Learn me a new thing: Quantum Physics

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lolsup.

Deezee and I just had a discussion about Quantum Physics/Theory of Relativity/etc. and I want to learn more. Any experts out there, or is Deezee > All on QP's?

For those of you who are like "wtf" here is a site that you can take a look at, it shows the very basics of Relativity/Quantum Physics/String Theory:

Elegant Universe (http://www.pbs.org/wgbh/nova/elegant/)

[scm007]

I know quite a bit, what's your question?

[DiscoDave]

I'm a big fan of this area of science, but I confess that I really don't understand any of it. I can ALMOST get my head around relativity, but Quantum Physics completely befuddles me. I can memorize some of the rules, but they've never "made sense" to me.

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Ok: How can matter have a negative mass? IE a tachyon.

Since it has negative mass, it would be able to accelerate past the speed of light no? How would that relate to an observer sitting on the front of a tachyon particle, racing a beam of light. Would the light still appear to move away from him at lightspeed, or would he be able to pass?

[DiscoDave]

So far as I'm aware, the speed of light is not dependant on objects with positive mass, or mass at all.

Radio waves are energy rather than matter...they have no mass yet are still limited to the speed of light.

So far as I'm aware, the only thing that MAY be able to surpass the speed of light is gravitational effects. If the Sun were to magically disappear, the earth may start flying off into space faster than the sun's light (or rather, lack of light) arrives at Earth.

I'm not sure if this has been confirmed or not, but last I heard evidence was mounting to say the above is accurate.

[Legal Disclaimer: I'm not a physisisist...everything above may be complete BS]

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Originally posted by DiscoDave
So far as I'm aware, the speed of light is not dependant on objects with positive mass, or mass at all.

Radio waves are energy rather than matter...they have no mass yet are still limited to the speed of light.

So far as I'm aware, the only thing that MAY be able to surpass the speed of light is gravitational effects. If the Sun were to magically disappear, the earth may start flying off into space faster than the sun's light (or rather, lack of light) arrives at Earth.

I'm not sure if this has been confirmed or not, but last I heard evidence was mounting to say the above is accurate.

[Legal Disclaimer: I'm not a physisisist...everything above may be complete BS]

That's actually how it was proven wrong Disque. Einstein disagreed with Newton (he thought gravity was instantanious) and stated that gravity moves at the speed of light, thus if the sun were to dissapear it would hold the earth in it's "orbit" for 8 seconds before letting it go on it's merry way into space. It wouldn't accelerate after being let go either, because there is no additional force affecting it, thus it undergoes inertia.

Watch Chapter Three in Hour One for a better description of why.

http://www.pbs.org/wgbh/nova/elegant/program.html

[scm007]

Its seem to me that you have the idea of the tachyon all wrong. In the equations of Special Relativity, namely that of the energy of a relativistic particle, there exists solutions which give the particle speed greater than the speed of light. In order for these solutions to work out, the particle must have imaginary masses, that is in the equation e^2 = m^2 etc. etc. the m^2 is negative. So the solutions which give such values are usually disregarded. Physics isn't perfect, and the math of it most certainly isn't.

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Originally posted by scm007
Its seem to me that you have the idea of the tachyon all wrong. In the equations of Special Relativity, namely that of the energy of a relativistic particle, there exists solutions which give the particle speed greater than the speed of light. In order for these solutions to work out, the particle must have imaginary masses, that is in the equation e^2 = m^2 etc. etc. the m^2 is negative. So the solutions which give such values are usually disregarded. Physics isn't perfect, and the math of it most certainly isn't.

I suppose I am somewhat confused about it... So what you're saying is a particle is considered a tachyon if it posseses more energy than it should, (In relation to it's mass) and thus, can move faster than the speed of light?

I'll teach you about computer hardware, and you can teach me physics! K deal. ^_^

[DiscoDave]

http://physics.about.com/cs/gravity/a/speedofgravity.htm

I didn't say gravity was instant, and I understand the above test is inconclusive...but interesting it is.

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Originally posted by DiscoDave
http://physics.about.com/cs/gravity/a/speedofgravity.htm

I didn't say gravity was instant, and I understand the above test is inconclusive...but interesting it is.

I know, I just went into a little extra detail for those who may not know.