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kottke.org posts about Kurzgesagt

Travelling to The Most Extreme Place in The Universe

posted by Jason Kottke   Mar 02, 2023

In a 1959 talk entitled There’s Plenty of Room at the Bottom, physicist Richard Feynman casually invented nanotechnology, inviting the audience and then the world to imagine exploring and making use of the “inner space” of the micro and nano realms. In this video from Kurzgesagt, thye imagine how things would seem if you could somehow shrink yourself down to the size of a grain of sand or a molecule or even smaller, sort of a more educational (but still fun) Ant-Man and the Wasp: Quantumania.

You are the size of a grain of sand just 2 mm high, standing on a blade of grass that seems as tall as an eight storey building to you. A square meter of lawn is now a dense metropolitan area, with 100,000 blades, or two Manhattans worth of grass towers. From your new tiny perspective, the park that you could quickly stroll through before, is now the size of France. Crossing it would take at least a week. Human-sized humans loom over you, 4 times taller than the Empire state building, their steps falling from horizon to horizon.

A bee the size of a helicopter lands near you, making the ground shake, as its hairy carapace vibrates with each wingbeat. You try to escape but are barely able to move because the air is so… gooey. Before you clicked the button air resistance was barely noticeable — but as you’re now a thousand times smaller, it is as if the air has become a thousand times denser. It feels like you are moving through honey.

Flying insects like bees use this to their advantage. Their wings are not made for gliding but like paddles that row through the air. Scaled up to human size, the bee would outrun a Concorde Jet — except it couldn’t even take off because it would be too heavy for its wings.

See also Meet the Nano Sapiens, Scaling Laws and the Speed of Animals, The Biology of B-Movie Monsters, and Powers of Ten.

Proteins and Life: How Do Dead Things Become Alive?

posted by Jason Kottke   Feb 15, 2023

DNA and RNA get all of the headlines, but it’s not difficult to argue that much of the glorious complexity and possibility of life is due to proteins. In the latest episode of Kurzgesagt, they explain the role of cellular proteins in creating life.

You are cells. Your muscles, organs, skin and hair. They are in your blood and in your bones.

Cells are biological robots. They don’t want anything, they don’t feel anything. They are never sad or happy. They just are, right here, right now. They are as conscious as a stone or a chair or a neutron star. Cells just follow their programming that has been evolving and changing for billions of years, molded by natural selection.

They are impossible machines and yet, here they are, driven entirely by the fundamental forces of the universe. The smallest unit of life, right at the border where physics becomes biology.

Sometimes, to get a truer understanding of how amazing something is, you need to hold your breath and dive in really deep. So, what are cells and how do they work?

As always, you can see a list of their sources and further reading for the video.

How to Change Your Life, One Tiny Step at a Time

posted by Jason Kottke   Jan 20, 2023

Here’s Kurzgesagt on the deceptively simple way we can make changes in our life: build new routines and turn them into habits.

If you are like most people, there is a gap between the person you are and the person you wish to be. There are little things you think you should do and big things you ought to achieve — from working out regularly, eating healthy, learning a language, working on your novel, reading more or simply actually doing your hobby instead of browsing Reddit.

But it can seem that to achieve your goals, you have to become a different person. Someone who is consistent, puts in more effort, has discipline and willpower. Maybe you have tried your hardest to be like that. And it worked! For a while. Until you find yourself slipping back into your old ways. In the end, you always seem to fail. And with every failed attempt, you become more and more frustrated and annoyed with yourself.

If you believe “success and hustle” internet, it is all your own fault: if you don’t succeed, you just didn’t want it enough and the failure is all you. But change is actually hard. But as with most things in life, understanding why makes things easier.

The Brain Eating Amoeba, the Most Overhyped Monster on Earth

posted by Jason Kottke   May 03, 2022

In retrospect, maybe today wasn’t such a good day to watch a video about how incredibly scary brain-eating amoebas are. But, as you might guess from the title, we don’t actually need to worry too much about them.

While the Naegleria fowleri is clearly extremely deadly and the infection truly horrible, there have only been a few hundred cases in the last few decades. You are way more likely to drown in a pool than to get infected.

