stop dreaming of warp drives
So much science fiction is about a world after the invention of FTL technologies, but that day will not come, and we should confront the radical consequences of relativity.
Did you know
that if you somehow managed to build a spaceship that could fire continuously, so that you were constantly accelerating at 10 meters per second every second, you could reach the Andromeda galaxy in your lifetime? It would take a couple of decades, but if you could simply accelerate consistently for long periods of time, you could in your lifetime see another galaxy, despite them being millions of light years away!
The magical part of this is that it doesn’t require any magic. You don’t have to imagine some fundamental breakthrough in the laws of physics. As we understand it, slower than light travel could move you across the galaxy in your lifetime because time-dilation would extend your lifetime as viewed from the Earth’s reference frame. So why do all of our dreams conform to the same faster than light framework?
[F]aster [T]han [L]ight
I have loved Star Trek since I stumbled upon it back in the days when Netflix was new and not overwhelmed with non-Union Sabrina the Teenage Witch rip-offs. A life among the stars, exploring strange new world, was everything I dreamed of. In the world of Star Trek the technology that defines the transition from primitive human society to the Federation of planets is the Warp Drive. It bends spacetime around the ship allowing it to break the speed of light and travel vast distances very quickly. This makes travel from Qo’nos to Earth, kilo-parsec apart, in a reasonable amount of time, possible.
Radical Relativity
But, what’s the problem with FTL travel? Well, the problem is that you cannot travel faster than light! FTL drives break the very geometry of the universe beyond what most people realize. The light-speed barrier is not like the sound-speed barrier, which was simply very difficult to exceed. Exceeding the speed of light, if possible, has much more radical implications… time travel…
Imagine Benjamin Sisko watching a baseball game in San Fransisco. Quark leans over and bets him a bar of gold-pressed latinum that the Giants will lose the game. Sisko gets up to use the restroom, but does not return. He watches the game from a different seat, sees the Giants win the game, boards a ship, warps to Mars, warps back to Earth, beams down to the stadium, arriving just at the moment that he originally left for the restroom, and takes the bet knowing that he will win.
But wait, that’s not how the warp drive works! In an episode of Star Trek Quark would simply be confused about why Sisko never comes back. That’s because Star Trek is not a relativistic universe, there time passes the same for everyone in the galaxy. But we live in a universe where time does not pass equally for all observers.
The S[lower ]T[han ]L[ight] Future
Barring an even more radical revision to our understanding of how the universe works, the future will either be STL, or will include time-travel. But, what would an advanced STL future look like? Very little sci-fi has adventured into this realm, and to my knowledge none have really taken a look at human travel at relativistic speeds.
Lets hop aboard a space ship accelerating to the galactic center at 10 meters per second per second. What do we experience?
At first things seem eerily normal. You don’t even see the strange zero-g antics we associate with space because of videos of astronauts aboard the ISS. Because we are accelerating at 1 g everything feels the same as on the ground.
2 hours in you are passing by the moon. You’re already going really fast, but its only 0.03% the speed of light, so nothing’s too wacky yet. With instruments you can confirm that light coming from the galactic center is blue-shifted and signals from the Earth are red-shifted, but onboard computers can easily compensate. You can even say your goodbye’s to loved ones in real-time. At the Moon you are only on a 1 second delay because (fun fact) the Moon is 1 light second away.
