• Michael Ossipoff
    1.7k
    Is the probe garbage? Why, I wonder. It would seem our computers, laptops, etc. would just as well be garbage. Stop using them and other such things if you find them offensive, lest you add to our violation of the universe.Ciceronianus the White

    The disused probe will be garbage when it falls into the Sun, even by the common ordinary definition of garbage: Disused material.

    I didn't say that using materials and manmade things is offensive. I said that sending them into the Sun's corona, and then letting them eventually fall into the sun, is offensive and objectionable.

    People here evidently believe that there's literally nothing that should be inviolable by human-monkey tinkering.

    ...and that not being in agreement with you is the definition of being wrong.

    In other topics here, everyone seems to be a science-hater and an evolution-denier.

    But here in this topic, people, reverse-chameleon-like, have the ability to remarkably transform themselves to staunch Defenders-Of-Science and Scientificism.

    Michael Ossipoff
  • Michael Ossipoff
    1.7k
    While the sun IS the source for solar energy, it isn't the immediate physical origin of the earth. ↪noAxioms
    already pointed this out. The disk of dust that spawned our system spawned the sun along with the planets.
    Bitter Crank

    Incorrect.

    NoAxioms didn't say that.

    The Sun wasn't formed from a disk of matter. The matter that formed the Sun was a cloud, but it almost surely wasn't a disk.

    How did a disk later form?

    The gravitational contraction of the cloud that formed the sun resulted, via the law of conservation of angular-momentum, in a disk of material spreading out from the Sun, in what we now call "the plane of the ecliptic". ...a plane perpendicular to the newly-formed Sun's axis of rotation.

    Of course the planets were later formed within that ecliptic disk, which took only a small fraction of the Sun's mass.

    Aside from that, you're confusing the meaning of "immediate origin".

    The Sun was formed from a cloud of material.

    Then the planets were later formed from the Sun.

    Yes, the Sun was was the immediate origin of the planets. They were formed directly from the Sun's material.

    Michael Ossipoff
  • noAxioms
    1.5k
    NoAxioms didn't say that.Michael Ossipoff
    Yes, I did say that.

    Nobody here has so far agree that the planets formed from the sun. The disk is not the sun. It didn't emit from the star. That's our opinion, and you differ. OK, we get that.
    In actuality the disk formed from the collective center of gravity of the cloud, and the critical mass of the central object that later ignited into the sun is not required for disk and planets to form.

    The Sun was formed from a cloud of material.

    Then the planets were later formed from the Sun.

    Yes, the Sun was was the immediate origin of the planets. They were formed directly from the Sun's material.
    The sun does emit material, so I cannot deny that there is some sun material in each planet, but since most of that blows away (especially on the inner planets), I think I can say that nobody is going to agree with your assertion that they were formed directly from the sun's material. The sun does not emit iron and oxygen for instance, and Earth is more of those than anything else.
  • Ciceronianus
    3k
    The disused probe will be garbage when it falls into the Sun, even by the common ordinary definition of garbage: Disused material.

    I didn't say that using materials and manmade things is offensive. I said that sending them into the Sun's corona, and then letting them eventually fall into the sun, is offensive and objectionable.

    People here evidently believe that there's literally nothing that should be inviolable by human-monkey tinkering
    Michael Ossipoff

    Well, our computers, etc., will be garbage some day as well then. They're disposed of on Earth, for the most part. You seem relatively indifferent about that. The Sun, then, must have a special, greater significance than the Earth. Since the probe will likely be incinerated, it will have a lesser impact on the Sun than our other garbage has on the Earth. As that's the case, your objection presumably has nothing to do with any harm to its environment which can be anticipated after the probe becomes garbage. But if it has nothing to do with that, what's the basis of the objection? Is it the mere fact that the probe, as it transforms into garbage, does so in the vicinity of the Sun and falls into it?

    If that's true then it would appear you believe the Sun should be immaculate, inviolate, untouched by man. Rather like Mary the mother of Jesus in the Catholic tradition (beatæ Mariæ semper Virgini).
  • Michael Ossipoff
    1.7k
    NoAxioms didn't say that. — Michael Ossipoff

    Yes, I did say that.
    noAxioms

    No, you didn't say that.