A reminder that in our current media environment, calibrating personal risk can be challenging.

We Have the Tools to Fix the Climate. We Just Need to Use Them.

posted by Jason Kottke   Apr 06, 2022

A new video from Kurzgesagt is designed to provide a little hope that humans can figure a way out of the climate crisis, without being overly pollyannish.

And so for many the future looks grim and hopeless. Young people feel particularly anxious and depressed. Instead of looking ahead to a lifetime of opportunity they wonder if they will even have a future or if they should bring kids into this world. It’s an age of doom and hopelessness and giving up seems the only sensible thing to do.

But that’s not true. You are not doomed. Humanity is not doomed.

There’s been progress in the last decade, in terms of economics, technology, policy, and social mores. It’s not happening fast enough to limit warming to 1.5°C, but if progress continues, gains accumulate, people keep pushing, and politicians start to figure out where the momentum is heading, we can get things under control before there’s a global apocalypse.

Are There Lost Civilizations in Earth’s Past?

posted by Jason Kottke   Mar 02, 2022

The Earth is some 4.5 billion years old and the first life on Earth appeared 3.7 billion years ago (if not earlier). That’s a lot of time…so maybe it’s possible that a civilization existed at some point during that time and then vanished without a trace. In this video, Kurzgesagt explores the Silurian hypothesis.

When we think about alien civilizations we tend to look into the vastness of space, to far away planets. But there is another incredibly vast dimension that we might be giving too little thought to: time.

Could it be that over the last hundreds of millions of years, other civilizations existed on earth? Indigenous technological species that rose and died out? And that they or their artifacts are buried beneath our feet? What does science have to say about this and what are the implications for us?

See also Could an Industrial Prehuman Civilization Have Existed on Earth Before Ours? and Was There a Civilization on Earth Before Humans?.

The Dark Forest (Or, Why We Should Keep Still and Not Look for Aliens)

posted by Jason Kottke   Dec 15, 2021

Inspired by the second book in Liu Cixin’s excellent Three-Body Problem trilogy, Kurzgesagt made a video about the Dark Forest solution to the Fermi paradox.

Confronted with the seemingly empty universe, humanity faces a dilemma. We desperately want to know if we are alone in the Milky Way. We want to call out and reveal ourselves to anyone watching but that could be the last thing we ever do. Because maybe the universe is not empty. Maybe it’s full of civilizations but they are hiding from each other. Maybe the civilizations that attracted attention in the past were wiped away by invisible arrows. This is the Dark Forest solution to the Fermi paradox.

I have The Dark Forest on the Kindle, so I looked up how this is explained in the book (spoilers, obvs):

“The universe is a dark forest. Every civilization is an armed hunter stalking through the trees like a ghost, gently pushing aside branches that block the path and trying to tread without sound. Even breathing is done with care. The hunter has to be careful, because everywhere in the forest are stealthy hunters like him. If he finds other life-another hunter, an angel or a demon, a delicate infant or a tottering old man, a fairy or a demigod-there’s only one thing he can do: open fire and eliminate them. In this forest, hell is other people. An eternal threat that any life that exposes its own existence will be swiftly wiped out. This is the picture of cosmic civilization. It’s the explanation for the Fermi Paradox.”

Shi Qiang lit another cigarette, if only to have a bit of light.

“But in this dark forest, there’s a stupid child called humanity, who has built a bonfire and is standing beside it shouting, ‘Here I am! Here I am!’” Luo Ji said.

“Has anyone heard it?”

“That’s guaranteed. But those shouts alone can’t be used to determine the child’s location. Humanity has not yet transmitted information about the exact position of Earth and the Solar System into the universe. From the information that has been sent out, all that can be learned is the distance between Earth and Trisolaris, and their general heading in the Milky Way. The precise location of the two worlds is still a mystery. Since we’re located in the wilderness of the periphery of the galaxy, we’re a little safer.”

That’s the basic idea, but there’s more to it…you should watch the video or, even better, read the series — I’ve read the entire trilogy twice and this makes me want to read it again! (I loved the Drive Easter egg towards the end of the video. Well played.)

