Water IS blue, not just because of the sky

Many believe that lakes and oceans are blue "only" because they reflect the blue sky.

Actually water looks blue because water is blue; the water molecules do absorb some light, and they absorb red frequencies more than blue.

The effect is small, so the blue color only becomes obvious when observing layers of water many meters (or more) thick. (This effect is noticeable to a lesser amount in white-painted swimming pools.) In salt water or mineral-laden fresh water, the color of dissolved minerals can also be seen. Sky-reflection does play a role, but only when the water surface is very calm, and only when the water is observed at a glancing angle less than approximately ten degrees.

 

Electricity does NOT travel at the speed of light

Many textbooks claim that Electricity (electrons) within wires flows at nearly (or even exactly at) the speed of light. In fact it's the electrical energy which flows rapidly ("rapidly" is still slower than the speed of light).

Electrons, which have mass, can never travel at the speed of light due to the theory of relativity. The drift velocity of the charges in an electric current is extremely slow, on the order of centimetres per hour.

Where the electric current is visible, as in electrophoresis, the slow movement of charge carriers can be seen directly. As a very rough analogy, imagine a line of people at an amusement park. When the people at the front board the ride, a space opens up, and rapidly spreads to the back of the line.

However, the average velocity of any one person is far slower than the speed at which the space moves.

Seasons are NOT the same length

Due to the earth moving fastest in its orbit when closest to the Sun, the southern summer / northern winter is the shortest season, with northern summer / southern winter being the longest.

However, the difference on earth is only a matter of a few days, while on Mars with its more eccentric orbit the difference is more distinct.

 

You WON'T get a cold just from low temperature

It is a very widespread misconception that the common cold can be caused by (or the chance of getting infected by it is increased by) exposure to cold weather.

In reality, the common cold is caused by viruses and has nothing to do with low temperatures.

Saturn is NOT the only planet with rings

Jupiter, Uranus, and Neptune also have rings, though those of Saturn are the most visually striking (and the only ones easily seen).

 

 

Meteors are NOT hot when they land on Earth

When a meteor lands on Earth, it usually is not hot. It's usually warm.

A meteor's great speed is enough to melt its outside layer, but any molten material will be quickly blown off (ablated), and the interior of the meteor doesn't have time to heat up because rocks are poor conductors of heat.

Also, atmospheric drag can slow small meteors to terminal velocity by the time they hit the ground, giving them some time to cool down.

Clouds do NOT form because of the air's temperature

It is incorrectly believed that clouds form because cold air "holds" less water vapor than warm air. Air has no capacity to hold water vapor. It is the temperature of the water itself (and its surroundings) that causes humidity, condensation and clouds to form.

 

People DID know earth was not flat before Columbus

Some believe that Christopher Columbus had a hard time receiving support because Europeans believed in a flat Earth. In fact, sailors and navigators of the time knew that the Earth was spherical, but (correctly) disagreed with Columbus's estimates of the distance to the Indies.

If the Americas did not exist, and Columbus had continued to the Indies (even putting aside the threat of mutiny he was under) he would not have survived long enough to reach them.

The Great Wall of China is NOT particularly visible from space

While at a low orbit, the Great Wall of China can certainly be seen from space but it is not unique in that regard.

From a low orbit of the earth, many artificial objects are visible on the earth, not just the Great Wall of China. Highways, ships in the sea, dams, railroads, cities, fields of crops, and even some individual buildings. As to the claim that it's the only man-made object visible from the moon, Apollo astronauts have reported that they could not see any man-made object from the moon, not even the Great Wall.

There is NO "dark side" of the Moon

The Moon is in synchronous orbit --this means, it takes exactly the same time to rotate once around its axis than it does to make one orbit around the Earth-- so it has a far side, because it always keeps the same hemisphere pointed towards Earth.

When the Moon is roughly between the Sun and Earth, it is daytime for the "far side" and night time for the "near side". When the Moon gets "behind" the Earth, it is night time for the "far side" and daytime for the "near side".

