I’m learning about cosmology and I’m struggling understanding the size and shape of the universe.(adsbygoogle = window.adsbygoogle || []).push({});

If the universe has a radius of approximately ~46 billion light years, then the maximum distance between any two points in the universe today is ~92 light years. It follows then, that if I am standing at Point A and Point B is ~46 billion light years away, while Point C is ~46 billion light years in the exact opposite direction of Point B, then the distance of B to C would be ~92 billion light years. However, if my friend is standing at Point C, then they would measure Point A at ~46 billion light years away and Point D in the opposite direction of Point A at ~46 billion light years away. Thus, the distance from A to D would be ~138 light years, making it longer than diameter/length of the universe. How can the distance of A to D, exceed the size of the universe?

Am I making the mistake of treating particle horizon as the radius of the universe?

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# Measuring the size the universe

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