PBS Space Time

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.

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

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.

If we discover how to connect quantum mechanics with general relativity we’ll pretty much win physics. There are multiple theories that claim to do this, but it’s notoriously difficult to test them. Let’s talk about some ideas for quantum gravity experiments that can be done on a non-galaxy-sized lab bench, and in some cases already have been done.

The holy grail of theoretical physics is to find the long-sought theory of quantum gravity. But what if this theory is as mythical as the grail of legend? What if gravity isn’t weirdly quantum at all, but rather … just a bit messy? Or random? So says the postquantum gravity hypothesis of Jonathan Oppenheim.

Scientists have been slowly extending the periodic table one element at a time, pushing to higher and higher masses, and have discovered some incredibly useful materials along the way. But the elements at the current end of the table are so unstable that they decay almost as soon as they’re created in our particle accelerators. Astronomers have found a cosmic phenomenon that may populate table.

It turns out there is a way to make a coloured black hole—as long as by colour you mean quantum chromodynamic charge.

Nobel laureate Roger Penrose is widely held to be one of the most brilliant living physicists for his wide-ranging work from black holes to cosmology. And then there’s his idea about how consciousness is caused by quantum processes. Most scientists have dismissed this as a cute eccentricity—a guy like Roger gets to have at least one crazy theory without being demoted from the smartypants club.

Warp drives may or may not be possible, but if they are then could a distant alien civilization’s warp fields produce gravitational waves that we could see here on Earth? According to a recent study.. Actually maybe, at least eventually. And we now know just what to look for and how to look for it.

All particles belong to two large groups: fermions like protons and electrons make everything we consider "matter", while bosons like photons and gluons transmit the fundamental forces. And that about covers the universe: matter moving through space and time under the action of forces. But what if we could create particles in between these two possibilities. Physics says these neither matter nor f

Solar activity is still increasing in a sunspot cycle that is proving way more intense than scientists predicted. Just how much stronger is it going to get?

So you’ve decided to jump into a black hole. Good news: as long as the black hole is big enough you can sail through the event horizon without harm.