kottke.org posts about Kurzgesagt
In a recent video, Kurzgesagt explores what we know about the first human civilizations that formed some 12,000 years ago and how they led to the first cities and the invention of writing.
What we know about human history is only a fraction of the full story. Much of the rest is like dark matter, invisible to us. We can’t see it, and we can only see the effects of its presence. But thanks to new techniques for DNA sequencing, dating ancient detritus, mathematical models, and aerial and lidar archaeology, we are now able to get a faint idea of what this world might have looked and felt like.
One thing I really appreciate about Kurzgesagt is how each of their videos is accompanied by an extensive list of sources. For instance, I’m not sure I’d heard about the massive Lake Agassiz draining into the world’s oceans and disrupting the entire planet’s climate some 8200 years ago — and there are several primary sources listed for further reading. Here’s how Kurzgesagt tells it:
Around the year 3800 of the human era a sudden catastrophe happened in North America. The receding glaciers of the last ice age had created one of the largest lakes in Earth’s history, larger than the Caspian Sea today. It was held back by super massive ice sheets, which formed a gigantic dam.
Surprising no one, the dam melted and suddenly failed – the whole lake suddenly drained into the ocean. Global sea levels rose by 1-2 meters and the great conveyor belt that carried warm water northwards slowed down. Across the North Atlantic and Europe, and into the Near East, the climate turned colder and drier – in some regions by several degrees. Rain patterns shifted, summers grew longer and harsher, and a drought lasting well over a century parched the land.
And:
We know that during this time all over the world migration towards rivers and lakes sped up — bringing agriculture and technology with them. Some of the most consequential journeys led into the Nile Valley, where farming villages took root and slowly laid the ground for the rich civilization that would one day rise there.
From Wikipedia:
Lake Agassiz’s major drainage reorganization events were of such magnitudes that they significantly impacted climate, sea level, and possibly early human civilization. The lake’s enormous freshwater release into the Arctic Ocean has been postulated to have disrupted oceanic circulation and caused temporary cooling. The draining of 13,000 years ago may be the cause of the Younger Dryas stadial. Although disputed, the draining at 9,900–10,000 years ago may be the cause of the 8,200 yr climate event. A study by Turney and Brown links the 8,500-years-ago drainage to the expansion of agriculture from east to west across Europe; they suggest that this drainage may also account for various flood myths of ancient cultures, including the Biblical flood narrative.
Fascinating.
From Kurzgesagt, an hour-long animated music video that shows all of human history in an hour.
So here’s an experiment: every second, 2 generations or 50 years will pass. You are on a musical train ride looking out the window, as you watch our ancestors hunt large animals, tell stories around campfires, and slowly spread around the globe. Experience all of human history in one hour. You can have this in the background, study with it, or just enjoy the ride. From time to time, I’ll say a few words.
Stress in pre-modern times was a “biological superpower” that helped humans hunt for food and survive in harsh environments and situations. But our bodies can’t easily tell the difference between the stress of encountering a lion in the jungle and a worrying email from your boss.
Our world has changed so quickly and profoundly that our biology couldn’t keep up. Stress is still the same it was fifty thousand years ago: Sense a stressor. React immediately and with full force. Prioritize present moment survival, make sacrifices if necessary.
That works well when you have to jump out of the way of a car. But most stressors we encounter nowadays are abstract, acute and more numerous, often intangible, persist for much longer and usually don’t even require physical action. The tigers of the past are now angry emails, deadlines, online dating, rush hour traffic or doom scrolling the news and social media.
Note: Watching this video might actually stress you out, at least until you get to the solutions part of it.
Caveat: In places with a lot of economic insecurity & few social safety nets, like the US, the solutions presented by this video may not be super helpful. Slowing down, disconnecting, and taking time for mindfulness can be difficult under the best of conditions and nearly impossible if you’re working two jobs as a single mother to just make ends meet.
The latest video from Kurzgesagt imagines a scenario in which an advanced civilization called the Noxans can potentially survive the heat death of the universe.
With five hours of the full energy emitted by the Sun, we could power present day humanity for about 10 billion years.
So the Noxans harvest the last stars and build a gigantic complex of batteries around their home star. In principle, this energy could keep them alive for a few hundred trillion years, a long time but not even close to forever.
So now the hard part of the plan begins. The Noxans need to change the nature of life itself.
TIL I learned about gravastars (aka a gravitational vacuum star), theoretical objects related to black holes. Both are massive & dense, but instead of a singularity surrounded by an event horizon, gravastars are made up of dark energy surrounded by a extremely thin shell of exotic matter.
The shell of the gravastar is utterly dark and the coldest thing in the universe, only a billionth of a degree above absolute zero. If we look at it in deep infrared, even the cosmic microwave background glows bright in comparison. It is made from an entirely new, unique and extreme matter that is at the very limit of what is physically possible in nature and doesn’t have a name yet. Actually, the shell is so incredibly thin that atoms seem truly gigantic next to it.