    You didn't say that the Sun formed from a disk of material.

    That's what I was correcting BitterCrank about in that passage. ...his use of the word "disk", in BitterCrank's sentence.

    The ecliptic disk formed the planets, but not the Sun.

    Nobody here has so far agree that the planets formed from the sun. The disk is not the sun. It didn't emit from the star. That's our opinion, and you differ. OK, we get that.

    You're quibbling about how we should define the point at which the gravitationally-contracting material became what we could rightly call "the Sun".

    When the equatorial disk was formed, it was formed, not from a loose cloud of material, but rather from an already-formed, gravitioinally-contracted, relatively dense sphere of material.

    Maybe you're saying that that dense, already-contracted sphere of material wasn't the Sun yet, if it wasn't yet emitting radiation, or generating energy from fusion. That's a matter of definition. It was already a formed compact sphere.

    I don't know at what point fusion energy began being generated. But, by the time the equatorial disk was formed, there had already been so much gravitational contraction that surely, due to compression-heating, some radiation was already being emitted from the surface of what you don't want to yet call the Sun.



    In actuality the disk formed from the collective center of gravity of the cloud, and the critical mass of the central object that later ignited into the sun is not required for disk and planets to form.

    So you're defining 'the Sun" based on fusion-reactions, rather than from the already compactly-formed sphere that's already emitting some radiation (from compression-heating).

    Fine. That's an individual matter of definition.


    The sun does emit material so I cannot deny that there is some sun material in each planet, but since most of that blows away (especially on the inner planets), I think I can say that nobody is going to agree with your assertion that they were formed directly from the sun's material. The sun does not emit iron and oxygen for instance, and Earth is more of those than anything else.

    You're asserting your definition of the Sun that says the Sun didn't exist until it had fusion-reactions.

    See above

    Having answered you here about that matter, I'm not going to argue any more about your different definiiton regarding when the formed, radiation-emitting, contracted sphere of material became the Sun

    Michael Ossipoff
  • Michael Ossipoff
    1.7k
    Well, our computers, etc., will be garbage some day as well then. They're disposed of on Earth, for the most part. You seem relatively indifferent about that.Ciceronianus the White

    I didn't say that I'm indifferent about the garbaging of the Earth. In fact, I've said the opposite,above in this topic. I said that the garbaging of the Earth is more likely to harm us, than is the Parker probe's garbaging of the Sun.

    Then what's the difference?

    The difference is that the Earth was never inviolable. We never expected the Earth to be inviolable.

    Though I oppose harmful pollution, what are you going to do with garbage? It isn't feasible to launch it into space, and so it ends up in landfill. Yes, we garbage the Earth that we're standing on. I don' like that either, but there never was a chance that the Earth could have been inviolable.

    In contrast, garbaging the Sun, intrusively experimenting on the Sun, is entirely and easily avoidable.

    The Sun, then, must have a special, greater significance than the Earth.

    See above.


    Since the probe will likely be incinerated, it will have a lesser impact on the Sun than our other garbage has on the Earth.

    See above.

    As that's the case, your objection presumably has nothing to do with any harm to its environment which can be anticipated after the probe becomes garbage.

    Incorrect. I've (repeatedly) said that the "justification" for the experiment is science's lack of knowledge about the corona in particular, and the Sun in general. That lack of knowledge can't be the basis for any assurances.

    Yes, the probe probably won't do any harm. Probably.


    But if it has nothing to do with that, what's the basis of the objection?

    I've answered that very, very many times, in this topic.

    I can't be expected to repeat it for each person who hasn't read it, above in this topic.




    Is it the mere fact that the probe, as it transforms into garbage, does so in the vicinity of the Sun and falls into it?

    ...sent into the solar corona, and also eventually falling into the Sun.


    If that's true then it would appear you believe the Sun should be immaculate, inviolate, untouched by man. Rather like Mary the mother of Jesus in the Catholic tradition (beatæ Mariæ semper Virgini).

    You know more about your Catholicism than I do.

    But yes, the Sun needn't be regarded as violable by the monkeys that refer to themselves as humans.

