is not just a case of having enough testing kits: you also need the downstream laboratory to process the samples. It is pointless having a test that you do not get a result from for weeks or months. Tales of countries or organisations ordering tens of thousands of kits seem to neglect the downstream processing. This processing means it is perfectly possible for (say) 10,000 tests to be performed in a day, but for results of only 8,000 to come through, as there is a lag between tests and results - especially if the labs are inundated with tests.</li>
<li>The test takes time. Getting samples to a lab takes time. Extracting the RNA takes time. Mixing it with the chemicals takes time. Performing the PCR test itself takes time. Even when samples are batched up, it can tale many hours for a sample to be tested, and that does not include transport from patient to lab.</li>
<li>The tests require consumables: from reagents to protective equipment for the lab workers. These consumables and workers are in short supply at a time when every country in the world is demanding them.</li>
<li>The tests may be inaccurate. False positives (a patient reported to have the disease when they do not), is less important, as the patient will then be treated with caution, e.g. self-isolation. The big problem is with false negatives: where a patient is reported to be clear of the disease when, in fact, they have it. Some reports give the current test an accuracy of about 70%: in other words, it will only detect Covid-19 within a patient 70% of the time.</li>
</ul>
<br />
Why might false negatives be reported? (2)<br />
<br />
<ol>
<li>In the early stages of the illness, the patient may have too low a viral load to be detected.</li>
<li>The swabs are taken from the nose and/or the back of the throat, and if the patient's respiratory illness is not too severe, not much of the virus may not make it up the respiratory tract.</li>
<li>The sample may be simply incorrectly taken.</li>
<li>The samples may have been poorly handled.</li>
<li>There might be technical issues in the test.</li>
</ol>
<br />
PCR is a tool, and as with any tool, it needs using with care, and with a deep understanding of the tool's limitations.<br />
<br />
As an aside, PCR tests are used in Low Copy Number (LCN) DNA fingerprinting techniques, which allow tiny amounts of DNA to be fingerprinted in criminal cases. This is particularly useful in cold cases, where DNA might have degraded over time. The LCN technique proved somewhat controversial a little over a decade ago (3).<br />
<br />
Hopefully we will get better, more immediate tests that do not require such a complex process. But in the meantime, thanks to all the companies, organisations and people who are working their socks off to increase the availability of testing kits and increase the testing capability.<br />
<br />
(1): <a href="https://www.genome.gov/about-genomics/fact-sheets/Polymerase-Chain-Reaction-Fact-Sheet">https://www.genome.gov/about-genomics/fact-sheets/Polymerase-Chain-Reaction-Fact-Sheet</a><br />
(2): <a href="https://ourworldindata.org/covid-testing">https://ourworldindata.org/covid-testing</a><br />
(3): <a href="https://en.wikipedia.org/wiki/Low_copy_number#Criticism">https://en.wikipedia.org/wiki/Low_copy_number#Criticism</a><br />
<div>
<br /></div>
<br />
<br />
<br />David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com0tag:blogger.com,1999:blog-2896552808274455196.post-49344689021850877042020-03-20T12:37:00.000+00:002020-03-20T12:37:10.441+00:00Critical workersFollowing on from <a href="https://walkerramblings.blogspot.com/2020/03/what-is-critical-worker.html">yesterday's post</a>, the government has published their list of critical workers on the gov.uk website:<br />
<br />
<a href="https://www.gov.uk/government/publications/coronavirus-covid-19-maintaining-educational-provision/guidance-for-schools-colleges-and-local-authorities-on-maintaining-educational-provision">https://www.gov.uk/government/publications/coronavirus-covid-19-maintaining-educational-provision/guidance-for-schools-colleges-and-local-authorities-on-maintaining-educational-provision</a><br />
<br />
So, how did I do? I think fairly well. I missed off police (annoyingly, as I had them on my written list), and totally missed off prison officers, and the military.<br />
<br />
In fact, the list is broader than I expected, with categories like 'essential financial services provision'.<br />
<br />
I'd also hope that companies can apply for exemptions for their staff, e.g. if a company is working making ventilators (or components thereof), or scientists working on vaccines and tests, or companies making tests.<br />
<br />
All in all, I think it's a good, comprehensive list. I wonder how many people it covers? Five to ten million, at a guess.David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com0tag:blogger.com,1999:blog-2896552808274455196.post-256945597682585992020-03-19T09:55:00.001+00:002020-03-19T09:55:55.931+00:00What is a 'critical worker' ?With the shutdown caused by Covid-19 slowly rushing towards us like a particularly laggardly iceberg, it has been announced that special measures are being put in place to help 'critical workers' - such as creche schools for their children allowing them to still go to work.<br />
<br />
This leads to a question: what is a 'critical worker' ?<br />
<br />
Firstly, it probably depends from crisis to crisis: in a war situation, anything to do with the military, logistics, and wartime production would be critical.<br />
<br />
But we are facing a health emergency, and therefore doctors, nurses, and all the frontline staff are undoubtedly critical.<br />
<br />
In trying to work out how we as a family will cope with an extended stay in our home, I made two assumptions:<br />
1) We will continue having power (i.e. gas, electricity).<br />
2) Water / sewage will not be interrupted.<br />
<br />
In my view, both of these are critical. A population left without power, water or sanitation for any length of time will soon see deaths occurring regardless of Covid-19. People need power, even in the milder weather of a UK spring. Much food will be frozen, and all that dried pasta needs cooking. And to ensure these services, people need to be working on maintaining them. If not serviced, things break. And when things break anyway, we need people to fix them.<br />
<br />
Then there is telecoms. We are being told to work from home where possible, and it can be argued that this is not critical. However people rely on the Internet nowadays, and being able to keep in contact with family and friends far away will be a boon, and in many cases a lifesaver. Your elderly friend has run out of food? With communications, you have a hope of getting some to her. Likewise, our son's school is understandably leaning heavily on online resources to teach during this extended break. And the Internet could be a great morale raiser to people trapped in their homes.<br />
