Jupiter is deep | Hacker News Reader

Jupiter is deep

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424 pointsrbanffy71 comments

One thing that might not be related but I found fascinating is that Jupiter is “木星” in Chinese, where “木” means wooden. The first time “木星” was mentioned in Chinese literature was in 东汉, year 25 - year 220 (around 1800 years ago). So Chinese people back then thought the planet was made of wood! And as a child, this planet has the name easiest to remember, because it looks exactly like a wooden ball.

Edit: I digged deeper and found that it was a coincidence that Jupiter was called the Wooden Planet. The Chinese assigned the name not because they were able to observe the wood like texture (due to the lack of telescope), but they were able to observe the existence of the planet with naked eye as early as 2300 years ago, along with the Mercury, Venus, Mars, and Saturn. These five planets were assigned to the name in the order of "金 gold (Venus)","木 wood (Jupiter)","水 water (Mercury)","火 fire (Mars)"."土 rock (Saturn)" superstitiously. What's really surprising is Venus does look like gold in color and Saturn does look like wood in color. What a coincidence!

I'm pretty sure the ancient Chinese could see the colors of at least some of the planets. You don't need a telescope to tell that one celestial object looks redder than another, especially if you have good eyesight and no light pollution.

Venus is indeed golden; Jupiter is red-brown like some type of wood; Saturn looks like it's covered in sand (土 can mean dirt as well as rock, and there's a lot of yellow dirt in China); Mars is unmistakably red; and Mercury looks plain white so why not assign it to the only remaining element. Four correct guesses out of five = probably not a coincidence.

White is also prominently used to mean clear, clean water in hydronyms (there's the german city weisswasser, for example).

Not an interesting coincidence. Jupiter is hot but Mars gets named fire. Mercury looks like rock (thin atmosphere) but Saturn get called rock. You could find some reason to make almost any naming seem like a coincidence.

Not interesting to who? Coincidences can interesting even if they don't point to a causal relationship. I find it interesting that word for Jupiter in Chinese is wood simply because it's an interesting association to make.

Mars at least probably isn't a coincidence, in terms of the element assigned, since it's visibly red to the naked eye.

Not knowing Chinese, I also had to look up '星', as parent comment does not explain it. It means planet, so literally 'Wooden Planet'. Nice.

It can also mean star, it’s pretty general for various astronomical bodies. You can also see it used in the word satellite (卫星), shooting star (流星), etc. gotta love Chinese :)

And in these 5 planets and associated elements https://en.wikipedia.org/wiki/Wu_Xing rooted a large number of traditional beliefs: Feng Shui, Traditional Chinese Medicine, Martial Arts.

And arguably stunted progression from them. But that's getting off topic.

Jupiter is so cool.

Fun fact, Jupiter’s Great Red Spot is a huge storm that has been raging for at least 188 years if not much longer. It also has a diameter about 2-3 times as wide as Earth’s.

Jupiter also is believed to be a gravitational shield that protects us from asteroids and comets.

Jupiter is also Home to some of the coolest Moons in our solar system, my favorites being Io, Europa, Callisto, and Ganymede (the Galilean moons), in that order.

One question I’ve always had and hope to learn one day: what the heck is Jupiter’s “surface” like? I know it’s believe to be essentially layers of metallic hydrogen, but what the heck does that even mean? What would it look like? So interesting.

It might not exactly answer your question, but you may enjoy this description of what it would be like to fall into Jupiter:

https://space.stackexchange.com/a/5041

Thanks, that link is fantastic, informative and entertaining at the same time.

Our local cafe recently re-opened as Kallisto; when I first went in, I set up a loyalty card and the owner said 'The system needs a surname, but I discourage using your real personal details.'

So I entered myself as 'Jacob Ganymede'; we've been friends ever since.

> Fun fact, Jupiter’s Great Red Spot is a huge storm that has been raging for at least 188 years if not much longer. It also has a diameter about 2-3 times as wide as Earth’s.

It's also shrinking at an increasing rate and may be gone within a couple decades.

One way I know I had an ok childhood was that when I found out the gas giants didn’t have a surface I could stand on, it was a notable and memorable low point

Check this out: https://www.youtube.com/watch?v=pMCrPvtN1G8

I think analogy breaks down.

