PBS Space Time

Recent findings have brought us closer than we’ve ever been to confirming life beyond the Earth. As we wait for confirmation or otherwise, let’s think about what this will tell us about life everywhere, and also about our own imminent destruction.

To observe the quantum nature of gravity and of spacetime itself, we need a particle collider the size of the solar system. Or we could just physics smarter and build one on a lab bench. Here’s how.

One of the most important reasons we go to space is to know our own planet better. Today I'm going to tell you about an orbiting facility that literally watches Earth's biosphere breath and grow and die with incredible resolution. I'll talk about its profound existential and economic importance, and about why it's in danger of being lost.

In 1987, Steven Weinberg wrote a cute little paper entitled “Anthropic Bound on the Cosmological Constant”. Weinberg was foundational in establishing the standard model of particle physics, but his little 1987 paper, though more obscure, may tell us something about how the multiverse works, and can even be thought of as evidence for the existence of an enormous number of other universes.

The multiverse pops out of quite a few theories in physics, and has been proposed as a solution to certain vexing problems. But it’s also been argued that the very idea of a multiverse is just bad science. That it’s unfalsifiable and a dead-end to inquiry and as bad a violation of Occam’s razor as you could imagine. But the multiverse might also exist. Can something that exists be bad science?

The molecular basis of all life is mysteriously asymmetric, only using molecules on one side of what should be the equivalent mirrored pairs. The universe has a similar mirror asymmetry, and it may be that our very DNA inherited its twist from the underlying handedness of reality.

Did God have any choice in creating the world? So asked Albert Einstein. He was being poetic. What he really meant, was whether the universe could have been any other way. Could it have had different laws of physics, driven by different fundamental constants. Or is this one vast and complex universe the inevitable result of an inevitable and unique underlying principle, perhaps expressible as a su

Big things are made of smaller things, and those smaller things are made of smaller things still. That’s reductionism in a nutshell, and digging our way to the smallest layer has been one of the primary goals of physics for ever. But what if, just before we reach the bottom, we find out that reductionism fails?

The biggest news in cosmology in recent years is that the mysterious universe-accelerating entity we call dark energy may be fading away. The evidence for this is now strong enough that enormous effort is going into confirming this result. So what’s it going to take, and when are we going to know?

The biggest news in cosmology in recent years is that the mysterious universe-accelerating entity we call dark energy may be fading away. The evidence for this is now strong enough that enormous effort is going into confirming this result. So what’s it going to take, and when are we going to know?

Around 2 billion years ago, life had plateaued in complexity, ruined the atmosphere, and was on the verge of self-annihilation. But then something strange and potentially extremely lucky happened that enabled endless new evolutionary paths. The first eukaryote cell was born. This may also explain why there are no aliens.

The vacuum of space is a chaotic sea of quantum fluctuations. Some have said that this vacuum energy can be harvested to build our future starship engines. It can't. But it is technically possible to move real energy through the quantum vacuum without it passing through intervening space. Quantum energy teleportation may be as close as we get to transporter beams. But how close is that?