Friday, January 25, 2019

Now you see it, now you don't

        Well, actually, now you don't see it, now you still don't. I'm referring to Nibiru, or Tyche, Planet X or Planet Nine. A trans-Neptunian object in a 15,000-year orbit, much loved by pseudo-astronomers including Messrs. Hoagland & Bara. These two half-educated speculators wrote about it in their 2007 book Dark Mission (NOT a NYT best-seller despite its authors' frequent claims). The speculation was, actually, either one massive planet in a posigrade orbit, or two smaller ones going retrograde (p.115, 2nd edn.). It was based on a diagram plotting specific luminosity (W/kg) vs. specific angular momentum (sq cm/sec) that hoagland took from a book called The New Solar System then slapped his own copyright on it. The figures the diagram uses include, in each case, the named body plus anything in orbit around it.

        According to him, the solar system as a whole has less angular momentum than it should, and Planet X (or Planets -y and -z) would bring it into line. I don't think either Hoagland or Bara understand what specific angular momentum means (it means angular momentum per unit mass, so to arrive at the true angular momentum of the solar system, you'd need to multiply that number for 'Sun' in the diagram—4 x 1020 approx—by the mass of the whole kit and caboodle).

        When, in January 2016, Batygin & Brown of CalTech lent their support to Planet X on the basis of the orbital anomalies of six Kuiper Belt objects, Mike Bara did the Toldya dance on his blog. But he got totally confused between Planet X and Nemesis, a hypothetical brown dwarf companion of the Sun that has nothing to do with the Kuiper Belt. Stuart "astroguy" Robbins expressed more than a modicum of skepticism about the announcement from CalTech.

An icy disc
        This week Sefilian and Touma of Cambridge University and the American University of Beirut have come up with a model that explains the orbital anomalies without requiring a massive trans-Neptunian object (TNO).note 1
 "We wanted to see whether there could be another, less dramatic and perhaps more natural, cause for the unusual orbits we see in some TNOs. We thought, rather than allowing for a ninth planet, and then worry about its formation and unusual orbit, why not simply account for the gravity of small objects constituting a disc beyond the orbit of Neptune and see what it does for us?
"If you remove planet nine from the model and instead allow for lots of small objects scattered across a wide area, collective attractions between those objects could just as easily account for the eccentric orbits we see in some TNOs." --Antranik Sefilian
        The hypothesised icy disc probably has a mass equivalent to ten Earths—not very muchnote 2, but Sefilian and Touma say it's enough. They aren't claiming to have actually observed such a disc, just to have worked out the physical implications assuming it exists. It's important to understand that nobody claims to have actually observed Planet X, or Nibiru, either. Now you don't see it, now you still don't.

=========================/ \========================
[1] Antranik A. Sefilian, Jihad R. Touma. Shepherding in a Self-Gravitating Disk of Trans-Neptunian Objects. Astronomical Journal, 2019

[2] Neptune is 17 Earths, Jupiter 318


astroguy said...

For what it's worth, many of us were very skeptical of the "Planet 9" stuff by the CalTech folks. For several (real science) reasons.

Chris Lopes said...

To some of us, it would be planet 10 if it existed. Pluto is still a planet and Han shot first! ;)

Two Percent said...



Not sure which him you refer to here:

" According to him, the solar system as a whole has less angular momentum than it should, "

but I don't know why the Solar System "should" have more angular momentum than it does. On what basis? Compared with what? I haven't read any of the relevant material, but I'm wondering if you can enlighten us, please?

Basically, what that means in my simple understanding is that it "should" all be spinning faster than it is, but that would change everything, surely? All planetary orbits would be larger, and Earth might then be outside the Habitable Zone so I don't see where they are coming from. Do you? Can you throw any light on the reasoning - or unreasoning, as the case may more likely be?

Or, are they trying to suggest that the sun is spinning too fast compared to the planets, or what the heck? How so, if so? Any fascinating pearls of wisdom for us?

expat said...

"Him" is Hoagland.

Look at the diagraam. Since five planets (plus their moons) fall roughly on a straight line, he speculates that there is some underlying law of physics accounting for that. However, projecting upwards towards the specific angular momentum (and luminosity) of the solar system as a whole, it does not adhere to this imagined law. He is saying that if there are undiscovered outer planets, perhaps the SS would hit that line.

Yes, it's extremely dodgy reasoning and I really do not think Hoagland understands that these figures are per unit mass.

Chris Lopes said...

Hoagland doesn't need to fully understand a particular scientific concept as long as he understands it better than his audience. So he can conceivably no nothing at all about what he's talking about and still make the sale if his audience is even more ignorant. That's been his business plan since the 1980's anyway.

Two Percent said...

Hi expat,

Thanks for that. Clearer now. I agree:

"Yes, it's extremely dodgy reasoning and I really do not think Hoagland understands that these figures are per unit mass. "

Who cares about the per unit mass issue? Not Hoagie, obviously. But that makes it all the more interesting.

Actually, it's damn interesting (ignoring the luminosity for now at least).

The most interesting point is the fact that the planets listed (not to mention the few that have been omitted, no doubt because they don't fall near the line at all) do actually appear to fall near that line, Oh... ignoring the Sun of course, which is by far the major player and should by rights be the first one through which the line passes. But that would be just 'inconvenient'.

It's ridiculous to suggest the line should not include the Sun, and the fact that the Sun is off that arbitrary line shows how idiotic the proposer is.

In addition, all the planets listed, except Earth, are giant, outer ('gas') planets, so really Earth is the odd man out, in every respect. I'd love to see where Mercury, Venus & Mars (and Pluto) would fall on that graph.

