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Submission + - First Nuclear Clocks Start Ticking in Vienna and Beijing (phys.org)

Submitted by necro81
necro81 writes: Two groups, one in Vienna and one in Beijing, have successfully demonstrated the world's first nuclear clocks. Standard atomic clocks, like the caesium clocks that define the second, operate by observing the transition of electrons between different orbits about the nucleus. The resulting radiation is usually in the microwave range, and can produce clocks accurate to one second in 100 billion years.

Nuclear clocks go a step further, and probe energy transitions within the nucleus itself. Nuclei can arrange their protons and neutrons into different configurations, called isomers. The isomer with the lowest energy is the one usually found; higher-energy ones are only metastable and decay quickly. Usually it takes serious energy — x-rays and gamma rays — to excite a nucleus into a higher-energy arrangement. It so happens that thorium-229 can be excited using UV light with a wavelength of 148 nm — just within the capabilities of some exotic lasers.

It's still been quite a challenge. For one thing, Th-229 is not found in nature; it must be extracted from the decay chain of uranium-235. The Beijing team used just a microgram mixed in a crystal of calcium fluoride.

Although these prototype nuclear clocks are not yet more accurate than existing atomic clocks (one second in millions, rather than billions, of years), they show the way towards what may be possible. Because the energy transition is in the nucleus, rather than the electron cloud, it is less susceptible to outside disturbances like magnetic fields. And the fundamental frequency is much higher (five orders of magnitude), which should yield more precise timing. This development could lead to smaller and more reliable time standards across the world (and solar system).

Submission + - Wisconsin U–Madison Prof Francis Halzen named 2026 Nobel laureate in physi (wisc.edu)

Submitted by schwit1
schwit1 writes: Halzen is the principal investigator of the NSF IceCube Neutrino Observatory, the world’s largest — and perhaps strangest — telescope. The U.S. National Science Foundation-funded observatory is operated by an international collaboration of scientists led by the Wisconsin IceCube Particle Astrophysics Center based at UW–Madison.

Embedded in a cubic kilometer of Antarctic ice, IceCube uses thousands of light sensors to survey the universe for neutrinos, nearly massless particles that rarely interact with other matter. Neutrinos provide information about the workings of black holes, galaxies and other objects in the cosmos.

“IceCube is like no other telescope in the world,” says UW–Madison interim Chancellor Eric M. Wilcots. “And there is no other scientist quite like Francis Halzen, whose idea to create a neutrino detector under almost a mile of ice has led to a remarkable multinational and multi-institutional scientific collaboration and a fundamental shift in how we think about the universe.”

Comment Re:So what's it good for? (Score 2) 72

by smooth wombat (#66365226) Attached to: OpenAI Is Adding Text Watermarking In ChatGPT and Codex
I don't think that makes the document any less your own than having a human copy editor conduct a similar review which has been done since forever.

Which is what I've been saying as well. If all you're doing is asking for suggestions to something you have already written, using AI is no different than using a human editor. It's your work. It's been written. You're just looking for advice on how to improve it.

This is completely different than people who tell AI what they want and it does all the work.

Comment Re:Well above the ocean [Re:Uh HUH] (Score 1) 83

Let me be perfectly clear about this: I am insulting you. I am calling you out as either being such a plonk that you keep old copies of People magazine around just in case ... or you are such a plonk that you google and select the answer you want.

Either way, you are a plonk. Your memory is reliable and truthful, mine is full of lies.

Comment Re:Well above the ocean [Re:Uh HUH] (Score 1) 83

That's not how it was reported at the time, and I have no reason to trust People magazine.

If you were an anti-alarmist, you'd be crowing this shows sea levels dropping.

For another indication of how sloppy sea level rise claims are, the alarmists published a list of sea level changes along the US Atlantic coast, and funny thing, they differed considerably, as if the ocean were rising more in some places than others. The alternative explanation of sinking land levels was pooh poohed as climate denialism. But another funny thing: California's central valley was once reported as having sunk 22 feet since the gold rush days 150 years earlier, due to pumping out so much underground water. Gosh, could the same thing be happening along the Atlantic coast?

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