Does light speed apply to all waves traveling in vacuum?

In summary, all electromagnetic waves, including light, travel at the speed of light in a vacuum. This is because the wavelength and frequency are inversely proportional, so the product is always equal to the speed of light. This applies to all massless waves and particles, including gravity. The speed of light is constant in all inertial frames, regardless of the speed of the source. Any perceived difference in speed can be explained by relativistic velocity addition.
  • #1
Crazy Tosser
182
0
Seriosly, waves have different frequencies, and light is somewhere in the middle of the EM spectrum, then maybe the right or left side could travel faster than c
 
Science news on Phys.org
  • #2
Light is generally the term used to refer to electromagnetc waves in the visual spectrum (but its really the same as other E&M waves, just at different energies).
They all behave generally the same, i.e. all E&M waves travel at the speed of light.
 
  • #3
All massless waves (and all massless particles) travel at the speed of light.
 
  • #4
That includes gravity, by the way.
I think that in one regard, you can say that not all waves travel at c in vacuum, but I'm not sure if my reasoning applies. It seems to me that the matter waves associated with a particle can't do so, since the particle itself can't.
 
  • #5
CT, all EM waves travel at the same speed in a vacuum. As far as I am aware this is not the case when dealing with a medium in which the waves are traveling slower.

Phlogistonian said:
All massless waves (and all massless particles) travel at the speed of light.

If by speed of light you mean around [itex]3\times10^8[/itex] then I can't see how that is correct.
 
  • #6
Crazy Tosser said:
Seriosly, waves have different frequencies, and light is somewhere in the middle of the EM spectrum, then maybe the right or left side could travel faster than c
The phase velocity of a wave is a product of the frequency and wavelength:

L*f=v

The electromagnetic wave equation has solutions with different frequences, but the wavelength must be inversely proportional to the frequency, so the product is always the same:

L*f=c
 
  • #7
Danger said:
That includes gravity, by the way.
I think that in one regard, you can say that not all waves travel at c in vacuum, but I'm not sure if my reasoning applies. It seems to me that the matter waves associated with a particle can't do so, since the particle itself can't.


Has it been experimentally proven that gravity waves travel at the speed of light.
 
  • #8
_Mayday_ said:
If by speed of light you mean around [itex]3\times10^8[/itex] then I can't see how that is correct.

The original question was about waves in a vacuum.
 
  • #9
Phlogistonian said:
The original question was about waves in a vacuum.

That doesn't make what you said correct.
 
  • #10
_Mayday_ said:
That doesn't make what you said correct.

You can think what you want. I won't engage in a pointless argument over semantics.
 
  • #11
Well, how about traveling slower than the speed of light? If you are in a car that's goin at 100mph and you light a flashlight backwards, does the light travel at c-(100mph)?
 
  • #12
Crazy Tosser said:
Well, how about traveling slower than the speed of light? If you are in a car that's goin at 100mph and you light a flashlight backwards, does the light travel at c-(100mph)?

Please refer to the basics on relativistic velocity addition.

http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/einvel.html

The speed of light is constant in all inertial frames, no matter the speed of the source.

Zz.
 
  • #13
bassplayer142 said:
Has it been experimentally proven that gravity waves travel at the speed of light.

only to within 20%, IIRC.
 
  • #14
Crazy Tosser said:
Well, how about traveling slower than the speed of light? If you are in a car that's goin at 100mph and you light a flashlight backwards, does the light travel at c-(100mph)?

Excellent question, CT, and the answer is very important (ZapperZ already mentioned it). Make sure to keep reading every text you can get your hands on, because we've all asked this question at one time or another; if you can accept the true answer it will blow your mind.
 

1. What is the speed of light in a vacuum?

The speed of light in a vacuum is approximately 299,792,458 meters per second (m/s). This is often denoted as c in equations.

2. Does the speed of light apply to all types of waves?

Yes, the speed of light applies to all types of electromagnetic waves, including radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma rays.

3. Why does light travel at the same speed in a vacuum?

This is due to the fundamental properties of vacuum, which is the absence of any medium. Light is made up of electric and magnetic fields that are self-sustaining and do not require a medium to propagate. Therefore, the speed of light is constant in a vacuum.

4. Is the speed of light the fastest possible speed in the universe?

Yes, according to Einstein's theory of relativity, the speed of light is the fastest possible speed in the universe. Nothing can travel faster than the speed of light in a vacuum.

5. How does the speed of light in a vacuum compare to the speed of light in other mediums?

The speed of light is slower in other mediums, such as air, water, or glass, due to the interaction between light and the particles in the medium. The speed of light in a medium is denoted as v and is always less than the speed of light in a vacuum.

Similar threads

Replies
4
Views
2K
Replies
5
Views
5K
Replies
25
Views
1K
Replies
13
Views
2K
Replies
18
Views
1K
Replies
29
Views
3K
Replies
13
Views
2K
  • Optics
Replies
4
Views
1K
Replies
12
Views
919
Back
Top