27th February, 2024
CHIRANJIT MITRA
● Time travel is a staple of science fiction, but could it be grounded in reality? ● Surprisingly, the work of Albert Einstein, one of history's greatest physicists, offers some tantalizing possibilities.
● In 1905, Einstein's theory of special relativity turned our understanding of space and time upside down. ● Key ideas: ● Time is relative: It passes differently for observers moving at different speeds. ● Time dilation: The faster you move, the slower time passes for you relative to an observer at rest.
● Einstein's theory suggests a way to travel into the future. ● If a spacecraft travels close to the speed of light, time slows significantly for those on board. ● They could return to Earth to find that they've aged less than everyone else – effectively traveling into the future.
● A thought experiment illustrating time dilation: One twin stays on Earth, and the other journeys near the speed of light. ● Upon the traveler's return, they would be younger than their Earthbound twin, having experienced less time.
● In 1915, Einstein expanded his ideas with general relativity. ● Gravity isn't a force but a curvature of spacetime (the fabric of our universe). ● Massive objects like black holes or planets distort spacetime.
● General relativity suggests time is also affected by gravity. ● Time passes slower in stronger gravitational fields. ● Someone near a powerful source of gravity (like a black hole) would age slower than someone far away.
● Wormholes are hypothetical tunnels through spacetime predicted by general relativity. ● They could offer a shortcut between distant points in the universe or different moments in time. ● However, wormholes are highly theoretical, and whether they exist or could be manipulated is unknown.
● While Einstein's theories hint at possibilities, time travel faces tremendous obstacles: ● The immense energy is required to reach near light speed, create wormholes, or overcome gravitational effects. ● Paradoxes: Changing the past could erase your existence, creating logical contradictions.
● Einstein's work revealed time is far stranger than we imagined. ● Whether time travel is ultimately possible remains a captivating question for physicists and dreamers alike.