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Speed of Gravity Experiment Challenged
An anonymous reader writes "The previous hoopla over the discovery of the speed of gravity has an opponent from the Lawrence Berkeley National Laboratory. Read about the latest calculations."
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If gravity was instantaneous, how is it that we couldn't use it to transmit information? Surely it would be difficult in practice, but it seems pretty simple in theory.
"When we're ready, I'll start moving this ball'o'mass towards and away from you."
What's impossible? Moving the mass around, detecting the mass in motion, or detecting it instantaneously?
Let's not stir that bag of worms...
What about quantum intertwining? Create 2 nanoscopic black holes at opposite ends of the earth. Then find ways to alter the âspinâ(TM) of one, and the other should instantly alter to match. There are all sorts of weird and spooky things that we know little or nothing about.
Teleportation is simple, in theory. Just get 2 massive superconducting plates (a metal, for example) and place them very close together, just close enough that you can still walk between them. Then repeat at opposite end of the universe. Find a way to instantly, evenly charge all the atoms in all of the plates at the exact same time with the exact same energy properties and... Wooomph... teleportation. Oh, did I forget to mention you would need more energy than the sum of everything man has ever produced in our existence? Iâ(TM)ve heard estimates like the energy of a super massive star going supernova, but who knows. Then you have to contend with who-knows-what types of unknown forms of energy. Iâ(TM)m assuming weâ(TM)d probably need to be radiation proof to survive that. Lots of things look cool and useful on paper, but practicality is completely different.
Contrary to popular opinion, the ability to travel or send information faster than light does not allow one to travel backwards in time.
Maybe not "travel", but you can send a message backwards in time. This assumes that you can send faster-than-light messages in two different reference frames that are moving with a high relative velocity - you bounce the message back and forth between the reference frames, and the net result is that it arrives at its point of origin before it was sent.