Simply, it appears the data has been cherry-picked to try to imply some "great discovery" where there truly isn't one. If the line was drawn correctly, Jupiter (and Saturn) would be off the line, and he should be raving about that instead.

I agree entirely, Chris.

Anonymous said...

In setting this pseudoscience up, did Hoaxland invoke his HyperDimensional Handwaving Numerology? Tell me he did, I'd be heartbroken if he hadn't invoked his pet "arctangent of pi over whatever" voodoo!

David Evans said...

Hoagland should have considered that extrapolating from a small subset of planets does not always work. See Bode's Law.

expat said...

Nonsense comment from Theadora disallowed. Yes, dear, I'm "censoring" you and I will every time you invoke astrology.

Aleck Schmart said...

Why do Ice Ages only occur when Earth is at an apex of the elliptical path of Precession, if they occur and why is that the location and time when Earth is most frequently impacted by bollides?

Two Percent said...


I think the Milankovitch cycle(s) is/are (part of) the answer to part (a) of your question. Increased axial tilt causes reduced temperatures, I think due to increased reflection by the polar ice caps but I'm not certain.

As for part (b), is it? Didn't know that. What's the source, please?

Two Percent said...

I did a little research on this Angular Momentum fantabulation.

According to various sources, the Sun accounts for less than 4% of the total angular momentum of the Solar System (as Rotational A.M., naturally), so its S.A.M. must be relatively insignificant, making that graph completely up the creek. Jupiter has the bulk (60% of the O.A.M., I read), and the other giants, by virtue of their sizes and distance, must hold most of the the remainder.

Found this page:

from which Excel calculated the following Orbital S.A.M. values (also in cm2/s):

Mercury 4.43E+16
Venus 6.01E+16
Earth 7.13E+16
Mars 8.76E+16
Jupiter 1.62E+17
Saturn 2.20E+17
Uranus 3.11E+17
Neptune 3.90E+17
Pluto 4.46E+17

I haven't bothered with their Rotational S.A.M. values as they are orders of magnitude less in each case. (Not to mention problematic, with multi-phase planets.) Most notably, and not so unexpectedly, all the gas giants have increasing Orbital S.A.M. values with distance from the sun, contrary to what is depicted in 'that' graph. Perhaps more surprising, ALL the planets (inc. Pluto) fit the same pattern.

I also haven't bothered graphing these results, but someone else may like to.

Unless Hoagie is somehow calculating the entire SS's angular momentum as it orbits the centre of the galaxy, I dunno what he's talking about. But I guess, nor does he.

expat said...

Thanks for the research, 2%, it's useful. I wasn't aware that orbital was so much greater than rotational.

There's a point you are missing, however. The graph constructed by The New Solar System calculates rotational AM inclusive of any satellites. In the case of the Sun, the satellites are the planets.

Aleck Schmart said...

Clube and Napier, Cosmic Winter, 275

Figure 20. An early temperature record of the last major glaciations, after Dansgaard and
his colleagues, from a study of cores extracted from the Greenland ice cap. According to
the theory described here, this is essentially a record of stratospheric dusting due to
material from the progressively disintegrating Comet Encke progenitor. Note the rapid
flickering, the suddenness of onset of individual ‘flickers’, each a cosmic winter, and the
rapidity with which the ice age ended. These sudden changes are not consistent with
slow orbital and polar variations as the prime movers, but are expected on the giant
comet picture.

expat said...

Aleck: This is wildly off topic. I've allowed it but no more of these, please.

Aleck Schmart said...

Niberu be damned, a rock by any other name would hit just as hard. There's major shit on the way as usual this neck of the woods.

Two Percent said...

Aleck, expat,

Many thanks for the link. 28 years old now, but pretty darn interesting all the same. More grist for the mill. Cheers.

Regarding the SS AM and Luminosity topic. Been pondering it overnight.

Thanks, expat, for pointing out what I had presumed was unintended. IF the "Sun's" AM DOES include the AM of all orbiting bodies, then isn't the whole thing even more meaningless?

Can't honestly see how Luminosity has any meaningful relationship to Angular Momentum anyway. Not to mention that the sun, unlike the rest of them, is undergoing nuclear fusion. (Reflective) Luminosity is most often dependent on purely superficial planetary features - the colour of the surface or most optically relevant layer, which may arise from any number of causes. Take Europa, for example.

Thus, I think it's pure Hoagwash.

Besides which, errors have been made. My calculations of SAM are 10^2 off. But they align with Hoagie's, so maybe he made the same error, and the whole thing is a crock! Oh, and of course, SAM is entirely dependent on the characteristics (size, period) of the orbit and nothing more, so Crock^2 to that!

Afterthought: Maybe Hoagie has heard of the H-R Diagram, and is hoping to become famous for 'his' "H-W" Diagram for planetary systems. Fat Chance!

Anonymous said...

Has someone cloned the OrbDrooler? Makes about as much sense.

expat said...

« Can't honestly see how Luminosity has any meaningful relationship to Angular Momentum anyway. »

I'm 99.99999999% sure that it doesn't. I'm also 99.999999999999% sure that two undiscovered planets in retrograde orbits would decrease, not increase, rotational ang. mom.

In other words, this whole thing is as much bollocks as the rest of Dark Mission.

Anonymass said...

There is a concerted effort to prohibit poignant bloggers from gaining notable reputation. I'm the most notorious troll on the Internet. I don't care about fame. Truth exists irrespective of futile efforts to erase it.

Two Percent said...

Gutsy AHA Poster said:

Makes about as much sense.

Referring to what, I wonder... Nothing like a good bit of ambiguity.

And Anonymaas “I'm the most notorious troll on the Internet. I don't care about fame.”:

Please accept the annual ‘Goat of the Day’ Award!