There's probably not any light at the transition between the liquid and metal layers of hydrogen, the liquid layer is thousands of kilometers thick (the deepest ocean is ~11 km). And it's sort of hot. Not stove top pan hot, 10x hotter than that.

Oh and the pressure is a couple million times Earth surface pressure.

Maybe it's like Earth's liquid iron mantle?

Somehow, I knew this was Phil Plait from the title. Love his stuff. And this reminded me that I forgot to migrate my RSS feeds with Phil Plait to his new blog location. Thanks!

The renderings are amazing looking! It makes Jupiter looks like an evil planet.

Those aren't renderings, they are composite images made from photographs taken of Jupiter using an infrared camera on the Juno spacecraft.

What word would you use for composite false-color images produced by a computer if not "renderings"?

It really depends on how you define picture. I guess you could argue that it is still a picture in the sense that it is captured using an array of sensors that are sensitive to some electromagnetic waves.

edit: Wikipedia defines photography as "the science, art, application and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor, or chemically by means of a light-sensitive material [...]

It could fit

computer "renderings" has a very specific meaning, creating images from 2D or 3D models.

I would call this a 'composite image.'

You might wish to check out the below Wikipedia page, specifically the section titled "types of color renderings"

https://en.m.wikipedia.org/wiki/False_color

I think that's the fault of the infrared thing.

Infrared is by definition not what you would think of as a color. The colors in that picture are false, and a stylistic choice made during the rendering process. It would be just as accurate to use shades of blue and make it look icy. Perhaps more accurate as the upper atmosphere portrayed here is very, very cold.

Sometimes I wonder how different our world might be if it were the size of Jupiter but at the surface still had the same gravity we have now.

It could take days to download something from the other side of the planet. And probably a month of airplane travel just to get there.

Latency would be higher, and might make phone calls a little awkward perhaps?, but it shouldn't make any longer to download a file. You might want to modify protocols so they send acknowledgements less often, or use larger packets perhaps.

Exactly this. It's always amazing to me how latency gets confused with bandwidth.

Ah yea, I guess you’re right. With a small planet it’s something I never have to think much about since things always seem fast enough.

I wonder if it would be possible for such a planet to exist and be habitable. Obviously it would have to be far less dense than Earth (or Jupiter); I'm guessing gravity would therefore compact it to a smaller size, unless maybe it was made out of some kind of lattice structure?

Better question might be what's the largest feasible (or likely) potentially habitable planet with earth-like gravity.

That's an interesting question. I'm sure it's been considered in science-fiction before. But as I think about I keep thinking about a hollow planet, and then I think about a Dyson sphere. Does that count as a planet?

Mass of Saturn is 100x earth and the gravity is only 6% higher.

But not with a solid surface at that size.

You should read Robert Silverberg's Majipoor series. It is a fantasy series about a planet that's much larger than earth, but less dense. https://en.wikipedia.org/wiki/Majipoor_series

Assuming the existance of something like early human hunter-gatherers, if the earth were the size of Jupiter, we would not have transitioned to living in cities yet. There would be no downloading.

Why not? Why does a bigger planet mean slower progress?

Not a specialist here, but bigger distances will mean - more time to discover other places and other people which means you won't find new knowledge for some time and then you will need more time to bring it to your people. Slower trade too.

But it doesn't imply resources are more spread out. The only thing a smaller planet means is that your civilisation will more quickly be able to circumnavigate it, but that doesn't seem relevant at all.

>But it doesn't imply resources are more spread out

No, but what the point of resources if you don't know how to use them? For example - paper. China had it for more than a thousand of years before it reached Europe. Papermaking gave a great boost to our civilization, but imagine our world with papermaking just being introduced to the middle east.

Less population density means less specialism. Higher population density allows the ability for some of the population to have the ability specialise (and by mixing with others in the same or allied specialisations in higher and higher populations, can allow increased returns to scale of what the individual is already specialised in).

>And probably a month of airplane travel just to get there.

Space travel would probably be more advanced by now.

It would be drastically harder to get out of the gravity well on the planet. Even if the strength of gravity at the surface was the same as Earth’s, the field would be stronger farther out than Earth’s —- 11x as much due to the geometry. It would take 11x more energy to escape the planet, though low orbit would be practically the same difficulty.

