The sky fell on me head

The ‘bits of satellite might fall on your head’ story that has been all over the news this week (see e.g. the Telegraph here) has provided a nice chance for people to get the wrong end of the statistical stick.

For instance, as I was having the last of my breakfast this morning I heard the BBC Today programme bods responding to emails and texts. Paraphrasing:

“In response to messages, we should make clear that it ISN’T a 1 in 3200 chance that you personally will be hit by a bit of falling satellite. It is a 1 in 3200 chance that someone, somewhere will be hit by some debris. The chance of it being any one particular person are millions and millions to one”

Which is, of course, the exact inverse of the lottery logic used to sell you tickets. The chance of you, personally, winning the lottery is many millions to one against. But the lottery company advertising plays strongly upon the idea that SOMEONE has to win:

“It could be you”….

…but only if you’ve bought a ticket. Or better still, several tickets – that’ll be five pounds, please.

The point is that they are deliberately playing on many people’s tendency to have trouble distinguishing logically between the odds of a rare event befalling somebody, and the odds of it befalling you in particular.

(BTW, for the satellite example, MSNBC have a discussion of where the numbers come from here).

Mind the reindeer

The mention of satellites falling to earth always reminds me of a famous story about “risk perception”, and one that I  sometimes use when teaching the medical students. The version that I know appears in Michael O’Donnell’s entertaining compendium Medicine’s Strangest Cases. I’ve told this one before on the blog, but it seems apposite here.

The story was that debris from a satellite in a decaying orbit was predicted to fall in an remote area of Lapland that was virtually unpopulated save for a few nomadic reindeer-herders. The Swedish Govt. offered to helicopter airlift the reindeer herders out of the area, at significant cost to the Swedish taxpayer.

Hermann Bondi, a famous British mathematician and Government science adviser, heard the story, crunched the numbers and confirmed that the probability of any reindeer herder who stayed put having the satellite land on them was several orders of magnitude less than the chance they would be killed in a helicopter crash on a routine helicopter flight.

So the Swedish Govt’s decision was plain daft.

Well, that depends.

Purely on the statistics, it was a wholly illogical decision. But Bondi pointed out that the Swedes had undoubtedly factored in that if they didn’t offer to evacuate people, and the satellite then landed on someone, the headlines would scream

“Heartless and negligent Govt leaves reindeer herders to die”.

While if a chopper crashed, the headline would be

“Tragic helicopter crash kills herders”

– and the Govt. would be off the hook.

The point being that it was less about the actual risk of events, and more about how people felt about both the event and the risk of it, and who was to be held responsible.

And also, looking at it from a 2011 perspective, how media reporting plays a major role in what things people worry about, and how much

Anyway, given the above, I dare say that the people hoping most fervently that the satellite debris splashes down harmlessly in an ocean somewhere are the men from NASA.

Perceptions not risk. Unfortunately.

Finally, there is another interesting point about people’s differing perception of the risks of different kinds of rare event.

Though the Today programme has obviously had some worried callers this morning, I dare say that relatively few people will be altering their actual behaviour much due to fretting about being hit by a bit of  communications satellite falling from the sky.

Similarly, the finite risk of a plane crashing does not seem to put the vast majority of people off travelling on airplanes.

But then compare the number of people – some of them among the parents at my kids’ school – who seem to believe that the exceedingly small risk of adverse events following vaccination is a good reason for not having their children vaccinated.

Risk, and perception of risk.

It’s a *****


Update – Sat 24th: the reports are now telling us the satellite probably came down ‘somewhere over the Pacific’. Wonder if any of the bits will turn up on land?

Update – Sun 25th:  reports are still suggesting the debris probably fell into an ocean, with none reported on land. An amusing sequel is that someone apparently hoaxed some of the Canadian media with a video clip purporting to show the satellite burning up other Northern Canada.


50 Responses to “The sky fell on me head”

  1. Dr Zorro Says:

    Think of it as a form of Darwinian evolution. Those who don’t vaccinate, and turn to woo rather than evidence based medical care will have a slightly increased early mortality, which, over generations will cause them to die out.

