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Previously unknown isotope of uranium discovered (phys.org)
121 points by wglb on April 10, 2023 | hide | past | favorite | 61 comments



I am not a physicist, so I am hoping someone with more understanding can explain this to me. Why do we say that we "discovered" a new uranium isotope that scientists effectively created in a lab under very specific, man-made conditions? How come we don't say that we "manufactured" this new isotope? For all intents and purposes, this kind of atomic configuration would not exist except for man's specific efforts.


Because whether or not an element/isotope can exist is a property of nature. We have to discover whether it can exist.

Manufacturing implies we can have any element/isotope we want, which is not the case. By attempting to manufacture, we discover whether manufacture is possible. We discover the existence of a new isotope.

Whether an isotope can exist is a property of the universe. We similarly discover the speed of light, discover quantum mechanics, discover radiation, etc.


Great explanation!

This also fixes a misconception that resources is something we just find and use.

Resources are properties of nature we discover.

There are lack of resources, only lack of knowledge to help discover how we turn things into resources.


It takes a lot of energy to create matter...


More like can exist for an observable amount of time. Can smash particles together, and for a tiny moment you can have an arbitrary isotope.


Couldn’t you say the same thing about cars? You can’t just manufacture a car that gets 200k mpg. So we discovered a car that can get 30mpg. Which we don’t say.

Or is it different?


It's different because with properties of the universe, we use the word discover.

Cars aren't properties of the universe. Elements and isotopes are fundamental enough, though, that we put them in that category.


I am not satisfied with the other answer, because while it is correct I don’t think it makes the distinction clear enough. So I’m gonna ELI5 it, dumb it down far more than you need it to be, because it gives me the chance to make silly metaphors.

The atom that they found - let’s call it Bob - was, for all intents and purposes, created.

The discovery isn’t of Bob. He’s cool and all, but he doesn’t stay around for a long time so there isn’t much that he can pers… atomly do for us.

So what’s cool about Bob that we can record and know for later? Well, there are two things to point out. First is that Bob stuck around for a while. The second is that Bob is governed by the laws of physics.

Therefore an atom with the same properties as Bob can, according to the laws of physics, stay around for a while. That’s the actual discovery.

Well, this discovery can be summarised more succinctly than “we found that things with the same properties as Bob can exist for a while”, because the name for the class of all things that have the same properties as Bob is the isotope Uranium-241.

Now, we can say that Bob is Uranium-241 just like we can say that I am a member of the human race, but just like we can’t say the human race IS me, we can’t say Uranium-241 IS Bob. Uranium-241 is the mere category of things that we know Bob was one of.

If aliens created a wormhole that accidentally sucked you away to their planet and they saw you, did they discover nonethewiser? Or is it more profound that they discovered the human race?

Same goes for this. We can say that we discovered Uranium-241 (which is shorthand for “we discovered that Uranium-241 is stable enough to survive long enough to be measured”). We did so by creating Bob, which merely acted as proof.


The ideal thermodynamic cycle was discovered in the 19th century [1]. We've known ever since why 200k MPG is impossible and we later discovered the design that evolved into the modern internal combustion engine, a process which was mostly engineering, metallurgy, and the development of industrial quality control.

[1] https://en.wikipedia.org/wiki/Carnot_cycle


In addition to what other posters have said, I think some of it is just historical.

Before we had the ability to manufacture & detect new isotopes & new elements, we really did discover them. We could go poke around, explore new conditions that we hadn't explored before, and sometimes you'd actually discover a new isotope or element.

Imagine you light something on fire, you capture the gasses and analyze them, and for the first time in human history you see sulphur. Did you manufacture the sulphur? Or discover it? Intuitively it probably feels like the sulphur was discovered but the uranium in the OP was manufactured, but really it's just a spectrum of how much work one needs to do to create the conditions that the universe requires to show you the element or isotope.

Another interesting language question (IMO) is, once you can predict the existence of elements, their behavior, etc., what do you call it when you see the physical version for the first time? Did the person who first predicted the configuration & properties discover it? Did the person who created the physical version for the first time discover it? Did anyone discover it? Does it matter how much insight was required to make the prediction?

