# Can light travel through a vacuum?

• jaypee
In summary, the conversation discusses the concept of light traveling through a vacuum and how it does not require a medium to do so. The existence of the ether as a medium was proposed but has been disproven by experiments. Current theories explain light as a group of mutually supporting electric and magnetic fields and have made the ether irrelevant. The conversation also touches on the concept of special relativity and how it is mathematically derived from the Lorentz transformations. It is also mentioned that the laws of nature, such as h, c, G, and e, should have the same numerical values regardless of the observer's velocity.
jaypee
Can light travel through a vacuum? If so, can you provide an example.

thx.

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Have you ever seen the moon?

Space is essentially a vaccuum. Furthermore, C is the speed of light in a vacuum, so how do you think we got that?!?

Yeah, unlike most other waves, light doesn't need a medium to travel through..It was proposed that there was some medium called the ether, but I think experiments could not find conclusive evidence supporting it.

And current theories of light as a group of mutually supporting electric and magnetic fields have made the ether rather pointless, as well as explained several other phenomenons...

light is a electromagnetic waves...
sure can through a vacuum

No ethir means no difference for any experiment in moving vs non-moving with any velocity lab. So, h, c, G, e and all laws of nature shall not depend on lab's velocity. This in turn requires that h, c, G, e shall be invariant values (shall not depend on velocity of moving by them pobserver). This in turn requires space and time to be transformed very certain way (called Lorents transformations). Special relativity then precepitates from those transformations mathematically.

No ether means no difference for any experiment in moving vs non-moving with any velocity lab. So, h, c, G, e and all laws of nature shall not depend on lab's velocity.

This in turn requires that h, c, G, e shall be invariant values (=shall have the SAME numerical values measured by DIFFERENT observers regardless their mutual motion). Say, observer moving with some velocity past electric charge shall measure same charge as non-moving observer. Or observer moving by flashlight shall measure same c as non-moving one.

This in turn requires space and time to be transformed very certain way between moving systems (called Lorents transformations).

Special relativity then precepitates from those transformations mathematically.

## 1. Can light travel through a vacuum?

Yes, light can travel through a vacuum. A vacuum is an area devoid of matter, including air molecules, which are usually responsible for scattering and absorbing light. Therefore, in a vacuum, light can travel unobstructed in a straight line.

## 2. How does light travel through a vacuum?

Light travels through a vacuum in the form of electromagnetic waves. These waves do not require a medium to propagate, unlike sound waves, which need a medium such as air or water to travel. Therefore, in a vacuum, light can travel at its maximum speed of 299,792,458 meters per second.

## 3. Why can't sound travel through a vacuum like light?

Sound is a mechanical wave that needs a medium to travel. When sound waves encounter a vacuum, they have no molecules to vibrate and, therefore, cannot propagate. On the other hand, light is an electromagnetic wave that does not require a medium and can travel through a vacuum without any obstacles.

## 4. Can light be blocked or stopped in a vacuum?

No, light cannot be blocked or stopped in a vacuum. Since there are no particles present to absorb or scatter light, it can travel indefinitely without any loss of energy. This means that in a perfect vacuum, light can travel forever at its maximum speed.

## 5. Is a vacuum necessary for light to travel at its maximum speed?

Yes, a vacuum is necessary for light to travel at its maximum speed. In any other medium, such as air or water, light will encounter particles that can slow it down. However, in a vacuum, there are no particles to interact with, allowing light to travel at its maximum speed without any obstructions.

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