PBS
JWST Discovered The Farthest Star Ever Seen!
To understand where we came from—how earth, the solar system, the galaxy became what they are today—we need to understand the beginning of time. For example, how did the first galaxies pull themselves together from the dark...
PBS
What If Gravity is Not Quantum?
The holy grail of theoretical physics is to come up with a quantum theory of gravity. But after a century of trying we really have no idea how close we are, or it it's even possible. But we shouldn't feel bad because it turns out that...
PBS
Does Antimatter Create Anti-Gravity?
From hoverboards to flying cars to cloud cities, anti-gravity is a staple of science fiction and our dream of a less Earth-bound future. But in the real universe gravity appears to be a purely attractive force. Feels like its main MO is...
PBS
Can We Test Quantum Gravity?
New ReviewIf 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. They seem to require absurd...
PBS
What If The Universe Did Not Start With The Big Bang?
Here’s the story we like to tell about the beginning of the universe. 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...
PBS
How Many Black Holes Are In The Solar System?
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,...
PBS
Does Timescapes Disprove Dark Energy?
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....
PBS
How Astrophysics Can Literally Save the World
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...
PBS
Earth Had Rings (and Might Regain Them)
Planet Earth is the jewel of the solar system—the shimmery blue oceans, the verdant green forests, the wispy whimsical cloud formations. Saturn is the only competitor for most gorgeous planet with that giant ring system. Hmm… what if we...
PBS
Is Gravity Random Not Quantum?
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...
PBS
Was the Gravitational Wave Background Finally Discovered?
A few weeks ago a large team of gravitational wave astronomers announced something pretty wild. The moderately confident detection of pervasive ripples in the fabric of space time that presumably fills the cosmos, detected by watching...
MinutePhysics
Gravitational Waves Explained Using Stick Figures
This video is about gravitational waves in the weak field limit as discovered by the LIGO collaboration, explained by parallels to electromagnetic radiation, sound waves, water waves, etc. I want to see Cat LIGO ASAP!
PBS
How Black Holes Spin Space Time
If there’s one thing cooler than a black hole it’s a rotating black hole. Why? Because we can use them as futuristic power generators, galactic-scale bombs, and portals to other universes. Black holes are self-sustaining holes in the...
PBS
How Does Gravity Warp the Flow of Time?
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...
PBS
How The Penrose Singularity Theorem Predicts The End of Space Time
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...
PBS
What Happens After the Universe Ends?
Conformal Cyclic Cosmology is a story of the origin and the end of our universe from great mathematical physicist Sir Roger Penrose. It’s goes like this: the infinitely far future, when the universe has expanded exponentially to to an...
PBS
How Does Gravity Affect Light?
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...
PBS
Is ACTION The Most Fundamental Property in Physics?
It’s about time we discussed an obscure concept in physics that may be more fundamental than energy and entropy and perhaps time itself. That’s right - the time has come for Action.
PBS
How Luminiferous Aether Led to Relativity
As the 19th century came to a close, physicists were feeling pretty satisfied with the state of their science. The great edifice of physical theory seemed complete. A few minor experiments remained to verify everything. Little did those...
PBS
The Strange Universe of Gravitational Lensing
Niels Bohr, a Danish Physicist said “Everything we call real is made of things that cannot be regarded .” Is what we see perceived to be real or is it an illusion? In the world of our mind’s eye, light travels in a straight line. In...
PBS
Loop Quantum Gravity Explained
The holy grail of physics is to connect our understanding of the tiny scales of atoms and subatomic particles with that of the vast scales of planets, galaxies, and the entire universe. To connect quantum physics with Einstein’s general...
PBS
Does Time Cause Gravity?
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 flow...
PBS
The Evolution of the Modern Milky Way Galaxy
When we scan the heavens with giant telescopes we see galactic cannibalism everywhere. We see moments that appear frozen on the human timescale, but are really snapshots of the incredibly violent process of galaxy formation. This is how...
PBS
Why String Theory is Right
Some see string theory as the one great hope for a theory of everything - that it will unite quantum mechanics and gravity and so unify all of physics into one glorious theory.