People take the C being constant too literally. There is no real reason why C cannot be faster than vacuum constant and we have already proved many times that light can travel far slower than the vacuum constant.
Putting something in light's way slows it down. But if you put nothing in its way then you get it moving at c. To get it to move faster how can you put less than nothing in its way?
When you say 'there's no real reason' what are you basing that on? Anything more than your gut feeling based on little to no real experience with physics of this type?
Also, sending a signal faster than light wouldn't mean sending a signal back in time. What it means is that by current theory the effect would happen before the cause. Another thing take too literally. They are saying the signal would be there before you see it, mimicking time travel. But it isn't time travel at all.
You should look up what relativity actually says. Faster than light means altering the causal structure of a system. The light cone of an event divides the space-time into 3 regions, those connected to the event by time-like vectors, null vectors and space-like vectors. These regions are mapped into themselves by Lorentz transforms, so if something travels faster than light to another point in space-time these exists a frame of reference where the second event happens
BEFORE the first. If the something moves slower than light than it remains within the light cone and
every frame of reference has its destination event occur
after the emission event.
More formally, suppose a particle is emitted at event E1 at time t1 and absorbed at event E2 at time t2. If the particle moves slower than light then all frames of reference will have t1<t2, ie emission occurs before absorption. If the particle moves faster than the speed of light then there exist frames where t2<t1, absorption happens before emission.
This stuff is pretty simple relativity, it's covered in 1st year courses. Anyone competent at A Level mechanics mathematics can pick it up without too much bother.
But the E=MC2 hasn't stood up to everything questioned about it, a lot of the questions we simply haven't been able to test but that doesn't mean they shouldn't be asked.
Special relativity has passed every test it's been put under, which includes all particle physics and all gravitational experiments since SR appears in both *** and GR.
For instance, send a football beyond the speed of light to a destination. When the ball arrives at it's destination and it has stopped you should be able to see the ball stationary at it's new destination, but the light reflecting from the ball is still travelling to get there from where it came. Will we see two balls superimposed over each other when the light finally catches up? We simply do not know but that is something E=MC2 says can only be impossible and at the same time other proven theories say is the only possible outcome.
I really think you need to learn some physics before you try to tell others what it says. This is what I was referring to, science in the news brings out the people who don't know science but think they do and then proceed to tell people their
impression, their
mistaken impression, of what science says.
All we can truly say is that E=MC2 has been 'accurate enough' to help us discover more things and like all things science it is entirely possible that it is entire wrong.
No, it is not entirely possible that it is entirely wrong. It is entirely possible that relativity is only 99.9999% accurate and messes up in the 7th or 10th decimal place. It is obviously very accurate else we'd not even be able to turn on the LHC, never mind use it to discover new physics. Newton is known to be not entirely right but that doesn't make him entirely wrong, you can still put a man on the Moon using Newtonian physics.
Scientific models aren't an all or nothing thing. When a better model comes along we don't throw out the old ones. We still teach people, including engineers, Newtonian physics even though it's surpassed in every possible way by better models. We still teach electromagnetism even though it too is surpassed in every possible way. They are much simpler than more accurate models but they are still accurate enough to be of use.
This reminds me of the BBC 10 o'clock news I just saw. It said things like "For a century relativity has not been challenged" but it HAS. It has been challenged by hundreds of different experiments all over the world. Every time you use a SatNav it is challenged and it passes! Even the BBC is reporting this poorly!
Does quantum entanglement not send information at any distance in an instant?
No, there's always something which means you can't get the information unless you communicate classically, via some method which is bounded by light speed.
smiley was because of the extremity of the claim it might be travelling through a substance unknown to man, not because it isn't possible.
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