There's a theory that fans of time travel stories like to toss around: Time travel not only hasn't been invented yet, it won't be in the future either. Otherwise, we'd see time-travelers popping up in history. Here's an alternate — and pretty unsettling — theory.
After reading about the likelihood that any travelers who go too far back in the past would find themselves in dire need of an atmosphere suit, commenter Cool_Breeze shared this spooky theory about where we should look for time-travelers:
Not only does a time machine have to travel backwards in time, but also in space. Earth is constantly moving, and pinning down it's exact location x years ago can get tricky. Think about it:
1. Earth's rotation on an axis that shifts approximately 20 degrees every couple of million years. The Earth's wobble must be taken into account;
2. Earth's position relative to the Sun;
3. The Solar System's position relative to the center of the Milky Way Galaxy. Our system orbits once every ~250 million years;
4. The position of the Milky Way Galaxy in relation to other galaxies, and their gravitation effects on the Milky Way;
5. The position of the local galactic cluster in relation to other clusters, and its position relative to the gravitational effects of the big bang; and
6. Any number of random gravitational encounters that may affect any of the above, including but not limited to rouge stars disrupting our Sun's orbit around the galaxy, rouge planets' and stars' gravitational effects on Earth's rotation around the Sun, past and future galactic collisions (Milky Way v. Andromeda, etc.), Plate tectonics and climate changes on Earth that affect the location, altitude, and existence of various places ON Earth.
Get one of those wrong, and the lack of oxygen in Earth's atmosphere will become a very minute problem.
My theory is that the reason we don't see any time travelers now is not because they don't exist - but rather because they calculated wrong and are floating in space somewhere, never to be seen again.
Of course, there are other options than time travelers being stuck out in our planet's surrounding space debris: Perhaps our time period is just considered too dull to visit or maybe time-travelers are also exceptionally clever at blending in. Still, we're curious — would you cheerfully take the risk of not returning or even surviving, in exchange for the possibility of moving a little further beyond the confines of our own little patch of time? And, if you did, what is it that would convince you — a demonstration of technical safety or simply the call of adventure? Tell us in the comments.
Top Image: "Sling-Sat", a possible space debris removal system designed at Texas A&M