<br />
Another example: food and logistics. Many people I know are relying on online grocery deliveries for their food. This has meant they have done little or no hoarding, and will rely on as much of their deliveries making it through as possible. This is probably a good, centralised way of restricting social contact. If this was to be a prolonged situation, you could use logistics and central distribution instead to 'fairly' dole out essentials rather than ration cards, although that's admittedly a very rocky road.<br />
<br />
Finally, there is what I would call the essential support staff - a good example in this crisis being the teachers who will look after the children of all the critical workers.<br />
<br />
So, I'd create a rank of essential services for this outbreak:<br />
1) Medical and related.<br />
2) Essential services (gas, electric, water, sewage)<br />
3) Logistics / deliveries<br />
4) Telecoms<br />
5) Assorted support (e.g. teachers, planners, decision makers)<br />
<br />
I am almost certainly missing some. for instance, how long can society last without bins being emptied? For individual households, that might be less problematic. For many communal spaces, it might be. How about postal services (i.e. Royal Mail) ?<br />
<br />
It will be interesting to see what the government comes up with later.<br />
<br />
Any thoughts?David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com0tag:blogger.com,1999:blog-2896552808274455196.post-86237556171125355742020-03-13T14:37:00.000+00:002020-03-19T09:20:27.733+00:00Okay, I thought I'd put my tuppence forwards on the current Covid-19 crisis, and the decisions that the government have to make. I am not an expert; I have no particular knowledge on medical matters or pandemics - so I'm in the same boat as most of us!<br />
<br />
Feel free to disagree, but these are my current thoughts, and please forgive the length:<br />
<br />
1) We are working on incomplete data, and are having to make decisions based on assumptions. This is always risky. Just a relatively small change in one piece of data might invalidate one approach, whilst validating another. For instance, if a working vaccine is not developed before the end of the year, then isolating everyone now becomes a less valid approach. If a working vaccine is developed by mid-year, then isolating everyone now makes more sense.<br />
<br />
Likewise, the number of asymptomatic cases (that means, the people who get Covid and are not recognised as such because they don't get major symptoms) is important. As we don't have a reliable mass antibody test yet, this is a major unknown that again has a major effect on the decision made. If there are a small percentage of asymptomatic cases, then isolating now makes more sense than if there is a high percentage.<br />
<br />
Experts and politicians can look at the data and come up with different conclusions. Reasonable people can reasonably differ, especially in the presence of uncertain data.<br />
<br />
2) Every country is different: in their stage of the epidemic, the way it is progressing, and in their social mores. In some countries, the epidemic is in only one or two regions, and therefore the rules applied to those regions can be specialised. Here in the UK, we do not have particular hotspots, and no reason to believe it can be contained in particular areas or regions of the country. Likewise, we do not live in a state where (allegedly) doors to apartments can be welded shut to keep them from leaving. We appear to be a week or two behind other countries in the outbreak; what works for them now might not work for us, now; it (or another approach) may work for us in a week.<br />
<br />
Blindly comparing our decisions to those of other countries without factoring in such differences is, at best, pointless. This is not about some Union Jack-waving British exceptionalism; it's about the reality that our situation differs - as does every country's.<br />
<br />
3) There might not be a 'right' way to handle this. There is a good chance that no approach is perfect, and that even when the current situation has died down, we won't know what the 'right' thing to do was. We are living through a massive experiment.<br />
<br />
4) What is 'obvious' is often non-obvious. A common call is for schools to be closed, as has been done in other countries. Yet that can have side effects: children (who, unlike the 1918 flu pandemic, appear to be least affected by the illness) have to be cared for, and that burden will often fall on grandparents - who are most affected. Likewise, Madrid has had to lock shut the gates to playgrounds, as children were just meeting up there instead. What happens with exams? Coursework? A 'simple' decision has massive consequences - and not all in one direction.<br />
<br />
5) I'm very glad I'm not the one who has to make these decisions.<br />
<br />
In the UK's case, I don't see any reason to believe that Boris Johnson, the government, the Chief Medical Officer, the Chief Science Adviser et al *want* this awful disease to spread and for lots of people to die. They're having to use incomplete data to come to a decision in a terrible situation. I hope they've made a good one.<br />
<br />
6) Finally: much of this is up to individuals. If you want to keep you and yours well, don't be silly, and follow the advice. Bulk-buying toilet roll is of little use. Wash your hands. Avoid touching your face. If you feel unwell, rest and isolate yourself as much as possible.<br />
<br />
Help your relatives. Help your friends. Help your neighbours.David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com0tag:blogger.com,1999:blog-2896552808274455196.post-17205077032413536272020-03-04T09:35:00.001+00:002020-03-04T09:35:45.820+00:00Chris PackhamApparently Chris Packham is launching a judicial review of HS2, saying it does not take carbon emission targets into account.<br />
<br />
<a href="https://www.bbc.co.uk/news/business-51722251">https://www.bbc.co.uk/news/business-51722251</a><br />
<br />
Which I found slightly odd, because a little blip in my memory recalled something. So I look on his website, and find nothing under the 'travel' link:<br />
<a href="https://www.chrispackham.co.uk/category/travel-with-chris-packham">https://www.chrispackham.co.uk/category/travel-with-chris-packham</a><br />
<br />
However the wonderful Wayback machine shows the following:<br />
<a href="https://web.archive.org/web/20191214183301/https://www.chrispackham.co.uk/category/travel-with-chris-packham">https://web.archive.org/web/20191214183301/https://www.chrispackham.co.uk/category/travel-with-chris-packham</a><br />
<br />
So Chris Packham feels it's perfectly fine to make money out of taking adoring fans on trips to Alaska, Antarctica, the Gambia, Kenya etc - which of course involve environmentally-harmful flights to and from the ships or locations - but does not want the hoi polloi in the UK to be able to travel.<br />
