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!”

  • billwashere
    link
    English
    1303 months ago

    And that point is inside the sun.

    • @V0lD
      link
      English
      683 months ago

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

      • @RememberTheApollo_
        link
        English
        193 months ago

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

        • @starman2112
          link
          English
          26
          edit-2
          3 months ago

          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

          • @[email protected]
            link
            fedilink
            English
            15
            edit-2
            3 months ago

            Easy reminder:

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

            so the ratio is always 1000:1

      • @[email protected]
        link
        fedilink
        English
        113 months 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!

      • billwashere
        link
        English
        83 months ago

        Cool. I learned something today

      • @niktemadur
        link
        English
        5
        edit-2
        3 months ago

        But I think the math of the argument is only about the common center between Earth and the sun, taking away all other planets out of the equation, especially Jupiter.

    • @[email protected]
      link
      fedilink
      English
      31
      edit-2
      3 months ago

      No the comic is pointing out that the sun and the earth are both orbiting the milky way galactic center.

      Edit: While also true, I was wrong, they orbit the center of mass of the two body problem (earth and sun). I still think that’s too simple of a way to look at it. It’s not a two body problem and the other planets and the whole galaxy are also in play.

      • @[email protected]
        link
        fedilink
        English
        193 months ago

        I mean technically every body in the entire universe exerts gravity on everything else as long as it’s in your light cone

          • @[email protected]
            link
            fedilink
            English
            13 months ago

            https://en.wikipedia.org/wiki/Light_cone

            this doesn’t give a very good explanation but I’m sure there’s some good YouTube video that breaks it down. essentially maps out everywhere in space and time that could possibly interact with you in any way. this maximum is represented by how fast light can move away from you.

            for example if you stole my car and ran away from me, I can draw a circle on the map every hour for how far you could have gone (assuming I knew my car’s maximum speed). if I put those circles on top of each other it’ll make a cone.

      • BlanketsWithSmallpox
        link
        English
        13 months ago

        True in reality it’s just the sun and Jupiter orbiting each other in a common point…

        Inside the sun lol.

    • @WoahWoah
      link
      English
      53 months ago

      Wait I’m sorry, are we saying that the earth’s orbit isn’t almost entirely dictated by the gravitational pull of the massive star at the center of our solar system? I am a simple man, I apologize if that is a stupid question.

      • @[email protected]
        link
        fedilink
        English
        23 months ago

        When dealing with gravitational systems the gravity of each object has to be taken into account. So even though the sun is 99.999% (hyperbole) of the gravity in the equation, the earth’s gravity contributes that small 0.001% and thus the “center” of where they orbit isn’t truly the center of the sun. Tack on Jupiter, which is much more than a fraction of a percent and that “center” moves even farther away from the middle of the sun.

        To look at it further, if you had two objects of perfectly equal mass and no other gravitational interference, they would orbit around a point in the middle of each other since their pull is equal. So it’s basically a sliding scale of sorts.

        Hope that explains it!

        • @WoahWoah
          link
          English
          13 months ago

          That did help, thanks for taking the time. I think I was thinking about mass and gravity not orbits. Again, I’m an idiot, so that’s probably why I missed the central point of the cartoon. 😁

    • @[email protected]
      link
      fedilink
      English
      52
      edit-2
      3 months ago

      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
        link
        English
        133 months ago

        You know, you are technically correct.

  • @niktemadur
    link
    English
    78
    edit-2
    3 months ago

    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
      link
      fedilink
      English
      223 months ago

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

      • @niktemadur
        link
        English
        193 months ago

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

    • @ByteJunk
      link
      English
      43 months ago

      I don’t think the barycentre is inside the sun? Wikipedia says on the barycentre article:

      When the less massive object is far away, the barycenter can be located outside the more massive object. This is the case for Jupiter and the Sun; despite the Sun being a thousandfold more massive than Jupiter, their barycenter is slightly outside the Sun due to the relatively large distance between them.[2]

      • @[email protected]
        link
        fedilink
        English
        223 months ago

        I don’t think the barycentre is inside the sun?

