The Science Thread

[Pol]

I known that before (from kid age) , am I so much exceptional?

I don't think so.

[Corribus]

You've known what since kid age?

[winterfate]

Well, I have a wireless connection now...so I'll be able to connect whenever I please (mostly ) once again!

[Pol]

Fact that size and shape of the crystal affect theirs produced color (or spectrum) when light is coming through the crystal structure. This concept is old and known. And really very old... (ancient would be the right word)

...break it up into small crystals that are several nanometer in diameter...

So, logically, this is one of expected things.

[Corribus]

Quantum dots were discovered only about 20 years ago by Luis Brus and coworkers, and were not able to really be synthesized in any reliable, controllable fashion until 1993 by Bawendi at MIT. So they're not really ancient.

[Pol]

Heh, yes. But theory doesn't need quantum dots to exists. I believe this effect is one of implications from the law of light refraction.

[Corribus]

I believe this effect is one of implications from the law of light refraction.

No, it's not. But we'll get to it in due time.

Edit: Ah, perhaps you are referring to stained glass? Nanoscale metal particles do have size-dependent color properties and were used (not knowing the science behind it, of course) to make stained galss during the middle ages. However, these are not quantum dots.

[Pol]

But you don't need quantum dots to form a theory and thought out some "possible ends". Quantum dots are only practical confirmation. The knowledge how the light will be refracted is one of oldest.

If you look at the medieval alchemists (hypothetically because they weren't correctly called alchemists, physician for our needs would be a more suitable term) then they certainly known how to handle a light. And could pressume what would happen with light if you would gift them with some spare quantum dots. :-p So yes, it's fascinating effect but it's in "line".

The unexpected thing would be if quantum dots, cut into different sizes, would cause let say radioactivity when placed into the ray of day light. This would classify in my book like transformation out of "line".

[Corribus]

But you don't need quantum dots to form a theory and thought out some "possible ends". Quantum dots are only practical confirmation. The knowledge how the light will be refracted is one of oldest.

Quantum dots have nothing to do with light refraction.

[Pol]

No light no colors. > light refraction
(That maybe too simplified but I don't have time to chase right words/def in dictionaries. As to these color effects I learned that from some man from lcd factory. So I'm assumming that I'm correct. )

[ThunderTitan]

Hey SCIENCE, stop all that annoying theoretical stuff and start doing more practical stuff... I WANT MY RAY GUN ALREADY!

[Muszka]

I usually don't pay attention for what drunk/stupid people talk, or at least I forgot it very quickly. but today I heard a good one:

the first guy asks the second for the measure of the speed of light, the other answers that is 2000 square KM. Than the first guy ask the measure of sound, the second hesitates, so the first tells that its around 300 m/s, when the second replies that he know for sure that it's 300 KM/H, than again he changes it to 300 KM/minutes.

Just could not leave this jewel of human stupidity to die

[ThunderTitan]

i'm sorry, but what one says when drunk doesn't count... u don't believe? then be enlightened, get wasted.... you'll see.

[Muszka]

I guess I saw more drunk people than you (even plural), I work with them 7 days of 7, so I know that alcohol can make men stupid, but this one was just too much, the guy wasn't even hammered.

[ThunderTitan]

Pfft... as if watching from the side lines give you any idea how it is to be drunk...

And FYI, being hammered = inability to be coherent... at the very least.

[Muszka]

Since when you are a professor in pub-life TT?
And FYI pub-owners sometimes close the doors from inside, and....
Also FYI a man who is wake enough to speak coherently can know what's the difference between square meter and meter....

[ThunderTitan]

As anyone that's gotten drunk would know, all drunks are philosophers...

[Veldrynus]

I just watched a great documentary on string theory:

http://video.google.com/videoplay?docid ... 6942339345
http://video.google.com/videoplay?docid ... 5491416735
http://video.google.com/videoplay?docid ... 8304155609

[ThunderTitan]

On the other hand, many detractors criticise string theory because it has not yet provided experimentally testable predictions.

And that one is old... right now the theory has probably changed a few times...

[Kristo]

Are there any theoretical physicists in the house? I've been reading The Black Hole War and it's gotten me thinking about the one thing that's prevented me from understanding Special Relativity et al. I get that the speed of light should be constant in all reference frames, given that it's composed of photons with no mass and thus has no inertia or momentum (i.e., I couldn't "throw" light even if I wanted to). What I don't get is why you apparently can't move relative to light. Why does the speed of light have to be the same constant in every reference frame?