Category Archives: Astronomy

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime While recent news about the Chinese Long March 5 Rocket made a lot of people very nervous because a 22-ton rocket was going to fall out of the sky, this sort of thing happens all the time. Boosters, dead satellites, and sometimes […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime It’s fair to say that black holes may be the scariest objects in the universe. Happily for us, the nearest is probably many light-years away. Unless of course, Planck relics are a thing – in which case they might be literally everywhere. […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Quantum mechanics forbids us from measuring the universe beyond a certain level of precision. But that doesn’t stop us from trying. And in some cases succeeding, by squeezing the Heisenberg uncertainty principle to its breaking point. Check out the Space Time Merch […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime There’s one rule on Space Time: It’s never Aliens. But every rule has an exception and this rule is no exception because: It’s never aliens, until it is. So is it aliens yet? And on today’s Space Time we’re going to examine […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime That Einstein guy was a real bummer for our hopes of a star-hopping, science-fiction-y future. His whole “nothing travels faster than light” rule seems to ensure that exploration of even the local part of our galaxy will be an excruciating slow. But […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime​ It may be that for every star in the universe there are billions of microscopic black holes streaming through the solar system, the planet, even our bodies every second. Sounds horrible – but hey, at least we’d have explained dark matter. Want […]

Support Us On https://www.patreon.com/pbsspacetime When a theory makes a prediction that disagrees with an experimental test, sometimes it means we should throw the theory away. But what if that theory has otherwise produced the most successful predictions in all of physics? Then, that little glitch may be pointing the way to layers of physics deeper […]

To learn more, check out: https://www.TheGreatCoursesPlus.com/spacetimepbs Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime “A moving arrow is at rest.” This is obviously a nonsensical contradiction. But Zeno, a Greek philosopher famous for his metaphysical trolling, devised a paradox whose conclusion is just this. Here’s how it goes: if you […]

https://www.patreon.com/pbsspacetime I have good news and bad news. Bad news first: two years ago we reported on the Crisis in Cosmology. Since then, it’s only gotten worse. And actually, the good news is also that the crisis in cosmology has actually gotten worse, which means we may be onto something! The most exciting thing for […]

https://www.patreon.com/pbsspacetime​ We know that gravity exerts its pull on light, and we have an explanation for why. Actually, we have multiple explanations that all predict the same thing. And at first glance, these explanations seem to describe completely different causes. So what is the true connection between light and gravity, or is truth, in fact, […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime​ We know that gravity must cause clocks to run slow on the basis of logical consistency. And we know that gravity DOES cause clocks to run slow based on many brilliant experiments. But I never explained WHY or HOW gravity causes the […]

Check Out Overview on PBS Terra: https://youtu.be/Pgj95EntvW0 Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime​ It was pretty impressive when LIGO detected gravitational waves from colliding black holes. Well we’ve just taken that to the next level with a galaxy-spanning gravitational wave detector that may have detected a foundational element […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime There’s a deep connection between gravity and time – gravitational fields seem to slow the pace of time in what we call gravitational time dilation. And today we’ll explore the origin of this effect. And ultimately, we’ll use what we learn to […]

Check out Weathered on PBS Terra: https://youtu.be/q1hj9RCWuH0 Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime By the time you’ve read this, a billion billion dark matter particles may have streamed through your body like ghosts. The particle or particles of the dark sector make up the vast majority of the […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Today we’re going to delve into a couple of the most famous paradoxes of special relativity: the Twin Paradox, The Ladder Paradox (aka the Barn-Pole Paradox), and a paradox suggested by our very own viewers, which asks whether a spaceship could wrap […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Since the very beginning of quantum mechanics, a debate has raged about how to interpret its bizarre predictions. And at the heart and origin of that debate is the quantum jump or quantum leap – the seemingly miraculous and instantaneous transitions of […]

Check Out Weathered on PBS Terra Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime We often think of quantum mechanics as only affecting only the smallest scales of reality, with classical reality taking over at some intermediate level. But in his 1944 book, What is Life?, the quantum physicist Erwin […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Good news everyone: it looks like the universe is going to end with a series of catastrophic explosions. The very, very long story short is that the universe ends in heat death, as it approaches maximum entropy, and its eternal exponential expansion […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime The laws of physics don’t specify an arrow of time – they don’t distinguish the past from the future. The equations we use to describe how things evolve forward in time also perfectly describe their evolution backwards in time. So the brain […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Ever wish you could travel backward in time and do things differently? Good news: the laws of physics seem to say traveling backward in time is the same as traveling forwards. So why do we seem to be stuck in this inexorable […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Physicists have a long history of sticking our noses where they don’t belong – and one of our favorite places to step beyond our expertise is the question of consciousness and free will. Sometimes our musings are insightful, sometimes incoherent, and usually […]

Our universe seems pretty complicated. We have a weird zoo of elementary particles, which interact through very different fundamental forces. But some extremely subtle clues in nature have led us to believe that the forces of nature were once unified, ruled by a single, grand symmetry. But how does one force separate into multiple? And […]

The Nobel prize in physics this year went to black holes. Generally speaking. Specifically, it was shared by the astronomers who revealed to us the Milky Way’s central black hole and by Roger Penrose, who proved that in general relativity, every black hole contains a place of infinite gravity – a singularity. But the true […]

Einstein’s special theory of relativity combines space and time into one dynamic, unified entity – spacetime. But if time is connected to space, could the universe be anything but deterministic? And does that mean that the future is predestined? Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the […]

Is all that exists just whatever exists right now? Is the past erased and the future a void yet to be filled? Well, the answer lies in between the past and the future – in the elusive, ever-moving eye-blink that we call the present. Sign Up on Patreon to get access to the Space Time […]

