Research Paper Theory Relativity
These stations (and the GPS unit in your car) are all experiencing higher accelerations due to gravity than the satellites in orbit.
To get that pinpoint accuracy, the satellites use clocks that are accurate to a few billionths of a second (nanoseconds).
This makes gold appear yellowish in color since yellow, orange and red light is a longer wavelength than blue.
The relativistic effect on gold's electrons is also one reason that the metal doesn't corrode or react with anything else easily.
Thomas Moore, a professor of physics at Pomona College in Claremont, California, uses the principle of relativity to demonstrate why Faraday's Law, which states that a changing magnetic field creates an electric current, is true."Since this is the core principle behind transformers and electric generators, anyone who uses electricity is experiencing the effects of relativity," Moore said. When a direct current (DC) of electric charge flows through a wire, electrons are drifting through the material.
Ordinarily the wire would seem electrically neutral, with no net positive or negative charge.
[Top 10 Inventions that Changed the World]Most metals are shiny because the electrons in the atoms jump from different energy levels, or "orbitals." Some photons that hit the metal get absorbed and re-emitted, though at a longer wavelength. Gold is a heavy atom, so the inner electrons are moving fast enough that the relativistic mass increase is significant, as well as the length contraction.
The satellites are also sending signals to ground stations on Earth.Electrons in the inner orbitals carry energy that is closer to the energy of outer electrons, and the wavelengths that get absorbed and reflected are longer.[Sinister Sparkle Gallery: 13 Mysterious & Cursed Gemstones]Longer wavelengths of light mean that some of the visible light that would usually just be reflected gets absorbed, and that light is in the blue end of the spectrum.To the astronaut on board, however, all would seem normal.In addition, the mass of the spaceship would appear to increase from the point of view of people on Earth.Since each satellite is 12,600 miles (20,300 kilometers) above Earth and moves at about 6,000 miles per hour (10,000 km/h), there's a relativistic time dilation that tacks on about 4 microseconds each day.Add in the effects of gravity and the figure goes up to about 7 microseconds. The difference is very real: if no relativistic effects were accounted for, a GPS unit that tells you it's a half mile (0.8 km) to the next gas station would be 5 miles (8 km) off after only one day.That's a consequence of having about the same number of protons (positive charges) and electrons (negative charges).But, if you put another wire next to it with a DC current, the wires attract or repel each other, depending on which direction the current is moving.Any object in a big gravity field is accelerating, so it will also experience time dilation.Meanwhile, the astronaut's spaceship will experience length contraction, which means that if you took a picture of the spacecraft as it flew by, it would look as though it were "squished" in the direction of motion.