    Michael Ossipoff
  • noAxioms
    1.5k
    So you're defining 'the Sun" based on fusion-reactions, rather than from the already compactly-formed sphere that's already emitting some radiation (from compression-heating).

    Fine. That's an individual matter of definition.
    Michael Ossipoff
    If there is a point of the beginning of the what is the sun, it would seem to be the moment of ignition. The change is quite abrupt and it isn't a star if it doesn't happen. The opinion of apparently all the other posters on this thread is that the material that makes up the vast bulk of the planets was never part of this central condensing pre-star. If the central mass had enough angular momentum to throw out the planets, our solar-system would likely have sported a binary star as so many of them do.
    The star does eject material, but that only goes into orbit if deflected by something already in orbit. Otherwise it escapes, or falls back into the sun.
  • Michael Ossipoff
    1.7k


    So you don't believe that the ecliptic disk was formed via conservation of angular momentum, when the initial cloud contracted?

    Well, yours is a minority position, but suit yourself.

    On another subject, I don't dispute your definition of the Sun, as beginning with fusion-ignition. Definitions can be different, but not wrong. It isn't something to argue about, wouldn't you say?

    The formation of the ecliptic disk wasn't a throwinlg-out of planets. The planets later formed from the ecliptic disk.

    Michael Ossipoff
  • noAxioms
    1.5k
    So you don't believe that the ecliptic disk was formed via conservation of angular momentum, when the initial cloud contracted?Michael Ossipoff
    Trying to figure out how you got that from what I posted.

    On another subject, I don't dispute your definition of the Sun, as beginning with fusion-ignition. Definitions can be different, but not wrong. It isn't something to argue about, wouldn't you say?
    I acknowledged your altered definition and still find the planets not coming from it. I called the Sun a central condensing pre-star. Not ignited, but it was what has now become our sun.

    The formation of the ecliptic disk wasn't a throwinlg-out of planets. The planets later formed from the ecliptic disk.
    You said the sun was "the already compactly-formed sphere that's already emitting some radiation", not the ecliptic disk. If you're equating the entire disk to the sun, then any landfill is already garbage being dumped into the sun, so the probe is no different than that.
  • BC
    13.6k
    Michael Obstinate:

    Before the solar system, there was a nebula in this general region of the MW. Some disturbance (a big one -- probably a relatively nearby super nova) roiled the amorphous nebula and the dust in the nebula started moving. Particles collided, and got bigger, and began to accrete more particles. In the fullness of time, the accretion of particles begat little blobs, little blobs begat bigger blobs, bigger blobs begat still bigger blobs. The nebula, now kind of lumpy-bloby, started to turn--first slowly. As it turned, and as very slight gravitational pull of little blobs gradual attracted more matter and became bigger blobs, the messy-shape of the nebula began to be pulled by gravity into a flattened disk, still with a great deal of dust (organic and inorganic molecules). The biggest blob collected the most stuff and became the center of the disk, and the other blobs were stretched out away from the center, in some sort of order.

    The biggest blogs attracted the most dust -- and the WINNER was... the envelope please, the sun! However there were two runners-up -- the blobs that would in the far distant future bear the names of Jupiter and Saturn.

    The proto-planets and future sun began sweeping up most of the dust in the system, except the stuff out at the edges which has it's own less well understood history.

    Meanwhile, back at the ranch, the big ball of stuff at the center of the disk got so big that it fell in on itself and got denser and denser and denser until it ignited. The proto-plannetary blobs also compressed themselves and the heaviest material sank to the center of the compressing bodies and became extremely hot. The planetary bodies (the inner ones especially, being rocky) heated up so much they were balls of molten stuff.

    Besides dust and the planets, there was a big batch of chunky matter that had formed, here and there. The big outer planets' gravitation stirred up this stuff and it began to move, but it was shepherded by the various gravitational pulls of the planets. This chunky hard matter started moving toward the center, and was thrown this way and that by the rotating planets, and bombed the daylights out of the rocky planets (Mercury, Venus, Earth, Mars...).