  2. Cybertiger Says:

    The following article may be of interest to expert vaccinologists like Drs Zorro & Draust and ignorant mcscientists like David ‘the dog’s bollocks’ Colquhoon.

    Of course, I’m a believer: Richard Feynman was right, ‘science’ is the belief in the ignorance of experts.

  3. Stuart Says:

    Another important point about very rare, catestrophic events is that – from an individual’s perspective – there are only two outcomes, you are either hit or you are not.

    The chances may be several million to one but, if you are the unlucky one, it is no comfort to be told that your chances of being flattened by huge chunk of space debris were several million to one.

    As you say – the inverse of lottery logic.

    On the other hand people will quite happily live in San Fransisco secure in the knowledge that, sooner or later, there is going to be a huge earthquake.

    People will carry on smoking despite clear evidence that the habit will cause severe health problems in 20 – 30% of smokers.

    Tne smoking one is actually quite intesting too – you can turn the statistics on their head and say that the habit has absolutely no effect upon the health of 70 – 80% of smokers. When people say “it won’t happen to me” then they are probably right.

  4. Cybertiger Says:

    Would ‘Stuart’ care to scientifically quantify the “absolutely no effect upon the health of 70 – 80% of smokers”?

  5. Stuart Says:


  6. Cybertiger Says:


    Well done, Stuart! Good thinking! Spoken like a true medical statistician with a masters degree in scientific gobbledegook.

  7. Cybertiger Says:

    Draust said,

    “But then compare the number of people – some of them among the parents at my kids’ school – who seem to believe that the exceedingly small risk of adverse events following vaccination is a good reason for not having their children vaccinated.”

    The mantra of the vaccine industry – and assorted ignorant mcscientists like Draust, Zorro and Professor ‘Bollocks’ Colquhoon – is that the benefits of vaccines outweigh the risks. But these buffoons don’t know the risks …

    Draust: do you have a daughter? Listen and learn from this recent YouTube presentation …

    Draust said,

    “Risk, and perception of risk. It’s a *****”

    It’s a what, Draust?

  8. Stuart Says:

    I don’t have a masters degree in anything!

  9. Cybertiger Says:


    I disagree: you are a master of meaninglessness.

  10. Rob Says:

    Since you seem so obsessed with degrees, perhaps you’d care to let us all know what your qualifications are, “Cybertiger” so that we can judge how qualified you are to rubbish distinguished scientists.

  11. Cybertiger Says:

    It’s 6 September 2011 at the NIH in Bethesda, Maryland – and another expert vaccinologist speaks her mind,

    “The festering nastiness, the creepy repetitiveness, the weasly, deceitful, obsessiveness, all signal pathology to me.”

  12. draust Says:


    If you’ve not come across Cybertiddles before, he is a GP so has a medical degree, amazing as that may seem.

    BTW, to save them answering themselves, Stuart is a PhD bioscientist at a UK medical school. Dr Zorro is a hospital consultant in the NHS. David Colquhoun is a distinguished Emeritus Professor and Fellow of the Royal Society, and wrote an excellent textbook on biostatistics. I would venture to suggest they all understand a lot more about science, statistics, epidemiology and causality (inter alia) than Shabbytabby does.


    If the best you can come up with is an uber-crank like serial conspiracy nut Mike “Health Ranger’ Adams interviewing the utterly discredited (and disbarred) Andy Wakefield of MMR infamy, then you really are desperate.

  13. Rob Says:

    Thanks, @draust. Just hope he isn’t my GP. And I’ll add that all my qualifications are in English Literature, so feel free to attack me if I pontificate about medical matters.

  14. Cybertiger Says:

    Thanks, @Drippy. Dreary Draust explained that …

    “… Stuart is a PhD bioscientist at a UK medical school. Dr Zorro is a hospital consultant in the NHS” …

    … Which amply explains the utter fatuousness of their opening remarks … respectively …

    “Tne smoking one is actually quite intesting too – you can turn the statistics on their head and say that the habit has absolutely no effect upon the health of 70 – 80% of smokers. When people say “it won’t happen to me” then they are probably right.”


    “Think of it as a form of Darwinian evolution. Those who don’t vaccinate, and turn to woo rather than evidence based medical care will have a slightly increased early mortality, which, over generations will cause them to die out.”

