It seems that you're using an outdated browser. Some things may not work as they should (or don't work at all).
We suggest you upgrade newer and better browser like: Chrome, Firefox, Internet Explorer or Opera

×
Community
General discussion (archive)Let's debunk some myths!(82 posts)(82 posts)
(82 posts)
Pages:
1
2
3
4
5
6
This is my favourite topic
Posted December 28, 2012
Einstein never said 'The definition of insanity is doing the same thing over and over again and expecting different results.' This phrase was coined by a journalist in the 80s and, regardless, doing the same thing over and over again is a part of the scientific process to identify anomalies.

You can't catch a cold from being cold. If you were in a vacuum and the air temperature was below freezing you would never get rhino-virus. The only way you can get it is through another person's fluids, such as breath vapor, mucus, saliva, etc. You can get hypothermia from being very cold which can have similar symptoms to a bad cold or influenza.

As for the dark clothing, a study was done on the Bedouin people of the Sahara Desert who regularly wear black cloths, often times that covers their entire body. The study found that the loose clothing diffused the heat faster than it was absorbed so wearing white was about the same as wearing black. However, black does absorb more light, and therefore heat, so if you are wearing heavy clothing or if you have a black car, in intense sunlight the dark will be hotter than white clothing or a white car, respectively.

Edit: And caffeine in itself has a negligible amount of glucose so it does not wake you up. It does cause your body to produce chemicals that do 'wake you up', so indirectly it has the same effect. It is a poison plants have evolved to ward off pests and if you were the size of an insect and ate a coffee bean you would die of cardiac arrest.
Post edited December 28, 2012 by Parvateshwar
Posted December 28, 2012
avatar
iuliand: I don't get this one. If you stay in the shade then there is no difference but exposed to the sun there is a huge difference. So what's the situation discussed here?
avatar
keeveek: Yeah, I don't understand that either. Black clothes absorb the light and heat while white clothes repel most of the sunlight.

You don't even need to wear them - just put two t-shirts in the sun for an hour, and then touch both of them.
Similar concept to an experiment I remember doing when I was still at school and a lot younger with Tin Foil (Aluminium / baking foil)

Cover the back of your hand with the shiny side of the foil facing up then put your hand under a heat lamp, you won't actually get burnt no matter how long you keep your hand there.

Then paint the same side of the foil with some black paint and do the same again. This time the heat passes straight through and you will feel it instantly.

PS : Anyone that gets burnt from actually trying this out is their own fault!!

Be warned that when you paint the foil black the heat passes through without any reflection and gets hot instantly
Posted December 28, 2012
The story about the black clothing was done in Nature magazine during the 80s. Here's the link. So, yes, dark colours do absorb more heat than light colours, whether it is hotter depends on the material and how tight or loose it is.

http://www.nature.com/nature/journal/v283/n5745/abs/283373a0.html
Post edited December 28, 2012 by Parvateshwar
Posted December 28, 2012
One I at least think is a myth:

If you are in a desert or beach on a hot sunny day with a warm bottle of water (or soda or whatever), you can make the bottle/liquid cold by putting it into a wet thick sock, towel and somesuch, and leave it hanging somewhere in the sun.

The theory is that the evaporation from the sock/towel also dissipates so much energy from the bottle that it becomes cold, even close to a freezing point. Allegedly e.g. US army is using this trick all the time whenever they attack some Arab country, in order to get cool drinks in the hot desert.

I don't remember where I read that, but I say, hogwash. Yes, I even had to try it in Thailand in a hot day, the bottled Oichi ice tea stayed as warm as ever in the sunlight. I felt I'd been had. :) And yeah, it doesn't make sense because otherwise wet socks left in the sunlight would become cold as well...
Post edited December 28, 2012 by timppu
Posted December 28, 2012
avatar
timppu: One I at least think is a myth:

If you are in a desert or beach on a hot sunny day with a warm bottle of water (or soda or whatever), you can make the bottle/liquid cold by putting it into a wet thick sock, towel and somesuch, and leave it hanging somewhere in the sun.

The theory is that the evaporation from the sock/towel also dissipates so much energy from the bottle that it becomes cold, even close to a freezing point. Allegedly e.g. US army is using this trick all the time whenever they attack some Arab country, in order to get cool drinks in the hot desert.

