A blog about science, medicine, media and the ramblings of Irish hack....

Wednesday, February 2, 2011

20 Science and Medical Myths

Assuming you're not a sociopathic hermit with all the social skills of lobotomised hamster, there's a good chance you've been to some form of social engagement in your life. And one great thing about a good gathering is good conversations - sometimes though, you hear something that triggers a distant alarm bell. Is that true ? I must check that. Of course, half the time we forget. And then maybe we hear it again. And again. Then after a while, we tactitly assume it is true and repeat it. But if it is wrong, are we just perpetuating falsehoods? The following is a list in no particular order of things I have either heard at parties, or at some stage, in some form, implictedly assumed to have some merit.  Each of them a juicy tidbit on science, technology or medicine that gets repeated so much it is ingrained in our collective consciousness. They share one thing in common - they are all, without exception, falsehoods. Here's a list of 20 such claims that I have heard at least once in the year. So in no particular order and with no real rhyme or reason....

1. You should never wake a sleepwaker - Sure, waking a sleep walker may result in them being disorientated and confused. But waking anybody can render them a little confused, whether they're idly lying in on a weekend or ambling around in a walking coma. Sleepwalking is a REM sleep disorder and as a parasomnia is damn interesting; there have been cases of sleep walkers writing semi-coherent emails, having sex with strangers and even murdering people (not all at the same time .. yet) so on balance , the disorientation they may feel is somewhat less dangerous than other sleepy stunts they may pull. Even though observing may be much more hilarious as a spectator sport, walking them gently is probably more humane

2. You only use 10% of your brain - Somewhere right now there is a neurologist hearing this and cringing. This little piece of lore is so oft-repeated that it is almost accepted as fact but it does a massive disservice to our brains to accuse them of being so lazy. We use practically all of our brains, but usually not all at once. This can be observed looking at a PET scan or fMRI image. So why has this myth endured so long ? One of the big reasons is that it is constantly trotted out by psychics and those with a vested interest in obscuring rational thought. "The hidden 90%" rubbish serves as a convenient Deus ex machina for those trying to peddle nonsense and they have succeeded admirably.Despite this, one could be forgiven for suspecting that people who part with their hard earned cash for psychics may be using less than their whole mental capacity.

Amazingly, even this man uses most of his brain. Notice how I avoided the juvenile 'bender' joke; it's all class here...

3. Water in Sinks washes down the other way in different hemispheres - The claim here is that due to the Coriolis effect, water drains down sinks and basins in different directions of rotation depending on the hemisphere of the Earth it is measured in. This one is almost plausible; the Coriolis effect does describe the apparent deflection of an object in a rotating reference frame but in reality, this effect is minuscule except for huge bodies of water. The shape of the basin is essentially what decides the direction water goes down. You can test this in very fancy hotels by repeatingly flushing toliets and observing your results. I tried this with a friend; the most common result is that we were asked to leave the hotels the next day.

4. Sugar makes kids hyperactive - This is one classic example of getting it wrong. In all double blind trials, sugar has had no effects whatsoever on the hyperactivity of children. Interestingly, studies did show that parents and teachers rated children who they thought had been given sugar as more active, despite the fact the children were controls who had been given no sugar - a beautiful display of both observer effect and testament to why double blind tests beat anecdotal observation; people tend to look only for evidence that confirms their hypothesis, which is textbook bad science. A good scientist, by contrast, looks for data to invalidate their hypothesis.And a tired parent, it seems, looks for a convenient scapegoat rather than entertain the possibility they may have been birth to the devil.

5. Pennies dropped off skyscrapers can kill / crack pavements open - At first glance, this looks almost true; acceleration due to gravity over a long distance can produce some pretty scary velocities at impact. The kinetic energy at impact is half the velocity squared by the mass. The mass may be little but the velocities are huge, so the end product is a big scary number, right ? Well not quite - that may happen in a vacuum but in reality, falling objects are falling through a fluid (air) are limited by terminal velocity, which happens when the force gravity exerts on the object is matched by the air drag the object creates, meaning a penny for example couldn't hit the ground any faster than 55-65mph; not enough to do damage. The verdict ? A very cheap but utterly ineffectual assassination method.