Now that we're pretty good at predicting elements & isotopes, maybe the better way to phrase it is "discovered a process that produces xyz". Or if something unexpected happens, "discovered xyz is able to physically exist".


I'm reminded of Victor Ninov, who made a career out of fraudulently 'discovering' superheavy elements. It's kindof the perfect crime, since they were all theoretically well understood, you just fabricate a detection of those predicted properties. It helps too when you're the only person the planet who understands the data-analysis software.

https://www.chemistryworld.com/features/victor-ninov-and-the...


It's a cultural convention. Physicists are not rewarded for manufacturing things, they are rewarded for discovering things. So even if the process resembles manufacturing, they call it a discovery so they can publish a paper.

Alternatively, you could say that "discovering a new isotope" is shorthand for "discovering the process by which a new isotope can be produced".


The fact that this process leads to the creation of an isotope is the interesting part, not the fact that they managed to do it.


It was likely created in the same process that created other isotopes of Uranium (probably neutron star collisions) but didn't last very long.

Plutonium was long considered a "man-made element" and it mostly is but if you look carefully at natural uranium you will find occasionally a neutron hits a ²³⁸U atom and winds up making ²³⁹Pu but it doesn't last long so you find only the smallest traces of it.

https://www.epa.gov/radiation/radionuclide-basics-plutonium


It's a matter of convention. As you go up the chain away from more applied fields, you stop "designing" and "creating" things and start "discovering" that they are possible. Mathematics and Physics are discovered, Chemistry uses both depending on the specific topic, pretty much all engineering is designed.

A good way of thinking about it is considering intent. An engineer designing and then manufacturing a new car wants a to build a new car. A physicist making a new isotope just wants to prove that such an isotope can exist. In fact, often "discoveries" are can be purely mathematical: if you show a particle can exist in theory, that can be given a similar amount of weight as "proving" it by actually creating the particle.


Because the conditions for the universe to allow for this configuration of matter existed before man.

Humans, a product of the universe itself, just discovered or found a way to configure matter this way.

Great question though and one I like to ponder myself.

Like the logic to describe math itself is put down by humans but that that logic is able to exist at all for humans to discover or exlore is perplexing.


> Because the conditions for the universe to allow for this configuration of matter existed before man.

> Humans, a product of the universe itself, just discovered or found a way to configure matter this way.

If you accept this as the distinction between "discovery" and "manufacturing", then everything in existence is discovered rather than manufactured, which feels like a useless distinction to make. I think this is just an inherently fuzzy line. An ancient example of this is the debate around whether mathematical concepts are discovered or invented.


> then everything in existence is discovered rather than manufactured

The first time this is true. But the second time it's a known process with a known outcome (and if it isn't, then you've just discovered something else). The first time is always science. The second time is usually technology.


Sorry, yes, I should have specified that


"everything in existence is discovered rather than manufactured, which feels like a useless distinction to make."

Is it all that fuzzy or useless if you shift your thinking to view things as discoveries made by you rather than manufactured by you?

Manufacturing something could be a process carried out by human intelligence but the knowledge to process stuff into something 'more' is a discovery to be made.

i.e. people make/invent chairs but discovered/experience a universe that lets them sit on chairs.


So humans discovered a way for matter to be configured in a new configuration for this uranium isotope, but we didn't discover how to arrange things into the shape of a chair?


No?

You just showed up to observe the universe and was gifted some ability to manipulate it to your advantage.

You can say you were first to have an idea and we have a society that says you can have a right to 'own' that idea to sell or make money from it.

But you didn't make a universe; a universe made you and you get to have ideas that are new, hopefully.


It was discovered that it was something that can be created.


In addition to the other comments, I think what differentiates a discovery like this from manufacture is the serendipitious nature of the act of discovery. Manufacturing something implies that you have a regular process to make it on a large scale. But this was a chance discovery.