<br />
He also says 'Bakotu Hotel – the base for my first tour – is my second home.' How nice it must be for him to have a second home in the Gambia. I bet he walks there ...David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com0tag:blogger.com,1999:blog-2896552808274455196.post-71378824323606311092019-07-31T08:40:00.001+01:002019-07-31T08:40:55.426+01:00RED month, July 2019On July 1st, I set out to do an early morning run. A task I repeated the next day, and the next. This morning I completed my 31st run of July, and I had Run Every Day.<br />
<br />
So, the stats: I ran 176 miles in the month, or an average of 5.89 miles per day (and yes, I wish I could have made that up to a round 6). I spent a smidgen under 32 hours running, and ran at a rather pedestrian 5.5 MPH average (more of a jog, really). My total ascent was 488 metres - a consequence of living in rather flat Cambridgeshire. My earliest start time was 04.20, my latest 09.20. All bar three runs were started before six in the morning, so I could get home and showered before Sencan left for work.<br />
<br />
The most I'd ever run before was 10K runs on 10 consecutive days, so it feels good to have somewhat smashed that. I exceeded my target distance on every run.<br />
<br />
The lessons are numerous. After about the fifth day, I gave up on trying to go fast, as it only meant I'd go slower the next day. Recovery time is important for speed, and running every day does not allow for recovery time. I hate doing stretches. Running in light rain in summer is very pleasant. Seeing the sun rise is always uplifting. Running up slight gradients is wonderful. A 15km (9 mile) run is harder than a 20-mile walk with backpack. Running sans shirt is wonderful in warm weather, although alarming for anyone who sees a hairy bear running towards them!<br />
<br />
I have suffered some chaffing on my inner thighs and, rather embarrassingly for a man, one sore nipple that was cured by liberal applications of vaseline that caused my running shirt to appear as though I was lactating. My knees are surprisingly fine, and my bad ankle only gave me trouble on a couple of occasions. I am very tired, but have lost over 5kg in weight.<br />
<br />
The worst thing is:<br />
<br />
I hate running!<br />
<br />
And I shall get up tomorrow and run again. But I might take a day off after that. Or not ...David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com0tag:blogger.com,1999:blog-2896552808274455196.post-84366784870709885352019-05-16T14:38:00.002+01:002019-05-16T14:38:21.031+01:00Blue Moon<br />
Yesterday, Jeff Bezos (of Amazon fame) gave an hour-long presentation about his views on the future of mankind and space. This might seem like an odd topic for the world's richest man, except for the fact he is investing a billion dollars of his own money into a space company, Blue Origin.<br />
<br />
The presentation is well worth watching in full:<br />
<div>
<br /></div>
<br />
<div class="separator" style="clear: both; text-align: center;">
<iframe width="320" height="266" class="YOUTUBE-iframe-video" data-thumbnail-src="https://i.ytimg.com/vi/GQ98hGUe6FM/0.jpg" src="https://www.youtube.com/embed/GQ98hGUe6FM?feature=player_embedded" frameborder="0" allowfullscreen></iframe></div>
<br />
<br /><br /><h3>
Some thoughts on the presentation:</h3>
The presentation was slick and well-done. Bezos comes across as very knowledgeable about the topic: which is slightly surprising given the number of hats he wears. His presentation skills are good (at least when compared to the sometimes-stuttering Elon Musk).<br /><br />We are not the intended audience for the presentation; Bezos was trying to talk directly to the movers and shakers in the US government. The Trump administration want to get Americans back to the Moon before the end of a possible second term in office, and Bezos wanted them to know that they have a system under development that could fit directly into their current plans.<br /><br />The presentation had four broad sections:<br /><ul>
<li>Define the problem: mankind's resource and energy usage is increasing. Unless something changes, this means eventually they will have to be rationed.</li>
<li>Define a vision of the solution: take mankind off the Earth via things such as O'Neill cylinders and the use of in-space resources to replace Earthbound primary industries.</li>
<li>Define the strategy: build the infrastructure that will allow others to fulfil that vision.</li>
<li>Define the tactics: initially, rockets such as New Glenn and the Blue Moon lander.</li>
</ul>
The first three sections all seemed logical: you can argue for other solutions, but his vision encompasses one possible solution. He is also willing to put vast sums of his own money towards the first steps in securing his vision.<br /><br />The highlight of the presentation was the unveiling of the Blue Moon lunar lander (see <a href="https://www.blueorigin.com/blue-moon">https://www.blueorigin.com/blue-moon</a>). This was impressive. They had obviously thought deeply about the details: from high-bandwidth laser communications, to the landing angle (i.e. platform stability) of 15 degrees; to using lifeboat-style davits to unload from the cargo platform on the top, to looking at landing accuracy and the issues caused by the debris from the rocket blast on landing. <div>
<div>
Bezos also unveiled a new liquid hydrogen / liquid oxygen (hydrolox) engine, the BE-7. rIn this section, Bezos mentioned that the technology of both the engine and the Blue Moon lander were direct consequences of the New Shepard sub-orbital craft that his company is current;ly developing, and which they hope will take tourists to the edge of space later this year.</div>
</div>
<div>
<br /></div>
<div>
This explains many of the criticisms that the New Shepard system gets: it is part of a plan to gain liquid hydrogen and vertical landing experience. Personally, I had been expecting them to use the existing BE3 engine (used in New Shepard) for their Moon lander, or to use another company (e.g. Masten and something based on Xeus technology - see <a href="https://www.masten.aero/xeus">https://www.masten.aero/xeus</a>).<br /><br />The modularity of the Blue Moon system is slightly reminiscent of the Apollo Lander. This was expanded slightly for the J-class missions (Apollo 15,16 and 17), but much larger enhancements were proposed under the 'Apollo Extensions System' - for instance to create a long-stay lunar shelter (see <a href="http://www.astronautix.com/a/aeslunarbase.html">http://www.astronautix.com/a/aeslunarbase.html</a>). These developments sadly never occurred because the program was cancelled.<br /><br />They are partnering with others for payloads, something I see as a positive and in line with his strategy. I also like the fact they've formed a science advisory board, and the 'kids club' could be either a damp squib or an inspired move - depending on how much effort they put into it.<br /><h3>