 

--
Source: 2spare.com


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Date: 8 Jul 2007 | Author: mesmerX | Category: News | Views: 226875

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Comments: 50

BEBA | 28 Apr 2012 - 00:11
The Earth travels aruond the sun.The moon travels aruond Earth spinning on its own Axis.The Earth is round like a ball,but it is also slightly squashed. We say that it's shape is roughly spherical.The Earth travels round the sun once every year, theEarth even spins on it's own Axis.The Moon travelsaround Earth, It goes round once every 28 days.The sun is a star and gives out heat and light.It is roughly spherical and is much much bigger than Earth!

Vlad | 16 Jun 2010 - 13:23
I like the dark side of the moon the best. Never really gave it much thought, but it makes perfect sense. For those that still think there is a side of the moon that's always dark, get an education:

en.wikipedia.org/wiki/Dark_side_of_the_Moon

Emily | 21 Dec 2009 - 00:51
Everyone knows that the seasons are not the same length - if you've ever lived in Buffalo, NY (or visited it any time between October and May), you'll know that winter lasts approximately six months.

MrBitches | 4 Dec 2009 - 10:40
*cough*

Guest | 12 Nov 2009 - 00:22
Man, I dunno what kinda textbooks the person who posted this article has been reading. All of this stuff is trivial.

TonyW | 12 Nov 2009 - 00:11
The article claims the moon is in synchronous orbit when it is not. Communications satellites are in synchronous orbits.

The moon is in synchronous rotation.

Kenetha | 11 Nov 2009 - 22:48
OH my. So many of those "your" instead of "you're" typos. It makes it really hard to take the post seriously.

Jameilious | 12 Aug 2009 - 22:11
The main reason people associate cold with the common cold is because you stay indoors more in winter, which is perfect for spreading of the virus

jameilious | 12 Aug 2009 - 22:10
yaa101... that is the aether theory which was disproven years ago. light does travel... even in a vacuum! Also light isn't in the same spectrum as sound, sound is particles passing on energy, light is electromagnetic, which includes gamma, microwaves ETC

jeremy | 3 Jun 2009 - 02:52
actually mike viruses are neither living nor dead so it is the cold affecting your immune system not the viruses(which are very different from bacteria)which is the issue.

nick | 21 Mar 2009 - 06:03
and even if you disregard the previous moon comment,
there IS a dark side of the moon.
ALWAYS.
ONE side IS always DaRk.
LOOKS like you've got some RESEARCH to DO before your NEXT post.
I HOPE it doesn't attract a BUNCH of ASS holes like this one DID.
HAHAhaHA

youallmakemelaugh | 17 Mar 2009 - 04:46
laughing

Don | 15 Mar 2009 - 18:32
As for the cold thing, I think people missed the point. The temperature is not what causes the infection. The viruses do. The temperature may influence how strong your immune system at the time of infection, but the temperature will not give you the virus.

mike | 10 Mar 2009 - 17:53
Bacteria can survive better in a warm enviornment than it can in a cold one. Thus, if you go running in freezing cold weather a virus will more actively seek out the inside of your body where it is warm. In colonial time, far more people died of disease during the winter and during my XC season my entire team would have runny noses by the end. THe cold itself doesn't cause the disease, but it does contribute.

mike | 10 Mar 2009 - 17:52
Bacteria can survive better in a warm enviornment than it can in a cold one. Thus, if you go running in freezing cold weather a virus will more actively seek out the inside of your body where it is warm. In colonial time, far more people died of disease during the winter and during my XC season my entire team would have runny noses by the end. THe cold itself doesn't cause the disease, but it does contribute.

Annoying | 23 Jan 2009 - 17:18
Why do you Bold random shit in your little tidbits, its really annoying when your trying to read it

jeff | 21 Jan 2009 - 21:54
Calling somebody an idiot is not an argument. Or at least, it's not an argument that brings its author any credibility, to say the least.

Nobody here justified any of their claims other than by stating contradictory assertions (except maybe the first commentator 'On catching a cold'). Unless you had any direct contact with this type of knowledge (which I doubt), you all learned your 'facts' from somewhere, so if you're going to jump into this, at least take the time to check up your info and give your references. And this goes to the author of the article above all.

And this goes to Christopher: taking an authoritative, professoral stance to spray vain and condescending insults around is the oldest form of sophism. Worthless rethoric, where you attack the person itself instead of commenting their claims. You're giving bad grades to everyone? Why is that? What you're trying to do, it seems to me, is to refute by showing off, when you don't have anything to say. It's irrational and un-scientific. I'll go as far as saying that going public with your post is a narrow-minded manifesto for ignorance and dimwitness.

