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I wonder if in other places (galaxies and planets), the atoms could behave differently thus creating other forms of life. But I have no idea if that makes any sense.



No - the laws of nature are the same. https://en.wikipedia.org/wiki/Cosmological_principle

> Astronomer William Keel explains:

> The cosmological principle is usually stated formally as 'Viewed on a sufficiently large scale, the properties of the universe are the same for all observers.' This amounts to the strongly philosophical statement that the part of the universe which we can see is a fair sample, and that the same physical laws apply throughout. In essence, this in a sense says that the universe is knowable and is playing fair with scientists.

There is no evidence that the nature of the electron or carbon atom is different in different parts of the universe. This would be detectable (if it was) by shifts in the spectral lines for atoms or differences in ratios of elements.

The law of gravity appears to be consistent throughout the observable universe. The physics of atoms and ratios associated with nucleosythesis have been shown to be consistent.

The constants of physics appear to remain constant over billions of years ( https://apod.nasa.gov/apod/ap050220.html - " Oklo by-products are being used today to probe the stability of the fundamental constants over cosmological time-scales" )

How do we know that distant galaxies are composed of matter rather than anti-matter? If equal quantities of each were produced in the big bang, might not some parts of the universe contain primarily matter and other parts primarily anti-matter? - https://www.scientificamerican.com/article/how-do-we-know-th...


Just reinforcing what you say, spectroscopy offers an exquisitely precise test of our laws of physics in remote places.


Molecular physics is apparently quite different in strong magnetic fields, like those on the surface of compact stars.

https://www.nature.com/articles/nature.2012.11045 ("New molecular bonding mechanism predicted in exotic stars’ atmospheres")

Maybe one could speculate about a white dwarf star, cooled down to room temperature over astronomical eons, with some sort of life then evolving on its extremely magnetized surface. Its laws of chemistry would work differently.


From my understanding, there is a strong assumption backed by observations that matter and physics work the same way everywhere in our universe.


Chemistry is somewhat environment- and temperature-dependent, but there's no other element that behaves like carbon in any known conditions.

Carbon's chemistry comes from three major factors:

(1) It forms four bonds readily. (2) It can form double- and triple-bonds readily. (3) It bonds strongly to itself in a configuration that allows it to form long chains.

(1) is satisfied by other elements in its column on the periodic table, but silicon (the next element down in its group) and the following members (germanium, tin, and lead) fail (2) and increasingly (3). Silicon will form chains, but is reluctant to form double bonds; in general, double bonds become weaker for atoms further down the table. Silicon (and silicone, chains of Si-O bonds) are the most promising analogs but they have a lot of problems.

(2) is satisfied by most other light nonmetals, but those nonmetals mostly fail (3) and almost all fail (1).

The highly-electronegative oxygen doesn't really want to bond with itself (failing 3) and almost always takes a -2 oxidation state (failing 1).

Nitrogen actually does form four-bond atoms decently often (most notably the ammonium ion), so it somewhat satisfies (1) to some extent, but is so eager to form N2 that most polynitrogen compounds are wildly unstable to the point that "nitro" is a term even laypeople know is associated with explosives (failing 3).

Boron can form three bonds, allowing some of the complexity of (1), and will form nice polyboron compounds (3), but doesn't like forming double bonds (failing 2), and the bonds in boranes are so weak that they're mostly quite reactive (weakening 3).

Sulfur will form polysulfur chains (the most common form is an eight-membered ring), but sulfur (like its cousin oxygen) usually doesn't form more than two bonds except with extremely electronegative partners (like its effective total bond order of 3 in sulfur dioxide or 4 in sulfur trioxide).

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There's another problem here too: life is likely to form out of common elements in its environment, and carbon is just WAY more common than the alternatives. The mechanisms by which the elements are formed in stars very strongly favors elements with even atomic numbers (because they are mostly formed from helium-4 nuclei) and the burning processes peak at carbon/oxygen, neon, magnesium, and silicon.

As a result, carbon is very common. It's the fourth most common element in the Universe (after hydrogen, helium, and oxygen), and ~an order of magnitude more common than any of the elements discussed above except oxygen (which has basically no analogs to carbon chemistry).




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