Some minor criticisms</h3>
<ul>
<li>It would have been good to mention SpaceX wrt vertical landing, and perhaps even congratulate them, whilst specifying the differences in their vision, goals and strategy. I can understand why they did not, but the elephant in the room is too large to ignore.</li>
<li>New Glenn is not fully reusable; only the first stage is. This was glossed over in the discussions wrt cost.</li>
<li>It would have seemed good to thank and congratulate NASA. Both SpaceX and Blue Origin are building on science done by NASA before, during and after the Apollo landings: this would be unachievable without that science and the general infrastructure.</li>
<li>The Blue Moon mock-up showed on stage was for an unmanned craft, and yet he also showed a picture of an enhanced, crewed version. In my view it is doubtful that a crewed version will be ready for 2024.</li>
<li>Liquid hydrogen is nasty stuff, and it took NASA and various militaries years to understand how to handle it reliably. Blue Origin have developed good knowledge on this through their New Shepard rocket, but keeping liquid hydrogen liquid in space and avoiding boil-off is *really* difficult. Although he somewhat addressed this in the talk, it is IMV the biggest issue facing the project.</li>
</ul>
</div>
<div>
<h3>
Conclusions</h3>
Can Blue Origin get a large lander to the Moon in five years? It's tight, but probably. Can they get a crewed lander onto the Moon in five years? That is *much* tighter, and I'd give them only a 20% chance of that (figure plucked out of the air).<br /><br />The fact they've had the BE-7 engine under development for three years shows they're looking at the problems, and are developing solutions out of public view. That might even extend to other problems I foresee, for instance EVA-capable spacesuits or life support - one billion dollars a year buys a lot of skunkworks.<br /><br />The Blue Moon lander seems utterly (almost boringly) feasible. liquid hydrogen storage issues aside.</div>
<div>
<br /></div>
<div>
Good luck to them.<br /><br /><br /><br /></div>
David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com0tag:blogger.com,1999:blog-2896552808274455196.post-57655013076670689202019-04-08T18:57:00.000+01:002019-04-08T18:57:01.761+01:00The Venezuelan Petro.In February 2018, the government of Venezuela - well known for its financial acumen - announced they were jumping on a digital bandwagon by launching their own cryptocurrency the Petro. The new currency had many stated aims, including to bolster the crashing Venezualan Bolivar currency, and to circumvent US sanctions.<br />
<br />
This was an interesting move. The initial sale allegedly raised $3.3 billion for the Maduro government, although there has been no independent verification of that claim.<br />
<br />
I personally feel that government-backed cryptocurrencies are a good way forward for the technology. Although governmental backing reduces some of the advantages of such systems, it also gives a currency increased trust - and trust has been one thing holding cryptocurrencies back.<br />
<br />
It is therefore interesting that Venezuela, a country that is in the depths of a massive financial and political crisis, is the first country to make such a move. So what has happened in the last year?<br />
<br />
The answer appears to be 'not much'. You cannot go onto a market and buy a Petro or Petro Gold. No-one seems to have an idea about the value of a Petro. To make matters worse, the technology behind the Petro has changed several times of the year, even after launch - and there are even doubts that the currency even exists in any practical form.<br />
<br />
I won't go into any jokes about the failure of a socialist state to create a reliable currency - after all, we capitalist countries haven't been brilliant at that, either. But the Petro does seem to be yet another scam cryptocurrency - albeit one created by a government that is in real trouble.<br />
<br />
And meanwhile ordinary Venezuelans suffer.David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com0tag:blogger.com,1999:blog-2896552808274455196.post-55720907447816183782019-04-06T18:14:00.000+01:002019-04-06T18:14:52.698+01:006 April 2019 - it's GPS rollover day!Today is a special day! You could be the lucky recipient of a rollover!<br />
<br />
No, not a lottery win, but something even more unusual: the 1,024-week GPS week-number rollover! Stay tuned to see if you are a winner!<br />
<br />
Okay, time to be serious. Twenty years ago the news was full of the upcoming Millennium Bug, where ancient (and sometimes recent) computer systems that used two digits to represent dates - e.g. '99' for 1999, would roll over and start using '00' for 2000 - which causes all sorts of problems when you perform operations on the data and 2000 is seen as being before 1999.<br />
<br />
Fortunately many good engineers worked for years to ensure that the effects of the Millennium Bug were not as bad as some forecast. Some say that this means the Bug was overwrought nonsense: in fact, problems were avoided because people did lots of work to prevent those problems.<br />
<br />
The Millennium bug was an epoch event: dates and times in computer systems have to be represented by numbers, and those numbers are of finite size. The larger the number, and the larger the granularity each number represents, the greater the length of time the number can represent.<br />
<br />
Another example is GPS,which has exploded in popularity over the last twenty years. Most cars now have GPS receivers, they are in all smartphones, and many of us even have receivers in our wristwatches. Many vital system require timing and positional information from GPS. Yet GPS receivers also have an epoch - in this case, the data sent from the satellites to the receiver uses 10 bits to represent the week, allowing 1024 distinct values. This means that every 1024 weeks, it resets. If for some reason it gets the 'wrong' week, the receiver may start giving incorrect data to the user.<br />
<br />
Today, the 6th of April, the week number rolls over. It is not the first time it has happened (it last happened on August 21st 1999. There were far fewer receivers back then (in fact, is it about the time I got my first Magellan handheld GPS), and the problems were not as significant.<br />
<br />
However today it may be different: manufacturers will have been aware of this issue, and will have put some protections in place. However if your receiver is over a decade old, and has not had its firmware updated, then there might be problems.<br />
<br />
The good news is that the GPS constellation is being updated, and the new signals have a 13-bit week, enough for 8,192 weeks - or 157 years. I doubt a rollover of those new signals will affect me much!<br />
