How to put 170 atoms in an atom | Hacker News Reader

How to put 170 atoms in an atom

signoregalilei.com

120 pointssurprisetalk26 comments

> So in 2018, an international team of scientists created a BEC out of strontium atoms, and hit one of those atoms with a carefully tuned laser, exciting its outermost electron and turning it into a Rydberg atom. Several other atoms from the BEC were caught within between that outer electron’s inflated orbital.

This is not so much putting 170 atoms in one, but inflating one beyond the size of its 170-atom neighbourhood.

The hard part being to cool the neighbourhood to such an extremely low temperature that the inflated atom doesn't ionize.

Isn't there some hand-waving going on here?

The outer orbital is being treated as the last layer of an onion and the atoms are "inside" that. But orbitals are not spherical so our geometrical intuitions kinda fail.

Edit: Sorry for unclear wording: well, s-orbitals are spherical overlapping probability clouds, but they are not shells like an onion. Nor are they spheres as we commonly think of the geometrical object. To say something is "inside" a probability cloud gets difficult. Disclaimer: my memory/understanding of physics/chemistry/probability is poor. Edit 2: when orbitals of atoms overlap for molecules, don't the orbitals get funkier shaped probability distributions? Surely the same thing happens here and the cloud shapes would change - orbitals are not independent things you can just smoosh together or overlap willy-nilly due to qwuantum blah blah.

Not spherical huh, where did you learn that and where would I go to learn that

Look up "molecular orbitals" should be enough of a search to get the info

That's the Bohr model. It works surprisingly well for hydrogen. Then there's the probability-cloud model, which works much better. And then there's the “strictly speaking, the orbital isn't actually a probability distribution at all; it's a wavefunction, Ψ, and ∣Ψ∣^2 gives you the probability density” model.

It gets weird. Like, maybe-there's-only-one-electron-in-the-universe weird.

Large orbitals like this approach the classical limit, I believe.

So I thought of a nice question: how close-in does the hydrogen in Rubidium Hydride sit. For gaseous RbH and thinking in solid spheres instead of clouds:

  The bond length of RbH is ~4.5 units.

  The Hydrogen proton is *inside* the empty 5s radius (~4.7 units).

  If we added an electron ("an antibonding electron") it would go into the 5s orbital. But that stretches the bond making the distance between the nuclei ~4.8 units.

  In RbH, the Rb atom gives up its single outer 5s electron to the H atom, so there is no populated 5s electron shell in a Rubidium Hydride molecule.

A little bit of hand waving, but I don't mind it much. A cloud of steam rising from a boiling pot doesn't have a well defined border or consistent shape, but a human looking at a nearby object can usually make a clear and reasonable decision about whether or not that object is "inside" the steam cloud.

The article, rather shallow, is about Bose-Einstein Condensate (BEC).

I found it a bit more interesting that the author's middle name is Galileo, and that he is participating in a "blogging" residency [0]:

Inkhaven residency: A 30 day residency for you to grow as a writer. For one month, you'll publish a blogpost every day. Or pack your bags.

[0]: https://www.inkhaven.blog/

Hey! That's me, yep. It's a combination of a BEC and a Rydberg atom called "Rydberg polaron". This isn't the scientifically deepest article I've written, but if you want to read a more detailed description, feel free to check out the sources at the bottom.

Since the end of the 30 day residency in November, I and a few other participants have been posting weekly, so I've got a decent back catalogue and there will be more to come!

Not only Bose-Einstein condensate, which is a textbook topic in condensed-matter physics, but also Rydberg atoms, which are a very weird phenomenon that has been mostly studied recently as a sort of edge-case where quantum physics starts to look like classical physics.

I wish there were some similar "communes" for gamedevs who only make engines :')

Wait - if the 170 atoms are a Bose-Einstein Condensate, then they are really just one atom. That's the whole deal with Condensates.

Does this type of atomic engineering have the potential for creating new types of materials, like polymers?

Great way of saving space at home :)

One of my sci-fi future ideas, every time I hear about someone thinking of a new way to make warp drives, is that if we ever sort it out someone will make TARDISes for the filthy rich - a static warp bubble that moves space into a ground floor closet or room from space in an upstairs or in the attic.

Like a milder version of the gimmick in Ultraviolet.

Are we getting closer to sophons?

as a naive , it is non-intuitive for me how the lower bound is 0 kelvin, is this the temp where things truly stops oscillating (quantum level) or we just dont care .

All fields have a zero point energy/ground state energy they cannot go below. So, no they won't stop. The Heidelberg uncertainty principle also disallowes zero momentum and a fixed position.

I am here to just appreciate the article how clear it is .

The article is well-written, and is very clear, thank you!

Poor atoms. They froze them to absolute zero, of course they're going to huddle together!

As someone who did blue sky chemistry research decades ago: is this completely pointless?

How could anybody really know? You might need to travel pretty far into the future to say for sure.

From a position of naivety, anything relating to electron dissociation sounds potentially useful for nano-components to use for computation, or for superconductivity?

Honestly, no. These weird states of matter have extremely different properties to ordinary matter. Weird properties is how we get things like superconductors, magnets, semiconductors, photovoltaics.. so strange state of matter with weird properties could very well produce some magic

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