I think that the solar system is a very small part of the visible universe-- The farthest planets from the sun are at about 40 times the earth-sun distance, making the planetary system about 80AU or 8 billion miles across.
We think we know how far it is to the nearest star from the drift it makes in the sky as the earth goes around the sun. This drift (called parallax) is about a second (1.3) of
arc (1/3600 of a degree) when the earth moves
180 million miles. So if light travels in nearly straight lines, the nearest star is on the scale of 1.3*57*3600*1 AU = 268,000 AU = 25 trillion miles.
Scientists have studied stars for about 150
years, and have developed models which seem to
correspond to observations and using these models
we can predict the brightness of a star from its
spectrum. For stars in the Milky Way, this gives a
size for the galaxy of 90-100,000 parsec =
90,000*206,000 AU =1.7x1018
Finally, galaxies seem to bear out a
distance scale by their red shift (again measured spectroscopically) to indicate a visible universe of radius 14 billion light years. (A parsec is 3.26 light years). So that makes a visible universe with a radius of
900 trillion AU = 8x1022 miles.
Is it 'really'
this big? It is hard to say... the current
understanding of the physics involved (assuming
physics act there as it does here) seems to
indicate it. Indeed, most modern theories of
cosmology predict a 'real' universe (beyond what
we can see) that is millions of times larger yet.
I'd be very surprised if the solar system
distances were off by 0.0001%, surprised if the
nearest start distance were off by more than 2%,
not surprised if the galaxy size was off by 30%
and/or the universe size off by 50%. (The age
estimates and hence size of the visible universe
have changed by 40% in the last 20 years...and are
destined to change again as theories
As to the technology -- there is no
telling. 20 years ago, high energy physics needed
kilometers and Megawatts to make electrons at 1 GeV --nowadays, it can be done in a meter with a 10 Watt laser.