<br />
But if you have an older receiver, I hope you don't win the GPS rollover lottery!David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com0tag:blogger.com,1999:blog-2896552808274455196.post-77504020034166901192019-04-04T14:28:00.000+01:002019-04-04T14:28:22.336+01:00Brexit and Julian MayIn the 1980s and 1990s, the late Julian May wrote a series of eight books: the four Pliocene Exile books, the standalone vinculum 'Intervention', and the three novels of the Galactic Milieu trilogy.<br />
<br />
In them, she describe a world where alien races have come to Earth whilst we were on the brink of nuclear war and offered us the stars. Since then, mankind has moved out from Earth to planets around the Galaxy: the large nations have many worlds, the smaller a few, and the smallest share some. Vast liners travel the ether between worlds, and mankind is flourishing.<br />
<br />
Yet there are discontents. Humans - often powerful and influential ones - who rail against the aliens with whom we share control. We once controlled the world, but we are now a small piece of a gigantic Galactic cog. We should be in charge.<br />
<br />
So these discontents start a rebellion that destroys worlds and kills billions. It is a pointless rebellion: one where they shake their fists at the very beings who have treated us well.<br />
<br />
And it ends with Humanity chastened and still part of the Milieu. Little has changed, for the course was inevitable, and changing it would destroy everything.<br />
<br />
And that is now what might happen to Brexit. We in the UK have a history that is littered with glory, and it is easy to sit back and want those glories to return. Britannia ruled the waves, and we ruled the world. But that world has changed: first came America, and then other countries overtook us. We are a small country: proud and brilliant, but small - in a world where size matters.<br />
<br />
In such a world, is the EU an inevitability?<br />
<br />
So we have a choice: to join up with other small countries (and smaller ones) to form a bloc that has more power together, or to be small and alone. It seems that the former might be inevitable. If so, perhaps the wettest of wet dreams of hardcore Europhiles are correct and, like Humanity after the rebellion, we will eventually become leaders of the group.<br />
<br />
If so, then Brexit may be, like the rebellion in the books, a felix culpa - a blessed fall.David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com1tag:blogger.com,1999:blog-2896552808274455196.post-17476960495698105452019-01-31T14:37:00.001+00:002019-01-31T14:37:18.588+00:00Six new walks on my websiteI've just updated my website with six new walks:<br />
<br />
<table bgcolor="#DDDDDD" border="1" style="font-family: arial, helvetica, Verdana, Geneva, sans-serif;"><tbody>
<tr><td>1033</td><td><a href="http://www.britishwalks.org/walks/2019/1033.php">London Loop: Erith to Farnborough, and then on to Chiselhurst</a></td><td>23.5</td><td>19/01/2019</td></tr>
<tr><td>1032</td><td><a href="http://www.britishwalks.org/walks/2019/1032.php">London Loop from Rainham to Purfleet, then on to Basildon and Pitsea</a></td><td>23.6</td><td>12/01/2019</td></tr>
<tr><td>1031</td><td><a href="http://www.britishwalks.org/walks/2019/1031.php">London Loop: Loughton to Rainham</a></td><td>23.7</td><td>05/01/2019</td></tr>
<tr><td>1030</td><td><a href="http://www.britishwalks.org/walks/2019/1030.php">London Loop: High Barnet to Loughton</a></td><td>20.7</td><td>01/01/2019</td></tr>
<tr><td>1029</td><td><a href="http://www.britishwalks.org/walks/2018/1029.php">Ebor Way: York to Wetherby</a></td><td>23.3</td><td>28/12/2018</td></tr>
<tr><td>1028</td><td><a href="http://www.britishwalks.org/walks/2018/1028.php">Gipping Valley River Path: Stowmarket to Ipswich</a></td><td>20.9</td><td>22/12/2018</td></tr>
</tbody></table>
<br /><div>
There are one in Suffolk and another in Yorkshire to complete 2018, and four around the London Loop to start 2019.</div>
<div>
<br /></div>
<div>
I've also fixed a few bugs that were preventing links from working on the named walk pages.</div>
David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com0tag:blogger.com,1999:blog-2896552808274455196.post-70274312529415182752019-01-30T10:59:00.001+00:002019-01-30T10:59:36.944+00:00Brexit: the current situationLast night's vote gave Mrs May a smidgen of authority to go back to the EU and ask for changes to the withdrawal agreement. With the right changes, the deal might - perhaps, with a following wind - pass through parliament. Even that is far from assured, given the small margin of 'victory' in the vote.<br />
<br />
There are many problems. The first and foremost is that the EU has said it will not renegotiate. Even if it did, there is no indication that they would agree to whatever quasi-magical alterations to the backstop people have in mind. And there is nothing stopping other countries - for instance Spain - from wanting to reopen other aspects of the agreement to their advantage.<br />
<br />
And all of this has to be done in a few weeks.<br />
<br />
It really is an almighty mess.<br />
<br />
Another problem is that we have MPs saying what they are *against*, and not what they are *for*. There are also far too many of them who seem to think that negotiation is a case of demanding, and then stamping your feet like stroppy children until the party you are negotiating with relents.<br />
<br />
I fear this is not going to end well for us. And it is all our own fault.David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com0tag:blogger.com,1999:blog-2896552808274455196.post-39666269528454550282019-01-29T15:13:00.001+00:002019-01-29T15:13:53.587+00:00John ButlerWhen I started walking as a hobby a couple of decades ago, there were relatively few websites and guides available online. One that I did come across was John Butler's landscape photography website. At the time John was walking - and taking beautiful photos - on a Land's End to John O'Groats walk.<br />
<br />
We emailed each other a few times, and I found his website to be a very useful and beautiful resource. It is therefore somewhat of a shock to revisit his website and discover that he died over seven years ago. I'm glad to see his website has been preserved and is still available to read.<br />
<br />
<a href="http://www.jbutler.org.uk/">http://www.jbutler.org.uk/</a><br />
<br />
