like a drunk dolphin
May 21, 2022 2:39 AM   Subscribe

You Are Not Where You Think You Are The latest offering from Kurzgesagt.
posted by lazaruslong (43 comments total) 15 users marked this as a favorite
 
Thanks, I hate love hate love it.

Kurzgesagt genuinely caused me to have an existential crisis a few years back when I learned about the Great Filter. I absolutely love their videos but I do feel a little unmoored after some of them.

Jiggly orbit indeed.
posted by slimepuppy at 4:25 AM on May 21 [5 favorites]


Thanks, this is fabulous.
posted by fantabulous timewaster at 5:31 AM on May 21 [1 favorite]


I like to think that Doc Brown only got this right after several tries, and there’s a wake of Deloreans behind earth.
posted by condour75 at 5:34 AM on May 21 [3 favorites]


kind of going the other way: Just How Small is an Atom?
posted by kliuless at 6:24 AM on May 21


Kurzgesagt genuinely caused me to have an existential crisis a few years back when I learned about the Great Filter . I absolutely love their videos but I do feel a little unmoored after some of them.

I think I know what you mean. I definitely felt A Way after watching the Great Filter one, and this. I experience that feeling as a little unsettling perhaps but I also find it....fulfilling in a way that I can't really describe. Possibly spiritual is the closest word to it, though I don't think of myself as a spiritual person. But I like that feeling -- struck with the awesomeness of the universe, in the original sense of the word awesome.
posted by lazaruslong at 7:11 AM on May 21 [1 favorite]


why does he keep saying "it gets worse"?
posted by philip-random at 7:23 AM on May 21 [1 favorite]


That’s your perspective.
posted by ashbury at 7:42 AM on May 21 [2 favorites]


I was thinking along these lines about the possibility of true antigravity.

If you could suddenly shield an object on your desk from the gravitational forces exerted by the Earth, it would shoot off at thousands of miles a hour (depending on your latitude); if you blocked the Sun's field too, it would fly off at tens of miles per second.

But if you could block all the gravitational fields from everywhere, what would it do?

As it flew off at some huge speed in an unguessable direction, you could measure that velocity, and by measuring that speed and direction, you would have gone a fair amount of the way toward establishing an ether-like ground state of the universe that everything is moving with respect to.

But we have very good reasons to believe that such a ground state cannot exist, therefore complete antigravity can’t exist either, and since gravitational fields at any given location don’t come indexed by origin, local antigravity can’t exist either.

So much for antigravity then — and any prospect of easy interstellar travel too, really.
posted by jamjam at 8:08 AM on May 21 [2 favorites]


Kurzgesagt genuinely caused me to have an existential crisis a few years back when I learned about the Great Filter

hm you probably would not want to read Kim Stanley Robinson's Aurora which presents a scenario in which multi-generational starships sans workable cryogenics would have an incredibly difficult time colonizing Earth-like planets, that Earth's resources would likely be long depleted before we were able to master it, and that the bacteria aboard the ships would evolve at a much faster rate than the humans aboard would be able to counteract/develop resistances to, leading to deteriorating conditions, lower lifespans, intelligence, etc
posted by paimapi at 8:59 AM on May 21 [7 favorites]


why does he keep saying "it gets worse"?

That bothered me, too. It smacked of a bit of subtle sensationalism. There’s nothing about any of the video that should be considered “worse” by anyone, save for the three or four people who might still believe in a geocentric universe. And, none of those folks would believe any of that video anyway.
posted by Thorzdad at 9:20 AM on May 21


"It gets worse" because the fundamental problem of precisely answering the question becomes magnitude more difficult with each additional step to factor in.
posted by GoblinHoney at 10:21 AM on May 21 [8 favorites]


It's definitely a great resource for me when I'm pointing out that the reason that I hate time travel plots in sci-fi is that unless your time machine is also a space machine (see also: time and relative dimension in space), you will basically always land in open space.

This is also a great illustration of why I'm perfectly exhilarated by driving a 2-cylinder, 602cc car, riding a bus, or bicycling at the pace of a Dutch grandma—I'm already rocketing through outer space at 220 kilometers per second, so where's the thrill in going slightly faster?
posted by sonascope at 10:24 AM on May 21 [4 favorites]


I think much of this material was covered by Animaniacs [2m] quite a while ago.
posted by hippybear at 10:47 AM on May 21 [1 favorite]


Incidentally, "the jiggle of existence" is my next sockpuppet name.
posted by Greg_Ace at 11:08 AM on May 21 [4 favorites]


I think it needs to be some kind of exotic jello shot served at an IRL event sometime.

