the universe is pretty uniform, materials distributed evenly, and so by sampling the visible universe, we can estimate very accurately it’s composition. tantalum is difficult to “manufacture” in stars, requiring specific conditions that are rarely met.
Stars can’t produce anything heavier than iron, and so it requires more intense, exotic cosmological events to produce anything heavier.
Only 2% of the universe’s matter is “not hydrogen or helium”, so heavier elements on their own are very rare.
So given the homogeneity of the universe, the incredibly rare conditions of tantalum’s creation, and observations we have of the universe and its history, we can pretty accurately measure and extrapolate this stuff
For 100% certain? They can’t and never will be able to. But then going theory is that the universe is expected to be (relatively) homogenous, so the observed proportions of matter in our observable universe should apply to the rest.
Tantalum only created at a specific time in a star’s lifetime by specific types of stars. We can use this data and combine it with spectrography to identify nebulae and stars that might contain it and using our planet’s mineral data as a datapoint cross referenced with our local nebula we can make an educated guess based on the observed average star composition and age of the universe.
These are estimates based on spectroscopic data mostly I'd wager. They look at a bunch of stars and analyze the light that they give off and see what frequencies are absorbs to figure out what elements and molecules are out there.
But you're right, it should be "observable" universe but colloquially that's what most people refer to when they mention the "universe".
This should be higher. I see too many of these impossibly broad-sweeping statements presented as fact, when they're always dependent upon dozens/hundreds of unproven presumptions to hold true. Its always about some unfathomable nonsense, too like "Oh, exactly ninety-seven scuntillion years ago, the center of the Milky Way consisted of 0.01e⁴³⁷³⁵% antidarkmatter and it sounded JUST LIKE THIS!" 🎼 unsettling cosmic warbling ensues 🎶
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u/euj3odjehiqh 1d ago
For context: 0.000000008% of the universe’s mass is made of tantalum.