6. Swimming after eating causes cramps and drowning - Nay, not true. In any case, even with a cramp, a swimmer wouldn't actually drown. Though studies HAVE shown an increase in water mortality when large amounts of alcohol have been imbued. Which is kinda what you'd expect really, as drunks don't make the most graceful movers at the best of times.

7. The Twin towers came down in a controlled explosion - It's not a proper college party discussion until someone trots this out but to prove the WTC towers didn't fall in a controlled explosion is rather straightforward. For starters, controlled demolition starts at the bottom, not the top, of large structure. Otherwise it would achieve little save strewing debris everywhere. On top of that, numerous groups ranging from structural engineering organisations to popular mechanics have, after rigorous investigation, reached the same engineering conclusions: The WTC towers fell because of a fire induced, gravity driven collapse. But, the conspiracy theorists scream, if controlled explosives didn't bring down the WTC, what else could have ?! Oh I don't know.. perhaps someone FLEW A BLOODY PLANE INTO THEM? Speculate all you want about the motives of those flying the planes, but the engineering is fairly solid.

September 11th Attacks - obviously masterminded by a secret cabal of Jewish - Pagan - Neo-Con - Facist - Muslim - Templar - Illuminati - Freemason - Liberal - Bilderburg - NWO - Lizard People - scientologists. OBVIOUSLY.

8. HIV does not cause AIDS - This little gem is often repeated by AIDS denialists, claiming (usually) that HIV is a harmless passenger virus and that AIDS is caused by drug use and specifically, the use of antireteroviral drugs - the class of medicine used to treat AIDS. This view has been well and truly debunked but in certain places it still has an impact; in South Africa, this incorrect assertion has lead to the deaths of an extra 330,000 people when the government  under Thabo Mbeki invited several HIV/AIDS denialists to join his Presidential AIDS Advisory Panel, claiming AZT caused AIDS. Doctors and medical scientists responded with the Durban declaration which stated categorically that HIV lead to aids. Finally, years later, this one seems to be dying down but curiously.....

9. AIDS Was created as a man made biological weapon - Ladies and gentlemen, presenting the most pointless biological weapon ever; it takes too long to kill, may or may not kill / disable, is relatively difficult to transmit and impossible to control. If AIDS were man made, it would be up there with trying to use your testicles as ammunition in a slingshot as dumbest weapon ever. There is a wealth of scientific information on the birth of HIV/AIDS and it's been in the human population since as early as 1930 so the iatrogenic theory is right out the proverbial window. Note to potential biological weapon developers - Ebola is WAY more effective. Just sayin'.
10. A coin on a train track will derail the train - Not a hope. Bigger objects can cause serious trouble though  - The South shore passenger train in Indiana jumped track in 1999 after three youths left bricks on the track. Luckily no one was hurt. But small coins cannot derail a train yet plenty of people have died trying this by making a poor judgement on when the train is actually arriving.  Moral of the story: if you intend to smash pennies using a freight train, invest in a timetable. Though in Ireland, that may be of somewhat limited use. Another word of warning; high speed trains can shoot the coins off the track like high speed projectiles. So invest in a suit if armour too for good measure. It may not save your life but it will look awesome.

All this for a souvenir penny......

11. It takes 7 years to digest chewing gum - Poor chewing gum gets a bad reputation for pretty much everything. While chewing gum is mainly indigestible, it goes through the digestive system at the same rate as anything else and is expelled in the same way. Whether the expelled waste is as a result more consistent is an area of research that is currently lacking. Thankfully.

12.  If you handle a baby bird, its mother will reject it - Not true. In fact, most bird have a lousy sense of smell and won't care either way. Wildlife advice is generally return the nestling to the parents / nest as quickly as possible, or leave it in such a place as it can be readily found by the parents. It is useful to determine if the bird is a nestling or fledgling - if it's the former, returning to nest is vital. If the latter, leaving it be should be alright. And if it's a seagull, give it a smack for good measure.