The largest nuclear weapon ever tested was Tsar Bomba, a 50-megaton device detonated by the Soviet Union in 1961. That made it “3,300 times as powerful” as the bomb dropped on Hiroshima — an almost unimaginable level of potential destructive power. But Tsar Bomba wasn’t even close to being the biggest nuclear weapon ever conceived. Meet Project Sundial, courtesy of Edward Teller, one of the inventors of the hydrogen bomb, and his colleagues at Los Alamos:
Only a few months later, in July 1954, Teller made it clear he thought 15 megatons was child’s play. At a secret meeting of the General Advisory Committee of the Atomic Energy Commission, Teller broached, as he put it, “the possibility of much bigger bangs.” At his Livermore laboratory, he reported, they were working on two new weapon designs, dubbed Gnomon and Sundial. Gnomon would be 1,000 megatons and would be used like a “primary” to set off Sundial, which would be 10,000 megatons.
10,000 megatons. In the video above, Kurzgesagt speculates that exploding a bomb of that size would result in a fireball “up to 50 kilometers in diameter, larger than the visible horizon”, a magnitude 9 earthquake, a noise that can be heard around the entire Earth, a 400 km in which everything is “instantly set on fire – every tree, house, person”, and, eventually, the deaths of most of the Earth’s population.
Sundial would bring about an apocalyptic nuclear winter, where global temperatures suddenly drop by 10°C, most water sources would be contaminated and crops would fail everywhere. Most people in the world would die.
Fun fact: Edward Teller was one of Stanley Kubrick’s inspirations for the bomb-giddy character of Dr. Strangelove in the 1964 film of the same name.
The folks at Kurzgesagt have done a few time travel videos now, but this one is notable for its concise, intuitive explanation and visualization of our constant speed through spacetime (special relativity).
Everything in our universe moves at the speed of light through four dimensional spacetime. Your speed through spacetime is the sum of your separate speeds through time and space. It is impossible for you to stay still. Even if you are not moving through space dimensions, you are moving through the time dimension, blasting face first into the future.
You can slow down in the time dimension, by moving faster through the space dimensions but in total, you will always move at the speed of light through spacetime.
And you can “trade” moving through space for moving through time: “Move faster through space, go slower in time. Move slower through space, go faster in time.” Or as a commenter put it:
Your speed is constant. So the faster you move through the space dimensions, the slower you move through the time dimension, and vice versa.
Not sure this textual explanation makes as much sense as the visualization in the video, so maybe just watch that? Oh, and check out the sources for the video.
Humans are the first and, to our knowledge, only entities on Earth to develop general intelligence, which has allowed us to dominate and alter the planet in a way and at a speed that no other entity has managed. Now, some people are working towards building an artificial general intelligence. So what happens when humans are matched or even far outclassed by this new general intelligence?
Such an intelligence explosion might lead to a true superintelligent entity. We don’t know what such a being would look like, what its motives or goals would be, what would go on in its inner world. We could be as laughably stupid to a superintelligence as squirrels are to us. Unable to even comprehend its way of thinking.
This hypothetical scenario keeps many people up at night. Humanity is the only example we have of an animal becoming smarter than all others — and we have not been kind to what we perceive as less intelligent beings. AGI might be the last invention of humanity.
Kurzgesagt explores what happens when a virus or bacteria enters a human body and the essential role fever plays in helping your body fight off disease.
Fever feels bad. So we take medication to suppress it — but is this a good idea? It turns out fever is one of the oldest defenses against disease. What exactly is a fever, and how does it make your immune defense stronger? Should you take a pill to combat it?
We often mistake fever for the disease…it’s actually part of the cure. When my kids were young, I vividly remember our laissez-faire French pediatrician urging us not to give them medication to get rid of their fevers because that was the body fighting back and doing useful work — unless their temps got too high of course.
John Green recently teamed up with Kurzgesagt for a video on one of the world’s deadliest diseases: tuberculosis.
The white death has haunted humanity like no other disease following us for thousands, maybe millions of years. In the last 200 years it killed a billion people — way more than all wars and natural disasters combined. Even today it’s the infectious disease with the highest kill count.
The maddening bit is that tuberculosis is curable…it’s just that the cure is not equally distributed around the world.
4,000 people died of tuberculosis yesterday, and we simply don’t have to accept a world where so many of us still die of a disease we know how to cure. The White Death has been with us for millions of years. It is time to continue our journey without it.
Kurzgesagt attempts to answer the question (from the perspective of physics): Do we have free will? Here’s the deterministic perspective (from the show notes):
Now imagine that if right after the Big Bang, a supersmart supercomputer looked at every single particle in the universe and noted all their properties. Just by applying the deterministic laws of physics, it should be able to predict what all the particles in existence would be doing until the end of time.