    … which together are an ample explanation for the extreme poverty of science and medicine in this country … and the dreadfully impoverished state they’re in.

  15. draust Says:

    ZZzzzzzz…. *snores*

    I’m amused that you take other peoples’ slightly ironic or off-the-cuff remarks so totally seriously, Tiddles. What, then, should we conclude about you from your previous Herculean output of junior school scatological insults? (see examples passim ad nauseam).

  16. Cybertiger Says:

    Droopy Draust spews more scatologically pretentious crap in pathetic defence of his crappy medico-scientific friends … without realising the sort of state we’re in. It’s stupidity … and greed … that are now the drivers of medicine and science … and the economy … as the recent ‘wankergate’ tapes confirm,

    It’s the economy, stupid … and pudding proof of the appalling state we’re in. Sadly, the behaviour of our leaders is important: the BMJ is an integrity free zone, the editor of the Lancet appears to scrub up nicely as a pharma whore … and Colquhoon’s a buffoon.

  17. Cybertiger Says:

    Britain is suffering a plague of w**k**s. My MP appears to understand the danger we’re in …

    What chance a vaccine against the spreading contagion? Eh, Droopy?

  18. Stephen Moss (@stephenemoss) Says:

    Dr Zorro comments:
    “Think of it as a form of Darwinian evolution. Those who don’t vaccinate, and turn to woo rather than evidence based medical care will have a slightly increased early mortality, which, over generations will cause them to die out.”

    But surely what is happening is the opposite of Darwinian evolution. Wonderful as vaccines are, surely one consequence of their development is that for Homo sapiens,’survival of the fittest’ no longer applies. We are now able to save the lives of countless people who would have died miserable and painful deaths a few centuries ago, and what reasonable person could possibly argue against the alleviation of such human suffering? Judging by the number of people on the planet modern medicine is doing no great harm to the survival of our species, but I wonder whether, without the forces of natural selection, we might unwittingly be building in some long-term fragility?

  19. Cybertiger Says:

    Perhaps Droopy’s blog readers – including David ‘bollocks’ Colquhoon – have taken the time to watch the incredible performance of the BMJ editor in chief at the National Institutes of Health earlier this month,

    Of course, Droopy Draust desperately claims that Andrew Wakefield is “utterly discredited”. Now, please take the time to watch Andrew Wakefield’s spirited defence of his research …

    … and then take note of who is really the most credible spokesperson for medical science … and the most sincere and trustworthy human being.

  20. Dr Zorro Says:

    I am glad cybertiger is not my GP.

  21. draust Says:

    Ditto that, Dr Z…

  22. Cybertiger Says:

    Profound comment from Drs Draust & Zorro! Could these two great medico-scientific minds not think of something less feeble to say? Dismal! This is the age of the corrupt and stupid … and that’s an evidence based fact.

  23. Dr Zorro Says:

    I too have a troll on my site, but, unlike cybertiger, whose only aim seems to be to insult, “George” as I call him sometimes has a point he is trying to get across. I very rarely agree with him and that makes him cross but at least we can sometimes have a meaningful argument. Reading cybertiger makes me quite fond of George.

  24. Nash Says:

    Up here in Middlesboro we were hoping the satellite would hit us and cause hundreds of thousands of pounds of improvement.

  25. draust Says:

    @Nash. Good one, Actually, my brother in Manchester always jokes that the IRA did the city a big favour with the 1996 Manchester bombing, which kickstarted redevelopment of the city centre

  26. Cybertiger Says:

    I note that Drousy Draust has taken to dropping the odd warm turd on Doc McCartney’s blog.

  27. Neuroskeptic Says:

    You still around, Cybertiger? I’d have thought you’d have evolved into a higher form of life by now – with at least a few brain cells.

  28. Stuart Says:

    Just looked back at this….

    My grandmother started smoking when she was 14 and smoked enthusiastically until she died aged 89 (in 1989 as it happens). Her death had nothing to to do with cancer, cardiovascular or lung disease.

    “That proves smoking isn’t bad for you and so I’m not going to stop”.

    How often have you heard that one? People say it all the time….

