His eight papers in theoretical astrophysics would earn him no more in Russia than in America, but at least he could sleep on his father's couch. Boris was brooding when he noticed a portly, well-dressed man reading his poster. The man nodded.
How fast does it go? Professor Liu had said not to answer simple questions with abstruse mathematics. More free stories from Nature Futures. The man looked into Boris's eyes, and his voice dropped to a whisper. That statement had earned the man a good job and a dacha, and because his statement was literally true and because Brezhnev wasn't Stalin, nobody had got shot when it didn't work after a dozen years.
The speed of dark energy
Computers buy and sell stock to each other, and we hope our computers outsmart theirs. The best way to outsmart them is to get information faster, so submarine fibre-optic cables run the shortest routes. One goes through the Arctic Ocean from Tokyo to London. Now our competitors are laying a hollow-core fibre along that route, and because light goes faster through the empty core than through a solid glass fibre, it will be faster than our cable. So we need to send data faster than light. Can dark energy do it? Boris could invent equations, not cable systems, but this was no time to mention that.
Boris enjoyed theory. He filled bound quadrille-ruled notebooks with symbols and equations.
He wrote mathematical descriptions of the interactions between dark energy and ordinary matter, then converted them into code for models to run on the quantum computer and his desktop supercomputer. He tested the models for weeks, pored over the results, rewrote the code, and ran the models again.
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I also read about Relativity where Einstein stated that every event happening for you depends on how fast the light gets from where the event is happening to you. This is my particular problem with this Moon shadow experiment.
You cannot make a shadow travel faster than light, because in order for the "disappearance" of light to get to the Moon, it has to travel at light speed. Here is one way to understand my point. Consider we shine a flashlight on Moon, like the guy in the linked video did, we move the finger across the face of the flashlight, before we moved the finger it was casting the shadow at Point A on Moon, after we finish moving our finger, the shadow is at Point B on the Moon.
That means shadow traveled say across the diameter of the Moon in 3 seconds. How can these experiments conclude that Shadow could be made to travel faster than light? What is the obvious clue that I am missing here? This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question. A shadow or a light spot can seem to travel faster than light, because it's not a particular physical thing, but a series of separate things, separate physical particles emitted at different time and at different locations.
But first, this thought experiment might make things clearer. Imagine you have a light that's powerful enough to reach the planet Jupiter.
Imagine also that it casts that beam in a cone that's broad enough to cover the entire diameter of the planet. When you pass your finger over the lens, the shadow will cross the entire diameter of the planet — a distance of 86, miles , kilometers. The speed of light is , miles per second , kilometers per second. So if it takes you less than half a second to move your hand that distance, then that shadow will have "broken" the speed of light. So, remember how we said that nothing can move faster than the speed of light?
Well, that's the key.
Shadows aren't anything. Shadows are the absence of something — specifically, photons, or particles of light. Since there's nothing that's actually traveling the distance, the only thing that's "moving" is an area where photons aren't.
The Speed of Darkness by Muriel Rukeyser | Poetry Foundation
There's no information that's being transmitted faster than light, only a blockage of information. That means your interplanetary shadow-puppet show doesn't break any physical laws — only the hearts of your interplanetary audience. Get stories like this one in your inbox each morning.