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And Relativity also predicts that photons have non-zero momentum. Relativistic systems can have non-zero momentum even with no  

And Relativity also predicts that photons have non-zero momentum. Relativistic systems can have non-zero momentum even with no  

rest mass, due to ''mass-energy equivalence''. Relativity correctly predicts the momentum of a massless particle as p = h*f/c = h / lambda.

rest mass, due to ''mass-energy equivalence''. Relativity correctly predicts the momentum of a massless particle as p = h*f/c = h/λ.

31. The Twin Paradox: Consider twins who are separated with one traveling at a very high speed such that his "clock" (age) slows  

31. The Twin Paradox: Consider twins who are separated with one traveling at a very high speed such that his "clock" (age) slows