Back in 2015, to celebrate Albert Einstein’s birthday, I wrote a month-long series of posts about Special Relativity. I still regard it as one of my better efforts here. The series oriented on explaining to novices why faster-than-light travel (FTL) is not possible (short answer: it breaks reality).
So no warp drive. No wormholes or ansibles, either, because any FTL communication opens a path to the past. When I wrote the series, I speculated an ansible might work within an inertial frame. A smarter person set me straight; nope, it breaks reality. (See: Sorry, No FTL Radio)
Then Dr Sabine Hossenfelder seemed to suggest it was possible.
Earlier, in the March Mathness post, I mentioned Albert Einstein was born on March 14th. That’s also Pi Day, which deserved its own pi post (about pizza pi), so old Al had to wait for me to address a topic I’ve needed to address for several months.
To wit: Some guy was wrong on the internet.
That guy was me.
Back in 2015 (also celebrating Einstein’s birthday), I wrote a series of posts exploring Special Relativity. Near the end of the series, writing about FTL radio, I said (assuming an “ansible” existed) I wasn’t convinced it violated causality if the frames of reference were matched.
We’re finally sliding into home plate in this series (it’s baseball season, so I get to use baseball metaphors now). After spending a lot of time looking into how Special Relativity works, we’re able to at last explore how it applies to the idea of faster-the-light travel.
Last time we saw that FTL radio seems hopeless — at least at communicating between frames of reference in motion with regard to each other. It’s possible there might be a loophole for FTL communication between matched frames. (If nothing else, it may be fertile background for some science fiction.)
Today we examine the idea of FTL motion — of “warp drive!”
Over the last five weeks I’ve tried to explain and explore Einstein’s Theory of Special Relativity. We’ve seen that motion, velocity, simultaneity, length, and even time, are all relative to your frame of reference and that motion changes the perceptions of those things for observers outside your frame.
All along I’ve teased the idea that the things I’m showing you demonstrate how the dream of faster-than-light (FTL) travel is (almost certainly) impossible. Despite a lot of science fiction, there probably isn’t any warp drive in our futures.
Now it’s (finally) time to find out just exactly why that is.