PBS Space Time

If you track the motion of individual stars in the ultra-dense star cluster at the very center of the Milky Way you’ll see that they swing in sharp orbits around some vast but invisible mass—that’s the Sagittarius A* supermassive black hole. These are perilous orbits, and sometimes a star wanders just a little too close to that lurking monster, leading to a tidal disruption event.

Space is expanding evenly everywhere, but if you rewind that expansion you find that all of space was once compacted in an infinitesimal point of infinite density—the singularity at the beginning of time. The expansion of the universe from this point is called the Big Bang. We like to tell this story because it's the correct conclusion from the description of an expanding universe that followed

We know that the universe is getting bigger. And we know that the speed that the universe is getting bigger is also getting bigger. The standard assumption is that the acceleration rate is itself constant, which will result in ultimate heat death. But a recent survey of primordial sound waves frozen into the way galaxies are sprinkled through the universe reveals that this fate is now in question.

Neutron stars aren't dark matter--we figured that out a while ago. But new research is telling us that they may be dark matter factories. They may produce the exotic axion, one of the most popular dark matter candidates.

Imagine a world where humanity masters every planetary resource available to it—our first step on the famous Kardeshev scale of technological advancement. How distant is that step? Will we even become a true Type-1 civilization, and how can we get there?

There are cosmic events so powerful that they leave permanent marks on the fabric of the universe itself - a permanent mark etched in the fabric of the universe. They’re akin to gravitational tsunamis, and we’re on the verge of being able to detect them.

Every good nerd knows that E=mc^2. Every great nerd knows that, really, E^2=m^2c^4+p^2c^2 Want to know what that even means? Sure, I’ll tell you, but today I’d like to invite you to an even higher level of nerdom with extra bits to Einstein’s famous equation that will make even the greatest nerds quiver in their … space time merch if they turn out to be real.

The James Webb Space Telescope has found a quasar that simultaneously breaks a century-old theoretical limit and may explain the conundrum of gigantic black holes in the early universe.

What does an electron really look like? I mean, if we zoom in all the way. Is it a sizeless speck of charge? Is it a multidimensional vortex of quantum strangeness? Is it the boundary of a tiny universe with universe-electrons of its own? Let’s find out.

What do you get if you take something that’s infinitely massive and combining with something else that’s negative infinitely massive? You get a single electron, at least that’s what it looks like in our most precise way of describing the quantum world.

Dark matter has eluded us for many decades. Even our most advanced particle colliders and sophisticated underground detectors have come up short. But it may be that we can finally solve this mystery with a much simpler experiment, involving a ray of light, a good clock, and the planet Mars.

The universe is expanding and that expansion is accelerating under the power of dark energy and eventually all matter and energy will be dispersed over such unthinkable distances that nothing can stop space from blowing up infinitely. Unless of course cosmologists blundered and dark energy doesn't even exist. Then it's back to the drawing board.

Quantum physics predicts the universe should’ve collapsed right after the Big Bang, because all particles were immeasurably heavier. Yet it obviously didn’t. Observations confirm this puzzle, and experiments at the Large Hadron Collider still haven’t explained why. At its core is the lightness of the Higgs boson, part of the “hierarchy problem,” which many call physics’ biggest unsolved mystery.

One of the final challenges is deciding on the physical vessel to contain our mini artificial stars--and we have some pretty sci-fi options that are nearly ready to go.

How did the universe begin? How can something come from nothing? One way to “solve” this most difficult of philosophical conundrums is to avoid it altogether. Maybe the universe didn’t begin. Maybe the Big Bang was just one in an endless cycle.

Did you know that many of us have up to 4% neanderthal DNA? And that 100% of your DNA may come from outer space? No joke. The biochemistry that defined the coding system of your DNA may have happened off-world, and perhaps even long before Earth existed.

Giant space rocks are definitely going to hit the Earth again. We actually do know how to deflect them, but only if we find them and correctly assess their risk. But the solar system is a chaotic place. How is it even possible to tell if a space rock will one day collide with the Earth?