Reimagining Dinosaurs

posted by Jason Kottke   Oct 13, 2021

The fossil record has provided us with so much information about plants, animals, and organisms that lived hundreds, thousands, millions, and even billions of years ago. But we are actually only seeing evidence of a tiny fraction of the species that lived then and even for those we do know about, there’s often much we still don’t know. Traditionally, dinosaurs have been depicted as drab and often terrible lizards but recent finds of soft tissues (skin, feathers, etc.) and an increased sense of imagination based on our current vibrant biodiversity has people thinking differently about how they looked and behaved.

This Virus Shouldn’t Exist (But it Does)

posted by Jason Kottke   Sep 08, 2021

In one of their most popular videos in awhile, kottke.org favorite Kurzgesagt tells us about something I’d never heard of before: giruses. These giant viruses have only been discovered within the last 20 years and are so large and contain so much genetic material that maybe they are actually alive?

Hidden in the microverse all around you, there is a merciless war being fought by the true rulers of this planet, microorganisms. Amoebae, protists, bacteria, archaea and fungi compete for resources and space. And then there are the strange horrors that are viruses, hunting everyone else. Not even being alive, they are the tiniest, most abundant and deadliest beings on earth, killing trillions every day. Not interested in resources, only in living things to take over. Or so we thought.

It turns out that there are giant viruses that blur the line between life and death — and other viruses hunting them.

How the Human Immune System Works

posted by Jason Kottke   Aug 10, 2021

In the first part of a multi-video series on how the human immune system works, Kurzgesagt describes how the system’s first lines of defense work when your body is invaded by microorganisms.

The human immune system is the most complex biological system we know, after the human brain, and yet, most of us never learn how it works. Or what it is. Your immune System consists of hundreds of tiny and two large organs, it has its own transport network spread throughout your body. Every day it makes hundreds of billions of fresh cells.

It is not some sort of abstract entity. Your immune system is YOU. Your biology protecting you from the billions of microorganisms that want to consume you and from your own perverted cells that turn into cancer.

Kurzgesagt founder Philipp Dettmer is publishing a companion book to the series, Immune: A Journey Into the Mysterious System That Keeps You Alive; it’s out in late September.

I have read a lot about the human immune system over the past 18 months, but this video was still helpful in understanding how it all fits together. For more information, consult their extensive list of sources or watch their earlier video on what the SARS-CoV-2 virus does to a human body.

Size Comparison: The Largest Black Hole in the Universe

posted by Jason Kottke   Aug 04, 2021

Black holes are the largest single objects in the universe, many times larger than even the biggest stars, and have no upper limit to their size. But practically, how big is the biggest, heaviest black hole in the universe? (A: More massive than the entire Milky Way.)

The largest things in the universe are black holes. In contrast to things like planets or stars they have no physical size limit, and can literally grow endlessly. Although in reality specific things need to happen to create different kinds of black holes, from really tiny ones to the largest single things in the universe. So how do black holes grow and how large is the largest of them all?

Videos about space are where Kurzgesagt really shines. I’ve seen all their videos about black holes and related objects, and I always pick up something I never knew whenever a new one comes out. This time around, it was quasistars and the surprisingly small mass of supermassive black holes located at galactic centers compared to the galaxies themselves.

A Minute by Minute Account of the Day the Dinosaurs Died

posted by Jason Kottke   Jun 15, 2021

Perhaps the most consequential day in the Earth’s recent history was when a massive asteroid struck the planet 66 million years ago. It resulted in earthquakes, tsunamis, fireballs raining from the sky, volcanoes, atmospheric heat shocks, wildfires, global winter, and the extinction of 75% of all species on Earth, including the dinosaurs. This video by Kurzgesagt leads us through what happened that day, minute by minute.

This video reminded me of Peter Brannen’s eye-popping description of this event from his book The Ends of the World:

“The meteorite itself was so massive that it didn’t notice any atmosphere whatsoever,” said Rebolledo. “It was traveling 20 to 40 kilometers per second, 10 kilometers — probably 14 kilometers — wide, pushing the atmosphere and building such incredible pressure that the ocean in front of it just went away.”