    In fact tonight I have just had a conversation with someone (aged 73) who was told this afternoon that she has terminal lung cancer. She advanced exactly the same argument and was absolutely convinced that the fact that her father puffed away quite happily until he died at age 90 *proves* that her impending death has nothing to do with cigarettes. I just agreed with her…there was no point in doing anything else under the circumstances. She’s still smoking and I honestly hope she enjoys every cigarette she smokes. No point in worrying about it now so may as well enjoy them.

    The statistics are pretty clear – cigarettes cause serious health problems in 20 – 30% of people who smoke. Anyone who is able to subtract two numbers will understand the point I was making.

  29. Cybertiger Says:

    These days I seem to be constantly reminded of Einstein’s thoughts on stupidity and infinity,

    “Only two things are infinite, the universe and human stupidity, and I’m not sure about the former.”

    Sadly, Dr Stuart and DrOwsy Draust continue to remind me of the stupefying infinity of British pseudo-science … while Dr Zorro and the Right disHonourable Dr Liam Fox MP (upstanding-Medical-Military Plonker) are a sure reminder of the infinite brainlessness of the medico-vaccine-military-complex.

  30. draust Says:

    Just carry on playing with talking to yourself, Shabby. I’m sure you’ll be very happy together.

  31. Cybertiger Says:

    Oh, you are still awake, Drowsy: I thought you’d gone to sleep.

  32. Cybertiger Says:

    @Drowsy and his stupefied pseudo-scientific mates

    Did you watch Godlee’s pathetic performance at the NIH on 6 September? Did you notice her suggestion that Andrew Wakefield’s alleged ‘scientific fraud’ be the basis of a criminal prosecution?

    Drowsy: wake up from your stupor and smell the coffee. Watch Wakefield’s recent further defence of his research …

    … and savour the thought that Godlee, the Queen of the Stupid, has not heard the last of it … (24:40 minutes)

    And what about vaccine safety, Draust? Have you woken up and smelt the coffee? You’re an expert in vaccinology – and your brainless medical mates are too. What have you to say about recombinant DNA contamination of HPV vaccines? Let’s hear your cogent rebuttal to Andrew Wakefield’s thoughts on the matter. (40:30 minutes). Wake up, Drowsy!

  33. Dr Zorro Says:

    “while Dr Zorro and the Right disHonourable Dr Liam Fox MP (upstanding-Medical-Military Plonker) are a sure reminder of the infinite brainlessness of the medico-vaccine-military-complex.”

    Could anyone translate that into English please.

  34. Cybertiger Says:

    In plain English: Dr Zorro = decerebrate arsehole

    PS. Where’s the scatological vaccinologist’s idiots-rebuttal of Wakefield’s vaccine safety concerns?

  35. Dr Zorro Says:

    What I was asking was, what exactly is a “medico-vaccine-military-complex”?

  36. draust Says:

    @Dr Zorro

    Nope, beyond me, other than a garbled insult. One of many.


    Why would anyone take anything Wakefield said even the slightest bit seriously? You are talking about a man who anyone can see (or at least anyone with eyes, and without blinkers) sought to build a career on attacking vaccines, and who never let inconvenient facts get in his way. Oh, and who sought to make big bucks out of it too. He is so discredited that even his own supporters did not dare call him as an expert witness in the Autism Omnibus Proceedings.

    Anyway, he new seems to have found his true level addressing organisations of far-right wingnuts like the AAPS, or anti-vaccine conspiracy-fests like Autism One. And you posting up videos of his self-aggrandising speechifying here is not going to change that one iota.

  37. draust Says:

    PS For views on Wakefield’s ‘ethical compass’, one can consult the GMC decision or the blogs describing it, or Brian Deer’s BMJ series. But for the scientific validity (or rather, lack of it) of Wakefield’s work, one of the best places to start for bioscience folk is this post over at Respectful Insolence, which covers the breath-taking ineptitude (at best) of the Wakefield gang’s PCR testing for measles sequences in the gut biopsy samples.

    The similarities between this sorry saga and the recent collapse of the XMRV-in-chronic-fatigue story (where, similarly, what were claimed to be the critical results showing an RNA virus in clinical samples turned out to be the result of sample contamination with DNA) are quite striking.

