Why couldn't all the worlds telescopes stair at the same point in the deep sky and combine all...?

Question

...the images to form a one very large gathering surface telescope?

Answer 1

It is called interferometry.

It is possible but difficult to achieve (technically).

All signals have to be coordinated to the level of individual "phase"  (synchronized to an accuracy better than the period).

The wavelength of light is around 500 nm.  This means a frequency of around 500 THz (Tera hertz -- 500x10^12 Hz = 500 million million cycles per second).

The synchronization must be to a level of accuracy of 2x10^-15 s = 0.000000000000002 second (this is the "period" of green light, roughly)

This is done with pairs of telescopes that are "hard-wired" together (the light path is physically set so that both beams arrive together at the interferometer).

In radio astronomy (where this has been done for a long time), the wavelengths are much longer so that the requirement for synchronization are not as tight.  It is even possible to do this after the fact, using recordings that have very accurate "time tags".

Answer 2

Yes, it's called interferometry. And it's only just now becoming possible with optical telescopes.

Radio astronomers have been doing it for years.

BTW: Hubble Deep Field was an image from a single instrument, and had nothing to do with interferometry. And astronomers do talk about telescopes staring at targets.

Answer 3

Because the world ain't flat and telescopes don't "stair".

A stair is what you walk up and down on between floors of a building. They don't STARE either.

Answer 4

The Hubble ultra deep field image did a pretty good job of this. Many of the worlds telescopes are busy studying other things, plus I think you'de have a hard time just agreeing on what image to look at.

Answer 5

All that many will only give U an improvement  up to about 100 .After it will take another 100 to give just a 3 dB improvement and then the next 3dB would require to double that size ...