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Can We See the Beginning of the Universe?

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Just how far back in time can we see? Hear what Neil had to say when he set up his "Ask an Astrophysicist" booth in Central Park.

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6 Comments

How can our universe be a bubble? How can anyone imagine that bubble theory can be considered plausable? Does that mean infinity has limits. come on brainiacs.

As for me ,I like CJ AND CB,because it look more Professional .

Hello Richard, maybe I can answer your question. Imagine shining a very powerful flashlight directly ahead of you. If nothing blocks it, the light will follow the curve of spacetime all the way around the Universe and come from behind to the same point many billions of years later. Besides, Dr. Tyson said you could see the beginning of the Universe, not its end.

Sorry, Neil, but you are wrong. The best understanding right now is that from the very beginning the Universe absorbed its own light. After about 300,000 years, the Universe became cool enough for neutral atoms to form, which made the Universe transparent. The CMB dates from that event, not the original Big Bang. No telescope, no matter how big or well-designed, can see past that horizon, because there is nothing to see. You might argue that 300K years is insignificant compared to 14.7 Billion years, but they are not the same.

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How can you see the end of the universe if it is expanding at the speed of light? If it is expanding slower then where does the light go. We only see the light coming back? Right?

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Over 3,000 million years ago when life first began on the earth: 1. what were the temperature, pressure, %humidity, oxygen, nitrogen, carbon dioxide, etc. contents? 2. what were the magnetic field and gravitation force at the time?

Thank you.