*approaches with a tray* Would you like to try the jiggle of existence?
posted by hippybear at 11:14 AM on May 21 [7 favorites]


or bicycling at the pace of a Dutch grandma

having recently moved to the netherlands, the Dutch grandmas get moving on them omafiets haha
posted by lazaruslong at 11:35 AM on May 21 [2 favorites]


presents a scenario in which multi-generational starships sans workable cryogenics would have an incredibly difficult time colonizing Earth-like planets

If only they had Blast Hardcheese, Slate Fistcrunch, and Big McLargeHuge on board.
posted by They sucked his brains out! at 11:49 AM on May 21 [4 favorites]


Metafilter: a big bag of space that has things in it.

re the Gets Worse, thing, they are always using this in contrast to other (simpler) ideas about how to conceptualize it all, such as "while we see it (earth orbiting the sun) as pretty orderly, someone looking at it from outside would see something pretty messy," (going from memory, so this may not be the exact quote) and so on. So the earth circles the sun = pretty simple and easy to grasp, BUT (it -- the simplicity of it -- gets worse and more complicated because) it's not actually a circle, it's an ellipse, and (it gets worse, as in even more complicated) the ellipse changes, and (it gets worse, because here's yet another complicating factor) the moon makes things jiggly! etc.
posted by taz at 11:51 AM on May 21 [1 favorite]


While that Great Filter thing could scare me, their Optimistic Nihilism easily fixes me.

I close my eyes. I count to one.

I'm not feeling dizzy from "You Are Not Where You Think You Are", probably because most of those changes of direction take at least a few years to happen. The speeds may be truely scary, but it takes a while to complete an orbit around the milky way, way beyond what I'm expecting to experience.

Finally, I'm now worried about all the motion the atoms in my body are going through. And nuclei. And electrons. If anything fails, parts of me may move in a different direction than the rest. And they may pass through other important things, like the chair I'm sitting on.

I REALLY REALLY hope electromagnetic forces keep my smaller parts where they belong.
posted by flamewise at 12:17 PM on May 21 [1 favorite]


SPIRAL POWER!!!
posted by zengargoyle at 12:20 PM on May 21


When I was an undergraduate, deep in my studies which eventually resulted in my Astronomy BS, I achieved (or believed I almost achieved) what I called my Ultimate Orientation, visualizing at any given time my position on the spinning globe with respect to the sun and ("it gets worse") the celestial sphere. Or even the moon. Can't do it anymore.
posted by Rash at 12:32 PM on May 21 [1 favorite]


I think much of this material was covered by Animaniacs yt [2m] quite a while ago.

Oh hey, we still have nine planets in that one!
posted by Glinn at 12:39 PM on May 21




Unless I missed it he forgot to mention that, just as there's a wobble in Earth's trajectory around the sun b/c the barycenter (center of mass) of the Earth-Moon system is not identical to the center of Earth itself, there's also a wobble in the Sun's trajectory b/c the barycenter of the solar system is similarly offset. So the sun also does a rather complex wobbly dance around the solar system's barycenter itself as the whole system moves on its trajectory through the Milky Way. The center of that dance seems to be close to but outside the surface of the sun.

jamjam: "If you could suddenly shield an object on your desk from the gravitational forces exerted by the Earth, it would shoot off at thousands of miles a hour (depending on your latitude); if you blocked the Sun's field too, it would fly off at tens of miles per second."

Wasn't something like that part of the plot of Asimov's short story "The Billiard Ball"?
posted by Hairy Lobster at 1:30 PM on May 21 [3 favorites]


I'm playing Elite Dangerous and making my way out to Colonia to grind the engineers there. Is that all you got?
posted by sourcequench at 1:47 PM on May 21


I recently finished a 2nd pass through Immune, by Philipp Dettmer, creator of Kurzgesagt, narrated by Steve Taylor, who narrates all the Kurzgesagt videos. Thanks to the increase in brain size that this book gave me, I was able to read this CNN story about the hunt for new coronavirus vaccines and understand lots of things about it! I was also frustrated that a news article can't fully explain the concepts it introduces or tell any story in a linear fashion--the way Immune does--but forget that...Immune is a great book!
posted by polecat at 2:14 PM on May 21 [3 favorites]


Love this! For those interested in more along these lines, here are some more:

