Twin paradox
The twin paradox in physics is a thought experiment in special relativity. It involves identical twins, one of whom makes a journey into space in a high-speed rocket and returns home to find that the twin who remained on Earth has aged more.
The paradox depends upon the unspoken idea that the passage of time is the same in all circumstances. But this is not correct. Time is relative and the speed of light through a vacuum is the only constant.[1] And the universe is relativistic, not Newtonian. Every single test which has been made has shown this.
Twin Paradox Media
During the ISS year-long mission, astronaut Scott Kelly (right) aged about 8 1/2 milliseconds less than his Earthbound twin brother Mark (left) due to relativistic effects.
Minkowski diagram of the twin paradox. There is a difference between the trajectories of the twins: the trajectory of the ship is equally divided between two different inertial frames, while the Earth-based twin stays in the same inertial frame.
Light paths for images exchanged during tripLeft: Earth to ship. Right: Ship to Earth.*Red lines indicate low frequency images are received, blue lines indicate high frequency images are received
Twin paradox employing a rocket following an acceleration profile in terms of proper time τ and by setting c=1: Phase 1 (a=0.6, τ=2); Phase 2 (a=0, τ=2); Phase 3-4 (a=-0.6, 2τ=4); Phase 5 (a=0, τ=2); Phase 6 (a=0.6, τ=2). The twins meet at T=17.3 and τ=12.
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References
- ↑ Einstein A. & Infield L. [1938] 1966. The evolution of physics. New York: Simon & Schuster, p177–192.
