

Astrophysicist Neil deGrasse Tyson explains how relativity allows time to pass at different rates, making travel to the future conceivable, while returning to the past remains beyond known physics.

Astrophysicist Neil deGrasse Tyson explains how relativity allows time to pass at different rates, making travel to the future conceivable, while returning to the past remains beyond known physics.
Sure, Tyson says the future is “conceivable” thanks to time dilation, but nobody mentions the tiny problem: you only get there by waiting, and you can’t wait your way back. So what exactly is the “travel” in time travel? Sitting still while the rest of us age, and calling it a trip? Relativity gives you a one-way ticket and a shrug.