These numbers are precise without usefully conveying the scale of the calamity. What they mean is that a rock larger than Mount Everest hit planet Earth traveling twenty times faster than a bullet. This is so fast that it would have traversed the distance from the cruising altitude of a 747 to the ground in 0.3 seconds. The asteroid itself was so large that, even at the moment of impact, the top of it might have still towered more than a mile above the cruising altitude of a 747. In its nearly instantaneous descent, it compressed the air below it so violently that it briefly became several times hotter than the surface of the sun.

“The pressure of the atmosphere in front of the asteroid started excavating the crater before it even got there,” Rebolledo said. “Then when the meteorite touched ground zero, it was totally intact. It was so massive that the atmosphere didn’t even make a scratch on it.”

Unlike the typical Hollywood CGI depictions of asteroid impacts, where an extraterrestrial charcoal briquette gently smolders across the sky, in the Yucatan it would have been a pleasant day one second and the world was already over by the next. As the asteroid collided with the earth, in the sky above it where there should have been air, the rock had punched a hole of outer space vacuum in the atmosphere. As the heavens rushed in to close this hole, enormous volumes of earth were expelled into orbit and beyond — all within a second or two of impact.

“So there’s probably little bits of dinosaur bone up on the moon,” I asked.

“Yeah, probably.”

Your Wild and Precious Life

posted by Jason Kottke   May 25, 2021

How do you know what to do with your life? The introduction to this new and uncharacteristically existential Kurzgesagt video is some real truth:

Wrapping your mind around your life is pretty hard, because you are up to your neck in it. It’s like trying to understand the ocean while learning how to swim. On most days you are busy just keeping your head above water. So it is not easy to figure out what to do with your life and how to spend your time. There are a million distractions. Your family, friends and romantic partners, boring work, and exciting projects. Video games to play and books to read. And then there is your couch that somebody needs to lie on. It’s easy to get lost.

Thinking about this stuff can be kind of a downer, as the writer of this video admits in a comment:

It’s so easy to get lost in your daily life: there are so many “urgent” and “annoying” things that you forget that actually every day is special, sort of. And even more so the days we have with friends and family. I know watching a video like this can hit pretty hard. But at least for me, the message it tries to convey does make me actually change my behavior. Reprioritize things. You know. Hope it had a similar effect for some of you.

See also Your Life in Weeks by Tim Urban.

The Final Border Humanity Will Never Cross

posted by Jason Kottke   May 11, 2021

This video focuses on one of my favorite astrophysics facts: 94% of the observable universe is permanently unreachable by humans. (Unless we discover faster-than-light travel, but that’s fantasy at this point.)

This expansion means that there is a cosmological horizon around us. Everything beyond it, is traveling faster, relative to us, than the speed of light. So everything that passes the horizon, is irretrievably out of reach forever and we will never be able to interact with it again. In a sense it’s like a black hole’s event horizon, but all around us. 94% of the galaxies we can see today have already passed it and are lost to us forever.

“Since you started watching this video, around 22 million stars have moved out of our reach forever.” And future generations, billions of years from now, won’t even be able to see any other galaxies or detect cosmic background radiation, making knowledge about the Big Bang impossible.

An Animated Primer on Black Holes

posted by Jason Kottke   Apr 28, 2021

You’re probably aware that black holes are weird. You can learn more about just how extremely odd they are by watching this animated primer on black holes by Kurzgesagt. The explanation about how long black holes live starting at ~9:30 is legitimately mindblowing — that hourglass metaphor especially.

Using Nuclear Energy to Stop Climate Change

posted by Jason Kottke   Apr 13, 2021

This new video from Kurzgesagt takes a look at the possible role of nuclear energy in helping to curb the effects of our climate emergency.

Do we need nuclear energy to stop climate change? More and more voices from science, environmental activists and the press have been saying so in recent years — but this comes as a shock to those who are fighting against nuclear energy and the problems that come with it. So who is right? Well — it is complicated.

Rebecca Tuhus-Dubrow wrote about climate change activists who are embracing nuclear energy for the New Yorker back in February.

