Science!

[Glitch]

So I noticed there was a religion board, but no science board.  This thread is for all your science discussions.  Some topic starters:


Light!
I am very fascinated by light.  How can darkness be the absence of light?  If light can reflect and it moves at the speed of light, how can anywhere truly be "dark"?  Shouldn't light flood everywhere?  Right now, as I type this, the sun is going down where I live, so it's behind my neighbors house.  The only other source of light inside this room is my laptop.  And yet, I can clearly see my blue carpet.  Which begs the question:  Has light somehow managed to bounce around at four convoluted angles so that I might see the carpet?  And if it's able to do that, why can't the light reflect into, say... the dark room next to me.  And, if darkness is truly the absence of light, then how can shades of darkness exist?  Is light more like a swiss cheese slice, with random pockets of darkness strewn inside?  And what makes light unable to go there while it could go elsewhere?  If these random swiss cheese holes exist, why aren't the isolatable?  And even if they're just fluctuating rapidly, light travels at, well, the speed up light!  You'd think it'd fill up all the space...  Also: you can't travel faster than light?!  Why the heck not I say!  No one's ever tried it...

Quantum Physics!
So I've always thought Shröedinger's cat was a load of baloney.  The theory behind it being all possible instances happen at the same time until observed.  But, me and my not-a-physist brain thought that made no sense, and instead found it more likely that there's no such thing as multiple possible instances.  Chance is just the word that describes outside influences scientists don't understand, and if scientists did understand them, they'd know there's no such things as multiple possible instances.  And, following with this theory, all actions that occur with no outside influence have 100% consistency.  It all made sense to my not-a-physist brain.  That is, of course, until I saw the double-slit experiment.  Now I'm just confused.

Much much more!


So science away my friends, the science board is born!!!

[Xelax]

So I noticed there was a religion board, but no science board.  This thread is for all your science discussions.  Some topic starters:


Light!
I am very fascinated by light.  How can darkness be the absence of light?  If light can reflect and it moves at the speed of light, how can anywhere truly be "dark"?  Shouldn't light flood everywhere?  Right now, as I type this, the sun is going down where I live, so it's behind my neighbors house.  The only other source of light inside this room is my laptop.  And yet, I can clearly see my blue carpet.  Which begs the question:  Has light somehow managed to bounce around at four convoluted angles so that I might see the carpet?  And if it's able to do that, why can't the light reflect into, say... the dark room next to me.  And, if darkness is truly the absence of light, then how can shades of darkness exist?  Is light more like a swiss cheese slice, with random pockets of darkness strewn inside?  And what makes light unable to go there while it could go elsewhere?  If these random swiss cheese holes exist, why aren't the isolatable?  And even if they're just fluctuating rapidly, light travels at, well, the speed up light!  You'd think it'd fill up all the space...  Also: you can't travel faster than light?!  Why the heck not I say!  No one's ever tried it...

I don't understand the bit about 'How can darkness be the absence of light'. It just is- that's pretty much the definition. And a place can be truly dark if there's no way for light to reach it- an opaque container for example. And of course, light interacts with pretty much everything it hits, which is why you can't see a candle from 10 miles away- it's also the reason for orange sunsets and blue skys.
Light will reflect off anything except completely black surfaces, so yes it does bounce around a bit. Anywhere which gets no light is in shade. You can see the blue floor because, I imagine, there is a direct path from your screen to the floor, and possibly due to light being reflected off the walls and then onto the floor.
I don't know why the light can't reflect into the room next to you, not knowing the house plan. Probably because the door is shut. If you can see into the room then obviously the light *has* reflected into the room.  But remember, as light hits things, coloured things certain wavelengths are absorbed. Although it's not technically correct I guess it could just be used up.

Shades of darkness are just levels of light. If there's not much light then it's relatively dark.

Basically the main reason light isn't everywhere is because it hits thing. And the light in the visual spectrum can't move past a lot of the things it hits, so it stops. That's about it. As far as I know- it's been a while since A level physics

[smuglapse]

TED: Discovery channel on crack. (http://www.ted.com)

Here's a good video  (

)about a totally different subject but I was reminded of it when you mentioned light and darkness.  It's only a side-note, but what you can glean from it is light is in dark places, but human eyes are unable to detect it.  That's why night-vision goggles and telescopes were invented.

[harry959]

You can't travel faster than light because we can't even travel at light speed. The faster you travel, the more your mass increases so it would require more energy to go faster. At light speed mass becomes infinite and would require an infinite amount of energy to move. The only reason light can do this is because light has no mass. It has kinetic energy, but no mass. So to travel faster than light speed we would have to do at least infinity+1. I feel smart for a 13-year old .

[Bloodshadow]

I STRONGLY SUPPORT THE ESTABLISHMENT OF A SCIENCE BOARD.

YES, a place to discuss particle physics, quantum mechanics, special relativity, calculus, and all my favorite stuff!

