If we could take a giant step to the furthest point of the universe and look out, what would we see?
Herman D鈥橦ondt
Sydney, Australia
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The simplest answer is that nobody knows.
Right now we can see to a distance of about 46 billion light years, the edge of the so-called visible universe. However, most scientists will agree that, if we went there, the universe would look pretty much the same as it does from here.
Just how far the universe really stretches isn鈥檛 known, but there is agreement that it is larger than what we can observe. As for jumping that far away, it needs to be realised that points at that distance, while still visible, are moving away from us at speeds greater than light. In other words, we would need magic to get there.
There may not even be a 鈥渇urthest point鈥�, as it is possible the universe is positively curved, which means it bends in on itself.
This is similar to the surface of Earth. No matter how far you travel, there is never any edge, you can always keep walking further.
However, at least with our best measurements, it looks very likely the universe is flat, with a small chance it has a negative curvature. In both cases, the universe may literally stretch to infinity.
Then there are the various flavours of the multiverse, the idea that there may be additional universes beyond ours. There have even been suggestions that we may be able to spot points of contact with other universes by observing signatures of this in the cosmic microwave background radiation. That would mean we can see 鈥渙utside鈥� our universe without even moving to the 鈥渆dge鈥�.
Dennis Doren
Lake Mills, Wisconsin, US
You would see nothing at all. If the concept of 鈥渇urthest point鈥� has any meaning, then that concept necessarily means there can be no light coming from 鈥渂eyond鈥�, and hence literally nothing to see.
Eric Kvaalen
Les Essarts-le-Roi, France
There may not be a furthest point of the universe.
There is the furthest point that we can see, but that is simply the most distant location from which light has had time to travel to us (or a bit less far, because in the very early cosmos light couldn鈥檛 propagate far due to absorption). If we were to go to that part of the cosmos and look beyond, I think we would see more of the same. But God only knows.
Mike Follows
Sutton Coldfield, West Midlands, UK
In detail, the universe would look different from what we see, but it is isotropic and homogeneous. This means, on a large scale, it looks the same in all directions and viewed this way at two random places in the universe, it would look indistinguishable.
The universe has no centre and no edge and it can be imagined like the surface of a M枚bius strip, formed like a strip of paper with a 180 degree twist put in it before joining the ends. Tracing a course on this surface would have no beginning or end.
Bruce Cumming
Sydney, Australia
After taking that giant step, we would see a giant leg stretching back to where we stepped off from.
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