12 Events That Will Change Everything, Made Interactive. Lectures. 32 Nearby Stars. 10 Strange Things About The Universe. Space The universe can be a very strange place. While groundbreaking ideas such as quantum theory, relativity and even the Earth going around the Sun might be commonly accepted now, science still continues to show that the universe contains things you might find it difficult to believe, and even more difficult to get your head around.
Theoretically, the lowest temperature that can be achieved is absolute zero, exactly ? 273.15°C, where the motion of all particles stops completely. However, you can never actually cool something to this temperature because, in quantum mechanics, every particle has a minimum energy, called “zero-point energy,” which you cannot get below. One of the properties of a negative-energy vacuum is that light actually travels faster in it than it does in a normal vacuum, something that may one day allow people to travel faster than the speed of light in a kind of negative-energy vacuum bubble.
Relativity of Simultaneity Antimatter Retrocausality. Randy Wayne takes new look at relativity. When resolving why electrons can never beat the speed limit set by light, it might be best to forget about time. Thanks to insight from studying movement inside a biological cell, it seems that light itself -- not the relativity of time -- may be the traffic cop, according to a Cornell biologist. Any space with a temperature above absolute zero consists of photons.
As a result of the Doppler effect, the moving electron experiences the photons crashing into the front of it as being blue-shifted, and the photons colliding with the back of it as being red-shifted. Since blue-shifted photons exert more momentum than red-shifted photons, the photons themselves exert a counterforce on the moving electron, just as the cytoplasm in a cell exerts a viscous force on the moving organelles.