For your question regarding light, see this: http://en.wikipedia.org/wiki/Diffraction
Apparently light, and all other waves, bend and spread out whenever they hit obstacles. That's why light seems to "fill" space; they do not always travel in straight lines.

As for quantum mechanics and Schrodinger's cat, I don't really get it either. The basic idea of quantum mechanics is "nothing is real until observed", so I think the cat is neither alive nor dead until you take a peek at it. Maybe I should get some introductory quantum mechanics book to read...

[guolin]

Booh, I like my Quantum Physicis/Mechanics and the Theories of Perception that went with it. In fact, I may study it after I finish college.

[Glitch]

I STRONGLY SUPPORT THE ESTABLISHMENT OF A SCIENCE BOARD.

YES, a place to discuss particle physics, quantum mechanics, special relativity, calculus, and all my favorite stuff!

For your question regarding light, see this: http://en.wikipedia.org/wiki/Diffraction
Apparently light, and all other waves, bend and spread out whenever they hit obstacles. That's why light seems to "fill" space; they do not always travel in straight lines.

As for quantum mechanics and Schrodinger's cat, I don't really get it either. The basic idea of quantum mechanics is "nothing is real until observed", so I think the cat is neither alive nor dead until you take a peek at it. Maybe I should get some introductory quantum mechanics book to read...

That should explain why they believe Schrodinger's cat.

(Watch the entire documentary here: http://www.moviesfoundonline.com/what_the_bleep_do_we_know.php)

[Boingo]

Light!
I am very fascinated by light.  How can darkness be the absence of light?  If light can reflect and it moves at the speed of light, how can anywhere truly be "dark"?  Shouldn't light flood everywhere?

It turns out it isn't really dark at night, it's your eyes that are the problem (http://www.wimp.com/skydark/). [<--click linky] If you could see microwaves, you'd be blinded with the brilliance.

[harry959]

And if you could see infared, you might be able to see the brown dwarf stars. They're failed stars and are only about 350*F. In other words, only hot enough to bake a cookie.

[Toimu13]

...because light has no mass. It has kinetic energy, but no mass...

http://en.wikipedia.org/wiki/Photon

Experimental checks on photon mass

The photon is currently believed to be strictly massless, but this is an experimental question. If the photon is not a strictly massless particle, it would not move at the exact speed of light in vacuum, c. Its speed would be lower and depend on its frequency. Relativity would be unaffected by this; the so-called speed of light, c, would then not be the actual speed at which light moves, but a constant of nature which is the maximum speed that any object could theoretically attain in space-time.[19] Thus, it would still be the speed of space-time ripples (gravitational waves and gravitons), but it would not be the speed of photons.

I don't understand how a photon can be massless and still hit something like a tree and make a shadow due to lack of light.  I don't understand how anything can be massless.

...At light speed mass becomes infinite and would require an infinite amount of energy to move. The only reason light can do this is because light has no mass. It has kinetic energy, but no mass. So to travel faster than light speed we would have to do at least infinity+1.

http://en.wikipedia.org/wiki/Photon

Photons in matter

(Visible) light that travels through transparent matter does so at a lower speed than c, the speed of light in a vacuum. X-rays, on the other hand, usually have a phase velocity above c, as evidenced by total external reflection.

[Kurohami]

Here's something interesting. I'm a science nerd if you don't know. Today I was posting on the armorgames forum. I said something about "time is an illusion", and some guy called Endscape started getting real mad at me and we started this really interesting debate.  Just for the sake of the readers, I'll tell you that I said time is an illusion in the sense of philosophy and figurative speech. However, debates are always fun so I went along and started debating about it. Do not read my long essay if you are not interested in science, because it will be extremely dull for you.
Here's how it goes:

Endscape(he's staying to philosophy):
time is an illusion??? if anything time is ABSOLUTE life is the illusion, feelings are an illusion,money is an illusion, and so are problems kuro... anywayyy is there something u wish to talk about...billy.

Me(changed the subject to physics):
Sir, you are mistaken, time is not absolute it is relative, just like motion. Time can be affected by a lot of things, for example: a gravity well, didn't you know? 3 atomic clock placed at different altitudes on earth will eventually show different time as a result of being the difference in gravity. Also, when you exceed the speed of light, you can reverse time. If you use a telescope to reach into the stars, you see what happened a long time ago. The farther the celestial body is from us, the further back in time you will see when you look at it with a microscope. With a powerful enough microscope, it is theoretically possible to see the big bang that marked the creation of the universe. A lot of things are not as absolute as you think. Of course, I know I am dragging physics into philosophy, but here you go, time is not absolute. You've got to open your mind, sir.

