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speed of light question

Hestia

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Report this Aug. 11 2005, 5:03 am

How do we know for sure that there's nothing faster than the speed of light?

EnglishTrekkie

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Report this Aug. 11 2005, 6:43 am

But there is

lanceromega

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Report this Aug. 11 2005, 6:49 am

Quote (Hestia @ Aug. 10 2005, 3:03 am)
How do we know for sure that there's nothing faster than the speed of light?

Actually that not quite True.. No form of normal matter or  normal electromagnetic energy can travel faster than light in a vacuum.

Electromagnetic radiation can travel faster than C in certain form of Plasma and in rare conditions.

Space itself since it is not composed of either matter or energy is capable of moving faster than light and this occur seconds after the big bang during the inflation era.

X waves,special electromagnetic waves predicted by Maxwell equations would travel faster than light also, but like Tachyons would be unable to travel at C or slower.

Tachyons, a thereotical particle predicted by various Grand unification theories would also travel faster than light.

Whys is C a limit for normal matter and electromagnetic radiation, well Einstein first saw the reason by studying Maxwell equations on electromagnetism.

Light is created by oscillating fields of magnetism and electrical charge, the ratio of the change of the fields actually determine the value of C.

Due to formula The value of C doesnot depend on Velocity and he saw that if you could travel at C the change of the fields would be Zero, so he concluded that no form of matter or electromagnetic radiation should be able to exceed C in a vacuum.

The first proof of this were found during the experiment of  Michelson and Morely who were looking for the ether wind.
By measuring the speed of light traveling in the direction of earth moment around the sun they found no different from the speed of light coming at 90 degree to the first beam.

According to Classical mechanics on motion and waves, the Light traveling in the direction of earth moment around the sun should have been traveling with a combine velocity of both the earth and light.

Einstein recognized that this fit his studies on Electromagnetism and was able to show why this was so in his theory of special relativity.

As it stand that Einstein Theory on special relativity has been tested over and over again and its prediction matchs all experimental data, so as far as we presently know it is correct, but a handfull of experimental physicists still search for cases that it fails. If they can find such cases, then it would herald a new era of physics just like Einstein Theory did with present physics.

Hestia

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Report this Aug. 11 2005, 12:22 pm

Thank you.

EnglishTrekkie

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Report this Aug. 11 2005, 4:23 pm

Yeh man , i like people who no loads abou science. I find it interesting

Vold

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Report this Aug. 14 2005, 11:23 pm

i thought tachyon can travel faster than light?

admire

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Report this Aug. 15 2005, 1:26 am

ok... Special Relativity. If two people approach each other with a beam of light, the speed of light would be the same as to a stationary observer instead of being the added velocity...

ok, they tell me tat in the encyclopedias (im a grade 10r)... but HOW? and then they tell me something about TIME not being constant. i get really confused after that.

lanceromega

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Report this Aug. 15 2005, 2:20 pm

Quote (Vold @ Aug. 13 2005, 9:23 pm)
i thought tachyon can travel faster than light?

I already mention Tachyon, plus they are purely theorical.. No one has ever detected one. ;)

lanceromega

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Report this Aug. 15 2005, 2:28 pm

Quote (admire @ Aug. 13 2005, 11:26 pm)
ok... Special Relativity. If two people approach each other with a beam of light, the speed of light would be the same as to a stationary observer instead of being the added velocity...

ok, they tell me tat in the encyclopedias (im a grade 10r)... but HOW? and then they tell me something about TIME not being constant. i get really confused after that.

Time is a dimension like space, both are warped when an object travels at velocities approaching the speed of light. This is why light alway travel at C compared to the person measuring it speed.

Example of this are Muons, these are particles created when
cosmic rays strike atoms in the upper atomsphere.

They have a life span or around 2 micro seconds, even traveling at 99 % the speed of light they would never reach the surface, but they do. Why, first time is warped so that for the muon it passes slower, yet even this effect is not enought for the muon to reach the earth. Along with the slowing down of time the distant between the earth and the upper muon is actually warp in manner that the muon travels a shorter distant.

What causes the warpages of time and space? Energy and gravity does. The Kinetic energy of the Muon actually cause the structure of space and time to warp, and this is what the equation of special relativity show. Gravity has the same effect and additional equations in General relativity show the effect of Gravity on space and time..

ZeframCochran

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Report this Aug. 17 2005, 10:40 am

Isn't C relative to the observer? Maybe I could fly my starship 'relative' to another starship which is also flying at the speed of light. That makes 2C relative to Earth!

lanceromega

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Report this Aug. 17 2005, 5:03 pm

Quote (ZeframCochran @ Aug. 16 2005, 8:40 am)
Isn't C relative to the observer? Maybe I could fly my starship 'relative' to another starship which is also flying at the speed of light. That makes 2C relative to Earth!

Wrong it still C to earth, each observer will see light at traveling at C even if he observes another observer traveling close to that velocity

Luthienn

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Report this Aug. 17 2005, 5:52 pm

Stupid question, but by what method do we measure how much space and time are warped by a particle such as a Muon travelling near the speed of light?  When space and time are warped, is it like a wave that continues on affecting everything around it to infinity, or does it stop somewhere along the time-space continuum?  Sorry, I would just like to get my head around this, if anybody knows.

lanceromega

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Report this Aug. 17 2005, 7:16 pm

Quote (LuthienSkye @ Aug. 16 2005, 3:52 pm)
Stupid question, but by what method do we measure how much space and time are warped by a particle such as a Muon travelling near the speed of light?  When space and time are warped, is it like a wave that continues on affecting everything around it to infinity, or does it stop somewhere along the time-space continuum?  Sorry, I would just like to get my head around this, if anybody knows.

Well the amount that space is warp is actually predict by the lorentz equation:

L = Lr sqrt root ( 1-V square / C square)

We can measure this by actually observing the cross section of muons as they collide with other subatomic particles.

No when space warp it occurs over a area, while the effect get smaller and smaller as it radiate out from the center of the warpage.

ZeframCochran

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Report this Aug. 17 2005, 9:17 pm

Quote (lanceromega @ Aug. 17 2005, 2:03 pm)
Quote (ZeframCochran @ Aug. 16 2005, 8:40 am)
Isn't C relative to the observer? Maybe I could fly my starship 'relative' to another starship which is also flying at the speed of light. That makes 2C relative to Earth!

Wrong it still C to earth, each observer will see light at traveling at C even if he observes another observer traveling close to that velocity

Now, why exactly is Earth so special that it stays as the frame of reference? :question:

Luthienn

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Report this Aug. 18 2005, 7:17 am

Quote (lanceromega @ Aug. 17 2005, 4:16 pm)
[quote=LuthienSkye,Aug. 16 2005, 3:52 pm]
Well the amount that space is warp is actually predict by the lorentz equation:

L = Lr sqrt root ( 1-V square / C square)

We can measure this by actually observing the cross section of muons as they collide with other subatomic particles.

No when space warp it occurs over a area, while the effect get smaller and smaller as it radiate out from the center of the warpage.

Thank you!  Thank you!  I understand the second part about the effect getting smaller and smaller, and I wonder how much these small warps in space/time actually affect us on the earth surface.
As for the lorentz equation, I'll have to look into that more.  I'm slightly mathmatically challenged.  :question:

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