13. Homeopathy is a genuine medical treatment - Homeopathy has failed every major test it has been subjected to. Firstly, the mechanism of action is laughable - that highly diluted concentrations of an agent can be curative has no merit whatsoever when the dilutions are so massive none of the original substance is left. Homeopaths argue (and it is quite funny to watch them do so) that water has memory, which they provide zero evidence for and violates known physics anyway. Finally, there is the little fact that in every major study, homeopathy has failed by doing no better than placebo. Miserably. Die hard believers will cite individuals studies that might show some weak effect for a minor ailment but invariably these reports have low participants and high drop outs with subjective reporting, which screws the statistics - a technique called cherry picking the data. The more powerful tool of meta-analysis (which basically gets all studies together and weighs them) conclusively shows homeopathy doesn't work. It doesn't stop homeopaths defending it and rubbishing science, but why would it when they are trying to protect a livelihood which allows them sell vials of water / sugar pills at massive prices to gullible buyers?

14. Use of date rape drugs is common and rising - Seemingly not, unless you count alcohol as a drug; which, technically, it is. This has been covered in this blog in some depth here.

15. You can see the great wall of china from space - This could potentially be true, if you brought some form of telescope into space with you. But even from low earth orbit (LEO) you'd need a visual acuity of 20/3; roughly 7.7 times normal. So that's a resounding 'no'. From LEO, even as near as the moon it's impossible to see. In fact, the wall would have the same apparent width as a human hair viewed from 3.2km away. Some astronauts have claimed to see the great wall when in fact they were observing the Grand canal of China, near Beijing. The genesis of this legend predates space exploration by some time, being first recorded in writing in 1754. Strangely enough, certain cameras in LEO can just about pick it up, as camera lens operate in a much different fashion than human optics. If you really want to see the Wall from space, rather than going into orbit and setting up a camera, we recommend you just use Google Earth like everyone else.

16. Evolution states we evolved from apes - It is truly sad that in this day and age, there is still those who deny as abundantly observable a scientific theory as evolution. And to compound this, there is a lot of misunderstanding about evolution. Much of that misunderstanding is deliberately fostered by those with a religious agenda as it offends their particular holy text; allow me to stop there and ram that point home - science, which bases itself upon observable and testable evidence, disagrees with some arbitrary, self-contradictory and unverified text written aeon's ago and somehow this means science is wrong. Well that's an iron clad argument no doubt. Anyway, before I type myself into an incoherent fury, let's get back to the myth - that evolution states we evolved from apes. In fact, evolution claims no such thing and never has; rather, evolution states we share a common ancestor with other primates who are distinct cousins to us, but never that we descended from them. Though looking at certain intelligent design proponents, one would be forgiven for making this mistake...

No caption required - or indeed, even advisable.

17. MMR Vaccination causes Autism - This is the stuff nightmares are made of; it really is worth reading a little about how to the whole debacle came about. It's covered very well over at Bad Science and the wikipedia article. Indeed, I've mentioned it in passing in a previous entry. But in a nutshell, a doctor with zero ethics named Andrew Wakefield (who, it turns out, received money to make false claims..) decided, with zero evidence, to claim a link between MMR vaccination and autism; the media eventually get wind of this and have a field day, vaccination rates fall (as low as 60% in London at one stage, below herd immunity levels) because anxious parents don't want to risk autism - so their kids get measles, mumps or rubella and die instead. Good move. Wakefield is eventually struck off the register as the research shown to be fraudulent and vaccination rates have steadily increased but this is sometimes still repeated. This one is pure nasty - and should always be challenged. Screw being polite, if someone mentions this one, correct them - do not back down. This is precisely the sort of nonsense that results in dead kids. And while we're on vaccinations....

18.HPV vaccine has killed women - No, it hasn't. And it couldn't anyway. This absolute piece of tripe was first touted on the great bastion of medical research that is the Oprah Winfrey show. I've ranted about it before here so I'll spare you the repeat and me the hernia. But I do get angry - usually these myths are fun, harmless. These kind of ones are malignant and detrimental to all involved and really, they should be challenged more often. A piece of idiocy repeated enough eventually becomes accepted as fact, and while that may be just amusing with some things, it's downright dangerous with others. Still, to paraphrase an old idiom, you can lead an Alternative health advocate to reason but you cannot make them think.