I don't have anything to say about the content of this site, partly because if I would give a fuck about it, I would check it out myself in books. But anybody can strip a text to its form and see what is really being said. In this case: nothing.
I'm just surprised nobody noted this before.

It's so easy to take a stance on the internet, especially one you would be ashamed to take in public (or one that would simply bring you lots of unnecessary trouble). Most people who do it only contribute to making this source of information more unreliable than it already is, which is pretty fucking sad, considering the incredible potential of the medium.

I never commented on blogs before because their contents are, in my opinion, more often than not, worthless. There are some refreshing exceptions, though. But here I stopped to read because we have a text which aims at CORRECTING common scientific knowledge, followed by what could have been a real debate. I hoped I would learn something. I expected a more solid form of argumentation than simple undocumented assertions and vain commentaries that take all their force from their thickness and agressivity.

Oh well, too high expectations I guess, than to hope people would behave in a civilised and rational manner.

Here, that's my take. In the hopes that it would find some echo. Oh, and should you feel the urge to correct my spelling or grammar, I'd like to say right away that english is not my mother tongue. I'm still learning, everyday. My apologies, I hope this is still understandable.

Cheers!

Bob | 10 Jan 2009 - 15:01
ash, your right and

spongekill - being "a thousand times more likely to get a cold walking around in the snow in your underwear than staying indoors by the fire" is complete nonsense.

Your wrong. Being in the cold while in nothing but underwear WILL increase your chances of getting a cold granted the virus is present. Your Immune system won't be working as great in those conditions when your body is busy keeping warm

ash | 9 Jan 2009 - 13:23
i cba reading through all the comments but i do feel the need to point out a few things.

trev - you are right about the speed of light. only in the vacuum of space where there are few resistances can light reach its max of roughly 186,000mps. In all other cases the speed of light varies greatly depending on the matter it is passing through (as low as about 30-40mph has been recorded).

spongekill - being "a thousand times more likely to get a cold walking around in the snow in your underwear than staying indoors by the fire" is complete nonsense.

however the germs that make up the common cold do thrive in colder temperatures, but that does not mean simply being cold gives you more chance to catch a cold since you need to come in contact with the germs in the first place. being out in the snow in your underwear makes it more likely you will end up with something more serious than a mere cold!

spongekill | 7 Jan 2009 - 23:54
"You WON'T get a cold just from low temperature"

Clearly the common cold is a virus. It's equally obvious to any human with the life experience of an 8-year-old that you are a thousand times more likely to get a cold walking around in the snow in your underwear than staying indoors by the fire. Has the author of this post never set foot outdoors?

andriano | 4 Jan 2009 - 05:09
to interested_anon:

really? pretentious? condescending?

the reason for this article being written is to point out certain bits of "common knowledge" that are, in fact, wrong.

i enjoyed reading the article. there were a few flaws, but whatever.

Trev | 1 Jan 2009 - 01:01
You guys talking about light lol.light is both a Frequency and photons. Even Light travels at light speed only for a brief while. Due to contact with other particles it gains mass. And slows to near light speed.

Christopher | 31 Dec 2008 - 05:37
The author gets a B+ and most of the commentators get between a C and an F.

Black Adder: yes, all meteors are formed of rocks. many commets or formed of mostly water/ice and rocks

Yaa101: you've been reading too much New Age psuedo-science and you have no idea what you're talking about

Kurt: you are a Young Earth Creationist which means you know less what you're talking about than Yaa101

The moon: the space shuttle never goes behind the moon, only apollo astronauts did that. Earth satellites also do not go behind the moon and the objects that have gone out in the solar system to send us back wonderful information are not properly called "satellites" in most cases but "probes". technically, a "satellite" is simply an object that is in orbit around another (larger) object.

dobbsendhorror: seriously? does your mother lock you in the basement often?

interested_anon: the author did not come off as pretentious to me. maybe you should look in the mirror for the cause of that perception.

Mikey W | 31 Dec 2008 - 01:34
Fair few flaws there

While you're point on electricity is correct, flow is extremely rapid whereas movement of electron is not... but that doesn't necessarily define electricity, it's the flow of charge, not physical objects.