        The Jupiter-Sun barycentre in outside the sun.

        The Earth-Sun barycentre is inside the sun.

    • @[email protected]
      link
      fedilink
      English
      193 months ago

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

      • @[email protected]
        link
        fedilink
        English
        103 months ago

        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.

        • @[email protected]
          link
          fedilink
          English
          23 months ago

          you are the barycenter of your own opinion

          yo opinion so massive she needs a crane to get out of bed.

          • @[email protected]
            link
            fedilink
            English
            23 months ago

            I’m not sure about that but for sure I am the center of my personal narrow Overton Window

    • Teppic
      link
      fedilink
      -123 months ago

      …whoosh.
      In no logical sense does the sun orbit our moon. The earth does however indeed orbit the moon (or technically they both orbit a common centre between the earth and the moon).

      • Deceptichum
        link
        fedilink
        9
        edit-2
        3 months ago

        Are you saying that in no way shape or form, does the moon and its affect on the earth and earth-moon barycenter not influence the solar barycenter?

        Id accept no way worth caring about, but as an absolute?

        • Teppic
          link
          fedilink
          23 months ago

          You seem to be saying that the earth-moon barycente can be logically referred to as just ‘the moon’ ?

          • Deceptichum
            link
            fedilink
            23 months ago

            The earth does however indeed orbit the moon (or technically they both orbit a common centre between the earth and the moon).

            Heres you referring to the Earth moon barycenter as just ‘the moon’

            • Teppic
              link
              fedilink
              13 months ago

              You’ve got me there, but by logical extension you are now saying the celestial body the ISS orbits is …the moon?

      • @[email protected]
        link
        fedilink
        English
        53 months ago

        I’ve talked to the man in the moon and he said the sun rises and sets on the moon like it would if the sun orbits the moon. Same for the earth. Both orbit the moon. Face it.

  • @[email protected]
    link
    fedilink
    English
    353 months ago

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

    Am I accidentally learning something here?

    Guys?

      • jungle
        link
        English
        36
        edit-2
        3 months ago

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

        • @netvor
          link
          English
          53 months ago

          relativity plays no role here

          I still count that as learning.

        • moosetwin
          link
          fedilink
          English
          33 months ago

          I was more referring to the fact that xkcd’s comics have a lot of science in them, rather than the specific type of science

  • @[email protected]
    link
    fedilink
    English
    273 months ago

    As a middle ground kind of guy, I would like to pre-emptively state that a lot of us don’t actually think the answer is always the middle ground between two stances. It’s just that we’re more likely to propose a middle ground solution because we evaluate the plausibility of both stances in a more balanced way (as opposed to existing-stance-holders who are prone to bias towards their own stance.) When the two seem roughly equal in plausibility (which happens fairly often, otherwise the argument would be more one-sided,) that’s an indication to evaluate the middle ground as well.

    Middle ground folks are often caricaturized as wanting to find the middle ground between an objectively sensible point A and a radically wrong point B, when the spectrum of opinions is sort of like [ - - - - - A - | - - - - - - B ]. In that caricature, we’re looking for a middle ground at point C [ - - - - - A - | - - C - - - B ], when in actuality we’re evaluating (and not automatically accepting) something two or three steps closer to A. In some such cases, A might already be the most sensible middle ground.

      • @NewAgeOldPerson
        link
        English
        53 months ago

        I don’t know. But if I die, tell me wife I said hello.

      • @[email protected]
        link
        fedilink
        English
        53 months ago

        I’m actually not as neutral as I may seem. There are quite a few cases where I hold more extreme opinions, but as a general trend, I average somewhere around the middle.

    • kbal
      link
      fedilink
      9
      edit-2
      3 months ago

      In an n-dimensional problem space, the probability of the truth lying anywhere on a line between point A and point B is infinitessimally small.

