In the smallest sense, time is relative! Time flows at different rates in different places, like a river flows differently across different rocks. It essentially acts as the 4th dimension in life, as time cannot exist without space – they must exist together in whats called the time-space continuum. All events in the Universe must then happen within time and space.
Its a difficult concept to fully understand, but you should try read Stephen Hawking’s classic book “A Short History of Time” if you are interested, he explains it much better than me!
Hello, this is a super tough question, I’ll have my go, but I am sure I will not exhaust the topic. Please do ask follow up questions.
In physics, time is always flowing at a constant rate. However time intervals between two events can appear different to observers moving at different speed (thanks to Einstein’s special relativity). Moreover the presence of masses also affects the measurements of time intervals (Einstein’s general relativity) so that time intervals near very heavy objects like black holes are enormously increased. An interesting question is whether time has had a beginning like our universe with the big bang. According to general relativity the answer is positive, although cosmologist, physicists that study the origin of the universe are still investigating this.
That’s a really interesting (and profound) question Leah. Well done! So, since time isn’t destroyed then it must still be there with us imprinted on it? Can it be rewound? Well, as Karen and Gabriele have explained, time is relative, so it may appear slower or faster depending on the observer’s speed. We ll have to talk about scary quantum physics, i m afraid, which deals with tiny tiny particles (we can’t see these with our eyes!) with a lot of energy. Yikes! Physicists study time by looking at these tiny particles in instruments called ‘particle accelerators’. And in accordance with Einstein’s theory, time holds itself in a stretch of another dimension…. So where does time go? Combining all these facts, it apparently goes backwards and forward! Some particles move forward and others backward, but those particles that go backward in time, do not retrace their steps (or the same behavior) as they did going forward. It’s all still under debate, if we could understand this question we would be able to invent a time machine! Perhaps you ll be the next quantum physicist to do so? Great question! Hope that helps a bit 🙂