Thread: Faster-Than-Light Find Was Actually Loose Wire

Originally Posted by Peter Szarycz

Not if it's redshifted or blueshifted. If the observer and the emitter are moving relative to each other then they should detect the same frequency of the light they share if light was moving relative to each at the constant velocity of c. But they don't. They detect different frequencies of the same light which implies a shift, which implies a change in velocity of light relative to the observer. Have you read the above and can you dismiss it? Can you use the wavetrain concept of light propagation or the Poynting vector equation to prove what you've said?

How about you show research that shows that light speed is only constant for the emitter.

It is well known that the speed of light is a constant for all observers.

Originally Posted by excerpt from OT

Rewriting the theories based on this speed limit would have made an array of science fiction ideas more plausible -- even time travel.

Even with the speed of light constant in a vacuum at the agreed upon speed, 'time travel' (forward into the future) is theoretically possible due to the effects of time dilation and the relativistic effects or near light speed travel. No faster than light particles need apply.

reva

Time travel to the future is a scientific fact.

speed of light is a constant for all observers

Yes but as measured by the observer. I have always been interested in the relativistic aspects of objects moving at percentages of the velocity of light. Light has unique properties compared to other 'objects'. The speed of light, as that observer measures it, despite what the relative velocity is between the observer and that object is the same. The speed of light in a vacuum is a whats known as a universal constant. Light has the strange property that all observers measure the speed of light as c. And c= the speed of light in a vacuum or 299,792,458 metres per second.

reva

Originally Posted by Panzerkampfwagen

Time travel to the future is a scientific fact.

Yes it has been measured via atomic clocks. However some professionals take issue with the word time travel for some reason.

reva

Originally Posted by Panzerkampfwagen

Time travel to the future is a scientific fact.

That would mean it's already happened right?

Originally Posted by leftlegmoderate

That would mean it's already happened right?

Yes, scientific fact means observed.

It's done in atom smashers.

Originally Posted by Panzerkampfwagen

How about you show research that shows that light speed is only constant for the emitter.

It is well known that the speed of light is a constant for all observers.

You don't know the light speed relative to you just by detecting light. All you can measure is frequency and the wavelength. You can set up an experiment on Earth with a stationary emitter and then detect light some distance away and hence calculate light speed from distance/time. Once you start moving the emitter towards you and away from you, the light speed you measure will be exactly the same when you held the emitter stationary. That's because light speed is constant relative to the medium it travels through, and the medium (air) will be stationary relative to you and not the emitter. If you performed the same experiment in space in a perfect vacuum, the speed of light relative to you would change depending on whether the emitter was stationary or moving in relation to you.

Moreover, under natural conditions on Earth, the speed of light is never a c constant, it's always less. That's because light always travels through a medium, so light speed will be different for each observer depending on what medium they are in (place one observer in the water, and one in atmosphere). So it's an old given that light propagates through space filled with medium at speeds lower, and much lower than c, but never higher. In a perfect vacuum, light can travel faster or slower than c relative to an observer. The outer space inside the solar system is not a perfect vacuum, since it's occupied by the solar wind, a medium. Beyond the outer limit of the solar system called a heliopause where the solar wind violently collides with intra-galactic medium and runs out of steam, and where the magnetic effects from the Sun terminate, you would definitely stand a good chance of detecting these tachyonic effects on light, and beyond the galactic medium, these effects would predominate.

The reason why light cannot go faster than c in a medium is because when a photon with too high energy (and a photon travelling faster than c relative to the medium carries a lot of energy upon entering this medium) comes too close to the atoms of matter, it will convert into particles, starting with electron-positron pairs.

Originally Posted by leftlegmoderate

That would mean it's already happened right?

It would certainly have already happened in the future, wouldn`t it?

Originally Posted by aussiefree2ride

It would certainly have already happened in the future, wouldn`t it?

If it's possible to go back in time (which I doubt), then time travel has already happened.

I'm not sure what panzer is referring to though. I've only heard of experiments proving time travel is not possible. And by time travel I'm referring to the transportation of a tangible thing from one point in time to another... nothing to do with altering time or space.