Low orbit would also be a lot more difficult; when you scale a planet's radius and mass to preserve surface gravity, all delta-v requirements scale as the square root of the of radius.

Oh, yea, you're right.

Escape velocity is 6x the earths, 60km/sec or so.

That's Jupiter. We're talking about a hypothetical planet of Jupiter's size and Earth's surface gravity.

Really interesting content but this site has one of the most aggressive, unpredictable and annoying slide-down headers I've ever seen.

Displaying written content on the web should be so simple, yet all the content producers have invented their own special blend of ways to fuck it up.

Slide-down headers. Share links widgets that overlap content. Video plays without asking and follows you down the page. Entire page lags while 800 javascript snippets load. Text is some stylish but unreadable low-contrast color. Modals begging you for your email.

I manually edit the DOM and CSS of sites on an almost daily basis now just so I can read it.

It's a real shame how HTML completely screwed up the "markup" part by not offering a separate API for UI chrome. If Netscape had offered some way to define navigation separately from the textual content, it might still have saved us. Now it's all just a jumble: documents that describe UI views that describe document fragments that describe UI controls.

I hope annoy blockers will be next internet thing soon. Block interacts with scroll - blocked. Big blocks overlap - blocked one that has less text. Inserts itself in-between later than 3 seconds after load - blocked. Looks like header - blocked. “This site is completely idiotic and can harm your senses, are you sure you want to visit it at all?”

Flash ads seem like toys now compared to this weapon of mass ux destruction.

FYI I think you got down voted due to the phrase "f--- it up". HN is generally open to criticism of things like that but tends to prefer a more non-confrontational tone.

I do glassblowing as a hobby. I'd like to replicate some of the patterns in those pics in glass. Might have to deviate from the color spectrum in the pictures. The reds I use are nowhere near as intense.

Please post a 'Show HN' if you ever do! I'd love to see the process and results and maybe even buy one! What an amazing piece of art it would be.

> There's a single Southern Polar Cyclone (the SPC in this case), but only five cyclones around it! They're bigger too, and are different sizes, ranging from 5,600 to 7,000 km across. Again, it's not clear why the poles are different. The fact that there are fewer in the south and they're bigger may be related (I'm guessing, but if you have fewer they can grow to fill more space … ?), but no one really knows.

Maybe because the main cyclone escaped the South pole and now known as Big Red Spot?

That would mean 7 southern cyclones accounted for. This is still different from the 9 on the northern pole.

Maybe because central cyclone merged 2 side cyclones, so it has extra energy to escape South pole.

So... do astronomers truly have no idea why the 9 polar cyclones don't combine? I can't imagine what mechanism might prevent this.

It's a relatively common phenomenon in hydrodynamics (specifically, the formation of large separated cyclones in unstable flow), and the best explanation is delightful -- Onsager's "The Little Vortices Who Wanted To Play" (a letter to Linus Pauling, reproduced on page 33 of this PDF: http://bactra.org/sloth/eyink-and-sreenivasan-on-onsager-on-... ).

There's an interesting video I've seen before showing it being recreated in a lab. I do not, however, know the origin or reasoning behind why it happens.

https://www.youtube.com/watch?v=n_c9A9Auf0A

chaos theory

https://www.youtube.com/watch?v=eJAs9Qr359o

Isn't it pointless to ask why a chaotic turbulent system ended up this particular way? The author keeps repeating this question (or stating "nobody knows"), as if there's some fundamental and interesting answer to it.

I'm not sure if you're playing with words here, but asking questions like these is the most natural way to discover more about physics itself. Of course studying Jupyter is not as fundamental as studying particle physics or string theory, but it's an emergent physics that nobody has fully explored yet.

At least is a twisted planet, that's for sure.

The polar cyclone systems look like Magic Roundabouts.

Why the title change?

Hey, neat!

Jupiter almost has an octagon on it's north pole (and nearly a pentagonal version on it's south pole), similar to Saturn's northern polar hexagon!

[0] https://en.wikipedia.org/wiki/Saturn's_hexagon

[1] https://www.smbc-comics.com/index.php?id=1930

Well, that was mentioned in the article too.

Yes, and now you’ve mentioned that it was mentioned in the article. So here we are, mentioning things.

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