But if you are made of particles and it’s technically possible to calculate what particles will do forever, then you never decided anything. Your past, present and future were already predetermined and decided at the Big Bang. This would mean there is a kind of fate and you are not free to decide anything.
You may feel like you make decisions, but you are on autopilot. The motions of the particles that make up your brain cells that made you watch this video were decided 14 billion years ago. You are just in the room when it happens. You are only witnessing how the universe inside you unfolds in real time.
And the other side of the argument (in favor of free will):
We know that we can reduce everything that exists to its basic particles and the laws that guide them. While this makes physics feel like the only scientific discipline that actually matters, there is a problem: You can’t explain everything in our universe only from particles.
One key fact about reality that we can’t explain by looking just at electrons and quantum stuff is emergence. Emergence is when many small things together create new fundamental traits that didn’t exist before.
Emergence occurs at all levels of reality, and reality seems to be organized in layers: atoms, molecules, cells, tissues, organs, you, society. Put many things in one layer together and they’ll create the next layer up. Every time they do, entirely new properties emerge.
Having thought about this for all of 20 minutes (or, practically all of my life), the emergence argument against determinism makes a lot of sense to me. Then again, James Gleick’s Chaos and Steven Johnson’s Emergence both made a huge impression on me when I read it more than 20 years ago.
Kurzgesagt is back with another video about black holes; it has the innocuous-seeming title of The Easiest Way To Build a Black Hole. But the main topic of the video is the speculation that universes (like ours!) might exist within black holes.
Black holes might create infinite universes while destroying time and space. Everything in existence could be black holes, all the way down. We might live inside a black hole that is inside a black hole, that is inside a black hole. But let’s start at the beginning and build a black hole out of air.
This one is a bit of a brain-bender. From the show notes:
The first part of the script is based on the empirical fact that, somewhat intriguingly, the observable universe seems to have the exact size and mass that would be required to make a black hole as big as the observable universe itself.
The second, completely independent proposal we explore is the idea that our Universe could be born from the singularity of a black hole, and that in turn the universe that contains that black hole could be born from a black hole itself. If so, universes in later generations of this process could be better fitted to produce an abundance of black holes, in a sort of “natural selection” towards efficient black hole production.
Is the universe finite or infinite? If finite, what shape is it and how does that shape influence its overall size and properties? If it’s infinite, what meaning of “expanding” can be applied to it? I don’t know if this video provides any satisfying answers, but even being able to ponder these questions is thrilling.
Infinity gets much weirder though. As you travel with your spaceship in a straight line, you find new galaxies, stars and planets, new wonders, new weird stuff, probably new aliens and new lifeforms stranger than you could ever imagine. But after a long time, you might find the most special thing in the universe: Yourself. An exact copy of you watching this video right now.
How can that be? Well, everything in existence is made of a finite amount of different particles. And a finite number of different particles can only be combined in a finite number of ways. That number may be so large that it feels like infinity to our brains — but it is not really. If you have finite options to build things, but infinite space that is full of things in all directions forever, then it makes sense that by pure chance, there will likely be repetition.
Kurzgesagt’s latest video on the paradox of time is a bit more of a brain-bender than their usual videos. From the accompanying sources document:
This video summarizes in a narrative format two well-known theories about time: the so-called “block universe” and the “growing block”.
The block universe is an old theory of time which appears to be an unavoidable consequence of Einstein’s theory of special relativity. In philosophical contexts, basically the same idea is known as “eternalism”. Simplified, this theory posits that, although not apparent to our human perception, both the past and the future exist in the same way as the present does, and are therefore as real as the present is: The past still exists and the future exists already. As a consequence, time doesn’t “flow” (even if it looks so to us) and things in the universe don’t “happen” - the universe just “is”, hence the name “block universe”.
But then: “Quantum stuff is ruining everything again.” And so we have the growing block theory:
The Evolving/Growing Block: A relatively new alternative to the classical block universe theory, which asserts that the past may still exist but the present doesn’t yet, and all that in a way that is still compatible with Einstein’s relativity.
And there are still other theories about how time works:
Some scientists think that the idea of “now” only makes sense near you, but not in the universe as a whole. Others think that time itself doesn’t even exist — that the whole concept is an illusion of our human mind. And others think that time does exist, but that it’s not a fundamental feature of the universe. Rather, time may be something that emerges from a deeper level of reality, just like heat emerges from the motion of individual molecules or life emerges from the interactions of lifeless proteins.
Like I said, a brain-bender.
I’ve posted more than a few size comparison videos here over the years — Powers of Ten is the obvious one — but this one from Kurzgesagt is one of the best, showing how big everything in the universe is compared to humans, who seemingly find themselves smack in the middle. This video does an excellent job illustrating the similarity of structures and interdependency across different scales — how blood vessels are like city streets for instance or how very tiny proteins can affect the entire Earth.
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