Video: The biggest mystery in science

Recent scientific breakthroughs now allow us to detect gravitational waves from the Big Bang, the very beginning of space and time. Theoretical physicist Lawrence Krauss, a speaker at the World Economic Forum’s Annual Meeting of the New Champions 2014, explains how this might also allow us to test whether our own universe is just one of an infinite number.

Here are some quotes from the clip. You can watch the full video at the top of this page.

On what the universe is made of

The dominant stuff in the universe is stuff we can’t see – 90% is dark. It’s located around galaxies and between galaxies and it doesn’t shine. Our own Milky Way galaxy is dominated by this stuff. Because we’re not very creative, physicists call it dark matter. What’s particularly exciting is that we are reasonably certain that this stuff is not the same stuff as you and me. It’s made of a new type of elementary particle, something that we don’t see here on earth, and in fact was only created in the Big Bang.

On the energy in empty space

What we’ve also learned … is that throughout the whole universe, empty space – where there’s nothing – actually has energy. You get rid of all the particles and all the radiation and everything, so there’s nothing there, and it weighs something – and we don’t have the slightest understanding of why. It’s the biggest mystery in science, but 70% of the energy in the universe is made of nothing.

On looking back in time

If we try and look back far enough, we eventually get to a time when the universe is opaque and we are essentially seeing a wall, a wall of radiation coming to us from the moment the universe became transparent.

The problem is that while this is the nascent universe, it’s the universe when it was 380,000 years old. We can’t look back further than that if we want to use light. If we want to look back and see the Big Bang itself, or very close to the Big Bang, we have to use something else. And that something else, until recently – about four months ago – was just a gleam in the eye of theorists like me. In principle, however, we have now detected a signal from essentially the beginning of time.

On the idea of multiverses

Inflation happens and, boom, this is our universe. But there can be other regions where a universe is just being born now, and other regions where a universe may be dying. There could be literally an infinite number of universes.

On human life

Our existence could be a cosmic accident. Now, that sounds almost like design and I want to disabuse any of you from that notion. It’s not design. It’s just like Darwin. Darwin discovered that life isn’t designed. Bees can see the colour of flowers not because they were designed to do it, but because if they couldn’t, they wouldn’t be able to get the nectar and reproduce. So, if this is the case, we’re just here by some kind of cosmic natural selection. It would be amazing to find ourselves living in a universe in which we couldn’t live!

On the value of science

The real virtue of science, it seems to me, is cultural. It is ultimately answering the questions ‘why are we here’ and ‘where did we come from’. Those are the legacies of science.

Author: Lawrence Krauss, Theoretical Physicist, Professor and Director, the Origins Project, Arizona State University, USA

Image: The spiral galaxy M101 is pictured in this undated handout photo from NASA’s Chandra X-Ray Observatory on May 05, 2014. REUTERS/NASA/Handout via Reuters