    So, here we are, a few billion years ago: A sun, a string of planets -- all arising independently from one nebula, and a bunch of asteroids and comets.
  • BC
    13.6k
    Definitions can be different, but not wrong.

    Except when they are wrong.
  • Michael Ossipoff
    1.7k
    On another subject, I don't dispute your definition of the Sun, as beginning with fusion-ignition. Definitions can be different, but not wrong. It isn't something to argue about, wouldn't you say?

    I acknowledged your altered definition and still find the planets not coming from it. I called the Sun a central condensing pre-star. Not ignited
    noAxioms

    Well, I was referring to the forming-Sun, at the time of the outspreading of the ecliptic disk, as "the Sun", even if its fusion hadn't ignited.by that time. You're saying that it wasn't "The Sun" until that fusion-ignition.

    Either definition is fine.

    Since the Earth and other planets formed from that ecliptic disk, it seems not unreasonable to call that forming-Sun the immediate origin of the planets.

    Maybe you'd rather say that, due to the intermediary of the ecliptic disk, the forming-Sun wasn't the immediate origin of the planets, but that seems an unnecessary quibble. The Sun (or the forming-Sun) produced the ecliptic disk that formed the planets. For me, that's enough to call it the Earth's origin.

    But this definitional quibbling is unnecessary.

    If the forming-Sun, at the time that the ecliptic disk outspread from it, hadn't yet ignited fusion, and if you define the Sun's beginning as that ignition, then the forming-Sun wasn't the Sun yet. Then the ecliptic disk formed from the forming-Sun.

    If the facts and the chosen-definitions are like that, then.the forming Sun was the origin of the planets.

    With that word-change, we don't disagree. It isn't a significant disagreement.

    I'd said:

    The formation of the ecliptic disk wasn't a throwiing-out of planets. The planets later formed from the ecliptic disk.

    You repled:


    You said the sun was "the already compactly-formed sphere that's already emitting some radiation", not the ecliptic disk.

    That's right, because i was referring to the forming-Sun at the time that the ecliptic disk spread-out from the forming-Sun.

    If you're equating the entire disk to the sun

    I'm referring to the ecliptic disk as having formed from the forming-Sun.

    , then any landfill is already garbage being dumped into the sun

    No, I've just gone over and checked the nearest landfill, and it isn't being dumped into the Sun. It's just sitting there like it was yesterday.

    , so the probe is no different than that.

    Well, the probe is a little bit different from a terrestrial landfill, because the probe is a projectile that NASA is going to fire through the Sun. (The articles say that the probe will go through the corona, and that the corona is part of the Sun). ...and a projectile that will eventually hit the not-tenuous part of the Sun bounded by the chromosphere. (the luminous sphere whose image is visible on the ground, as spots of light underneath a tree, where sunlight is shining through small gaps between leaves).

    So NASA intends to shoot a projectile into the Sun twice--first into the corona, and then into the chromosphere.

    Maybe it's better not to shoot anything that you don't intend harm to. ...even if you're (almost) sure that your projectile is harmless. A 300 fps, roughly 1 foot-pound, BB, from a child's low-power BB-gun is harmless if it hits someone's clothes. So do you go downtown and walk down the sidewalk shooting people with a BB gun?

    Maybe it just isn't a good gesture.

    Michael Ossipoff
  • Michael Ossipoff
    1.7k
    Definitions can be different, but not wrong.


    Except when they are wrong.
    Bitter Crank

    Troll-talk.

    One part of the definition of a troll is his asserted assumption that what isn't in agreement with him must be wrong..

    Michael Ossipoff
  • Michael Ossipoff
    1.7k


    Bitter Crank, maybe your astro-history teaching needs a little work. Don't quit your day-job yet.


    Before the solar system, there was a nebula in this general region of the MW. Some disturbance (a big one -- probably a relatively nearby super nova) roiled the amorphous nebula and the dust in the nebula started moving.
    Bitter Crank

    Yes, it seems to me that it has been suggested that a nearby supernova might have produced a compression-wave that compressed some tenuous material enough for it to begin gravitational contraction, resulting in the gravitationally-contracting cloud that became the Sun.

