It takes a spy to hunt a spy.

For the first time, physicists have simulated what objects moving near the speed of light would look like — an optical illusion called the Terrell-Penrose effect.

The hyperdrive from Star Wars appears to depict an ultra-relativistic motion through space, extremely close to the speed of light. Under the laws of relativity, you neither reach nor exceed the speed ...

Potential energy is the latent energy in an object at rest, and is one of two forms of energy. The other form, kinetic energy, is the energy expressed by an object in motion. Potential energy is a ...

Sir Isaac Newton studied other scientists' ideas and thought a lot about how things on Earth and in the universe move. After a great deal of work, he developed three important laws that explain how ...

In a Universe governed by General Relativity, filled with matter-and-energy, a static solution is not possible. That Universe must either expand or contract, with measurements revealing very quickly ...

Spacecraft launches use liquid hydrogen and oxygen for main propulsion, sometimes supplemented by solid propellants. Gravity assists from planets help propel spacecraft, reducing fuel needs. Small ...

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