The helical model - our solar system is a vortex

Solar System 2.0 - the helical model

Which Planet is the Closest?
posted by greenhornet at 2:45 PM on May 21


our solar system is a vortex

But, according to the video in the FPP, lacking somewhat in Total Perspective.
posted by Greg_Ace at 5:49 PM on May 21 [7 favorites]


I like Eliza Carthy's cover.
posted by rhamphorhynchus at 6:16 PM on May 21


Beware that the “vortex” videos seem to put the Sun slightly out of the plane of the solar system, and have misleading text about the Sun “dragging the planets in its wake.” The Kurzgesagt video correctly shows the ecliptic plane inclined to the galactic plane and to the direction of the solar system’s collective motion.

The Sun’s orbit around the galaxy takes about 250 My, which means that the last time the Sun was at “this end” of the galaxy there were stegosauruses, and that the Sun has completed fewer than twenty orbits since the solar system formed.
posted by fantabulous timewaster at 7:20 PM on May 21 [2 favorites]


... the “vortex” videos seem to put the Sun slightly out of the plane of the solar system, and have misleading text about the Sun “dragging the planets in its wake.”

Ahhh, that must be why my GPS always claims my car's about 3-5 meters behind where it actually is.
posted by Greg_Ace at 7:49 PM on May 21


Weil ich Deutsch vor Englisch gelernt habe, weiß ich, dass „Kurzgesagt“ auf Deutsch „simply said“ bedeutet.

Meine Frau und Tochter lieben es, wenn ich ihnen das einmal erzähle.

Soy americano.
posted by kirkaracha at 7:57 PM on May 21


The weird idea of the sun dragging the planets in its wake entirely ignores the idea of the heliosphere which is that area within which the strength of the sun's particles streaming outward pushes actively against the particles loose in the interplanetary void, and this extends well beyond the orbit of Pluto. One of the Voyagers is there now and the other is getting close, but within this bubble (which is apparently teardrop shaped from moving swiftly though the Universe), the planets have no wake within which to be dragged.

It's a negative space with relatively few interstellar particles intruding, with anything the outward push of the solar radiation (which is what a solar sail spacecraft would use for propulsion) fighting against the orbits of the planets within their gravity-captured orbits. To a small degree.
posted by hippybear at 8:14 PM on May 21 [2 favorites]


Oh great, that helical-solar-system concept got another slick video presentation and now a whole new batch of people will misunderstand it.

This started about a decade ago, and Phil Plait did a good takedown of it at the time.

https://slate.com/technology/2013/03/vortex-motion-viral-video-showing-suns-motion-through-galaxy-is-wrong.html
posted by intermod at 9:03 PM on May 21


That Phil Plait article is about a completely different video, and none of the claims he objects to (e.g. the claim the heliocentric model is wrong, the sun leading the planets as the solar system moves through space, the use of the word vortex instead of helix, the solar system corkscrewing as it orbits the galactic center, etc) seem to be in this Kurzgesagt one. The one exception is Plait says the sun doesn't move up and down as it orbits the galactic center as many times per orbit as shown in the Kurzgesagt video, but the video says we haven't fully mapped those ups and downs out yet, so I wouldn't be surprised if that's just a case of science being complicated and uncertain on this point. I think this is just a case of a pseudoscience animation looking superficially similar to an actually well-researched one.

Anyhow, I enjoyed the Kurzgesagt video a lot! That said, they brushed over the idea that empty space, without mass in it, is uniform, and I'd like an entire video about that now tbh. It seems like a natural assumption, but how do we actually prove/find evidence of that? I remember reading in college about virtual particles and antimatter constantly popping in and out of existence in a vacuum, and about vacuum energy and the casimir effect, so it's not like there's actually true nothing going on in empty space. Maybe it's uniformly-not-nothing but I'm just wondering how we could be sure of that? Or does the idea of an empty universe existing without matter in it even make sense as a concept? I have no idea.
posted by Zephyr at 10:19 PM on May 21 [3 favorites]


I assumed that was meant as a figurative example ("if there were nothing in the universe, the concept of 'position' would have no meaning"), not as a literal fact.
posted by Greg_Ace at 10:30 PM on May 21




>> our solar system is a vortex

> But, according to the video in the FPP, lacking somewhat in Total Perspective.