    Particles collided, and got bigger, and began to accrete more particles. In the fullness of time, the accretion of particles begat little blobs, little blobs begat bigger blobs, bigger blobs begat still bigger blobs. The nebula, now kind of lumpy-bloby, started to turn--first slowly. As it turned, and as very slight gravitational pull of little blobs gradual attracted more matter and became bigger blobs, the messy-shape of the nebula began to be pulled by gravity into a flattened disk, still with a great deal of dust (organic and inorganic molecules). The biggest blob collected the most stuff and became the center of the disk, and the other blobs were stretched out away from the center, in some sort of order.

    No, gravity didn't pull the forming-Sun into a flattened disk. The gravitational attraction would have just formed a sphere. But conservation of angular momentum resulted in the contracting forming-Sun giving rise to the outspreading of an ecliptic disk.


    The biggest blogs attracted the most dust -- and the WINNER was... the envelope please, the sun! However there were two runners-up -- the blobs that would in the far distant future bear the names of Jupiter and Saturn.

    The planets formed from the ecliiptic disk after it was spread out from the forming-Sun.


    Meanwhile, back at the ranch, the big ball of stuff at the center of the disk got so big that it fell in on itself and got denser and denser and denser...

    The forming-Sun, at the time of the formation of the ecliptic-disk, was already the result of continuing gravitational collapse of the initial cloud of material. Gravitational collapse didn't wait until after the spreading of the ecliptic disk.

    Michael Ossipoff
  • Michael Ossipoff
    1.7k
    When I said "Chromosphere", I meant "Photosphere".

    Michael Ossipoff
  • noAxioms
    1.5k
    Well, I was referring to the forming-Sun, at the time of the outspreading of the ecliptic disk, as "the Sun", even if its fusion hadn't ignited.by that time.Michael Ossipoff
    If the forming-Sun, at the time that the ecliptic disk outspread from it,
    The disk spreads out?? Gravity is pulling it in, not out. You seem to envision the process as something like a ball of pizza dough spreading into a disk as it is spun in the air, and thus the planets forming as bits of dough get displaced further out.
    That requires an influx of angular inertia from the pizza guy, an influx that doesn't exist in the forming solar system. A large rotating cloud contracts (does not spread out) into a disk, losing mechanical energy (not gaining it) all the way to the heating of the places where it is collecting.
  • BC
    13.6k
    Troll-talk.

    One part of the definition of a troll is his asserted assumption that what isn't in agreement with him must be wrong.
    Michael Ossipoff

    By that definition, your insistence that the planets are derived from the sun is trollish.

    Bitter Crank, maybe your astro-history teaching needs a little work. Don't quit your day-job yet.Michael Ossipoff

    Michael Ossipoff, au contraire, it wasn't my astro-history, it was taken directly from a NASA page describing the formation of the solar system.

    I don't know where you acquired the idea that the planets were derived from a big ball that flattened out and would later turn into the sun. This erroneous belief will not interfere with your life in any significant way that I can think of, so carry on.
  • BC
    13.6k
    In other topics here, everyone seems to be a science-hater and an evolution-denier.Michael Ossipoff

    Well, there are a few science haters and evolution deniers here -- far less than in the population as a whole.

    But getting back to a sub-topic of your post, the formation of the solar system...

    One of the questions that arises, for which I don't have an answer, is how did the nebula from which the solar system is derived, pick up spin in the first place? They say nothing does not move in the universe--everything is always in motion--motion of some kind. We can see (thanks to the Hubble telescope) very large nebula (large on an astronomical scale) where stars are forming. What we can't see (given distance and time) is any circular motion. Still, the galaxy spins, stars spin, solar systems spin, and the disco ball of public relations spins (very fast).

    Whence all this spinning?
  • noAxioms
    1.5k
    Whence all this spinning?Bitter Crank
    It is statistically almost impossible that a random group of matter happens to have zero net rotational inertial. For instance, Andromeda is coming at us, but not exactly straight at us, and impossible point target. The amount off target represents an obscene angular momentum, enough to throw a great deal of the stars away when the two combine.