RIP John. I hope the sun is shining on the hills of Heaven.David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com0tag:blogger.com,1999:blog-2896552808274455196.post-55965753781665323972019-01-28T13:53:00.002+00:002019-01-28T13:53:33.385+00:00The HolodomorIf you stroll down Calton Hill in Edinburgh from a certain direction, you may see a little memorial stone sitting beside the path. It is a little off the beaten track, and many people will miss it during their visits to the city.<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhW09tR50N21nD0IoHuKcKNISAuvKdVmJEjX_eANeoIkInSDC7EzLUSpRNzE9MRHopV8o67gTukxIUTiklXrRGWHNpjRtBVKPVT60MwXGNXLX64tw0mlNzk5BPxCHddESaeehAbnKsO6MH0/s1600/P2018DSC04274.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1365" data-original-width="1024" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhW09tR50N21nD0IoHuKcKNISAuvKdVmJEjX_eANeoIkInSDC7EzLUSpRNzE9MRHopV8o67gTukxIUTiklXrRGWHNpjRtBVKPVT60MwXGNXLX64tw0mlNzk5BPxCHddESaeehAbnKsO6MH0/s320/P2018DSC04274.JPG" width="240" /></a></div>
<br />
Its grey stone is a little bright against its surroundings; then again, it is barely a year old, and will fade with time.<br />
<br />
As have, sadly, the memories and knowledge of the events it commemorates. For it remembers the millions of people who died between 1932 and 1933 in the Ukraine.<br />
<br />
It seems almost everything about <a href="https://en.wikipedia.org/wiki/Holodomor">the Holodomor </a>is disputed. Even its name is not settled: some call it the 'Great Famine', others the 'Ukranian Genocide'. Many argue it was a deliberate genocide to repress the Ukranian people, others that it was an accidental result of the collectivisation laws instituted by Stalin. Some say only a few million died; others up to 10 million (it seems likely the figure is between 3 and 7 million, in itself a frankly horrific range).<br />
<br />
These disputes - often scholarly ones - get in the way of the horror, and can almost downplay them - as if saying "7 million people didn't die; it was <i>only </i>6 million." makes everything fine.<br />
<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjau6xycL2cCxQy-hvSnN33-Csrt6Lbb_DlwNRs3V1OqUSB-TrUkNpND6AGC6o5M88hMFJM2QoUylK4dqtYCTrMSXit4B24Em4EuAb63ZvxrPVa0zW_4tcSnpfze3LfCeSgXUtnvgHmeKIx/s1600/P2018DSC04275.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em; text-align: center;"><img border="0" data-original-height="1365" data-original-width="1024" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjau6xycL2cCxQy-hvSnN33-Csrt6Lbb_DlwNRs3V1OqUSB-TrUkNpND6AGC6o5M88hMFJM2QoUylK4dqtYCTrMSXit4B24Em4EuAb63ZvxrPVa0zW_4tcSnpfze3LfCeSgXUtnvgHmeKIx/s320/P2018DSC04275.JPG" width="240" /></a></div>
<br />
The Holodomor deserves to be better remembered. And in so doing, more thought should be given to all those who died under Stalin's tyrannical regime.<br />
<br />
David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com0tag:blogger.com,1999:blog-2896552808274455196.post-10398312053875114632019-01-27T08:46:00.000+00:002019-01-27T08:46:14.783+00:00International Holocaust Remembrance Day<div>
Today is International Holocaust Remembrance Day. <a href="https://en.wikipedia.org/wiki/International_Holocaust_Remembrance_Day">From Wiki:</a></div>
<br />"(it) is an international memorial day on 27 January commemorating the tragedy of the Holocaust that occurred during the Second World War. It commemorates the genocide that resulted in the death of an estimated 6 million Jewish people, 5 million Slavs, 3 million ethnic Poles, 200,000 Romani people, 250,000 mentally and physically disabled people, and 9,000 homosexual men by the Nazi regime and its collaborators. "<br /><div>
<br /></div>
<div>
A few years ago we went to a talk by the great pilot <a href="https://en.wikipedia.org/wiki/Eric_Brown_(pilot)">Eric 'Winkle' Brown</a>. We expected an entertaining talk about his experiences in the air, and that is what we got. However we also got a long section on his experiences near the end of the war. As a German speaker and pilot, he interviewed Hermann Goering after his capture, and also was one of the first people to liberate the <a href="https://en.wikipedia.org/wiki/Bergen-Belsen_concentration_camp">Bergen-Belsen concentration camp</a>.</div>
<div>
<br /></div>
<div>
He spent a fair while talking about the horrors he saw in the camp, and his feelings about the people who staffed it. Wiki has the following: "he soon interviewed the camp's former commandant and his assistant Josef Kramer and Irma Grese, and remarked upon the experience by saying that; "Two more loathsome creatures it is hard to imagine" and further describing the latter as "... the worst human being I have ever met."</div>
<div>
<br /></div>
<div>
The very powerful and upsetting talk made me realise one thing: I'd never actually heard a first-hand account of the camps before. I'd seen plenty of TV interviews with survivors, but whilst horrific, they lacked the impact that first-hand testimony holds. And as old age takes those who suffered in the camps and survived, and those such as Eric Brown who helped liberate them, first-hand testimony will evaporate. We shall be left only with recordings, and like pictures of emaciated survivors, or of diggers bulldozing piles of bodies into graves, they are easier to deny.</div>
<div>
<br /></div>
<div>
And this is a reason why we should all pause for a minute today to remember the Holocaust and to consider man's potential to inflict mass suffering on his fellow man. The Holocaust was not the first such atrocity, and sadly it was not the last. I fear to say there will be more in the future. The people affected my be different, and it may be rooted in different causes, but remembering the horror and saying "Never again," are good baby steps in preventing their recurrence.</div>
<div>
<br /></div>
<div>
Denying the Holocaust - especially because of dislike of the groups who were killed - is the first step to allowing something like it to happen again.</div>
<div>
<br /></div>
<div>
So pause and think. If you are religious, offer a little prayer. If you are not, think how you'd feel if it was your mother and father in such a camp, or your son or daughter.</div>
<div>
<br /></div>
<div>
For the people who died in the holocaust were not statistics, nor were they nameless bodies in a black-and-white photo. They were real people, as real as you or I.</div>
David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com0tag:blogger.com,1999:blog-2896552808274455196.post-69016203699382907972019-01-26T08:00:00.000+00:002019-01-26T08:00:04.807+00:00Side by side mapsI spend a lot of time looking at maps. I obviously use them to plan walks, but I also find them objects of beauty in their own right.<br />
<br />
But maps can also be historical documents, and the National Library of Scotland have created an excellent resource that allows you to compare various historic and modern maps.<br />
<br />
The detail this shows can be amazing. You can see how villages have grown over time, or how factories and railways have disappeared from the landscape.<br />
<br />