      • @[email protected]
        link
        fedilink
        English
        13 months ago

        This is also true. I like to evaluate solutions outside the presented dichotomy in general, and that often means outside the line between them, but I didn’t want to complicate my initial explanation that much.

        • kbal
          link
          fedilink
          13 months ago

          It’s just the same point xkcd made.

    • @ForgotAboutDre
      link
      English
      53 months ago

      Middle of the ground people are mostly cowards too scared of conflict, or devoid of insight.

          • @[email protected]
            link
            fedilink
            English
            163 months ago

            I’m not scared of conflict, I’m averse to needless conflict. I may get involved in a conflict for the purpose of breaking it up, or I may initiate a conflict for a good cause such as combating hatred and averting future conflicts - if I feel it’d be productive.

          • @WhiteHawk
            link
            English
            73 months ago

            Why waste your time fighting when there’s a solution everyone is happy with?

    • @[email protected]
      link
      fedilink
      English
      53 months ago

      Wow. You just succinctly explained the position I’ve held most of my life. Very well done!

    • @ilinamorato
      link
      English
      33 months ago

      Ok, but let’s realize that you’re not necessarily the one who’s defining the spectrum of options; or put another way, there’s not an objective spectrum of options.

      For instance, in the case of Israel and Gaza, you could define the leftmost bracket as “give Israel to the Palestinians” or “the second-state solution” or just “a cease-fire,” and likewise the rightmost bracket could be “let Israel keep the war going but let civilians out through Egypt” through “Israeli settlement of Gaza” all the way up to “glass Gaza.” Depending on who’s talking, and how extreme each person is in the discussion, the most humane solution might not be in the middle at all.

      • @[email protected]
        link
        fedilink
        English
        13 months ago

        I’m not seeing a conflict here. The point I’m making is that the middle ground is not necessarily in the middle of any two given opinions, because the spectrum is wider than that. And also that the middle is not necessarily the best, just worth evaluating.

        • @ilinamorato
          link
          English
          13 months ago

          It’s not a conflict. What I’m trying to say is that what people hear when you say you want to “evaluate the middle option” is entirely dependent upon the options presented in the argument, which is why the caricature is so common.

    • @CazzoBuco
      link
      English
      -14
      edit-2
      3 months ago

      Middle implies middle. If you are leaning towards a side, then you’re side-leaning. You can’t have your cake and eat it too, centrist, that’s what everyone makes fun of ya’ll for.

      • @AeonFelis
        link
        English
        133 months ago

        It’s “somewhere in the middle”. You are putting to much emphasis on “middle” and not enough of “somewhere”.

        • @CazzoBuco
          link
          English
          -73 months ago

          Somewhere in the middle means there’s a middle and side-leaning, yes.

          • @[email protected]
            link
            fedilink
            English
            73 months ago

            This is why people hate pedants. You’re technically correct, it’s just a useless distinction that only exists to make you feel better.

          • @AeonFelis
            link
            English
            4
            edit-2
            3 months ago

            Somewhere in the middle means it doesn’t have to be dead center - it just has be between the two extremes and not exactly one of the extremes. To put it in numbers, somewhere in the middle between 0 and 1 is not just 0.5. It can also be 0.4. Or 0.7. Or 0.00000000001.

      • @[email protected]
        link
        fedilink
        English
        43 months ago

        a lot of us don’t actually think the answer is always the middle ground between two stances.

      • @Jarix
        link
        English
        33 months ago

        If i have a very plain boring hamburger. Bun cheese patty bun, are the cheese and patty in the middle? Middle doesnt always mean center, center doesnt always mean exactly in the center between 2 points either because thats why the term dead center exists

      • @RedditWanderer
        link
        English
        2
        edit-2
        3 months ago

        It’s hilarious he had to make us a little drawing making up his own scale that fits this narrative.