The scientists shot some uranium nuclei into doughnut shaped gas cell hitting a rotating target of plutonium nuclei. This was a new method of creating and measuring heavy isotopes that they say makes the process easier, so it would be fair to say that they "invented" the process. They ended up with a bunch of ionized particles produced by the collision. They then measured those particles via time-of-flight mass spectrometry -- essentially, the velocity of the particles in the gaseous medium could be used to precisely determine their weight to an unprecedented level of accuracy.

But to their surprise, among the various isotopes they measured, was one uranium isotope that nobody has ever encountered before.

You could say they "made" the isotope in the particle collision process, but it wasn't a deliberate goal or by product. Hence it was a discovery. If there turned out to be an industrial use for this newly discovered isotope, and engineers came up with a way to produce it on a regular basis, then certainly at that point you could say it was being manufactured.


A recent Periodic Videos episode (highlighting a newly discovered sodium isotope) went over the puzzle of which isotopes of elements are known to exist and showed a chart of what we know today -

Episode: https://youtu.be/vl0_DElyTZU

Chart: https://nawanagayasu.wixsite.com/mysite-1/nawa-s-hybrid-char...


Math proofs are also 'discovered'.

Another interesting thing to think about is cosmic rays are far stronger than anything we can create in a particle accelerator, but the current flow in an accelerator is a zillion times the intensity of cosmic rays, so thats why we build particle accelerators to "discover" things that already exist in cosmic rays.

Technically there are some atoms of this "stuff" in a lump of uranium ore, well, a big enough one, anyway, but it would take much fancier instruments to detect and manipulate it, its easier to make lots in close proximity to a detector.


> Technically there are some atoms of this "stuff" in a lump of uranium ore

Given it has a half-life of around 40 minutes and isn’t a decay product (even via irradiation) of anything that’s found in uranium ore, I think that’s quite unlikely.

It may occur somewhere else in nature, very briefly/rarely, however.


It has a half life of 31 minutes which means that whatever amount of it gets made in a supernova is reduced by a factor of 100 trillion every day.


My favorite are the largest/smallest/hottest/coldest/furthest/closest/etc things discovered.

Yeah, for now.


The conditions of the lab may/probably occur somewhere in the universe. Being able to transmutate one element into another, or to modify an element by adding more neutrons is useful because then we know more and it informs out imagination and understanding of what could be.


The universe is so vast that anything we are able to create must exist elsewhere at some time or place.


This isotope? sure!

but that isn't true generally. I think the boundary of what we can argue should or shouldn't exist elsewhere on the basis of statistical arguments is probably pretty interesting.

questions like: what is the simplest man made crystal that is very unlikely to occur naturally anywhere in the universe?



This specific atom was made, but the fact that this isotope can exist was discovered.


Vulnerabilities are discovered too


[flagged]


I know that a lot of people think HN is humorless, but it’s not entirely true. This kind of snarky, culture war laden humor is unlikely to go over well though.


I was being serious. I went to Brown.


You were going to be my first downvote. Instead I'll answer in the same vein, but from an opposed political stance, to show how ridiculous this is. All ethical stances assert various propositions, and defend those propositions by pointing out harms (physical, psychological, or imaginary) that occur when those propositions aren't followed.

If Uranium-241 was meant to exist in nature God would have made it. If Uranium-238 and Platinum-198 were meant to merge they would be discovered in the same deposits. Our founders fought and died for the right of Uranium-238 to exist, and destroying it in this experiment threatens our freedoms.

It's not as good as yours; my critique lacks your inspiration.


All isotope mass numbers are possible and God (if Xe/Fay(e) exists) loves them all. The mass number is a spectrum from negative to positive to infinity including fractions. Any claim otherwise erases the existence of isotopes which have yet to be "discovered" by white male "scientists".

(Check and mate.)


Sometimes the only winning move is not to place uranium and platinum in a collider in the first place.


applause


> ...one of them, uranium-241, had never been observed before and that it marks the first time since 1979 that a neutron-rich uranium isotope has been discovered. The researchers also calculated that uranium-241 likely has a half-life of just 40 minutes.

