this post was submitted on 24 Feb 2024
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xkcd

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https://xkcd.com/2898

Alt text:

"Some people say light is waves, and some say it's particles, so I bet light is some in-between thing that's both wave and particle depending on how you look at it. Am I right?" "YES, BUT YOU SHOULDN'T BE!"

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[–] niktemadur@lemmy.world 47 points 1 year ago* (last edited 1 year ago) (4 children)

It's called a barycenter, kids, a common center that both objects circle around. That common center happens to be inside the sun, but that's a topic for next week's class in this semester's AP Astrophysics program.

[–] Johanno@feddit.de 15 points 1 year ago (1 children)

Same for earth and moon. The center is inside earth. But not that close to the center of the earth itself

[–] niktemadur@lemmy.world 13 points 1 year ago (1 children)

Meanwhile, Pluto and Charon noticeably orbit each other, the barycenter being fully outside of Pluto's surface.

[–] Klear@sh.itjust.works 13 points 1 year ago

And Jupiter is so massive that its barycentre is (barely!) outside of the sun!

[–] WhiskyTangoFoxtrot@lemmy.world 5 points 1 year ago (1 children)
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[–] billwashere@lemmy.world 42 points 1 year ago (9 children)

And that point is inside the sun.

[–] V0lD@lemmy.world 41 points 1 year ago (5 children)

No actually. Due to Jupiter, the centre of mass of the solar system is actually very slightly outside of the sun

[–] afraid_of_zombies@lemmy.world 27 points 1 year ago (1 children)

Leave it to Jupiter to mess yet another thing up

[–] frezik@midwest.social 13 points 1 year ago

Stupid lazy ass diabetus planet doesn't even have enough mass to fuse its hydrogen.

[–] Flumpkin@slrpnk.net 11 points 1 year ago

So doesn't that mean the earth and sun do not orbit a common center but a varying point based on mostly Jupiter?

Centrists have bamboozled me again!

[–] RememberTheApollo_@lemmy.world 10 points 1 year ago (2 children)

Wouldn’t the center of mass constantly be shifting by the planets’ varying positions in orbit?

[–] starman2112@lemmy.world 13 points 1 year ago* (last edited 1 year ago) (1 children)

Yes, but it's mostly shifting because of Jupiter. It's just so dang heavy. Like, a couple times heavier than every other planet put together. I don't have the brain wattage to do the cool math right now, but a quick google search says that while the barycenter of the solar system does depend on all the planets, more often than not, it is outside the sun

[–] gandalf_der_12te@feddit.de 12 points 1 year ago* (last edited 1 year ago)

Easy reminder:

sun ~ 10^30 kg
jupiter ~ 10^27 kg
earth ~ 10^24 kg

so the ratio is always 1000:1

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[–] gandalf_der_12te@feddit.de 31 points 1 year ago (2 children)

Is this... an introductory course in relativity, disguised as a joke?

Am I accidentally learning something here?

Guys?

[–] moosetwin@lemmy.dbzer0.com 21 points 1 year ago (1 children)
[–] jungle@lemmy.world 36 points 1 year ago* (last edited 1 year ago) (3 children)

Not really, relativity plays no role here. It's classical Newtonian physics.

[–] netvor@lemmy.world 5 points 1 year ago

relativity plays no role here

I still count that as learning.

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[–] kurosawaa@programming.dev 5 points 1 year ago

XKCD is basically all math jokes.

[–] prex@aussie.zone 29 points 1 year ago (1 children)
[–] TimewornTraveler@lemm.ee 20 points 1 year ago* (last edited 1 year ago) (1 children)

I appreciate the origin story being included in this cliché, cuz it got repeated so often on Reddit that people seemed to forget it was said by a parody of an obnoxious heartless bureaucrat and repeat the phrase without irony.

[–] Huschke@lemmy.world 8 points 1 year ago (1 children)

You know, you are technically correct.

Which is a kind of correct.

What kind we’ll never know.

[–] Hamartiogonic@sopuli.xyz 22 points 1 year ago* (last edited 1 year ago) (2 children)

Apply that to the flat earth debate and you get an oblate spheroid.

[–] Thcdenton@lemmy.world 10 points 1 year ago

You're an oblate spheroid

[–] Telodzrum@lemmy.world 9 points 1 year ago
[–] lugal@lemmy.ml 18 points 1 year ago (7 children)

Sometimes, both can be wrong. Both orbit the moon

[–] RobotToaster@mander.xyz 9 points 1 year ago (1 children)

The Earth–Moon–Sun three body problem is apparently something that has been studied quite a bit in physics.

[–] lugal@lemmy.ml 5 points 1 year ago (2 children)

And of cause there are 3 camps and alot of disagreements but essentially, the majority of scientists argue, like me, that it is the moon which is the center. You can always cite some fringe scientists arguing otherwise, that doesn't change the general consensus.

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[–] hperrin@lemmy.world 18 points 1 year ago* (last edited 1 year ago) (2 children)

I mean, no, not really. The gravitational center of the sun-earth system is within the sun itself, so the earth definitely orbits the sun and the sun definitely does not orbit the earth. Let alone the fact that the sun’s movement is predominantly driven by Jupiter. (The gravitational center of the sun-Jupiter system is just above the sun’s surface.)

[–] gapbetweenus@feddit.de 11 points 1 year ago (4 children)

Pretty sure you can chose earth as fix point and have everything rotate around it on really strange orbits. Everything is kind of relative.

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[–] douglasg14b@lemmy.world 9 points 1 year ago* (last edited 1 year ago) (3 children)

Except that any two gravitational bodies orbit a common center...

The Earth orbiting the Sun causes the sun to wobble slightly, moving its orbital center away from its center of mass, which means the sun and earth actually orbit a common center point no?

Even if that center point is within the other body it still isn't the center of that body, therefore they both orbit a shared gravitational center that is not the center of either body.

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[–] LazaroFilm@lemmy.world 16 points 1 year ago (6 children)

Technically, the sun is pulled by the earth too so it’s sort of true.

[–] Bademantel@feddit.de 57 points 1 year ago (8 children)

I mean, yeah. That's the joke.

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[–] Jaytreeman@kbin.social 16 points 1 year ago (1 children)

Except it's still inside the sun, so depending on how big you view the center of the sun it could still be wrong.

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[–] lugal@lemmy.ml 12 points 1 year ago (3 children)

My thought exactly but isn't the common center still inside the sun?

[–] knatschus@discuss.tchncs.de 11 points 1 year ago (1 children)

Yes, but they still both orbit the black hole in the center of our galaxy

[–] kamenlady@lemmy.world 7 points 1 year ago (2 children)

The urge to orbit a black hole is universal

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[–] dev_null@lemmy.ml 7 points 1 year ago

Yeah, any 2 bodies actually orbit a common point in between themselves. In case of the Sun and Earth that point is probably still inside the Sun, not far from the center.

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[–] randomaccount43543@lemmy.world 12 points 1 year ago
[–] simin@lemmy.world 6 points 1 year ago (1 children)

the three body problem being one of my favorite scifi until it was kinda solved a couple years ago

[–] kajdav@lemmy.world 12 points 1 year ago (1 children)

What are you referring to? I haven't heard anything about the three body problem being "solved" - there's still no general solution afaik

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