Oh good, I'm not the only one who thought of the Total Persepctive Vortex form Hitchhiker's Guide to the Galaxy.
posted by Pronoiac at 1:42 AM on May 22 [1 favorite]


In general relativity, the connection between mass and spacetime is literal, not figurative. Suppose you have a spacetime which obeys all the symmetries of general relativity, and there are exactly two masses in it. You could say, “the two masses are moving apart.” Or you could say, “the space between the two masses is expanding.” In general relativity, those are literally the same statement. Likewise for “moving towards each other” and “space contracting.”

This almost feels like a non-statement. If two objects are moving apart, then of course the space between them is expanding.

The literal connection between mass and spacetime predicts that, in a universe where all of the mass over here is moving away from all of the mass over there, electromagnetic waves will have a different wavelength when they are detected “here” than when they were emitted “there,” because the space between “here” and “there” expanded while the waves traveled through it. This spacetime-caused stretching of light is called “cosmological redshift.” In our actual universe, the cosmological redshift is the best explanation for the correlation between redshift and distance for light from distant galaxies.

Relativity was invented-slash-discovered in order to make sense of electromagnetism in a world where different observers disagree about who is “moving” and who is “at rest.” A moving electric charge has a magnetic field, but a stationary charge doesn’t. But if I’m over here with a stationary charge, and you’re way over there without any of your own charges, you can’t create a magnetic field at my location by dancing. Instead, when you move, the electric and magnetic fields you observe rotate into each other, in a four-dimensional way that takes a couple of years to learn properly. If there’s not much mass around, this relationship between the electric and magnetic fields is an example of “Lorentz symmetry,” and it follows the same mathematics as the four-dimensional rotations between position and time which occupy most pop-science explanations of relativity.

Another comment above asked whether the virtual particles which pop in and out of the vacuum are consistent with empty space being empty and featureless. In fact, antimatter and related phenomena are predictions that were made by requiring quantum mechanics to have Lorentz symmetry. If you didn’t have virtual particles popping in and out of existence, then the vacuum would have a preferred reference frame.

The idea that “your rest frame is just as good as my rest frame” is pretty well-known from pop-science explanations about relativity. The idea that there’s no difference between “we are moving apart” versus “the space between us is expanding” is less well-known, but fundamentally the same approach. Symmetry arguments like these are all over modern physics. Physicists have an annoying habit of describing the Standard Model of particle physics just by listing the symmetries it obeys. Symmetry arguments are important in explaining the quantum-mechanical behavior of materials, especially at low temperatures. It’s hard to overstate their importance.
posted by fantabulous timewaster at 4:16 AM on May 22


Oh good, I'm not the only one who thought of the Total Perspective Vortex form Hitchhiker's Guide to the Galaxy.

The what, now?

(kidding, that's exactly what I was referencing)
posted by Greg_Ace at 10:03 AM on May 22 [1 favorite]


Kurzgesagt is pretty universally right-on for me, so I did have the momentary fear that it would invoke that new-agey-bullshit that was making the rounds when that stupid gee-whiz-magical-space-vortex video was making the rounds among the dumber corners of social media, but fortunately, Kurzgesagt did not let me down. They are absolute splendid at communicating big concepts and fully contrite about the difficulties and shortcuts often involved in the process of doing so.
posted by sonascope at 11:10 AM on May 22 [1 favorite]


So the sun also does a rather complex wobbly dance around the solar system's barycenter itself as the whole system moves on its trajectory through the Milky Way. The center of that dance seems to be close to but outside the surface of the sun.

The sun is basically a big blob of very hot fluid, so I wonder if that kind of orbit makes it change its shape, like swishing mouthwash around sides of your mouth.
posted by They sucked his brains out! at 1:07 PM on May 22


I think the Sun doesn’t slosh around in response to all of these different gravitational tugs on its motion, because gravitational trajectories are the same thing as free-fall. In a satellite in unpowered orbit around Earth, everything is falling at the same rate, so dropped objects don’t hit the floor because the floor is also falling. We call this “zero-gee,” even though Earth’s gravity is still pretty strong in low-Earth orbit. You’d still see this zero-gee in a more strongly curved orbit. You get “sloshing” in a fluid when different parts of the fluid are subject to different accelerations.

The biggest gravitational effect on the Sun’s shape are tides raised by Jupiter; next biggest are tides raised by Mercury. Tides go like mass per distance cubed, so a solar-mass star would have to pass through the Kuiper Belt to raise Jupiter-scale tides on the Sun.
posted by fantabulous timewaster at 4:47 AM on May 24


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