Time Travel Is Possible

Time travel is one of those topics that can be a headache. If we could time travel, wouldn't we already know? We would have had people from the future visit us by now. Additionally, many different movies explain time travel very differently.

Back to the Future describes it as, anything that you change in the past will have an effect on the future. Avengers: Endgame says, if you change something in the past, it won't magically change the future because going to the past IS your future.

Confusing.

Time travel is a concept that is explored a lot in media, but isn't something regularly practiced in day to day life-- and it's a lot more complicated in the movies.

The Future

Something that I recently heard about is that physical time travel is theorhetically possible, but only in one direction. While time travel doesn't exist for going into the past, we can use the speed of light to travel forward.

Remember how in Interstellar, while Matthew McConaughey and Anne Hathaway where on Miller's planet (the one primarily made of water), only hours passed for them, but decades passed on Earth?

While the astronauts were on the planet, time passed quickly for everyone who wasn't on the surface. It was a quick jarring jump into the future.

Although Interstellar explores the idea of time dilation, it pushes the boundaries of what is naturally likely.

This article from NASA explains it nicely.

In summary, the faster you travel, the slower you experience time. However, you need to be going the speed of light to actually have a significiant impact. Taking a flight on an airplane is not far or fast enough to show a difference, but past our atmosphere it can start having an effect.

Normal personal view: Your watch and body feel completely normal while you move.

Outside comparison: An outside observer sees your clock tick slower than theirs.

Extreme speeds: At 90% of the speed of light, time runs at less than half speed.

Scientists did a study where a twin went into space and returned younger than his twin brother.

Another interesting tidbit is that our GPS systems need to have their clocks adjusted, or else our maps would wrong about 10KM (six miles) a day.

Although we wouldn't necessarily be able to use a time machine like the movies, it time travelling is something that appears to be developable.

The Past

While we can't necessarily physically travel to the past, we can look at the past of other galaxies from afar.

When we view the solar system with The Hubble telescope, it takes time for the light to reach our eyes. The Sun is 93 million miles away, so it takes the light from The Sun 8 minutes to reach us on Earth. That means we are experiencing sunshine that is 8 minutes old, or if you were to look at the sun, you'd be seeing a sun from 8 minutes in the past! (Please don't look at the sun without proper protection).

The article from NASA goes into more detail, but here's a summary of the other cool places that we can watch from the future.

• The next closest star, Proxima Centauri: 4 Years

• Star named Betelgeuse: 700 years

• The Crab Nebula: 6500 years

• The Andromeda Galaxy: 2.5 million years

• Star named Earendel: 12.9 billion years

• Galaxy named GN-z11: 13.4 years

Astronomers are able to use telescopes to look into the beginnings of our universe and piece together its history.

So, maybe we aren't necessarily time traveling in the ways that we learn from the media, but science is always evolving and it is mind blowing that the ability to look at different times is even a possibility.