this post was submitted on 24 Feb 2024
710 points (99.4% liked)

xkcd

13409 readers
350 users here now

A community for a webcomic of romance, sarcasm, math, and language.

founded 2 years ago
MODERATORS
 

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!"

top 50 comments
sorted by: hot top controversial new old
[–] niktemadur@lemmy.world 47 points 2 years ago* (last edited 2 years 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 2 years 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 2 years 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 2 years ago

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

[–] WhiskyTangoFoxtrot@lemmy.world 5 points 2 years ago (1 children)
load more comments (1 replies)
load more comments (2 replies)
[–] billwashere@lemmy.world 42 points 2 years ago (9 children)

And that point is inside the sun.

[–] V0lD@lemmy.world 41 points 2 years 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 2 years ago (1 children)

Leave it to Jupiter to mess yet another thing up

[–] frezik@midwest.social 13 points 2 years ago

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

[–] Flumpkin@slrpnk.net 11 points 2 years 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 2 years ago (2 children)

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

[–] starman2112@lemmy.world 13 points 2 years ago* (last edited 2 years 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 2 years ago* (last edited 2 years ago)

Easy reminder:

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

so the ratio is always 1000:1

load more comments (1 replies)
load more comments (2 replies)
load more comments (8 replies)
[–] gandalf_der_12te@feddit.de 31 points 2 years 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 2 years ago (1 children)
[–] jungle@lemmy.world 36 points 2 years ago* (last edited 2 years ago) (3 children)

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

[–] netvor@lemmy.world 5 points 2 years ago

relativity plays no role here

I still count that as learning.

load more comments (2 replies)
[–] kurosawaa@programming.dev 5 points 2 years ago

XKCD is basically all math jokes.

[–] prex@aussie.zone 29 points 2 years ago (1 children)
[–] TimewornTraveler@lemm.ee 20 points 2 years ago* (last edited 2 years 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 2 years 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 2 years ago* (last edited 2 years ago) (2 children)

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

[–] Thcdenton@lemmy.world 10 points 2 years ago

You're an oblate spheroid

[–] Telodzrum@lemmy.world 9 points 2 years ago
[–] lugal@lemmy.ml 18 points 2 years ago (7 children)

Sometimes, both can be wrong. Both orbit the moon

[–] RobotToaster@mander.xyz 9 points 2 years 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 2 years 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.

load more comments (2 replies)
load more comments (6 replies)
[–] hperrin@lemmy.world 18 points 2 years ago* (last edited 2 years 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 2 years 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.

load more comments (4 replies)
[–] douglasg14b@lemmy.world 9 points 2 years ago* (last edited 2 years 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.

load more comments (3 replies)
[–] LazaroFilm@lemmy.world 16 points 2 years ago (6 children)

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

[–] Bademantel@feddit.de 57 points 2 years ago (8 children)

I mean, yeah. That's the joke.

load more comments (8 replies)
[–] Jaytreeman@kbin.social 16 points 2 years 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.

load more comments (1 replies)
[–] lugal@lemmy.ml 12 points 2 years ago (3 children)

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

[–] knatschus@discuss.tchncs.de 11 points 2 years ago (1 children)

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

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

The urge to orbit a black hole is universal

load more comments (2 replies)
load more comments (2 replies)
[–] dev_null@lemmy.ml 7 points 2 years 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.

load more comments (2 replies)
[–] randomaccount43543@lemmy.world 12 points 2 years ago
[–] simin@lemmy.world 6 points 2 years 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 2 years 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

load more comments (1 replies)
load more comments
view more: next ›