As an example, below is a comparison of the Purfleet gunpowder stores, with an 1892-1914 Ordnance Survey map compared to the latest Google Maps view.<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiSCatbjHn4V3D4ZqFO2uTPfMh2qzrxD1J0podSe8zayuSvM-iKG0gTnjLO4oN_JgWt53HaPaMP79MqYqDLeJRLFKXSwycDQpMAfxuLUUOH6lvbHYIa94URwkfTqsxnGF9WRnkprYQh6xA6/s1600/side-to-side.PNG" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="637" data-original-width="1600" height="157" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiSCatbjHn4V3D4ZqFO2uTPfMh2qzrxD1J0podSe8zayuSvM-iKG0gTnjLO4oN_JgWt53HaPaMP79MqYqDLeJRLFKXSwycDQpMAfxuLUUOH6lvbHYIa94URwkfTqsxnGF9WRnkprYQh6xA6/s400/side-to-side.PNG" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><a href="https://maps.nls.uk/geo/explore/side-by-side/#zoom=17&lat=51.4855&lon=0.2283&layers=168&right=BingHyb" style="font-size: medium; text-align: start;">https://maps.nls.uk/geo/explore/side-by-side/#zoom=17&lat=51.4856&lon=0.2293&layers=168&right=BingHyb</a></td></tr>
</tbody></table>
<br />
It is still recognisably the same location. However the pier has disappeared, whilst all but the southernmost of the gunpowder store buildings having been replaced with flats. Even though much of the surrounding area has been redeveloped, the outline of the old military area can still be seen in the landscape within the loop of Centurian Way.<br />
<br />
Or this one of the centre of Derby, where virtually nothing remains the same. The canal and basin and many streets of houses have disappeared, replaced with roads, shops and the massive Westfield shopping centre. Only a few streets have remained the same, and one of those, Morledge, has been radically reduced in size. Not even the street layout has been respected.<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi1VrN7F6LJnDsJ1SJRH-GCUGQ9dKVLpLY_45P1soxYbYYOrafOXTZ3gh61rNSYGU7SDirllNtGU_xblBrS44Uuj3pVe9Uow_aZ72J-qKPHYaljMkESMM5-xri12BVCA5L_d2f1C8lpVQac/s1600/2.PNG" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="634" data-original-width="1600" height="156" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi1VrN7F6LJnDsJ1SJRH-GCUGQ9dKVLpLY_45P1soxYbYYOrafOXTZ3gh61rNSYGU7SDirllNtGU_xblBrS44Uuj3pVe9Uow_aZ72J-qKPHYaljMkESMM5-xri12BVCA5L_d2f1C8lpVQac/s400/2.PNG" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: 12.8px;"><a href="https://maps.nls.uk/geo/explore/side-by-side/#zoom=17&lat=52.9210&lon=-1.4718&layers=168&right=BingHyb">https://maps.nls.uk/geo/explore/side-by-side/#zoom=17&lat=52.9210&lon=-1.4718&layers=168&right=BingHyb</a></span></td></tr>
</tbody></table>
This website has proven to be an invaluable resource for me, and one that is an utter time sink: I spend far too long just scrolling through the landscape, seeing how areas have changed.David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com0tag:blogger.com,1999:blog-2896552808274455196.post-16758563813910091952019-01-25T08:00:00.001+00:002019-01-25T08:00:08.830+00:00Brexit, part nWith yesterday's new that the peoples vote campaigners have <a href="https://www.bbc.co.uk/news/uk-politics-46987529" target="_blank">given up - for the moment - on forcing another referendum on parliament</a>, it looks likely that the Brexit probability waveforms are finally collapsing.<br />
<br />
It now seems there are three main ways forward:<br />
<ol>
<li>Revoke A50 (this splits into two other options, permanently or temporarily).</li>
<li>May's deal, or something akin to it.</li>
<li>Hard, crash-out no-deal Brexit.</li>
</ol>
It feels like we're finally reaching an end-game for Brexit, or at least this phase of it.<br />
<br />
Since option 3 is the default, it sadly still has to be the favourite. However there is probably a majority in parliament to avoid a no-deal Brexit, and not enough support for revocation. The ERG'ers are also starting to show some flexibility, so it may be that the dead corpse of May's deal is reanimated in some form.<br />
<br />
On a related point, it appears that polling on Brexit is being confused by people who say they want a 'no deal' Brexit, when they actually want to remain - they think that no deal means staying in.David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com0tag:blogger.com,1999:blog-2896552808274455196.post-13930158724919527492019-01-24T08:00:00.000+00:002019-01-24T08:00:10.762+00:00Starhopper down ...In a <a href="https://walkerramblings.blogspot.com/2019/01/starhopper.html">post twelve days ago</a>, I mentioned Elon Musk and SpaceX's new Starhopper rocket. This is a testbed for their planned massive BFS spacecraft.<br />
<br />
In it, I wrote:<br />
<blockquote class="tr_bq">
"Spacecraft are built inside buildings by highly-skilled aerospace engineers. They are not built outside, exposed to the elements - and certainly not by agricultural engineers."</blockquote>
It appears that there are very good reasons why such rockets are built indoors rather than outside. Susceptibility to high winds being one.<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://i.imgur.com/i1nmiAh.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="600" data-original-width="800" height="240" src="https://i.imgur.com/i1nmiAh.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Photo from NSF Bocachicagal</td></tr>
</tbody></table>
<br />
Ooops.<br />
<br />
All companies make mistakes: Boeing <a href="http://nasawatch.com/archives/2017/05/sls-lox-dome-dr.html">dropped and destroyed part of their new SLS rocket's tank</a> last year, and Lockheed Martin once <a href="https://en.wikipedia.org/wiki/NOAA-19#Damage_during_manufacture">dropped a satellite during manufacture</a> at a cost of $135 million.<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://upload.wikimedia.org/wikipedia/commons/4/43/NOAA-N'_accident.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="521" data-original-width="800" height="208" src="https://upload.wikimedia.org/wikipedia/commons/4/43/NOAA-N'_accident.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">From Wikimedia</td></tr>
</tbody></table>
But this is a very public mistake. Hopefully SpaceX will learn lessons from this, and their program will not suffer too much delay.David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com0tag:blogger.com,1999:blog-2896552808274455196.post-54238777993332810742019-01-23T17:57:00.000+00:002019-01-23T18:14:25.629+00:00Galileo and BrexitMy <a href="https://walkerramblings.blogspot.com/2019/01/the-galileo-satellite-constellation.html">previous post</a> outlined why access to a Global Navigation Satellite Systems (GNSS) such as the American GPS or European Galileo systems are vital for a country's commercial and military well-being.<br />
<br />
Unfortunately, in their infinite wisdom the EU have decided that a post-Brexit UK:<br />
<br />
<ul>
<li>will not be allowed to continue being involved with the system's development;</li>
<li>that UK companies will not be able to bid to construct hardware; </li>
<li>that they would restrict the UK's access to sensitive data. </li>
</ul>
<br />
This means that whilst the UK will be able to continue using the public signals, they will not have trusted access to the system's encrypted military codes (PRS) and its national security elements.<br />
