“We just don’t know,” says Andrew Pontzen, a cosmologist at University College London. “There is no evidence for an edge to the universe, but there is an edge to what we can see.” We can only see objects in space if the light from those objects has had enough time to reach us. For Andromeda that time is 2.5 million years, but for increasingly more distant galaxies that travel time also increases. There are galaxies so far away that light hasn’t managed to make it here yet. This marks out the edge of our visible universe – the part of it we are able to see – but not the end of the universe itself. “It’s rather like how you can’t see over the horizon but the Earth doesn’t end there,” Pontzen says. In theory, each passing day should bring with it new light allowing us to push our cosmic horizon outwards. Yet it doesn’t quite work like that.
この記事は All About Space の Issue 104 版に掲載されています。
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この記事は All About Space の Issue 104 版に掲載されています。
7 日間の Magzter GOLD 無料トライアルを開始して、何千もの厳選されたプレミアム ストーリー、8,500 以上の雑誌や新聞にアクセスしてください。
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