Why cant you Alter the speed of light?

Question

in an vacume throwing stones while travling @ 30mph will cause the stones to travel at 30mph + the speed my arm moved. If i was carrying a touch why doesn't the light emitted travel at the speed of light + 30mph?

Answer 1

The speed of light does not depend upon the characteristics or properties of the source from which it is emitted.

It depends upon the medium in which it travels.

It depends upon the properties of the medium in which it travels.

Since it is energy, it travels in vacuum also.

The permittivity and permeability of vacuum is such that its velocity is 3x 10^8m/s.

Before knowing about light's speed, note that even sound's velocity is not depended upon the source from which it is emitted.

The velocity of sound also depends upon the medium in which it travels and not upon the source producing sound.

The difference between sound and light is that the former depends upon the elastic (mechanical) properties of the medium, where as the latter depends upon electric and magnetic properties of the medium.

Since vacuum has eclectic and magnetic properties, light travels in vacuum.

The speed of the objects thrown depends upon the source which throws them.

Answer 2

In general relativity, by the definition of Minkowski space-time, light follows a straight 4D line. I believe this is the source of the myth that light has no mass. If light has no mass in GR, it is because "mass" doesn't have the same meaning in GR as the meaning given to it by Newton. In 3D Newtonian space, light bends when passing thru the gravitational field of a star. This changes the direction of the light's momentum vector. Subtracting the momentum before bending from the momentum after bending gives a non-zero momentum-difference vector pointing at the star. If momentum is to be conserved, an equal and opposite momentum must be imparted to the star. In other words, the star must feel a gravitational attraction to the light. Therefor, light has gravitational mass. Newton defined inertial mass by the formula, f = ma, which works well for particles with a rest mass, even at relativistic speeds. This formula works for photons, too, as long as the force and acceleration are lateral only. It doesnt work, at all, for a photon if the force has a non-lateral component, because the photon can't accelerate forward or backward. We need new definitions of mass and force. I am no mathematician, so I may be getting in over my head, but I believe the correct definitions are: m = p/v (where p is momentum and v is velocity), and f = dp/dt (where dp/dt is the rate of change of momentum). Those definitions are in perfect agreement with f = ma where particles with a rest mass are concerned. They have the distinct advantage, however, of applicability to photons and neutrinos. I suspect that the inertial mass and gravitational mass of the photon are equivalent. I defer to the mathematicians to verify whether these formulas contradict general relativity, bearing in mind that Minkowski tacitly altered the meanings of such concepts as "mass".

Answer 3

Your torch question can be answered simply, ha ha, with Relativity. It doesn't matter how fast you are traveling, light will leave you (the torch) at the speed of light. Even if someone observes you at a distance, the light from the torch travels at the speed of light. A good example is two people playing ping pong on a train. If you were 100m away and watched them play, you might "see" the ball travel 50m between the two people. However, the people playing the game would see the ball only travel the length of the table. So which is true? Both are. Now imagine that instead of ping pong its you with your torch. The light only travels the speed of light. It just depends on the observer. The math that proves this is relativity, and there are only a select number of people on the planet who truly understand this math. Most of us are looking through a window into a house. The house is filled with the Relativity Party and we can only see very little of it.

Answer 4

For physics to work the speed of light has to be constant in any other reference frame. If you you throw your torch at 30m/s any other observer would measure the speed of light emitted from it as c= 3x10^8m/s approx. The famous interferometer expt by michelson and morley showed that the speed of light was the same whether the earth was advancing/receding from a light source.(there is no luminiferous ether) To accomadate this, mass length and time vary according to the inertial ref frame of the observer.
To combine velocities you should use V=v1+v2/(1+v1*v2/c^2) which approximates to v1+v2 when v1,v2< I would speculate that after the big bang, if alternate 'universes' were created with different force laws then the actual value of 'c' would be different, but constant in any given ref frame.

Answer 5

As Timbo said above, you can change the speed of light as it is dependent on what it travels through. The 'speed of light' everyone talks about, is the speed of light through a vacuum.

In sodium at -272 degrees C light travels at 38 mph (quite a bit slower than the 80,000 miles per second in a vacuum). In a Bose-Einstein condensate of rubidium you can bring light to a complete standstill.

Answer 6

You can alter the speed of light. Light always travels slower than 'c' in a transparent material. It only travels at the 'c' (the speed of light) in a pure vacuum. So in a glass block light actually travels slower than in a vacuum. This is also why it gets refracted at the surface of the block, because it slows down. It speeds up again when exiting the glass block.

Answer 7

The speed of light is a universal constant as defined in Einstein's theorems of General Relativity and Special Relativity. However it is theorized that neutrinos - particles which have no mass and which normally pass right through our planet - are capable of super-luminal (faster-than-light) velocities - but that is only a theory because we can only measure their "impact" by using a water chamber to "capture" slower particles, not their actual speed.

Answer 8

That stone of yours as it approachs the speed of light will increase in mass ( you don't notice this at arm speeds). To Get it up to the speed of light you need more and more energy......As a result it can never get up to the speed of light. Light is likely mass less although it behaves like a particle at times and at others like a wave

Answer 9

Light isn't so much a thing to be altered, but an effect.

The speed of light changes according to the media in which is travels.

Fastest>> Vacuum - Air - Glass <
But thats about all you can manipulate its speed.

Light is kind of like sound.
In that a sound coming from something traveling toward you is of higher pitch than something moving away.

Light is similar.
It will be a more blue colour coming from something traveling toward you and more red from something moving away.

Though, it should be noted that at our relative speeds, you wouldn't notice the difference.

Answer 10

scientists dont actually know what would happen. Most of the theories are just that: theories, and no actual experiments have been done yet because the technology does not exist. But what most would say is that because the light is travelling at a constant speed already, the speed of the torch will only alter the direction and angle of the lights trajectory, not its own speed.