In which John Green teaches you about population. So, how many people can reasonably live on the Earth? Thomas Malthus got it totally wrong in the 19th century, but for some reason, he keeps coming up when we talk about population. In...

Spacetime on its smallest scales is a seething ocean of black holes and wormholes flickering into and out of existence—or so many physicists think has to be the case. But why should we take this spacetime foam seriously if we’ve never...

The Inca Empire used bundles of knotted string called khipu to store and convey information. But how do you read a bunch of strings? And was this a unique form of writing... or knot?<b<br/>r/>

Hosted by: Stefan Chin

In the desert of Peru, hundreds of enormous ancient drawings are carved into the dirt. They're called the Nazca Lines, and archeologists are still arguing over what they mean. <b<br/>r/>

Hosted by: Niba @NotesbyNiba (she/her)

In his 2000 bestseller "The Tipping Point," Malcolm Gladwell told the story of why crime fell in New York City in the 1990s. Now, 25 years later, he's back with a confession and a mea culpa: "I was wrong," he says. He shares how his...

Evolution vs Natural Selection

For years, geologists have been searching for an explanation for two strange blobs of Earth's mantle that are denser than the rest. It turns out, they may not be original parts of Earth at all.

SciShow Space takes you to the moon! Learn about the competing theories about how Earth's closest neighbor formed.

In 2010, NASA announced the discovery of a never-before-seen galactic object: two gigantic gaseous bubbles, each emanating an impressive 25,000 light years from the center of the Milky Way. Astronomers were perplexed: what created these...

If a photon leaves the train station shortly after the Big Bang ...

In his essay “The Unreasonable Effectiveness of Mathematics”, the physicist Eugine Wigner said that “the enormous usefulness of mathematics in the natural sciences is something bordering on the mysterious”. This statement was inspired by...

There’s this idea that beauty is a powerful guide to truth in the mathematics of physical theory. String theory is certainly beautiful in the eyes of many physicists. Beautiful enough to pursue even if it’s wrong?
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Hermann...

Life exists in our universe. There we go - one hopefully uncontroversial statement. Therefore our universe is capable of producing and supporting life. How am I going? Two for two? Let’s try for three: therefore there are countless...

In standard use, the S-matrix can be calculated if you understand the forces in the interaction region - for example, in the nucleus of an atom. But what if you don’t know those internal interaction forces? Heisenberg sought a way to...

The people behind the greatest leaps in physics - Einstein, Newton, Heisenberg, all had the uncanny ability to see the fundamentals - see the deepest, underlying facts about the world, and from simple statements about reality they built...

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...

The holographic principle emerged from many subtle clues – clues discovered over decades of theoretical exploration of the universe. Over the past several months on Space Time, we’ve seen those close clues, and we’ve built a the...

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.

Entropy is surely one of the most perplexing concepts in physics. It’s variously described as a measure of a system’s disorder - or as the amount of useful work that you can get from it - or as the information hidden by the system....

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?

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...

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...

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...

Sometimes our mathematical hacks point to strange new aspects of reality. For example Max Planck used a quantization trick to figure out the spectrum of light emitted by hot objects. The quantization part of his math trick was meant to...