In the course of years, Hoff grew increasingly comfortable at the plant. She switched roles, working in the control room and then as a procedure writer, and got to know the workforce — mostly older, avuncular men. She began to believe that nuclear power was a safe, potent source of clean energy with numerous advantages over other sources. For instance, nuclear reactors generate huge amounts of energy on a small footprint: Diablo Canyon, which accounts for roughly nine per cent of the electricity produced in California, occupies fewer than six hundred acres. It can generate energy at all hours and, unlike solar and wind power, does not depend on particular weather conditions to operate. Hoff was especially struck by the fact that nuclear-power generation does not emit carbon dioxide or the other air pollutants associated with fossil fuels. Eventually, she began to think that fears of nuclear energy were not just misguided but dangerous. Her job no longer seemed to be in tension with her environmentalist views. Instead, it felt like an expression of her deepest values.

For more reading on the topic, check out Kurzgesagt’s list of source materials used to make their video.

What If the Earth Turned to Gold?

posted by Jason Kottke   Mar 19, 2021

For their latest video, Kurzgesagt ventures into What If? territory with a hypothetical exploration of what would happen if King Midas turned the entire Earth into gold. This video did not go where I thought it was going to. Ten minutes of freefall? Shrinking mountains?

What If the Earth Got Knocked Out of the Solar System?

posted by Jason Kottke   Dec 03, 2020

The Milky Way galaxy may be home to billions or even trillions of rogue planets (planets that don’t orbit stars). In this video, Kurzgesagt considers how the Earth could go rogue (by following a nearby massive star away from the Sun) and what would happen to our oceans, atmosphere, and lives if it happened.

The first part of the video is pretty bleak — “as the days turn dark, the final winter of humanity would begin” — while the second part is hopeful: we’ll be able to predict our ejection thousands of years before it happens and may be able to prepare. In light of the world’s response to the pandemic and climate change, it would certainly be interesting to see if human civilization could get it together to save itself from a cold death in outer space. I have no doubt that scientist could accurately diagnose the problem and supply solutions, but the politics would be a total mess.

Is It Too Late To Stop Climate Change?

posted by Jason Kottke   Sep 29, 2020

For Kurzgesagt’s latest video, they explore the challenges the world faces in attempting to get the rate of climate change under control before it’s too late and how to get there.

Climate change is just too much. There is never any good news. Only graphs that get more and more red and angry. Almost every year breaks some horrible record, from the harshest heat waves to the most rapid glacier melt. It’s endless and relentless.

We have known for decades that rapid climate change is being caused by the release of greenhouse gases. But instead of reducing them, in 2019 the world was emitting 50% more CO2 than in the year 2000. And emissions are still rising. Why is that? Why is it so hard to just stop emitting these gases?

According to the video, global population growth and economic growth will be working against us over the next few decades and that increasing our energy efficiency and lowering emissions from energy sources are the main ways in which we will be able to slow things down. It’s worth noting that on the wizard vs. prophet continuum, this video is firmly in the wizard camp. That’s not wrong or bad; it’s just that other people have different ideas about how to combat climate change.

The Delightful New “Universe in a Nutshell” App

posted by Jason Kottke   Sep 22, 2020

The breadth of scale of measurable objects in the universe — our distance from the most distant objects we can observe (billions of light years away) to particles measured in something called a yoctometer (1×10-24 meters) — is staggering to think about. That’s where the Universe in a Nutshell app comes in. Developed by Kurzgesagt & Wait But Why (both kottke.org favorites), you can use the app to quickly and easily zoom in and out through objects at all the scales of the universe, like quarks, DNA, cells, earthworms, Europe, Jupiter, the black hole at the center of our galaxy, the Crab Nebula, galaxies, and galaxy superclusters.

Universe In A Nutshell

Universe In A Nutshell

You can tap on any object you encounter to learn more about it, like an interactive Powers of Ten. I spent 20 minutes just now playing around and it’s really fun. You can download the app for $2.99 from the App Store or on Google Play.

To mark the release, Kurzgesagt made a video comparing the sizes of stars:

And Wait But Why’s Tim Urban wrote a post about the scales of objects: The Big and the Small.

The Dynamic Treetop Kingdoms of the Weaver Ants

posted by Jason Kottke   Sep 01, 2020

In their third video of their ant trilogy (see also The World War of the Ants and The Billion Ant Mega Colony and the Biggest War on Earth), Kurzgesagt goes up into the treetops to tell us about the weaver ants.

