A semi-common theme in sci-fi is the dreaded “Joe Blow gets abducted by aliens, traipses across the galaxy having various and sundry adventures, and then finds his way home, happily ever after, blah blah” plot.
But - how the hell WOULD you find your way back home? Is there any piece of information that the average mope can arm him or herself with that would show a friendly and helpful spacefaring race how to get a lost soul back to earth? It obviously needs to use easy to find landmarks (spacemarks?) and use only universal values for distance and direction.
Ideally this would be something you could just memorize, but in a pinch I would accept something with written instructions that you could keep in your pocket or around your neck or whatever.
If you knew what the constellations looked like from Earth, if you saw them anywhere else, you’d know that you were in line with Earth and, depending if they looked larger or smaller, either behind you or ahead of you…
Constellations look mostly the same if you’re as far away as Proxima Centuri. While that’s our closest neighbor, that’s still a hella long way from Aunt Suzy’s house.
I think you’d need a handful of very distinctive stars, and then some highly accurate way to triangulate them.
If you’re still within our Galaxy, then your best navigation beacons would be the Magellanic Clouds and the various globular clusters. If you know the relative positions of several of those, you could get back into the general vicinity of Sol, and go by the constellations from there. This would probably require more information than the average “Joe Blow” would have, but it might not be out of reach of a skilled amateur astronomer with a good eye.
Or, of course, you could just hack into the aliens’ navigation computer and backtrack.
EDIT:
With two notable exceptions, of course, at least one of which should be familiar to someone from anywhere on Earth. And a few nearby stars like Sirius would also be in notably different locations.
This is the responsibility of the stellar cartography division. Presumebly in the far future, your iSpacePhone will have a MilkyWayMap app so you can plot your way home.
In theory, all you need are 3 points, e.g., the positions of our sun and one other star in relation to the galactic center. In actuality, you’d want the locations of multiple stars to aid in navigation, as a trivial error could land you very far from home.
Of course, the real sticking point would be translation errors between you and your extraterrestrial buddies. Look what happened with one of the Mars probes from a Metric to English unit conversion error. And that was just inside our solar system between two members of the same species.
The problem there is, of course, how do you find your marker stars in the first place? If you are in the other arm of the galaxy, you cant find anything over here. Which is why, of course, the constellation idea would not work at all.
You would need pulsars or some other unique radio phenomena, that is pretty clear. The problem remains, however, how to describe the distance and direction from them.
Same species? I hardly think that anyone who uses Imperial units counts as the same species
Ah - now we are getting somewhere. The pulsar map and the hydrogen “key” for the timing should be enough. Does a tattoo have enough resolution to keep the binary data legible at the size needed to fit conveniently on your body? Or are we looking at a market for groovy medallions here?
Also - how would that map work if it is only 2D? The directions would only work if you happened to be on exactly the right plane. Or are the relative DISTANCES also correct? They dont explain that part very well. Any Voyager geeks out there?
That’s why I recommended globular clusters, instead: You can see those pretty much across the Galaxy. They also have the advantage that they’re visible to the naked eye, or with only a small telescope: No other sensors or other devices needed.
For the language barrier, you wouldn’t need to describe the distances at all: Directions would be enough, if you have enough of them (at least four or five; a dozen would be better). And directions you can communicate just by pointing.
It wouldn’t need to be in binary, necessarily — the only reason that the distances on the Voyager record are expressed in binary and in units of hydrogen frequencies is that we don’t know what units or base number systems the aliens would use. If you’re going to be reading it, you could just tattoo in something like “236.7 milliseconds” instead.
As far as I can tell, the lengths of the lines correspond to the distances of the pulsars; the angles of the lines are chosen by demanding that the distance of the pulsars above & below the galactic plane are to scale.
The short answer is NO. Average Joe Blow would not be able to find his way back to earth if he were dropped somewhere else in the galaxy. What are you going to say? Uhhhh…it’s a kind of yellowish star…not too big, not too small. It’s sort of out on the outer arms of the galaxy. There’s nine planets (or eight and a sort-of planet).
If you have any time-keeping device, you can show them. If you don’t, you can demonstrate a unit of length (for example, I can define a metre by stating that I am 1.78 m tall), and then express the speed of light using that unit of length (it’s about 3*10^8 m/s) and derive a unit of time from there.
Of course, that requires you to be able to communicate, but if you’re patient, the aliens can probably teach you their language.
For that matter, if this alien species is more advanced than humans (it would have to be) they probably have better planet imaging methods, or have sent a network of unmanned probes to map solar systems. They may well have our solar system in their databases, and if you can describe it in sufficient detail, they may be able to figure out which one it is. That is, you can “ask for directions” :).
Hello , this is OnUniverse, our indicators show you are either lost in the Delta Quadrant, or are being devoured by a Bugblatter beast, would you like us to activate Constello-Jack or send assistance?