    Anyway, a cloud of dust is like that. You don't see the rotation in the nebulas when it is all spread out, but it's there. Contract it into a tighter radius and like the figure skater, spins far faster when the parts are pulled in. Ours actually had less rotation than is typical, and thus formed only the one star. Multiple-star solar systems are about as common as the single ones.
  • Hanover
    12.9k
    The difference is that the Earth was never inviolable.Michael Ossipoff

    The sun was never inviolable either. That's just your baseless assertion. I could just as baselessly declare the earth, mars, oxygen, my cat, or whatever inviolable. Your basis for not probing the sun is not based upon any scientific concern that we'll lose the sun, but it's based on some primitive sun worship theology that you can't understand why no one else will adopt.

    The OP can be summarized as: I worship the sun, do you? Those who agree with you might then agree with you that there should be no sun probe. Of course, their might be some sun worshipers (I'll call them Appolloians) who think the sun can successfully take on all comers and they welcome the beat down the sun will dole out to challengers. That's my view by the way, but I'm part of the Neo-orthodox wing, 1962 reformation sect Appolloian, so I'm a bit different than commoner Appolloians.
  • BC
    13.6k
    Neo-orthodox wing, 1962 reformation sect AppolloianHanover

    A memorable reformation in the sect of the far-seeing, boundary observing Apollo Sun God, if I remember correctly, which I, of course, do. We studied your sect in Classics back in 1979. I took notes. I got an A in the course.

    Yes, you have named MO's problem, obstinate sun-worship. But even sun-worshipers, worthy though they may be, should understand the origin of the disk of which their sun is the star performer. IF they don't, the TRUE worshipers of the sun will have to extirpate this heresy and burn them all at the stake. If stake-burnings happen to not be in vogue (it comes and goes), there's always the Cult Cure Camps to which they can be sent for re-education.

    False Sun Worshipers, consider yourselves warned.
  • Hanover
    12.9k
    It is statistically almost impossible that a random group of matter happens to have zero net rotational inertial.noAxioms

    True, but in an infinite amount of time, it occurs an infinite number of times, and that's nothing to sneeze at, cloud or no cloud.
  • noAxioms
    1.5k
    True, but in an infinite amount of time, it occurs an infinite number of times, and that's nothing to sneeze at, cloud or no cloud.Hanover
    Resutling in a rotation free and satellite-free system of one object, perhaps large enough to be a star, or perhaps a lonely dark planet with neither year, month, nor day. I wonder what religion they'd come up with.
  • Hanover
    12.9k
    Sneezism is the religious doctrine that holds that it was a sneeze that set off the stagnant dust form into a whirlwind that eventually evolved into ducks and cows, the two most primitive forms.
  • noAxioms
    1.5k
    But will the solar probe offending enough to bring about the coming of the great white handkerchief? Probably not, but is just 'probably' worth that kind of risk?
  • Arkady
    768
    "Since the dawn of time Man has yearned to destroy the Sun."
    -Mr. Burns of The Simpsons
  • Arkady
    768
    This picture depicts the scale of the size difference between the Sun and Earth (as well as some other planets). Even assuming that our solar probe was garbage (even muff garbage), I daresay we could toss an Earth-sized mound of garbage into the Sun and it would make little difference.

    2.jpg
  • Metaphysician Undercover
    13.1k
    The disused probe will be garbage when it falls into the Sun, even by the common ordinary definition of garbage: Disused material.Michael Ossipoff

    The probe will not be garbage when it is finished with its mission, it will be incinerated. And incinerated garbage is no longer garbage, that's why they incinerate garbage. So your argument that the probe will end up as garbage is itself garbage, because the probe will be useful until it is incinerated, and then it will not be garbage. It will never be garbage. You should perhaps direct this argument at all the unused satellites, and other things orbiting the earth, which are garbage, and not yet incinerated.

    I didn't say that using materials and manmade things is offensive. I said that sending them into the Sun's corona, and then letting them eventually fall into the sun, is offensive and objectionable.Michael Ossipoff

    I don't think you've stated very clearly why you think that this is offensive. At some point you said that it is offense to put garbage near the sun, but this is an untenable claim because the garbage will be incinerated. At another point you said that the earth, and all life derives from the sun, so the sun is somehow sacred, but this has also been shown to be untenable. You seem to believe that the sun should be, for some reason, regarded as inviolable. But how can you support this claim?