I don't remember where I read that, but I say, hogwash. Yes, I even had to try it in Thailand in a hot day, the bottled Oichi ice tea stayed as warm as ever in the sunlight. I felt I'd been had. :) And yeah, it doesn't make sense because otherwise wet socks left in the sunlight would become cold as well...
That works just fine (just not close to freezing point, or at least not easily). Evaporation requires energy; it will drain energy (heat) from the bottle. This is how refrigerators work.
Fridge:
Liquid is expanded so it's easier to evaporate in low temperature (lower pressure -> lower evaporation temperature)
The liquid evaporates inside the fridge and thus drains energy from it.
Then it's compressed to get the condensation point lower (higher pressure -> lower condensation temperature)
The compressed gas condensates back to liquid and releases the energy outside the fridge in condenser.
The liquid then goes back to evaporator inside the fridge through expansion valve.
https://upload.wikimedia.org/wikipedia/commons/5/5d/Refrigeration.png
Posted December 28, 2012
avatar
tinyE: http://www.snopes.com/
Thanks for the link - otherwise, I might have never found out about the dangers of dihydrogen monoxide
Posted December 28, 2012
It is a myth that the human body needs to ingest any glucose to survive.
Posted December 28, 2012
Though the Earth has an elliptical orbit, the seasons are not caused by the earth being closer/farther away from the sun. It is the axial tilt that causes the seasons. Apparently, this is a widely held misconception.

[url=]http://pwg.gsfc.nasa.gov/istp/outreach/sunearthmiscons.html[/url]
Posted December 28, 2012
avatar
tinyE: Just make sure that when you shoot a mosquito you shoot to kill. There is nothing more deadly than a wounded mosquito.*

*took that from Python.
+1
Posted December 28, 2012
I know it's cliche, but let's debunk the Moon Hoax Conspiracy.

Flag waving in the wind: If it was wind, why doesn't the lunar dust rise and make clouds? So the only logical answer is the astronauts caused the flapping

No Stars: The only reason why they didn't see stars is the same reason you don't see them in the day on Earth. Since they Moon has no Atmosphere, it turns out black.

Footprints need moisture: Depends on the rock. Regolith, which is what the lunar soil is, doesn't need any moisture for footprints because for example, you can make footprint in the sand because the rock can't bind together without water. But with Regolith, the jagged and irregular shape can stick together to make the famous footprints.

Astronaut lit in shadow: The Moon is very reflective, it's albedo is 7-10%. The Astronaut is lit up due to the reflection of lunar soil.

Non-parallel shadows: The Topography can alter the shadows. Mythbusters tested this with a large miniature and made the exact same topography of NASA's, and it set the shadows off parallel.

Radiation would kill them: In the Van Allen Belts, they are less dense concentrations of radiation, which what they would aim for. They would have a lot of metals, plastics, and plexy-glass around them that would stop alpha and beta radiation, and severally weaken Gamma radiation. Same with on the moon.

Micro meteors: Again, Apollo was armored,. In fact, they had Kevlar to protect them from anything they might encounter, and the probability of getting hit s pretty much zero.

Last but not least, the moon buggy: It was able to fold up to about the size of a large suitcase, and they would have two people bringing it out.
Posted December 28, 2012
Here's a seasonal one - Coca-Cola did NOT invent father Christmas nor was responsible for making his jacket red, they may have been responsible for making the modern vision of Santa be the one of a few competing ones that won out but that's about it

Also any magazine article that says that you should be drinking 8 pints of water a day is wrong, that one comes from a study that said in any given day we consume the EQUIVALENT of 8 pints of water - from all the water in our food etc.

Also, yes the debunking side of QI is very similar to Snopes but QI also often just shows you amazing facts and things that you never thought possible, those parts are more like
www.cracked.com
Yay cracked!
Posted December 28, 2012
avatar
Gowor: Coffee contains caffeine, which counteracts adenosine - a natural nervous system inhibitor. That means drinking coffe actually leads to increased activity of the nervous system. It definitely depends on personal metabolism, but there is a biological basis for the "energy boost" :-)
avatar
Red_Avatar: Well that's not an energy boost though - from what I've read, coffee affects different people differently but in general, it makes them edgier but all sorts of tests couldn't confirm that it actually wakes you up. I think the main thing everyone agrees on, is that it's a good laxative but the effects of coffee are pretty hit & miss which I think depends on your brain chemistry or some sorts. In any case, no energy boost though.
Caffeine prevents the reabsorption of the second messengers (among other things), which basically means that it slows down your cells' ability to rest. Rather than performing a single action and then resting immediately afterward as normal, the cells will continue performing that action until the caffeine is out of your system. Adenosine can't tell your cells to rest as long as the caffeine is there because they use the same receptors. This means that caffeine isn't technically a stimulant because it doesn't actually increase cellular activity directly, but caffeine still ACTS like a stimulant regardless because it stops your cells from going inactive. If you're already bone tired when you drink your coffee, it won't make you any less tired, but it will help you keep moving and keep working. By preventing rest on a cellular level it can easily help prevent rest on a higher level.

