3 ms·

Funny, just recently I was thinking about this since I have not heard about anything new regarding this in ages. Chemists call this an Island of stability. htt

Funny, just recently I was thinking about this since I have not heard about anything new regarding this in ages. Chemists call this an Island of stability. https://en.wikipedia.org/wiki/Island_of_stability https://en.wikipedia.org/wiki/Island_of_stability But claiming, with very limited data, that this asteroid consists of ultraheavy, unknown elements of the periodic table violates Occams razor. I predict he is wrong.

credit_guy 3y ago
Of course they are wrong. I can't read the actual article, it is behind a paywall, but my guess is that they qualify heavily any statements about superheavy elements on the 33 Polyhymnia asteroid, otherwise I can't see how it could pass peer review. From the abstract of the article, it appears that it is simply presenting some numerical calculation that show that the element 164 would have a density in a certain range (36-68 g/cm3) given some models of the nucleus and of the electron shells. The numerical methods could be innovative enough that the article is worth publishing. But 33 Polyhymnia being rich in this element is complete nonsense. There is no plausible scenario where an asteroid would be composed exclusively out of such an element. Heavy elements are created in supernova explosions. They are relatively rare. You can find them in small proportion among more frequent elements, such as iron, nickel, lead, etc. There is no scenario where you'd find only a superheavy element in isolation. Uranium has an average concentration of 2.8 parts per million on Earth. Much, much more likely is that the estimation of the mass of 33 Polyhymnia was erroneous. Here's why: you can't measure the mass of a celestial object by how far it moves around the Sun. All objects will move with the same speed on the same orbit. You can however determine the mass of the Sun by observing a single planet. Similarly, you can measure the mass of Jupiter by observing how fast its satellites go around it. You only need one satellite, but if you have more, it will only increase your confidence. You can estimate like this the mass of all the planets, with a very high accuracy. But you can't estimate the mass of small celestial objects that don't have satellites. Instead you look for n-body interactions, and there are such in the asteroid belt. But for any asteroid there, the main forces are the gravitational attraction to the Sun and Jupiter. A distant third will be Mars, and occasionally asteroids feel the gravitational influence of their neighbors. But not very often, because distances between asteroids are actually astronomical. So, the most likely explanation (virtually certain) is that whoever estimated the density of 33 Polyhymnia to be 75 g/cm3 was simply wrong. There was no subsequent confirmation. 75 g/cm3 is such an extraordinary claim, the it requires truly extraordinary evidence, and such evidence is entirely lacking.
- Beijinger 3y ago
  On the other hand, there is an obscure Russian paper about asteroids. https://www.researchgate.net/publication/279166139_Charge_spectrum_of_superheavy_nuclei_of_galactic_cosmic_rays_obtained_in_the_OLIMPIA_experiment https://www.researchgate.net/publication/279166139_Charge_sp... Abstract—In this paper, we present the last results of the OLIMPIA experiment on the search forand study of traces of heavy and superheavy element nuclei of galactic cosmic rays in olivine crystalsfrom meteorites. The charge spectrum of cosmic rays in the region of heavy nuclei is obtained, threesuperheavy nuclei of natural origin with charges in the range 105 <Z<130 and lifetimes longerthan 3000 years, being a part of the so-called “stability island”,areidentiﬁed.DOI: 10.3103/S1068335615050073
  - credit_guy 3y ago
    This is fine, but nothing to do with the claim that 33 Polyhmnia has a very high density. The study you cite mention "traces". Traces of heavy elements can't change significantly the density of an asteroid.
    - Beijinger 3y ago
      Fuck the traces or not. "being a part of the so-called “stability island”" This is still an extraordinary claim!
- finite_depth 3y ago
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credit_guy 3y ago

Of course they are wrong. I can't read the actual article, it is behind a paywall, but my guess is that they qualify heavily any statements about superheavy elements on the 33 Polyhymnia asteroid, otherwise I can't see how it could pass peer review. From the abstract of the article, it appears that it is simply presenting some numerical calculation that show that the element 164 would have a density in a certain range (36-68 g/cm3) given some models of the nucleus and of the electron shells. The numerical methods could be innovative enough that the article is worth publishing. But 33 Polyhymnia being rich in this element is complete nonsense. There is no plausible scenario where an asteroid would be composed exclusively out of such an element. Heavy elements are created in supernova explosions. They are relatively rare. You can find them in small proportion among more frequent elements, such as iron, nickel, lead, etc. There is no scenario where you'd find only a superheavy element in isolation. Uranium has an average concentration of 2.8 parts per million on Earth. Much, much more likely is that the estimation of the mass of 33 Polyhymnia was erroneous. Here's why: you can't measure the mass of a celestial object by how far it moves around the Sun. All objects will move with the same speed on the same orbit. You can however determine the mass of the Sun by observing a single planet. Similarly, you can measure the mass of Jupiter by observing how fast its satellites go around it. You only need one satellite, but if you have more, it will only increase your confidence. You can estimate like this the mass of all the planets, with a very high accuracy. But you can't estimate the mass of small celestial objects that don't have satellites. Instead you look for n-body interactions, and there are such in the asteroid belt. But for any asteroid there, the main forces are the gravitational attraction to the Sun and Jupiter. A distant third will be Mars, and occasionally asteroids feel the gravitational influence of their neighbors. But not very often, because distances between asteroids are actually astronomical. So, the most likely explanation (virtually certain) is that whoever estimated the density of 33 Polyhymnia to be 75 g/cm3 was simply wrong. There was no subsequent confirmation. 75 g/cm3 is such an extraordinary claim, the it requires truly extraordinary evidence, and such evidence is entirely lacking.

Beijinger 3y ago
On the other hand, there is an obscure Russian paper about asteroids. https://www.researchgate.net/publication/279166139_Charge_spectrum_of_superheavy_nuclei_of_galactic_cosmic_rays_obtained_in_the_OLIMPIA_experiment https://www.researchgate.net/publication/279166139_Charge_sp... Abstract—In this paper, we present the last results of the OLIMPIA experiment on the search forand study of traces of heavy and superheavy element nuclei of galactic cosmic rays in olivine crystalsfrom meteorites. The charge spectrum of cosmic rays in the region of heavy nuclei is obtained, threesuperheavy nuclei of natural origin with charges in the range 105 <Z<130 and lifetimes longerthan 3000 years, being a part of the so-called “stability island”,areidentiﬁed.DOI: 10.3103/S1068335615050073
- credit_guy 3y ago
  This is fine, but nothing to do with the claim that 33 Polyhmnia has a very high density. The study you cite mention "traces". Traces of heavy elements can't change significantly the density of an asteroid.
  - Beijinger 3y ago
    Fuck the traces or not. "being a part of the so-called “stability island”" This is still an extraordinary claim!
finite_depth 3y ago
[dead]