Deep in tropical jungles lie floating kingdoms ruled by beautiful and deadly masters: They are sort of the high elves of the ant kingdoms: Talented architects that create castles and city states. But they are also fierce and expansionist warriors and their kingdoms are ensnared in a never ending war for survival. Oecophylla weaver ants.

The nests that weaver ants build out of leaves and silk from larve (that the ants use as “tiny cute glue guns”) are incredible. Since Kurzgesagt is animated, I went looking for some actual footage of weaver ants doing their thing. Here’s a clip from BBC Earth:

I found this video via The Kid Should See This, who explains that a mango orchard in Thailand uses the ants to keep pests away without using chemical pesticides:

In this mango orchard in Northern Thailand, weaver ants are nurtured so they can thrive and protect the harvest. The ants hunt the pests that would eat the mangoes, eliminating any need to use harmful chemical pesticides. The farmer creates strategic highways of red string to connect the weaver ants to new trees, expanding where they forage.

You can also watch this documentary on Australian weaver ants and this video from AntsCanada (whose videos always have amazing narration) to learn more about weaver ants.

What Is Intelligence?

posted by Jason Kottke   Jul 14, 2020

How is it that I am sitting here writing this right now and you are sitting there reading this at some later point which seems like now to you? These behaviors are the result of a series of interconnected processes that have evolved over billions of years that we collective call “intelligence”.

In this video, Kurzgesagt takes a crack at explaining the simple view of intelligence as “a mechanism to solve problems” that involves several aspects: information, memory, learning, knowledge, creativity, the use of physical tools, the ability to plan for the future, and culture. As usual, their extensive list of sources provides more details and opportunities for further exploration.

Who Is Responsible For Climate Change?

posted by Jason Kottke   Jun 23, 2020

In their newest video, Kurzgesagt explores the question of responsibility around climate change: which countries are most responsible for carbon emissions and for fixing the damage they’ve caused. As always, their source material is worth a look.

An Explanation of How Coronavirus Damages Your Body

posted by Jason Kottke   Mar 19, 2020

This morning Kurzgesagt released their video about COVID-19 that they’ve been working on for a week, and it is excellent, particularly the first part where they explain exactly what the SARS-CoV-2 virus does to a human body and why it can be so dangerous. I hadn’t heard that described before, especially in such relatively simple terms.

The virus has not caused too much damage yet, but corona is now going to release a real beast on you: your own immune system. The immune system, while there to protect you, can actually be pretty dangerous to yourself and needs tight regulation. And as immune cells pour into the lungs to fight the virus, corona infects some of them and creates confusion. Cells have neither ears nor eyes — they communicate mostly via tiny information proteins called cytokines — nearly every important immune reaction is controlled by them. Corona causes infected immune cells to overreact and yell bloody murder. In a sense, it puts the immune system into a fighting frenzy and sends way more soldiers than it should, wasting its resources and causing damage.

Kurzgesagt always provides a list of scientific sources used to produce their videos, and the one for this video is particularly extensive and they are going to keep it updated.

Update: For more information on the coronavirus itself, SARS-CoV-2, see Ed Yong’s piece in the Atlantic and How the Coronavirus Could Take Over Your Body (Before You Ever Feel It) from New York magazine.

Why Don’t Blue Whales Get Cancer?

posted by Jason Kottke   Mar 02, 2020

Even though larger animals like elephants and blue whales have up to 100 billion more cells than humans in their bodies — and therefore many more chances for harmful mutations to develop — they are much more immune to cancer. This is called Peto’s paradox the subject of Kurzgesagt’s latest video. Scientists aren’t sure why this happens, but one hypothesis is that in order to have grown so large, the evolutionary process that resulted in these animals provided built-in defenses against cancer that other animals didn’t need. Further reading on the topic is available here.

How to Make a Kurzgesagt Video (in Just 1200 Hours)

posted by Jason Kottke   Feb 19, 2020

In this video, Kurzgesagt shares their process of making their unique brand of explainer video.

They estimate it takes about 1200 hours of time for each video. I love Kurzgesagt’s videos and am happy to support them on Patreon.

