ASTR 1020 NOTES

12/1/97

Ann: There will be a quiz on Friday. Look at problem 2 on page 665 in Chapter 30, and problems 3,4,5, and 8 on page 685 in Chapter 31.
Here are some famous cosmological quotes from our readings:
"Then I would have felt sorry for the dear lord". This was said by Einstein when he was asked how he would have felt had his general theory of relativity not been confirmed by Eddington's observation of the 1919 solar eclipse. He was saying that he was so sure his theory was correct, he hadn't even considered it being proved wrong.
"God does not play dice with the universe". This was Einstein's response to quantum mechanics, and specifically to the Heisenberg uncertainty principle. Einstein was not ready to accept that certain things in the universe were unpredictable.
"Not only does god play dice, but sometimes he throws them where they can't be seen". This was Stephen Hawking's response to the previous quote by Einstein. He meant that not only are certain things in the universe unpredictable, but when unpredictable events are occuring within the event horizon of a black hole, we can't observe them at all.
"Sorry Stephen, but this is absolute rubbish". This was the response of another Cambridge physicist to Stephen Hawking's presentation on Exploding Black Holes. At the time, Hawking himself was not so sure it wasn't absolute rubbish, but now the theory is widely accepted.
"My goal is simple, a complete understanding of the universe, why it is as it is, and why it exists at all". This quote is from Stephen Hawking and simply states his goal in theoretical physics.
"A universe like ours with galaxies and stars is actually quite unlikely. If one considers the possible constants and laws that could have emerged, the odds against a universe that would produce life like ours is immense". This quote is also from Stephen Hawking. He realized that if any one of a variety of things in the universe were only slightly different, we wouldn't be able to exist.
"THINGS ARE AS THEY ARE BECAUSE WE ARE". This is the central concept to the Anthropic Principle developed by Stephen Hawking. It very simply says that the reason the universe is as we observe it, is because if it were any different, we wouldn't be here to ask questions like, "Why is the universe as we observe it"?.

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