Is it possible to travel through time? The short answer to that question is yes. That’s right. Even if we don’t know it, everyone has the ability to jump forward in time. You can jump into the future by going to bed and waking up several hours later. This is cheating the question. We all want to be able go back and correct the silly mistakes that we made years ago. Who doesn’t want to be able to talk to their 15 year old self? You can tell them to not make the same mistakes as you made (or they will). Perhaps you would rather travel 500 years in the future to see the flying cars that we promised by 2000. Time travel is theoretically possible.
There is no law that prohibits time travel in physics. It’s possible to travel through time according to all known laws of physics. However, great power also comes with great responsibility. Time travel can have devastating consequences and be extremely dangerous. It is also fraught with paradoxes.
What if I could travel back in time to stop World War II? This sounds like a great idea. My actions would save many lives and I would be called a hero. Not necessarily. While I would be saving lives, my actions could also result in the destruction of others. Consider all the technology we depend on today, which was developed during wartime like jet engines and nuclear power. The world map could actually be entirely different. It is possible to do worse than leaving history as it is.
The grandfather paradox is another famous time travel paradox. It basically says that we could travel back in time to prevent my grandfather from meeting me grandmother. My parents could not have met, and I wouldn’t have been born. How could I go back in time to stop my grandparents from meeting?
We can see how time travel is a bad idea. But let’s suppose we really want time travel. How would we go about it? First, we must understand the nature of time.