Would it be possible to lay a fiber optic cable over long distances and use it to transfer information- for example, as a sort of telescope?
No, for a number of reasons.
- The distance varies somewhat, which would make keeping it straight difficult
- There is a small loss in light with fiber optics, making it somewhat redundant. If you put repeaters in place (Which is done on Earth, and would really be required), they would need to be powered. Solar power isn't really an option so far out there.
- Orbital parameters would make it difficult.
- The amount of high quality fiber required would be enormous.
- I suspect the temperature in the void of space would cause undesirable effects on the cable.
Far better would be to simply use an open aired system, as there would be no loss. Fiber optics is really only helpful with cable that can bend, for such a straight distance, a large telescope on each end would work better, and far cheaper.
That is absurd just by the required mass, a fibre cable can be made 1000 microns thin, and that is a total volume of 600000 cube kilometres for the whole length. A fibre cable works by sending information as light, and that can be done just as well through empty space.
Many reasons. But here is a fun one.
Volume of a cylinder is V=pi r^2 h. So Pi times the radius squared, times the height.
So lets say 10 mm optical fibre that is 4 light years high.
I get Pi * 0.01m^2 * 3.784e+16=11.9 trillion CUBIC meters of optical fibre.
Let us just say, that is an impractical amount of matter. Volume of the Earth is: 1,097,509,500,000,000,000,000 or about 1.1 septillion cubic meters? Ok, so that is like 10 to the negative 8 percent of the planets volume.
I cannot think of any large impractical volumes to compare that too. But almost 12 trillion cubic meters is a LOT of material.