You won't get a cold from JUST a low temperature, but the lowering in temperature, can cause various proteins involved in immune response to behave differently/slower. However that is largely peripheral. If core body temperature drops, many problems with defence enzymes not working correctly will have a big impact.

Erm Yaa101, nice concept but I think you really don't get physics at all.

And while technically there is no dark side of the moon... but for all intents and purposes it may as well be!

interested_anon | 31 Dec 2008 - 00:17
pretentious much? i mean, most of the facts are interesting, but you still come off as a bit condescending.

Astronomy Club | 29 Dec 2008 - 12:06
wow, wow, it is really interesting facts. First and last and great. i know that " Saturn is NOT the only planet with rings ", but others are too new and amazing. i linked your site in my forum. thanks for this great article.

Liam | 23 Dec 2008 - 16:28
That's whack dude! I remember just the other day when I heard about the old one yeah? Man, he had trousers, I knew we would make it - the truth will out Jah?

Anonymous | 19 Dec 2008 - 05:57
"Neither the space shuttle or earth satellites pass beyond the moon."

That is just plain incorrect. A great many space missions go beyond the Moon's orbit--how do you think we're receiving all those lovely Martian photos? Magic?

How about satellites which monitor solar weather, positioned roughly halfway between the Earth and the Sun? Think those might have to go beyond the Moon's orbit at some point?

School? | 19 Dec 2008 - 05:30
Oh also you shouldn't be trying to teach anybody this stuff is not researched, or positioned incorrectly in many areas.

School? | 19 Dec 2008 - 05:19
This is stuff you should know out of elementary school, I find it funny that someone could learn from this.

lol | 17 Dec 2008 - 06:20
ur all nerdz. tey make dis list n u guyz all cum on hear and tell dem tht their wrong. y cant u just for 1ce apprecaite they're work's?

gobler | 17 Dec 2008 - 04:54
tEhLi | 16 Dec 2008 - 20:58 wrote: "Low temperature does have an indirect effect on catching a cold. The decrease in temperature causes a weakening in an individuals immune-system making it easier to be affected by the cold virus."

I agree, your body raises its temperature to help fight off the viruses. That is why you get a fever.

dobbsucks | 16 Dec 2008 - 16:32
Listen, son. You need to go back to school and read about meteoroids, meteorites, and meteors before you start spouting about celestial nomenclature.

As a side note, if you call someone an "idiot" for getting one fact wrong (like commentators "the moon" and "Dark Side") then does that make you a five-fold idiot? You're at least that in my book.

tEhLi | 16 Dec 2008 - 09:58
Low temperature does have an indirect effect on catching a cold. The decrease in temperature causes a weakening in an individuals immune-system making it easier to be affected by the cold virus.

dobbsendhorror | 15 Dec 2008 - 09:49
One thing person who wrote list STILL is getting wrong.

Meteors do not hit the earth, METEORITES do.

dobbsendhorror | 15 Dec 2008 - 09:47
The dark side of the moon refers to radio communications. Although there was an idiot on here that said it was because of "space shuttles and satellites" has the type of craft wrong. The dark side of the moon was used to refer to the the side where there was no radio communications during the Apollo missions, in which several space craft DID pass on the dark side of the moon. People who corrected the "shuttles and satellites" idiot are idiots themselves because they corrected on the wrong premise.

EE | 15 Dec 2008 - 08:13
Yea, I disagree that electricity does not travel at the speed of light. While I agree there is a misconception that the "speed" of electricity is determined by drift velocity, anybody who's taken a bit of higher level physics knows otherwise.

Although individual electrons can have a very low drift velocity, electrical current is actually an electromagnetic wave and propagates as fast as any other emf in that conductor (i.e. it travels as fast as the speed of light in that medium). Note that be saying electricity is caused by an emf, this immediately means that it is composed of photons. This emf determines the "speed" of how fast electricity can be transmitted across a wire and, as stated in other comments, is related to the dielectric constant, and is exactly the speed of light in the medium of conductance. It is, however, fair to say that electricity travels slower than 'c', or the speed of light in a pure vacuum.

pete | 14 Dec 2008 - 22:53
when electrons flow through a wire they induce a magnetic field which propagates at...drum roll please....the speed of light! so while it's certainly not correct to say that electrons travel at the speed of light, current or electricity does.

dark side | 12 Dec 2008 - 22:50
"As space shuttles and satellites pass behind the moon, the moon becomes an obstruction between the earth and whatever is passing behind it. In the case of a space shuttle it would "go dark" indicating that we could not have radio communications with it. That is why the side of the moon we can't see is called the "dark side" of the moon."