  38. Cybertiger Says:


    Rather than attacking the man – your usual scatological tactic – I invited you to attack the vaccine safety allegations that Wakefield raised during question time at his recent AAPS talk – from 40 mins to 43 mins or so. What about the safety aspects of recombinant DNA found in the HPV vaccine? You’re an expert vaccinologist, so you must have an opinion on safe vaccinology. Is vaccine safety a concern to you? Or are you just the tosser who does not give a toss about science, safe vaccines or the future of vaccine safety?

  39. Dr Zorro Says:

    My understanding is that shabby, having been sacked from his GP position is now practicing as a prison doctor, reinforcing my view that the only patients he now has are those who have no choice in the matter. You would expect that the thought of being forced to have medical care from shabby would be an extra incentive to the felons of Bedfordshire to try and stay out of jail.
    Do correct me if I have my facts wrong

  40. Cybertiger Says:

    “Do correct me if I have my facts wrong”

    The facts speak for themselves: Zorro is possessed of a baffling superiority complex, a severe personality disorder (PD) of the conscienceless variety and the cognitive capacities of a decerebrate newt. Any thoughts on vaccine safety, Zorro? Obviously not!

  41. Dr Zorro Says:

    Enough to have my own children fully vaccinated against everything going.

  42. Cybertiger Says:


    And my two girls were fully vaccinated … but what has that got to do with the price of fish … or the cognitive capacities of decerebrate newts? Nothing!

    PS. And my youngest achieved a first class science degree this summer from Leeds University, despite a full vaccination history. And what’s that got to do with the price of anything … or the price of vaccine safety? Nothing!

  43. Cybertiger Says:


    You’ve flicked the censorship switch! Shame on you, Draust!

  44. draust Says:


    Nope, no censorship. For some Quixotic reason I don’t believe in it, even when the comment (and/or commenter) are as mad as a box of frogs.

    Interestingly, though, Akismet/Wordpress appears to have a (cyber) mind of its own and sometimes spamfilters comments unprompted. No obvious way to tell why it did this to Shabby’s 7.57 pm comment from last night – now restored – but something about it obviously looked spam-my. I wonder what?

    @ Shabby: BTW, I have never claimed to be an expert vaccinologist – because I’m not one. Ditto epidemiologist, and other things [though I think the evidence suggests I know more about the pitfalls of PCR than your hero St Andy]. But I do know how to recognise/where to find an expert vaccinologist, or epidemiologist, if I need one, or where to find their published thoughts.

    Wakers, of course, was/is no more of an expert vaccinologist than I am. In contrast, though, that has never stopped him thinking he was/is one – all evidence to the contrary aside.

  45. Cybertiger Says:

    It’s hard to be happy. It’s hard not to worry. Dreadful dolts like Draust and Zorro are worrisome drones. The medical and scientific establishments are underpinned by greed, corruption and infinite stupidity. All there is left is to sing along with Bobby McFerrin …

    …. and clap happily through gritted teeth.

  46. draust Says:

    Funnily enough, when you click Shabby’s Youtube link for Bobby McFerrin’s “Don’t Worry.. Be Happy”, the latest comment there says:

    ‘I play this when trolls try too hard to piss me off.’

  47. Dr Zorro Says:

    I still don’t know what a medico-vaccine-military-complex is.

  48. Cybertiger Says:

    Miserably worrisome drones and dreadfully dreary dolts tend not to be overendowed with imagination or anything much else on the synaptic front. Twat!

  49. Phillip Helbig Says:

    but only if you’ve bought a ticket

    Old joke: A man prays every day, asking God to do him a favour and let him win the lottery. Days go by, then weeks, then months, and he still hasn’t won, so he gets frustrated. He then prays again, asking if he has somehow offended God. Then a voice booms down from heaven “Try buying a ticket”. :-)

  50. draust Says:

    Thanks Phillip.

    That’s a relative of the oft-told religious parable / joke about the man who refuses to flee from the rising flood waters because he is relying on God to save him…, otherwise known as “But I sent two boats and a helicopter!” (see e.g. here).

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