Check Out Overview of PBS Terra: https://bit.ly/33otrUn If you rank the most habitable places in our solar system Venus lands pretty low, with surface temperatures hot enough to melt lead and sulphuric acid rain. And yet it may have just jumped to the front of the pack. In fact, we may have detected the signature […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the Space Time Merch Store https://pbsspacetime.com/ Sign up for the mailing list to get episode notifications and hear special announcements! https://mailchi.mp/1a6eb8f2717d/space… Your extensive posting history on r/birdswitharms and your old fanfiction-heavy livejournal are both one tiny math problem away from […]

Take the PBS Digital Studios annual survey: http://to.pbs.org/2020survey One of the most bizarre proposals for life not as we know it doesn’t even use atoms. It proposes that fundamental kinks and defects in the fabric of the universe – cosmic strings beaded with magnetic monopoles – may evolve into complex structures, and even life, within […]

The great physicist Hermann Weyl once said: “My work always tried to unite the true with the beautiful, but when I had to choose one or the other, I usually chose the beautiful.” But is this actually good advice for doing physics? Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime […]

Thank you to Target for supporting PBS. You can learn more at https://target.com/community Share your story today: https://to.pbs.org/3izZeXh Pin-pricks in the celestial sphere, through which shines the light of heaven? Or gods and heroes looking down from their constellations? Or lights kindled above middle earth by Varda Elbereth and brightened with the dew of the […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the Space Time Merch Store https://pbsspacetime.com/ Sign up for the mailing list to get episode notifications and hear special announcements! https://mailchi.mp/1a6eb8f2717d/space… If you wanna make an omelet you gotta break a few eggs. And by omelet I mean a theory […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the Space Time Merch Store https://pbsspacetime.com/ Sign up for the mailing list to get episode notifications and hear special announcements! https://mailchi.mp/1a6eb8f2717d/space… Our galaxy is full of dysfunctional stellar relationships. With more than half of all stars existing in binary orbits, […]

The second in our two event series about Theories of Everything! Watch the first one: https://www.youtube.com/watch?v=_izocEgArtQ Please subscribe to Brian Keating’s YouTube Channel to watch one-on-one interviews with the guest speakers and more: https://www.youtube.com/DrBrianKeating Existing Theories of Everything have not yet produced experimental evidence that solves the fundamental challenges facing physics. That lack of progress […]

Join two epic livestreams about Theories of Everything! Sign up for prizes, a download link to the videos, and more at http://www.pbsspacetime.com/events. Please subscribe to Brian Keating’s YouTube Channel to watch one-on-one interviews with the guest speakers and more: https://www.youtube.com/DrBrianKeating July 28 @ 4pm Eastern (8pm UTC) – What is a Theory of Everything? Moderated […]

Join two epic livestreams about Theories of Everything! Sign up for prizes, a download link to the videos, and more at http://www.pbsspacetime.com/events. Check out our co-moderator Brian Keating’s incredible channel at: https://www.youtube.com/DrBrianKeating July 28 @ 4pm Eastern – What is a Theory of Everything? Moderated by Matt O’Dowd & Brian Keating ​Featuring Max Tegmark, Stephon […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the Space Time Merch Store https://pbsspacetime.com/ Sign up for the mailing list to get episode notifications and hear special announcements! https://mailchi.mp/1a6eb8f2717d/spacetime When we detected the very first gravitational wave, a new window was opened to the mysteries of the universe. […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the Space Time Merch Store https://pbsspacetime.com/ Sign up for the mailing list to get episode notifications and hear special announcements! https://mailchi.mp/1a6eb8f2717d/space… The most precious substance in our universe is not gold, nor oil. It’s not even printer ink. It’s antimatter. […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the Space Time Merch Store https://pbsspacetime.com/ Sign up for the mailing list to get episode notifications and hear special announcements! https://mailchi.mp/1a6eb8f2717d/spacetime Black hole singularities break physics – fortunately, the universe seems to conspire to protect itself from their causality-destroying madness. […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the Space Time Merch Store https://pbsspacetime.com/ Sign up for the mailing list to get episode notifications and hear special announcements! https://mailchi.mp/1a6eb8f2717d/space… Black holes are about the worst subjects for direct study in the universe. But at this stage, it’s all […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the Space Time Merch Store https://pbsspacetime.com/ Sign up for the mailing list to get episode notifications and hear special announcements! https://mailchi.mp/1a6eb8f2717d/spacetime Conformal Cyclic Cosmology is a story of the origin and the end of our universe from great mathematical physicist […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the Space Time Merch Store https://pbsspacetime.com/ Sign up for the mailing list to get episode notifications and hear special announcements! https://mailchi.mp/1a6eb8f2717d/spacetime With the global pandemic of Covid 19 still encompassing the word, we are generally not big fans of viruses […]

It’s been 120 years since Henry Cavendish measured the gravitational constant with a pair of lead balls suspended by a wire. The fundamental nature of gravity still eludes our best minds – but those secrets may be revealed by turning back to the Cavendish experiment. That steampunk contraption may even reveal the existence of extra […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspaceSign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the Space Time Merch Store https://pbsspacetime.com/ Sign up for the mailing list to get episode notifications and hear special announcements! https://mailchi.mp/1a6eb8f2717d/spacetime This is a map of the multiverse. […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the Space Time Merch Store https://pbsspacetime.com/ Sign up for the mailing list to get episode notifications and hear special announcements! https://mailchi.mp/1a6eb8f2717d/spacetime As the 19th century came to a close, physicists were feeling pretty satisfied with the state of their science. […]

Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime Check out the Space Time Merch Store https://pbsspacetime.com/ Sign up for the mailing list to get episode notifications and hear special announcements! https://mailchi.mp/1a6eb8f2717d/spacetime The universe is precisely 13.8 billion year old – or so our best scientific methods tell us. But how […]