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Nuclear spectroscopy breakthrough could rewrite fundamental constants of nature
- Animats 2y agoRewriting the fine structure constant sounds dangerous.
- mass_and_energy 2y agoI'm listening?
- dekhn 2y agoIt's generally considered unlikely that the FSC or the gravitational constant has varied through time or space.
- Animats 2y ago"Nuclear spectroscopy breakthrough could rewrite fundamental constants of nature". That's UCLA's PR department in action.
- westurner 2y ago> When trapped in a transparent, flourine-rich crystal, scientists can use a laser to excite the nucleus of a thorium-229 atom. > [...] This accomplishment means that measurements of time, gravity and other fields that are currently performed using atomic electrons can be made with orders of magnitude higher accuracy
- pdonis 2y ago"Rewrite" is a misstatement; what is actually meant is "measure with greater accuracy".
- deleted 2y ago[deleted]
- karmakaze 2y agoAbbreviated from "Rewrite least significant digits of ..." /s
- nayuki 2y agoInterestingly: > One isotope, ²²⁹Th, has a nuclear isomer (or metastable state) with a remarkably low excitation energy, recently measured to be 8.35574 eV. It has been proposed to perform laser spectroscopy of the ²²⁹Th nucleus and use the low-energy transition for the development of a nuclear clock of extremely high accuracy. -- https://en.wikipedia.org/wiki/Isotopes_of_thorium https://en.wikipedia.org/wiki/Isotopes_of_thorium See also: https://en.wikipedia.org/wiki/Nuclear_clock https://en.wikipedia.org/wiki/Nuclear_clock
- staunton 2y agoStorage and cooling of thorium ions has also been achieved already. It's only a matter of time before a clock is built using such an ion-trap setup (and a matter of significantly more time until auch a clock can be used in real-world applications). The article is talking about avoiding this but I believe the first thorium clock will likely be an ion trap. A nice website collecting information about this is https://thoriumclock.eu https://thoriumclock.eu
- MostlyStable 2y agoWhat are the practical considerations of being able to measure time/gravity/etc more accurately? Will this make GPS cheaper/more accurate? Will this allow better astronomical observations? Note that I'm certainly not against blue-sky science where we don't immediately know of any practical uses. As the end of the article specifies, pure research often ends up paying dividends down the line. But I'm curious if there are any more immediate applications.
- JumpCrisscross 2y ago> What are the practical considerations of being able to measure time/gravity/etc more accurately? Likely nothing in the near term. Calibrating constants lets us project the limits of reality further and more confidently. The practical implications of that are in letting crazy shit get greenlit, e.g. the Manhattan project from nuclear physics or the light bulb from quantum mechanics.
- drdeca 2y ago> or the light bulb from quantum mechanics. ?
- notarealllama 2y agoElectricity is the flow of ions, it's literally atomic science (albeit not "quantum" in the sense highly specialized sub field we know today).
- perihelions 2y agoHere's the open-access arXiv preprint: https://arxiv.org/abs/2404.12311 https://arxiv.org/abs/2404.12311 ("Laser excitation of the ²²⁹Th nuclear isomeric transition in a solid-state host") Here's an HN thread with 215 additional comments, from two months ago: https://news.ycombinator.com/item?id=40194636 https://news.ycombinator.com/item?id=40194636 ("Atomic nucleus excited with laser: A breakthrough after decades (tuwien.at)") (Both threads are about an optical coupling to ²²⁹Th nuclear transitions; also, the top comment of that thread links to the paper underpinning this thread).
- munchler 2y ago[flagged]
- swayvil 2y agoWould it be upsetting if we sent a probe a lightyear away and found that some constant, I dunno, Planck's constant or whatever, had changed?
- mr_mitm 2y agoNot sure if upsetting is the right word, but people are looking for things like that. It would be a remarkable discovery for sure. There are markers in the spectra of distant stars that could give us a hint, so sending probes is not necessarily a requirement. So far, potential variances have been constrained to a very high degree.
- datameta 2y agoExcuse me, to a very high degree? Can you elaborate?
- Modified3019 2y agoTo put another way, the amount of change in plank’s constant that could potentially happen is highly limited (based on our current methods of measuring and inferring), and only getting more limited as we improve accuracy.
- staunton 2y agoNot OP, but this is talking about bounds on how different such constants can be across time and space. For example, wikipedia.org/wiki/Time-variation_of_fundamental_constants
- privong 2y agoHere's one example, where they measure the separation of spectral features from the OH molecule in a fairly distant galaxy and use that information to put a limit on how much variation there could be in the fine structure constant over the past 2.9 billion years: https://ui.adsabs.harvard.edu/abs/2018PhRvL.120f1302K/abstract https://ui.adsabs.harvard.edu/abs/2018PhRvL.120f1302K/abstra...
- slashdave 2y agoI love how university PR departments exaggerate the importance of research to almost a comical degree
- asdff 2y agoThey have to. Its written for lay people where most else they read is also exaggerated marketing versus boring truths. People in the field just read the underlying paper and have the experience to put the results of it into proper context.
- alan-hn 2y agoWe read the underlying paper while crying because we know one of our family members will come up to us talking about the incredible new world changing discovery
- j-wags 2y agoI don't disagree with what you meant here, but this sentence threw my mind through a loop. It shows how "have to" is a real weak point in how we communicate and think. Maybe we should rank our "have to"s on a scale from 1 to 5, where for example: - "objects in motion have to (1) remain in motion unless acted upon by an external force" - "humans have to (2) eat food to stay alive" - "developed countries have to (3) maintain a scientifically literate populace" - "university PR people have to (4) write like that to pay for food and shelter" - "university PR people have to (5) write like that to afford a new sports car" I think you meant something like the example for (4), but reasonable people might see it more like (5), and in both cases it's at odds with the more fundamental "have to" (3) for society.
- throwanem 2y agoThis constitutes a loose extensional definition of a spectrum between the positive (1) and the normative (5), or between "is" and "ought". In the original example, it is that university research PR has to be written this way to provide the grant substantiation its existence subserves, but arguably ought to be that the PR piece could just describe the research properly and without all the exaggeration. To be clear, I would have no quibble with such an argument and also do not care how anyone else feels about it. The point is to help demonstrate that "ought" is the domain of that which is always arguable and which must always be argued. "Is," like the gravity which holds us to the bosom of this planet, is.