Lawrence M. Krauss Quotes

When a star explodes, it briefly (over the course of about a month or so) shines in visible light with a brightness of 10 billion stars. Happily for us, stars don't explode that often, about once per hundred years per galaxy. But we are lucky that they do, because if they didn't, we wouldn't be here. One of the most poetic facts I know about the universe is that essentially every atom in your body was once inside a star that exploded. Moreover, atoms in your left hand probably came from a different star than did those in your right. We are all, literally, star children, and our bodies made of stardust.

Metaphysical speculation is independent of the physical validity of the Big Bang itself and is irrelevant to our understanding of it.

If you have nothing in quantum mechanics, you will always have something.

Curiosity-driven research may seem self-indulgent and far from the immediate public good. However, essentially all of our current quality of life, for people living in the first world, has arisen from the fruits of such research, including all the electric power that drives almost every device we use.

I've told you two things : First, you're much more insignificant than you ever imagined and second, the future is miserable. But you should be happy, because we may live in a universe without purpose but that means the purpose in our lives is the purpose we create. And we should consider ourselves fortunate to have evolved in this place in the middle of nowhere and evolved a consciousness so we can understand the universe from the earliest moments of the big bang to the far future. So instead of being depressed, you should enjoy your brief moment in the sun.

In our normal experience, it is time and space that are absolute, while speed is a relative thing: how fast something is perceived to be moving depends upon how fast you yourself are moving. But as one approaches light speed, it is speed that becomes an absolute quantity, and therefore space and time must become relative!

Now, almost one hundred years later, it is difficult to fully appreciate how much our picture of the universe has changed in the span of a single human lifetime.

As far as the scientific community in 1917 was concerned, the universe was static and eternal, and consisted of a one single galaxy, our Milky Way, surrounded by vast, infinite, dark, and empty space.

This is, after all, what you would guess by looking up at the night sky with your eyes, or with a small telescope, and at the time there was little reason to suspect otherwise.

The Universe must be flat. Why? Well, there is two reasons. There's the 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... talk 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 of matter. What's so beautiful about a universe with total energy zero? Well, only such a universe can begin from nothing, and that is remarkable because the laws of physics allow a 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 the Universe isn't flat we're worried, because then you've got energy at... the very beginning of Time.

In 5 billion years, the expansion of the universe will have progressed to the point where all other galaxies will have receded beyond detection. Indeed, they will be receding faster than the speed of light, so detection will be impossible. Future civilizations will discover science and all its laws, and never know about other galaxies or the cosmic background radiation. They will inevitably come to the wrong conclusion about the universe......We live in a special time, the only time, where we can observationally verify that we live in a special time.

one of the dumbest academic decisions ever made (and that is a tough list to top), Maxwell was unceremoniously laid off.

"A physicist, an engineer and a psychologist are called in as consultants to a dairy farm whose production has been below par. Each is given time to inspect the details of the operation before making a report.
The first to be called is the engineer, who states: "The size of the stalls for the cattle should be decreased. Efficiency could be improved if the cows were more closely packed, with a net allotment of 275 cubic feet per cow. Also, the diameter of the milking tubes should be increased by 4 percent to allow for a greater average flow rate during the milking periods."
The next to report is the psychologist, who proposes:
"The inside of the barn should be painted green. This is a more mellow color than brown and should help induce greater milk flow. Also, more trees should be planted in the fields to add diversity to the scenery for the cattle during grazing, to reduce boredom."
Finally, the physicist is called upon. He asks for a blackboard and then draws a circle. He begins: "Assume the cow is a sphere....

But what we've discovered is that, in fact... the total energy of the universe could be zero, which is a first clue that maybe it could come from nothing. ...In physics, ...once you include gravity, there's positive energy and negative energy, and our universe appears as if its total energy could be precisely zero, which is the first hint that maybe it could come from nothing. That, and the great discovery... that namely empty space, you take a region of space, get rid of all the particles and all the radiation ...so there's nothing there. That empty space weighs something, and we don't understand why.

But common sense is deceptive precisely because it is based on common experience.

The one thing that I want every single child to have experienced at some point in their life, as part of their education, is to have some idea they hold to be true, and at the very basis of their being, proved to be wrong.

Because that opens your mind to the realization that the world is different than you thought it would be, and you have to begin to open your mind to the possibilities of existence.

And opening your mind frees you, it doesn't constrain you. It makes the world more wonderful, more exciting, and more worth living in.

One of the most poetic facts I know about the universe is that essentially every atom in your body was once inside a star that exploded. Moreover, the atoms in your left hand probably came from a different star than did those in your right. We are all, literally, star children, and our bodies made of stardust.