Coffee and tea and soda have effects in addition to caffeine, too, so you will often get different results depending on your caffeine source, as well. Tea, for instance, has longer-lasting effects but it doesn't have the same quick jolt that coffee does, and soda can lead to crashes later because it's got so much sugar.
Posted December 28, 2012
avatar
tinyE: http://www.snopes.com/
avatar
etna87: Thanks for the link - otherwise, I might have never found out about the dangers of dihydrogen monoxide
I can't believe that many actually fell for this sort of thing. I'm in no way any chemist, but anyone that has gone through highschool/college should know how one names certain basic compounds:
Mono = 1
di = 2
tri = 3
etc...

H1 is thus monohydrogen or just hydrogen/hydrid, whether it's the first or last compound.
H2 = dihydrogen
O1 = monoxide (oxygen is gas = oxide)
O2 = dioxide (as in CO2 - Carbondioxide)
O3 = trioxide (ozon)

In other words, dihydrogen-monoxide (H2O) is just plain water.

Can't really name the greenhouse gas methane (CH4) right, but then again, I'm no chemist :D

avatar
Kristian: It is a myth that the human body needs to ingest any glucose to survive.
Yes and no. Mostly yes. Both fat and protein is essential for building blocks and also provide energy. Many can survive purely on fat/protein, however, for some, when removing glucose too fast, has caused serious complications. Especially elder people. It's like taking away the cola for someone that is addicted to it. (well, first get REALLY cranky, then they think they're are going to die :)

Got really scared the first time I sow a friend of my didn't get his daily dose of about 2-3L of (noname)cola, he got all shaky, headaches and whatnot. But that's because of both the sugar and the caffeine.

3; my grandmother told me that if I ate to much snow - I get worms. Period.
Many says this, but the real danger is that the body contracts the heat from less critical areas, to counteract the cold in the stomach. I.e; shortcut to hypothermia.

4; Columbus didn't discover America first - It was already "discovered" by it's first inhabitants some 15000 years ago. Then discovered by an Icelandic seafarer before Columbus. But it has always intrigued me whether or not he actually sow a "shiny object that flew from under the water, and into the sky".

bevinator; +1 for the post on caffeine. Interesting. There seem to be a correlation between people taking to many caffeine tablets over a long period of time - and the stagnant development of the hippocampus and other areas... especially long-term memory. Almost like sleep deprivation or going on with too high insulin levels.
Post edited December 28, 2012 by sanscript
Posted December 28, 2012
avatar
lukaszthegreat: Shut up and go watch it. it is incredibly good show although they do make mistakes. like everyone else.
the difference is they thrive on being corrected. A mistake in the past show? if pointed out they will gladly correct it.
Well, I applaud them for being willing to be corrected, but apparently they propagate as much wrong information as the myths they're debunking... so yeah, fuck them. Yes, I mean that, if they can't do a better job than that they really can get bent.
avatar
Red_Avatar: - alcohol does not warm you up. When you're out in the cold, it actually makes it easier for your body to freeze by opening up your pores. In short: don't drink alcohol to warm up. Even though you'll feel warmer, your body will get colder much faster.
avatar
SimonG: Alcohol doesn't enlarge pores, but your blood vessels. You feel warmer, because more blood is rushing through your system. This is also why alcoholics have a "red nose", they blood vessels are permanently widened. But you do indeed lose warmth faster due to that.
I love how this show has apparently gotten tons of this shit wrong and the average video game forum member has been able to correct most of it... I guess this reinforces my biases, but you know, I'm still not convinced my biases are wrong, just that they are biases:)

Your post hasn't been the only ding-ding-ding, but just the first one that made me reply;)
Post edited December 28, 2012 by orcishgamer
Posted December 28, 2012
avatar
orcishgamer: Well, I applaud them for being willing to be corrected, but apparently they propagate as much wrong information as the myths they're debunking... so yeah, fuck them. Yes, I mean that, if they can't do a better job than that they really can get bent.
The primary purpose of the show is entertainment. It is very good at that. It's not to be taken too seriously, and if you're watching it so you can compile an encyplopedia you'd be an idiot.

My post was just to point out it's also fallible, however if you have an infallible source of myths, please do share.
Pages:
1
2
3
4
5
6
This is my favourite topic
Community
General discussion (archive)Let's debunk some myths!(82 posts)(82 posts)
(82 posts)