How do we know the universe is 93 billion light-years across?

That’s because over time, space has been expanding, so the distant objects that gave off that light 13.8 billion years ago have since moved even farther away from us. Multiply times 2, and you get 93 billion light years, the diameter of the observable universe.

How many light-years in diameter is the universe?

93 billion light-years
The radius of the observable universe is therefore estimated to be about 46.5 billion light-years and its diameter about 28.5 gigaparsecs (93 billion light-years, or 8.8×1026 metres or 2.89×1027 feet), which equals 880 yottametres.

Why is the observable universe 46 billion light-years?

The universe is about 13.8 billion years old, so any light we see has to have been travelling for 13.8 billion years or less – we call this the ‘observable universe’. However, the distance to the edge of the observable universe is about 46 billion light years because the universe is expanding all of the time.

How can we see more than 13.8 billion light years?

Therefore, the longer we wait, the farther we can see, as light travels in a straight line at the speed of light. So after 13.8 billion years, you’d expect to be able to see back almost 13.8 billion light years, subtracting only how long it took stars and galaxies to form after the Big Bang.

How many light years can we see?

46 billion light years
In actuality, we can see for 46 billion light years in all directions, for a total diameter of 92 billion light years.

How old is the universe?

You might think, in a Universe limited by the speed of light, that would be 13.8 billion light years: the age of the Universe multiplied by the speed of light. But 13.8 billion light years is far too small to be the right answer.

How big is the universe in light years?

Based on what we can observe, the universe appears to be almost 28 billion light-years in diameter. However, it is far larger than that. However, it is far larger than that. Skip to main content

Is 92 billion light years big enough?

And so 92 billion light years might seem like a large number for a 13.8 billion year old Universe, but it’s the right number for the Universe we have today, full of matter, radiation, dark energy, and obeying the laws of General Relativity.

How far back in space can we see the universe?

Therefore, the longer we wait, the farther we can see, as light travels in a straight line at the speed of light. So after 13.8 billion years, you’d expect to be able to see back almost 13.8 billion light years, subtracting only how long it took stars and galaxies to form after the Big Bang.