Endscape(he started getting pissed off and starting going all leet on me):
1st i know ur not schooling ME
2nd even if it can be poked at it cant be stopped
3rd i already know as a result to how far away the star may be u will see it as IT WAS that long ago
4th i KNOW U DID NOT TELL ME THAT ITS POSSIBLE TO SEE THE BIG BANG
5th going beyond the speed of light isnt possible for humans, and if we did we would not travel in time once reaching or exceeding the speed of light it is IMPOSSIBLE to slow down so if u call that kind of existence time travelling be my guest
6th u have now been schooled i major in science plz dont attempt this again, and no time is absolute no matter wat we do it cant be controlled it cant be stopped,there are forces that can warp and distort it even tearing it but humans cant fathom feel tamper or even see these forces none the less, no matter wat we do OUR TIME IS LIMITED thus the name ENDSCAPE aka DEATH.

Me(I found the subject so interesting I just threw aside my homework and wrote an entire essay to argue with him):
I know you are pissed off right now, but I like scientific debates, so I will continue. Please don't get all fired up, because as someone who majored in science which is what you told me, you should be used to debates. First of all, what kind of science did you major in? I reckon it's certainly not physics, because else you would know what I am talking about. Time is something that scientists cannot yet entirely comprehend, but it is true that it could be slowed. This is proven, as I told you, there is a experiment done with atomic clocks set in three different altitudes, and they showed different after a period of time. And as someone majored in science, you should know that atomic clock is incredibly accurate. This experiment is officially recognized and can be repeated. It is proven that time can be affected by a gravity well. It is understandable for you to not know this if you did not major in physics or you never came across this article in your journey to pursue knowledge. I can completely understand that. About seeing the big bang with a immensely powerful telescope, I know right it's impossible, and it might or might not be possible in the future, that's why I said "theoretically". Archimedes said that he could lift the earth if he is given a lever long enough. That's also unrealistic, because you can't find a lever that long and it will have to be made of extremely dense material to not break under the mass of the earth. Also, as someone who is involved in science, you should never say impossible unless it's proven by a scientific law. You do not say x don't exist. You can only say because of the blah blah properties of x, and the blah blah properties of the environment, x could not exist in this particular environment at the current time. That lead to the next thing, you said surpassing light speed is impossible for humans, how do you know? Do you know everything about human and what human is capable of? As of currently, we are very far away from reaching that goal, but that doesn't mean it will never happen. Do not say impossible unless you have evidence that supports it. Also, I was not talking about human exceeding the speed of light. Physics don't deal with humans, they deal with everything in existence. I didn't say reversal of time will happen if human exceeds the speed of light.I said that for anything and everything. And there are things that could exceed the speed of light in the universe. You said something about "or exceeding the speed of light it is IMPOSSIBLE to slow down." You probably made typos so I could not comprehend what you are trying to say, but if you are saying light cannot be slowed down, you are wrong again. The speed of light is not absolute, it is different in different in different media, it could be slowed to extreme extent under certain conditions. In my argument I was talking about the speed of light in vacuum of course. I admit I don't have absolute confidence when I said that the reversal of time will happen when something surpasses the speed of light, but that is the conclusion of a theory made by a well respected scientist. A theory can always be proven wrong, but it is supported with tons of research and evidence. Simply denying its validity without evidence of your own is not persuasive at all. So, you maybe majored in some sort of science, but that doesn't make you an expert of everything in science, please be humble, it's only way we learn. It is debated whether time and space will become blurred after something exceeds the speed of light, but there are more than enough evidence that time and space is related. I have seen scientists publish complete gibberish on newspapers, so I know that even a PhD doesn't make you all knowing and all authoritative. So, please try not to intimidate me by saying you majored in science. Under the realm of science, everyone is equal, as long as they hold the truth. Enjoy life while exploring the wonders of the universe. Don't let debates get in the way of friendship. I am not trying to make you my enemy. I am simply a man who deeply loves the pursuit of knowledge and constructive debates. I think I'm running out of space.





Hahahaha, he never replied again. I wonder how he can argue with a 500 words essay. I called that PWNED! Anyways, that was good laugh. Then I looked at the clock and realized I'll be staying up quite late to finish my homework today.....

[Toimu13]

Hope you don't mind me editing out that 500 word essay.

I disagree with MANY about the definition of time.  I don't believe time moved/followed/passed at different spends for those clocks (or the ones orbiting the earth in ships).  The most accurate atomic clocks first cool the atoms to near absolute zero temperature by slowing them with lasers and probing them in atomic fountains in a microwave-filled cavity. (cited: http://en.wikipedia.org/wiki/Atomic_clock )  Gravity effects the clocks is what I take from it.  Not that time passed slower for that atom.

I look at time as a measurement like meters or liters.

Quantum clocks
http://en.wikipedia.org/wiki/Quantum_clock

In March 2008, physicists at NIST demonstrated a quantum logic clock based on individual mercury and aluminium ions. These two clocks are the most accurate that have been constructed to date, with neither clock gaining nor losing at a rate that would exceed a second in over a billion years.[14] In February 2010, NIST physicists have built a second, enhanced version of the quantum logic clock using a single aluminum atom. Considered the world's most precise clock, it offers more than twice the precision of the original.