how can they say they have spotted an object half way across the universe when the universe is infinite?

Answer 1

They mean that the galaxy that they found is halfway to the edge of the "visible universe". The visible universe is about 13.7 billion light years in radius. The small galaxy that they found was something like 7 billion years away. This is about half the distance to the edge.

Although it's a bit weird to say that it is halfway across the universe. Since we are right in the middle of the visible universe, we are halfway across it.

Answer 2

It has not been determined, yet, that the Universe is infinite. We only know what we can measure and to measure it, we must be able to see it. Using the Hubble Space Telescope, astrophysicists have found billions of galaxies about 18 billion light years out. We are probably not in the center of the Universe, so we can't say that the Universe is finite, either.

My guess, based on the Big-Bang Theory, is that matter makes up the Universe and the Universe is expanding into what could be an infinite void. It's more than a day-trip out to find out, so pack a really big lunch.

Answer 3

Who said that the universe is infinite? Surely not the people who know how to measure something halfway across.

;-)

Answer 4

The universe is theoretically infinite, but for all we know we really ARE seeing halfway across the universe...

But nonetheless, it's just a stupid phrase :)

Answer 5

There is a theoretical limit to haw far we can 'see' into the Universe, and it's about 15 billion light years. There isn't anything to see prior to the 'Big Bang' so there is no light that has been travelling any longer than that time.

Doug

Answer 6

Because 'halfway' shouldn't be taken literally.