        • @[email protected]
          link
          fedilink
          English
          73 months ago

          It’s an abstraction of a caricature I’ve seen. Point A was civil rights, point B was the KKK, and the middle ground guy was like “what if we only kill half of Black people?”

  • LazaroFilm
    link
    English
    223 months ago

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

      • LazaroFilm
        link
        English
        -233 months ago

        Oh thanks! I wasn’t sure. /s

      • @Nightwind
        link
        English
        -353 months ago

        No it’s not. The common center here is the center of our galaxy which both orbit. Even if the sun wobbles a miniscule bit there is no common orbit between them.

        • tryptaminev 🇵🇸 🇺🇦 🇪🇺
          link
          fedilink
          English
          24
          edit-2
          3 months ago

          it is possible for objects to orbit multiple objects at the same time. Add the moon to the system. The moon is orbiting the earth that is orbiting the sun that is orbiting the center of our galaxy. And yes each of them have a common center, just that it is very very close to the center of mass of the larger object in each case.

          For the moon the earth is the dominant gravitational force, for the earth it is the sun and for the sun it is the center of our galaxy

          • @Cypher
            link
            English
            33 months ago

            for the sun it is the center of gravity.

            You mean the galactic center, which in turn orbits a point somewhere in the middle of our local galactic cluster.

            • @Sylver
              link
              English
              103 months ago

              And our local galactic cluster is heading towards something ominous called the Great Attractor. It’s direction is hidden by the horizon of the Milky Way, but it is most likely another larger cluster of galaxies

        • @Donkter
          link
          English
          113 months ago

          There’s a very famous smart man with zany hair and a big tongue that says your comment is wrong and it’s all relative to your frame of reference.

        • @Zron
          link
          English
          33 months ago

          No the common center is called a barycenter and it’s somewhere just outside the middle of the sun.

    • Jaytreeman
      link
      fedilink
      193 months ago

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

      • @starman2112
        link
        English
        3
        edit-2
        3 months ago

        It’s usually not inside the sun thanks to Jupiter’s fat ass

      • @danc4498
        link
        English
        33 months ago

        So if the point is inside the sun, do we not consider the sun as orbiting that point? I would think it is still orbiting a point.

      • Ech
        link
        fedilink
        English
        23 months ago

        The sun isn’t orbiting itself, though, so to say it’s wrong is also wrong. The sun is orbiting a small point in space that is affected by the bodies around it. That the point is covered by the sun doesn’t change that.

        • kamenLady.
          link
          English
          113 months ago

          The urge to orbit a black hole is universal

            • @the_joeba
              link
              English
              8
              edit-2
              3 months ago

              Looks over shoulder Nobody’s going to take this? Sighs Fine. I’ll get this one. Clears throat

              Now we all orbit KidnappedByKitties mom.

              • @[email protected]
                link
                fedilink
                English
                23 months ago

                Get in line! It’s you, everyone and the rest of the universe!

                Orbiting…

                Slowly watching…

                Slowly descending towards the crushing abyss…

                Fast or slow, near or far, there is inevitably only Mother…

                And the complete annihilation of her touch

      • TWeaK
        link
        fedilink
        English
        5
        edit-2
        3 months ago

        The common centre is the galaxy they both orbit spiral around together.

        Then, the galaxy moves around some other point along with other galaxies.

        Then, a bunch of aliens are playing with marbles.

    • @[email protected]
      link
      fedilink
      English
      73 months 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.

    • @V0lD
      link
      English
      33 months ago

      I mean, yeah, but the bigger argument here is that due to the sheer mass of Jupiter, the centre of mass of our solar system is actually very so slightly outside of the sun

    • kronisk
      link
      English
      13 months ago

      deleted by creator

  • @hperrin
    link
    English
    18
    edit-2
    3 months ago

    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.)