Neither the space shuttle or earth satellites pass beyond the moon. The moon is dark to us in a figurative sense.

The moon | 12 Dec 2008 - 22:31
The "Dark side" of the moon doesn't refer to the moons relation to the sun and was never meant to.

As space shuttles and satellites pass behind the moon, the moon becomes an obstruction between the earth and whatever is passing behind it. In the case of a space shuttle it would "go dark" indicating that we could not have radio communications with it. That is why the side of the moon we can't see is called the "dark side" of the moon.

lol | 12 Dec 2008 - 01:43
kurt... gravity is only a "theory" does that mean that it doesnt affect the physical world?

Kurt | 9 Nov 2007 - 18:31
You write "Electrons...can never travel at the speed of light due to the theory of relativity." A theory cannot control the physical world.

| 21 Jul 2007 - 22:26
@Yaa101

Light does travel. When you get into quantum physics electrons and light share properties of matter and waves. Light can travel, seemingly as a particle, through empty space, and can also refract and reflect like a wave.

Electrons can also does not behave exactly like a particle of mass would be expected to. This is called wave particle duality and is detailed in the double slit experiment here:

http://en.wikipedia.org/wiki/Double-slit_experiment
Double-slit experiment - Wikipedia, the free encyclopedia

Yaa101 | 21 Jul 2007 - 16:01
Light does not travel, it's a contamination of energy from atoms to the next ones and so on, if light really traveled then it would not come far because it has to push away all those atoms in front of it which is called resistance.
Light speed is the speed of contamination and depends on the material and the resistance/conductivity of it's atoms how fast this light contaminates through it.
Electricity=Light=Sound, just at a different frequency and this frequency plus fase determines the pace of contamination besides the material it contaminates through.
Light does only seem to contaminate with good rendement through gasses, somewhat less through fluids like water, even less with non conducting fluids and does hardly contaminate through solids.
Electricity contaminates best through conducting solids and fluids and less through gasses, although nowadays batteries of computer mice are feed with the energy of the signal that travels between the tranciever of the mouseport and the one on the mouse.

Tharn | 21 Jul 2007 - 00:22
BlackAdder, you are right. I believe the speed of transmission of electricity is entirely a function of the "transmission line" characteristics. That is, the "speed of electricity" is determined by capacitance and inductance in the wire (inevitable). Usually this means that it is traveling at around 70% of the speed of light.

Tharn | 21 Jul 2007 - 00:21
BlackAdder, you are right. I believe the speed of transmission of electricity is entirely a function of the "transmission line" characteristics. That is, the "speed of electricity" is determined by capacitance and inductance in the wire (inevitable). Usually this means that it is traveling at around 70% of the speed of light.

Dart Vadder | 20 Jul 2007 - 21:42
not all meteors are formed by rocks, what about other minerals? so you can't affirm that all meteors land on earth's surface warm.

Black Adder | 20 Jul 2007 - 21:41
not all meteors are formed by rocks, what about other minerals? so you can't affirm that all meteors land on earth's surface warm.

| 20 Jul 2007 - 12:19
the claim is that "electricity does not travel at the speed of light" yet the reason given is that electrons don't travel at the speed of light.
That's not the claim.
It's like claiming that Lincoln wasn't ever president because there is a chap called Lincoln who is a plumber

On catching a cold | 20 Jul 2007 - 10:39
While it's true that the common cold is caused by viruses, it's not true that low temperature has nothing to do with catching one. When you're cold (as in feeling cold due to low temperatures), your heartbeat accelerates in order to properly compensate the loss of body heat in the extremities. More blood rushing through your body means more viruses are picked up, and faster, via various membranes. Which is actually why your nose runs slightly more than usual in low temperatures: the nasal mucus is there to protect you from viruses.

Unfortunately I don't have a reference for either of my claims (1. more blood -> more viruses and 2. mucus protects you from bacteria and viruses), but I'm positive I've read both from distinct medical sources. One interesting piece of info can be found here though: http://everything2.com/index.pl?node_id=643906

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