Lawrence M. Krauss

American particle physicist and cosmologist

Lawrence Maxwell Krauss (born May 27, 1954) is an American theoretical physicist and cosmologist who is professor of physics, Foundation Professor of the School of Earth and Space Exploration, and director of the Origins Project at the Arizona State University. He is the author of several bestselling books, including The Physics of Star Trek.

Lawrence M. Krauss


  • My area of research is something that in all fairness has no practical usability whatsoever and the thing is I'm often asked to apologize for that. It is interesting to me that people ask 'what's the point of doing that if it's not useful?' But they never ask that, or do they very rarely ask that about art or literature or music. Those things are not gonna produce a better toaster.
  • There is a maxim about the universe which I always tell my students: That which is not explicitly forbidden is guaranteed to occur.
  • Now, since the time of Newton there had been a debate about whether light was a wave---that is, a traveling disturbance in some background medium---or a particle, which travels regardless of the presence of a background medium. The observation of Maxwell that electromagnetic waves must exist and that their speed was identical to that of light ended the debate: light was an electromagnetic wave.
  • Richard Feynman used to go up to people all the time and he'd say "You won't believe what happened to me today... you won't believe what happened to me" and people would say "What?" and he'd say "Absolutely nothing". Because we humans believe that everything that happens to us is special and significant. And that — and Carl Sagan wrote beautifully about that in The Demon-Haunted World — that is much of the source of religion. Everything that happens is unusual and I expect that the likelihood that Richard and I ever would've met. If you think about all the variables: the probability that we were in the same place at the same time, ate breakfast the same. Whatever. It's zero. Every event that happens has small probability... but it happens and then when it happens; if it's weird, if you dream one million nights and it's nonsense but one night you dream that your friend is gonna break his leg and the next day he breaks his arm... *sound of revelation* So the real thing that physics tell us about the universe is that it's big, rare events happen all the time — including life — and that doesn't mean it's special.
  • Science simply forces us to revise what is sensible to accommodate the universe, rather than vice versa.
  • The amazing thing is that every atom in your body came from a star that exploded. And, the atoms in your left hand probably came from a different star than your right hand. It really is the most poetic thing I know about physics: You are all stardust. You couldn’t be here if stars hadn’t exploded, because the elements - the carbon, nitrogen, oxygen, iron, all the things that matter for evolution - weren’t created at the beginning of time. They were created in the nuclear furnaces of stars, and the only way they could get into your body is if those stars were kind enough to explode. So, forget Jesus. The stars died so that you could be here today.
  • The Universe must be flat. Why? Well, there is two reasons. There's one I normally say which is: it's the only mathematically beautiful universe. Which is true. But there's another reason. I don't usually say it talked about but I'll talk about here. It turns out that in a flat universe the total energy of the universe is precisely zero. Because gravity can have negative energy. So the negative energy of gravity balances out the positive energy and matter. What so beautiful about a universe with total energy 0? Well, only such a universe can begin from nothing. And that is remarkable because the laws of physics allow the universe to begin from nothing: you don't need a Deity. You have nothing: zero total energy, and quantum fluctuations can produce a universe. So if Universe isn't flat we're worried because then you've got energy at the very beginning of Time.
  • What's going to happen in the far future? Remember a hundred years ago we thought we lived into static eternal Universe. What will the future bring? The amazing thing is for civilizations that live in a far future: what will they see? Well, the Universe is accelerating. That means all the distant galaxies are getting carried away from us and, eventually, they'll move away from us faster than the speed of light, it's allowed in General relativity. The longer we wait - the less we will see. In a hundred billion years any observers evolving on stars around us, and there will be stars just like our Sun in 100 billion years. Any observers and civilizations are evolving around those stars will see nothing except for our Galaxy. Which is exactly the picture they had in 1915. All evidence of the Hubble expansion will disappear. Why? Because we won't see other galaxies moving apart from us. So they will have no evidence in fact of Big Bang. They won't see the Hubble expansion. They won't even know about dark energy and I won't go into that. They won't know about the cosmic microwave background - it will disappear too. It will redshift away, and it turns out for fancy reasons: there is a plasma in our Galaxy and when the Universe is 50 times its present age the microwave background will be able to propagate in our Galaxy. All evidence of the Big Bang will have disappeared and .And those scientists will discover quantum mechanics, discover relativity, discover evolution, discover all the basic principles of science that we understand today, use the best observations they can do with the best telescopes they will build and they will derive a picture of the Universe which is completely wrong. They will derive a picture of the Universe as being one Galaxy surrounded by empty space that's static and eternal. Falsifiable science will produce the wrong answer. In fact, I want to end with the good news: We live in a very special time - the only time, we can observationally verify that we live in a very special time.
  • The other thing people don't realise about science which differentiates it from religion is that, the most exciting thing about being a scientist is not knowing and being wrong. Because that means there is a lot left to learn.
  • It is a shame when nonsense can substitute for fact with impunity.
    • In a panel discussion on Real Time with Bill Maher, 02/08/2013

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