Making my last blog post left me bewildered about the wonders of time dilation, so I decided to Google it and make another post.
Apparently there's different kinds of time dilation: velocity time dilation, the one I mentioned in my previous post, has to do with the difference in the perception of time relative to something else. The other kind of time dilation is gravitational time dilation, which I'll get into later.
Velocity time dilation suggests that objects moving faster in relation to another object moves slower through time. As an object approaches the speed of light, the rate of time approaches zero. This suggests that a massless particle moving at the speed of light is completely unaffected by the passage of time. This form of time dilation supports a theory of forward time travel, where we can, as the title suggest, travel forward through time. This could theoretically be done if people were in a spacecraft moving at incredibly high speeds. 1 year of travel time for them could be over a decade of time here on Earth. In practice so far, it is calculated that people on the ISS (International Space Station) for 6 months aged about 0.005 seconds less than they would have here on Earth. 5 milliseconds is a start, right?
On the other hand, gravitational time dilation suggests that an observer under the influence of a strong gravitational field moves slower through time than those under the influence of a weaker gravitational field. This supports another method of forward time travel, which is why in the movie Interstellar, the crew had to spend extra fuel to land on a planet quickly and take off again during a survey mission. They were trying to save time because they were close to a giant black hole. In the movie, 1 hour spent on the planet was the equivalent to about 7 years on Earth if I remember correctly.
Remember to take all of this with a grain of salt, because I clearly don't know what I'm talking about. I actually skipped over all of the calculus sections of my sources in order to prevent my brain from throbbing any more than it already is.