PBS
What Caused the Big Bang?
Every astronomy textbook tells us that soon after the Big Bang, there was a period of exponentially accelerating expansion called cosmic inflation. In a tiny fraction of a second, inflationary expansion multiplied the size of the...
PBS
How Black Holes Kill Galaxies
Black holes are really only dangerous if you get too close. Ha, who am I kidding. It turns out they may be responsible for ending star formation across the entire universe. When we first realized that black holes could have masses of...
PBS
How To Become an Astrophysicist + Challenge Question!
Do you want to major in Astrophysics? Are you thinking about becoming (or ever just wondered how one becomes) an Astrophysicists? Do you want to know Matt O’Dowd’s origin story? Then buckle up and enjoy the ride and try your astrophysics...
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
Electroweak Theory and the Origin of the Fundamental Forces
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...
PBS
Could We Terraform Mars?
We already have the technology to bring humans safely to Mars and set up small settlements - or at least could do within a generation. But those settlements will need to be cocooned - shielded against the deadly cold, intense radiation,...
PBS
Are Cosmic Strings Cracks in the Universe?
Reality has cracks in it. Universe-spanning filaments of ancient Big Bang energy, formed from topological defects in the quantum fields, aka cosmic strings. They have subatomic thickness but prodigious mass and they lash through space at...
PBS
How Far Beyond Earth Could Humanity Spread?
We humans have always been explorers. The great civilizations that have arisen across the world are owed to our restless ancestors. These days, there’s not much of Earth left to explore. But if we look up, there’s a whole universe out...
PBS
Did Time Start at the Big Bang?
Our universe started with the big bang. But only for the right definition of “our universe”. And of “started” for that matter. In fact, probably the Big Bang is nothing like what you were taught. A hundred years ago we discovered the...
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 Real Science of the EHT Black Hole
So, how do you take a picture of a black hole? The beast in question is the supermassive black hole in the center of this – the M87 elliptical galaxy. It has an estimated mass of several billion times that of the Sun, which gives it an...
PBS
The Cosmic Dark Ages
In astronomy we study things that are very far away. It’s a powerful challenge because even the brightest objects are almost impossibly faint when you view them from the other side of the universe. But there’s an up side. If the light...
PBS
First Detection of Light from Behind a Black Hole
How do you see the unseeable - how do you explore the inescapable? Our cleverest astronomers have figured out ways to catch light that skims the very edge of black holes. Let’s find out what they learned. A few weeks ago a story made the...
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
What If Dark Matter Is Just Black Holes?
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.
PBS
The Alchemy of Neutron Star Collisions
Carl Sagan’s famous words: “We are star stuff” refers to a mind-blowing idea – that most atomic nuclei in our bodies were created in the nuclear furnace and the explosive deaths of stars that lived in the ancient universe. In recent...
PBS
Why Quantum Computing Requires Quantum Cryptography
Quantum computing is cool, but you know what would be extra awesome - a quantum internet. In fact if we want the first we’ll need the latter. And the first step to the quantum internet is quantum cryptography.
Be Smart
The Golden Ratio: Is It Myth or Math?
The golden ratio. Some say it’s the most mythical number in the universe. Others say it underlies everything from nature’s patterns to beauty in art and design. But, like, what is it? And does the myth of the golden ratio hold up to its...
Be Smart
The Mathematical Code Hidden In Nature
How do zebras get their stripes? How do leopards get their spots? And how do giraffes get their giraffe-shaped thingies, whatever they are called? Would you believe the answer is… math? This is the story of a WWII wartime codebreaker and...
PBS
Is Pluto a Planet?
You know what a planet is, right? A big round thing that orbits a star. Uh, not so fast. The surprisingly vicious debate over the planetary status of Pluto has given us a fascinating glimpse into what a scientific definition really is....
PBS
What Happened Before the Big Bang?
We actually have a pretty good idea of what might have happened before the Big Bang. That is, as long as we define the Big Bang as the extremely hot, dense, rapidly expanding universe that is described by Einstein’s equations. That...
PBS
The Quantum Internet
When we finally have a quantum internet you’ll be able to simultaneously like and dislike this video. But we don’t. So I hope you like it. The world is widely regarded as being well and truly into the digital age, also called the...
PBS
No Dark Matter = Proof of Dark Matter?
We’ve been failing to detect dark matter for decades. Finally, the latest failure to detect dark matter may have actually proved its existence. One of these is true: either most of the matter in the universe is invisible and formed of...