    • @[email protected]
      link
      fedilink
      English
      113 months ago

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

      • @[email protected]
        link
        fedilink
        English
        43 months ago

        Wouldn’t that break relativity tho if you treat the earth as a fixed point? Stuff really far out would have to be going absurdly faster than light to orbit the earth once every 24h. I feel like that’s one of the ways to tell whether or not you’re rotating, or stuff is orbiting you.

        • @[email protected]
          link
          fedilink
          English
          8
          edit-2
          3 months ago

          Relativity works when earth is the center because it’s relative, we just calculate everything with earth as the frame of reference. It does make a lot of math harder, but that’s what we already are doing when using earth based telescopes (although we try to shift the math to a more reasonable frame of reference for most stuff, but earth is always the starting point because we’re making all the measurements from here)

        • @[email protected]
          link
          fedilink
          English
          53 months ago

          If the earth is fixed (not just in position, but in rotation), you’re using a non-inertial reference frame, and things get wonky. But you can make the math work.

        • @[email protected]
          link
          fedilink
          English
          23 months ago

          Why would objects far out need to orbit earth every 24h?

          Wouldn’t that break relativity tho if you treat the earth as a fixed point?

          To be honest, physics was never my strong point. If I remember correctly you could chose any point as your observational (?) point but maybe someone with some real physics cred can chime in.

    • @douglasg14b
      link
      English
      9
      edit-2
      3 months ago

      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.

      • @hperrin
        link
        English
        03 months ago

        I would not call it orbiting if the center is within the body. So, since the center of the sun-Jupiter system is just outside the surface of the sun, I would say the sun and Jupiter orbit the center of their system, but since the center of the sun-earth system is within the body of the sun, I would not say the sun orbits the center of this system. The path the sun takes in this system is entirely contained within its body.

        Now, since the sun, Jupiter, and earth are all in the same system, there’s even less reason to say the sun orbits the earth, since the earth has a negligible effect on the sun’s motion.

        • @douglasg14b
          link
          English
          1
          edit-2
          3 months ago

          Just because you believe that a negligible effect means that it shouldn’t be called orbiting doesn’t change the fact of the matter that there is still a shared gravitational center that both bodies orbit around…

          It doesn’t matter if it’s negligible or not, the fact of the matter is that such a point exists and both bodies orbit around that point.

          • @hperrin
            link
            English
            1
            edit-2
            3 months ago

            Then literally everything is orbiting literally everything else, and the word orbit is completely useless.

            I have a gravitational effect on the earth. The earth-hperrin system has a gravitational center that both bodies revolve around. Does that mean the earth and I orbit that center? No, because my effect on the earth is negligible. The absolutely immeasurably small wobble my mass gives the earth is not an orbit. There are bodies much more massive than me that the earth orbits (despite how many Doritos I eat).

            To put in less hyperbolic terms, Mars’ moon Phobos and Mars have a gravitational center, deep deep deep within the Martian core that both bodies revolve around. Does that mean Mars orbits this point? I don’t think a reasonable person would say so. A massive body wobbling because of a small body orbiting it is not orbiting. Only one thing in such a system is orbiting.

  • Cosmic Cleric
    link
    English
    103 months ago

    If this topic proves anything, it’s that we should make sure everyone is assuming the same thing before discussing, or clarify before discussing.

    You can literally come up with different answers without further clarification.

    • @[email protected]
      link
      fedilink
      English
      33 months ago

      Remember when we had to list all of our assumptions before making an argument?

      Those were good times. (I don’t remember when, maybe in Linear Algebra or an engineer or philosophy course.)

  • @simin
    link
    English
    63 months ago

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

    • @kajdav
      link
      English
      123 months ago

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

      • @TheFonz
        link
        English
        23 months ago

        Oh shit I’m like four chapters in. Now I’m really scared.

  • MxM111
    link
    fedilink
    53 months ago

    All is relative. All are right. Or wrong. We are orbiting galactic center.