Milk - White Poison or Healthy Drink?

posted by Jason Kottke   Jan 27, 2020

When humans domesticated barnyard animals (goats, sheep, cows) starting around 10,000 years ago, they stumbled upon one of the most amazing schemes of all time. Instead of relying on the few human-edible plants scattered around for their energy needs, humans could raise animals that ate the plain old grass that was growing anywhere & everywhere and converted it into ultra-nutritious and energy-rich superfoods like meat and milk. Land back then was plentiful and the scheme allowed humans to produce many more calories with less effort using an energy source (the grass) that they didn’t otherwise have much use for.

But how does milk fit into the picture these days? It’s still a superfood that’s very beneficial to people in many parts of the world where adequate nutrition isn’t available from other sources. But as Kurzgesagt explains in this video, our land use has changed in the past 10,000 years, and cow’s milk production is a major source of carbon emissions (when compared to foods w/ similar nutritional value):

And don’t forget to check out the list of sources they used in producing the video.

How Do You Move a Star? Stellar Engines!

posted by Jason Kottke   Dec 30, 2019

In this episode of Kurzgesagt, they’re talking about building engines powerful enough to move entire stars, dragging their solar systems along with them.

At some point we could encounter a star going supernova. Or a massive object passing by and showering earth with asteroids.

If something like this were to happen we would likely know thousands, if not millions of years in advance. But we still couldn’t do much about it.

Unless… we move our whole solar system out of the way.

Kurzgesagt did something interesting for this one. Instead of relying on already available sources, they commissioned physicist Matthew Caplan to write a paper about a novel stellar engine design, a massive contraption that could theoretically move the solar system a distance of 50 light years over 1 million years.

Stellar engines, megastructures used to control the motion of a star system, may be constructible by technologically advanced civilizations and used to avoid dangerous astrophysical events or transport a star system into proximity with another for colonization.

Is this the first scientific paper published in a peer-reviewed journal commissioned by a YouTube channel? The 2019 media landscape is wild.

Spinning Tethers for Space Propulsion

posted by Jason Kottke   Nov 19, 2019

I love rocket launches. They are loud, carry cool things into space, and last a surprisingly long time considering how fast the rocket is already traveling when it clears the tower. But I think we’re going to look back on this era of space travel and marvel that launches & rockets were our only means of getting things into and around space (planetary gravity assists notwithstanding). We’re already moving in that direction; the initial tests of a space sail inspired by Carl Sagan have been promising. Another space propulsion idea is to use spinning space tethers to whip smaller, slower space vehicles from relatively low altitudes to higher orbits or even to the Moon, Mars, or beyond. This video from Kurzgesagt explains how these tethers work and what we could do with them.

I believe Neal Stephenson wrote about space tethers (or something very similar) in Seveneves.

Neutron Stars and Nuclear Pasta. Yummy!

posted by Jason Kottke   Nov 13, 2019

The latest video from Kurzgesagt is a short primer on neutron stars, the densest large objects in the universe.

The mind-boggling density of neutron stars is their most well-known attribute: the mass of all living humans would fit into a volume the size of a sugar cube at the same density. But I learned about a couple of new things that I’d like to highlight. The first is nuclear pasta, which might be the strongest material in the universe.

Astrophysicists have theorized that as a neutron star settles into its new configuration, densely packed neutrons are pushed and pulled in different ways, resulting in formation of various shapes below the surface. Many of the theorized shapes take on the names of pasta, because of the similarities. Some have been named gnocchi, for example, others spaghetti or lasagna.

Simulations have demonstrated that nuclear pasta might be some 10 billion times stronger than steel.

The second thing deals with neutron star mergers. When two neutron stars merge, they explode in a shower of matter that’s flung across space. Recent research suggests that many of the heavy elements present in the universe could be formed in these mergers.

But how elements heavier than iron, such as gold and uranium, were created has long been uncertain. Previous research suggested a key clue: For atoms to grow to massive sizes, they needed to quickly absorb neutrons. Such rapid neutron capture, known as the “r-process” for short, only happens in nature in extreme environments where atoms are bombarded by large numbers of neutrons.

If this pans out, it means that the Earth’s platinum, uranium, lead, and tin may have originated in exploding neutron stars. Neat!