# Talk:2100: Models of the Atom

No mention of the Platonic solid model? DanielLC (talk) 05:56, 18 January 2019 (UTC)

```   Not yet. My favorite of those 5 is the double cube, AKA the Octahedron. Haph (talk) 06:35, 18 January 2019 (UTC)
```
My good sir DanielLC: I presume that Randall neglected to mention it because the first evidence-based atom theory didn't come until 1810 and John Dalton. The atom theories of the ancient Greeks were mostly philosophical posturing, in my opinion.
We seem to be missing the [Acorm Atom] as well. Kazzie (talk) 10:16, 18 January 2019 (UTC)

According to [lecture notes by the astronomer Neil Trentham], mass in the universe ist 75% H (mostly 1p+0n=1) and 25% He (mostly 2p+2n=4). As He is 4 times as heavy and 3 times as seldom, there is 12 times more H than He => The ratio n/p is 1/7. We can assume that in the 538 model the statistics was done on atoms comprising few Hydrogene, e.g. only the earth's mantle. In heavier elements the ratio n/p > 1. Sebastian --172.68.110.70 07:39, 18 January 2019 (UTC)

What are the numbers? Is 173 an error for 137, the fine structure constant? Sabik (talk) 10:36, 18 January 2019 (UTC)

It reminds me of the mass of the top quark (even though the current best value is 172.44 GeV, 173, as measured at the time at Tevatron, was used as a good approximation for a long time. The latest Particle Data Group review also gives something rounding to 173) 141.101.107.174 13:55, 18 January 2019 (UTC)
Do they really need a table for explanation? wouldn't a simple list be much easier to read? in my POV (which AFAIK is shared by many here) a table with just 2 columns is not useful at all --Lupo (talk) 14:17, 18 January 2019 (UTC)

The tiny bird model puzzles me completely. Is it a reference to any interim (even if obscure) scientific model or is it a completely facetious Randall's invention? Or is it a reference to something unrelated? Any ideas? -- 162.158.92.34 12:55, 18 January 2019 (UTC)

The absolute scale of physical constants seldom has specific meaning. See h vs ħ (h bar). Neither is right or wrong and they can be used interchangeably (when putting the 2*pi in or removing it at the same time). The same is true for dimensionless constants. E.g. 4*pi *(h bar) = 2 *(h). So the 4*pi as dimensionless constant is as correct as 2 or any other dimensionless number, as you can rescale other constants. If you redefine some natural constants, the value 137 also changes. Most dimensionless constants can be deduced from mathematics with a known or yet unknown underlying physical theory. For example all chemical properties of elements (=chemical constants) can be calculated from the underlying physics by very complex mathematical terms. For an excursion that also mathematical constants are open for debate, see the Pi vs Tau debate. Both are correct. Sebastian --172.68.110.46 15:16, 18 January 2019 (UTC)