The speed of light

[kfinkelstein]

Forgive me if this is a stupid question. If two objects are moving toward each other at approximately the speed of light, would not their speed relative to one another be approximately twice the speed of light, thus breaking the light barrier?

[Gods_Mercenary]

I'm not theoretical physics wiz, but it's the velocity of one object that matters, not relative speed.

[Jack]

In actual fact, there are many trivial ways in which things can be going faster than light (FTL) in a sense, and there may be other more genuine possibilities.

Interesting reading here: Faster Than Light

[Will_00]

In actual fact, there are many trivial ways in which things can be going faster than light (FTL) in a sense, and there may be other more genuine possibilities.

But that is if it was created over the speed of light.

Quote by: kfinkelstein Forgive me if this is a stupid question. If two objects are moving toward each other at approximately the speed of light, would not their speed relative to one another be approximately twice the speed of light, thus breaking the light barrier?

The two objects would be approaching each other faster than if one were stationary and the other moving. However, as you point out neither object would be exceeding the speed of light. The "light barrier" is not, therefore, broken.

To clarify, if two passenger jets approached each other at 500+ MPH their closing speed would exceed the speed of sound, but there would be no sonic boom, because neither jet broke the sound barrier.

[gallo]

The answer has to do with relativity, i.e., two objects in motion relative to each other, and inertial frames of reference. You might try reading Hawking's books, A Brief History of Time and The Universe in a Nutshell. As I recall, the second is a bit more advanced. When you understand, please return and explain it to me.

[tommy5x]

Light has been slowed (at it slowest point) to approximately 36 m/ph through supercooled sodium. I shall try and find my point of reference. It's in my house somewhere.

I don't doubt that most of us have traveled faster than light.

[gallo]

Quote by: tommy5x Light has been slowed (at it slowest point) to approximately 36 m/ph through supercooled sodium. I shall try and find my point of reference. It's in my house somewhere. I don't doubt that most of us have traveled faster than light.

Yeah, but not through supercooled sodium. No need to find your reference as most of us are perfectly aware that the speed of light changes as it passes through various media.

In fact, even matter in the form of protons and neutrons can travel faster than light and does so all the time. It just so happens that the medium through which they travel is water and the source of the protons and neutrons is a fission reaction. The result can be seen as a beautiful blue light. I saw it when looking down through about 60 feet of water at a nuclear reactor under full power. There several such open reactors in the U.S. Three that I know of are the Advanced Test Reactor in Idaho, Ohio State University, and Texas A&M University.