19. Cell phone can cause brain cancer - There is zero evidence for this and loads of evidence against it. When you put a phone to your ear, there's a thermal effect - notice your ear gets warm, as does the handset. This is harmless, so investigations tend to focus on non-thermal effects. Specifically, can mobile / cell use cause cancer and is Wi-fi detrimental to health. The answer is a clear no - the energies involved (microwave / radio wave) are simply not high energy enough to ionize, and hence can't cause cancers. In depth studies have confirmed this and it seems that at lower than ionizing levels, we're simply not that sensitive to electromagnetic waves - which is a damn good thing, because our own sun and earth give off a hell of a lot of them. Visible EM radiation (or light)  has a lot more energy than radio waves (about a billion times more per photon) and microwaves (about a million times more) to put things in perspective.So if you worry a little about your wifi / cell phone, then worry about a billion times more about turning on your house lights.

20. Stem cells all come from unborn babies - Yikes. This one always generates controversy and pro-life / pro-choice antipathy. It needn't. There are in essence two types of stem cells; embryonic and adult cells. Embryonic stem cells can differentiate into all forms of human cell while adult stem cells act more like repair mechanisms, replenishing existing specialized cells. As you can imagine, the potential for these cells to treat disease is practically unlimited but there is a controversy, due in a large part of confusion between Adult and embryonic stem cells, and how these cells are gathered. Adult stem cells are more widely researched and come, as you may guess, from adults. On a side note, most Embryonic stem cells are gathered from excess embryos created for IVF treatments which are due to be destroyed anyway, which is why the controversy seems to me misplaced - it seems more pro-waste than pro-life. But I digress as the militant pro-life brigade may take offense, and they only seem to value the sanctity of life when it is in embryonic form.

This is a human blastoctye where Embryonic stem cells come from - Available at your local fertility clinic, no need to shoot up a family planning centre! Well, unless you're really bored or something.

And so ends my list. There are loads I've forgotten and some are wilder than others, but it's interesting to look into them. I find if in doubt, the urban legend reference site Snopes.com is meticulously researched and always worth a read.

Now ladies and gentlemen; YOUR nominations for most widely heard but totally wrong factoids?! Let's hear them!!!


  1. You didn't cover the "Gay" issue...that homosexuality is a choice...and that one could change if they would reject the devil and accept Jesus Christ as their savior...I am so disappointed David! ;)

  2. No Point over here - no one actually thinks that. Europe seems a little more liberal on gay rights.

  3. A thorougly brilliant written article (as always) Mr. Grimes! There was a few of those I didn't realise were just myths and had been told them so many times that I took them solely as fact i.e. the never waking a sleepwalker one!

    Also, I feel that I have to congratulate you on not making the obvious Yuri Geller bender joke... however, I made the joke in my little ol' noggin and my little ol' inner monologue joke voice was yours so in my head, you did make that joke and I laughed... oh how I laughed!

    Anyhow, I digress. Brilliant post!!

    Can you head over to my blog and make a suggestion on my how to improve piece? Methinks I need some motivation.

    Love as always Grimesy!


  4. Very Good Dave. I have to object to point 3 though "Water in Sinks washes down the other way in different hemispheres". Up until recently I too believed that this was a myth, Until I got the chance to test it for myself whilst standing on the equator in Equador. A Brass sink with a blog hole in it would drain straight down (i.e no swirling at all) when placed on the equator. It would also swirl one way when placed on one side of the equator and the other when placed on the other. Also it's surprisingly easy to balance an egg on a nail on the equator, but that's a story for another day!

    Why not check out my blog post about it...

    Gary B

  5. And by "blog hole" i mean plug hole. Getting ahead of myself there.

  6. Hey Gary - Will check that out now! It's technically not a myth but it only applies to large bodies of water; interesting you mention the equator, there's a good explanation on how you COULD show it here..



  7. Somewhat related to the cell phone myth, but another hoary old chestnut is that high voltage power lines are somehow correlated with an increase in cancer rates.

    Nice work. :-)


  8. So wait... you're saying my unborn cancerous autistic stem cells weren't caused by an MMR vaccined phone with 10% battery that evolved from a monkey?

    It's like NOTHING in The Secret was true.

    Nice font though.


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