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Trust matters. As non-EU members, the UK might be able to negotiate passive access to the encrypted PRS signals - but without direct knowledge of how the system has been designed at the broadcast end, and without people in the control rooms, the UK cannot guarantee that such access would be maintained. If the UK were ever in a conflict or war that EU members did not agree with, they could cut off or degrade the service. Such passive access is essentially pointless - if they do not trust the UK enough to give full access, then the UK cannot trust them to maintain access.<br />
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The Falklands Conflict is an example scenario. If such a small-scale conflict was to occur again, with the UK standing alone against another country, it can be assumed that both sides will be using GNSS - in fact, it is likely that our high-tech military would rely on them more. If one of the Galileo EU members was against the conflict, they could decide to degrade Galileo coverage over the relevant conflict zone, restricting the UK's ability to use it. The UK would have no voice or power to prevent it.<br />
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In the immediate future, this disrupts the MOD's plans to integrate secure global positioning, timing and navigation into their systems, which requires access to Galileo's PRS or GPS's M-Code. In addition, UK governmental agencies cannot use it to support critical national infrastructure.<br />
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It also means that UK companies that have been building parts of the satellites will not be able to continue doing so. Airbus has said that its bids for further work on the Galileo system is being moved out of the UK to Germany and France, along with 80 jobs.<br />
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Access to the enhanced capabilities of the MEOSAR search and rescue system may also have to be stopped.<br />
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So far, the UK has given £1.5 billion for our part in the project; in return UK companies have received back £1.15 billion in work. Teresa May has announced that we will not try to claim back the payments we have made to the project. Allegedly officials have been going around UK companies involved with the system to tell them to stop sharing propriety information with other Galileo parties.<br />
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So what can the UK do - assuming the EU is unwilling to change its mind?<br />
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The UK government has put aside £92 million to study the effects withdrawn access to the Galileo PRS codes would have. Much of the technology was developed in the UK; the first prototype satellite (GIOVE-A) was designed and built by SSTL in the UK, so the technical know-how exists. Some estimate that a replacement UK system could cost anything from £3 billion to £10 billion. Airbus claims £5 billion and five years of work.<br />
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There are problems: many of the people required to make such a system are EU nationals resident in the UK - would they want to remain to work on the project, and would the UK want them working on what would be a national security asset?<br />
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Perhaps the biggest problem is not monetary, but legislative. Any new system would need frequencies allocated to it internationally. This would need to be negotiated through the International Telecom Union, and this may be a slow process. Back in 2003, the US and the EU had a big argument over the frequencies used by Galileo, and it is going to be difficult to negotiate access to frequencies that will not interfere with other systems.<br />
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The radio frequency spectrum, especially in the frequency ranges required by this sort of system, is getting very crowded. It will also require us to use political capital that will desperately be needed elsewhere. To make matters worse, many cellular providers want to use these parts of the spectrum for 5G services.<br />
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The UK cannot start designing the system in detail until the frequencies are known, as it is the key factor in determining the design - and even the satellites' orbits.<br />
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Creating a UK GNSS constellation to replace Galileo is almost certainly a non-starter, if only because the cost is probably far too great for only military use. For that reason, the UK might want to cooperate with another player. Russia is rather unlikely, as is China. Japan's system is local and designed for their specific needs. Australia is a possibility, but do they really require such a system?<br />
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So how about India? They have the technology, and launchers - but their system is currently only regional. It might be tempting for them to have someone else pay for the system to be deployed globally.<br />
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A better approach may be to create a capability that the EU does not currently have - for example some form of secure global communications - and swap trusted access of that for trusted access to Galileo. Even this would be very expensive, although it might prove easier and quicker than the UK developing its own GNSS.<br />
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The Galileo debacle does not bode well for the rest of Brexit. It should have been easy to sort out, but it appears to have become an impossibility. The EU may gain slightly from the decision in the short term: work that was going to be done in the UK will now be done elsewhere in the EU, whilst the UK has already paid in more than they have got back in work. But the chances of the successor project to Galileo - already in planning - going ahead is reduced, and the running costs of the Galileo system will fall upon the other countries.<br />
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There will be second-order effects as well: for instance, the Galileo system was initially developed by ESA, before it was taken over by the EU. The UK is remaining part of ESA, which continues to administer and operate the system. It is possible that such disagreements will infect the UK's relationship with ESA, especially when many ESA projects involve EU funding.<br />
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But there are always silver linings: perhaps the UK government will decide to go ahead with their own satellite constellation (perhaps calling it 'Boudica' or 'Waterloo') and dust off their road pricing ideas to pay for it ...</div>
David Cottonhttp://www.blogger.com/profile/17662508558674678268noreply@blogger.com0