So - If the "hard" SF novel you're writing needs some sort of Unobtainium for its big hand-wave...this discovery probably doesn't fit the bill.


For that you are going to need something in the predicted "Island of Stability", which ironically is a great name for a hard SF series.

https://en.wikipedia.org/wiki/Island_of_stability


For SF you could also claim that an external magnetic field has a subtle influence on stability and is sufficient to go from 40 day halflife to indefinite stability. This can also be used as an additional critical element.


You dont have to use anything complicated, just accelerate it to the speed of light and the half life will stay the same but we would observe it for significantly longer.


Plus you get to invent portable closed-loop particle accelerators...net win, I'd say.


I was just thinking that theres another way to store short half lives or other perishables, just create a miniature black hole, it will fall for infinity but you could retrieve the item once you stop feeding the black hole energy and it'll evaporate by hawking radiation in microseconds.

Ive been watching too much doctor who and now I want a thermoscan based on black holes for my tea


Alas, the way you feed energy to a blackhole is by dropping things into it.

(Yes, there is a well-known paradox/open-problem implied by this.)


what kind of shielding would be required to keep all of that radiation from killing you? i still don't trust the shielding on my microwave, so i can't imagine trying to shield the effects of a black hole


There is no safe way to be near a black hole.

If you have one of a "mere" 606 million tons, the Hawking radiation is hot enough to directly include fast moving positrons (and has a luminosity of 1.178 GW), while still massive enough to spaghettify you (370g at 10cm).

If the black hole is lower mass, the radiation gets even more energetic. The radiation from 606 thousand ton black holes (sometimes suggested for Hawking radiation drives for spacecraft) is hot enough the radiation will either include antiprotons, or at least the photons will be energetic enough to spontaneously create them on impact: https://kitsunesoftware.wordpress.com/2022/05/14/no-a-black-...


Nuclear Isomers are a wonderfully complex landscape of what-ifs.


Cool idea! A million plot possibilities could easily plug into "whoever controls the Unobtainium Handwave Device absolutely must keep the Para-Critical Core Stabilization Magnetic Field Generators super-cooled and fully energized at all times...".


>> Cool idea!

Once upon a time I wondered if magenetic fields influenced nuclear reation rates. Some googling suggested the answer is no, but I found very little in the way of actual experimental results testing it. In more recent times I think I did see one referene to an actual effect but I don't recall what it was. So IMHO this door is clearly open for fictional exploration.


It's generally a bad idea to use an already known substance as Unobtainium, as it forces greater suspense of disbelief for those who know, or can predict, the properties of the substance.

Ice-9, Dilithium, magnetic monopoles, are all much better Unobtainiums.



Sort of, but not in context of their original usage. Vonnegut's Ice 9 predated the naming of the real Ice 9, and Dilithium in Star Trek is not Li2. But yeah, in general I agree about dilithium. It would have been better if Star Trek had chosen a different name.


Indeed. I like that in Babylon 5 they went with "Quantum 40".

SG-1 kinda has the same problem, when you learn that Naqada is 20 km from Luxor and Kelowna is close to where the show was filmed.


It's easy to imagine that Naqādah the place was named by the Goa'uld because it had something to do with Naquadah processing or experiments. The expository dialogue writes itself there.

Kelowna is more of a stretch, but I'm betting that someone in the writers' room said "Hey, we already had a Salish episode; if anyone asks, we could just say that some native spirits influenced the names on both planets!" Apparently those people actually were the first inhabitants of that area. So all they'd need to do is connect them to Langara!


Kelowna is just the name of the planet on which Naquadria is found, so it makes sense that it would be a place name.

And it's not like place names and material names are mutually exclusive. Silicon Valley is an example of a place named after an element, and Berkelium is an element named after a place. There are 26 elements are named directly or indirectly after places.


Someone, somewhere, always has to suspend disbelief about locations in movies and TV shows, especially TV shows. :)


40 minutes is a very long time, especially in the rare-isotope world.




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