Why Light Speed?

You got any ideas as to why light seems to be the most important thing in the universe? You know time slows down for it, why is that?

 

Light is important because it is energy. Energy is important for all things to exist, not even mass could exist if it were not for energy. I don't think time stops existing at the speed of light, I think it just stops. Possibly length also just stops in the same way. Then it would seem to take no time to get anywere because you don't have any distance to travel to get there. If we could control our mass increase we would be able to acually travel at light speed and explore the universe.

 

electricity, gravity, pretty much everything goes at that speed.....

energy goes at a speed, we just see light, so go with it.....

 

I guess theres nothing despararely special about the speed of light it is just another number 300000000m/s (give or take a bit) if your bothered. When Einstein discovered relativity he found that as you go faster strange things begin to happen one of which is that the energy required to accelerate a body to a given speed is not what everyone thought. That is everyone thought that KE = 0.5mv^2, so to double the speed and you need 4 times the energy. Einstein found that as you accelerate to the speed of light the energy required is infinite so the only particles that can do it have no rest mass such as photons. Gravity has been mentioned, no one is certian of the speed of gravity there was an experiment but its results were questioned, though if current particle theory is correct then the graviton (the particle that mediates gravity) has no rest mass and so could travel at the speed of light.

Other cool things happen at the speed of light such as time stopping and other blurb. I think ive written about that before here somewhere.

 

it's the relativity thread....

it's in here somewhere...

 

Wicked

 

Its not the light that is so special, its the speed. Light, neutrino's and all kinds of massless particles move at c. Light is the most obvious of those things, so the speed got named after light.

 

Tricky little jobs neutrinos. They dont interact with anything but I dont think you'll find they travel at c, nearly as they arent subject to any potential to slow them. Also they are not massless, admitidly they have very little and no one knows how much (thats a nice little interview question, i've had it done on me).

 

I thought neutrinos were massless. (0 rest mass). That's why they are always at c.
Or is the neutrino mass something new.

 

It was originally put into the standard model that they have no rest mass. Though its now thought that they do have a very small mass, they certainly seem to behave that way. There are experiments being built at the moment to try and put a figure on it but they are so hard to catch. Though their very small mass and ability to go through 1000's of km of Iron and not notice its there means they do go 99.(few 9's)%c.

 

Yeah, the standard model is about the limit of my understanding (or misunderstanding). Thanks for the update.

 

I think that science belives Time stops, is because at the speed of light, out in space for example, Blackness. Nothing else.
That's the way Mankind would view that speed.
I think its possible to go faster.

 

We used to always think that the travelling speed of energy (light) was a constant...and as a constant it is invaluable to a student of physics........of course, they are now discovering that is wrong.....

 

There is a theory called VLS (Variable Light Speed) which suggests that the speed of light has changed as the universe progresses. Although like many such theories it causes as many problems as it solves. As far as I know there is no experimental evidence to support it, personally it would suprise me if it was true but its not beyond the realm of possibility. In Physics you need a physical reason to change a number otherwise its just maths, something the theorists can forget, perhaps.

 

Im not sure why the time slows down just because some particles reach speed of light.. what about objects that reach half a speed of light - does time slows down too? (or 3/4 of speed of light.. etc.)

I thought the universe is black somewhere cause there is less photons (but couldn't it still be a bit bright anyway) or if there is no real mass around, do the photons just move faster? (or slow down?)

 

Yeah as you move faster time, from your perspective slows down. If you take an atomic clock on a aeroplane you can see this effect, though it needs to be very sensitive. Even at 99.99% the speed of light you would only perceive a second to be a few of % longer than a stationary person. If you want ot work the values out t' = gamma x t where gamma is 1/(sqrt(1-(v^2/c^2))), have fun

 

great.. c is the speed of light, right?

 

sorry. yeah but work in units of c, so that c=1
and v=(% of c) so say you wanted to work out time dilation at half the speed of light make v=0.5 and c=1. its easier to work with than v = 150000000 and c=300000000.

 

thanks again

 

at first I think einstein thought that time stops as well as it seemed to bend, yet with black holes study parts of the relativity theory were forced to break in recent times even in the most idealistic followers of relativity, and einstein himself in the later years of his study actually began to see his denial of the medium of the universe that forced him to consider "perhaps my castle in the sky was only an illusion"