    The difference is that the Earth was never inviolable. We never expected the Earth to be inviolable.Michael Ossipoff

    Why do you expect that the sun should be inviolable? If we live on the earth, and make use of all that is the earth, to support our comfortable existence, why should we not do the same with the sun as well? We already use the sun in many ways, beginning with the photosynthesis of plants, which in turn, we use for nutrition. Why do you not view the sun as there for us to use responsibly, like we tend to look at everything else? You really have not laid out clearly and explicitly why you think that this probe is an offensive, irresponsible act.
  • Michael Ossipoff
    1.7k

    "Well, I was referring to the forming-Sun, at the time of the outspreading of the ecliptic disk, as "the Sun", even if its fusion hadn't ignited.by that time". — Michael Ossipoff

    If the forming-Sun, at the time that the ecliptic disk outspread from it,

    The disk spreads out??
    noAxioms

    Yes.

    Gravity is pulling it in, not out.

    Yes, gravity is contracting the initial cloud and the forming-Sun.

    Angular momentum is conserved

    If the radius of a rotating object is decreased, that reduces its moment of inertia. Then, the only way for its angular-momentum to remain constant is for its angular velocity to increase.

    Here's the familiar example that's often given:

    A figure-skater begins rotating with her arms extended. Then she brings her arms in, and her angular velocity increases.

    You seem to envision the process as something like a ball of pizza dough spreading into a disk as it is spun in the air, and thus the planets forming as bits of dough get displaced further out.

    Yes, the centrifugal force experienced by material at the solar equator overcomes gravity, and the material spreads out as a disk in the plane of the forming-Sun's equator.

    ...but I can't take original credit for that explanation. I must admit that others beat me to it.

    Say you're stirring your drink. As you stir it faster, the outer part rises up the glass. Centrifugal force drives some of your drink up the sides of the glass, against gravity.
    That requires an influx of angular inertia from the pizza guy

    Yes, the pizza dough would have had no angular momentum if the pizza-chef hadn't provided it.

    The pre-Sun cloud of matter had angular momentum before it began contracting, as so many objects in the universe do.

    No pizza-man was needed to add angular momentum during the contraction. It was already there.

    But no, the angular momentum needn't have increased during the gravitational contraction. The pre-existing angular momentum, and the conservation of that angular-momentum, meant that, as the rotational radius decreased, thereby decreasing the forming-Sun's moment-of-intertia, the angular velocity had to increase.

    Yes, the forming-Sun was a nonrigid mass of material, rather than a rigid-body, but the conservation of angular-momentum still applies.

    , an influx that doesn't exist in the forming solar system.

    See above. The forming-Sun already had angular-momentum--that of the cloud from which it formed.

    No increase in angular-momentum was needed to spin-out the ecliptic disk. The decreasing overall radius of rotation, of the forming-Sun, meant that a large increase of angular-velocity was needed in order to conserve angular momentum.

    A large rotating cloud contracts (does not spread out) into a disk

    ...if only gravitational attraction were operating.

    Gravity tended to form a sphere. The pre-existing angular-momentum, and the reduction in moment-of-inertia, inevitably (due to conservation of angular-momentum) resulted in a great increase in angular-velocity, spinning-out the ecliptic disk along the plane of the forming-Sun's equator.

    That's not my idea. It's the now-accepted explanation for the formation of the ecliptic disk from which the planets were formed.

    , losing mechanical energy (not gaining it)

    Mechanical energy (gravitational potential energy) was of course being converted to heat of contraction, so, yes, mechanical energy was being lost.

    But no: Angular-momentum wasn't being lost. Angular-momentum is conserved.

    Michael Ossipoff
  • Michael Ossipoff
    1.7k


    You badly misunderstood what you read, BitterCrank.

    The formation of the ecliptic disk, spun-out from the contracting forming-Sun isn't my theory. It's the now-accepted explanation for the formation of the ecliptic-disk, from which formed the planets.

    Michael Ossipoff
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