Nuclear breakthrough (laser excitation of nuclei) could improve clocks/measurement and detect variance in currently-believed fundamental constants

Astonishing Nuclear Breakthrough Could Rewrite the Fundamental Constants of Nature

Using a laser to raise the energy state of an atom’s nucleus, known as excitation, can lead to the development of the most precise atomic clocks. This process has been challenging because the electrons surrounding the nucleus are highly reactive to light, necessitating more light to affect the nucleus. UCLA physicists have overcome this by bonding the electrons with fluorine in a transparent crystal, allowing them to excite the neutrons in a thorium atom’s nucleus using a moderate amount of laser light. This achievement paves the way for significantly more accurate measurements of time, gravity, and other fields, far surpassing the current accuracy levels provided by atomic electrons.

For almost half a century, physicists have envisioned the possibilities that could arise from elevating the energy state of an atom’s nucleus with a laser. This breakthrough would enable the replacement of current atomic clocks with a nuclear clock, the most accurate timekeeping device ever conceived. Such precision would revolutionize fields like deep space navigation and communication.

It would also allow scientists to measure precisely whether the fundamental constants of nature are, in fact, really constant or merely appear to be because we have not yet measured them precisely enough.

Now, an effort led by Eric Hudson, professor of physics and astronomy at UCLA, has accomplished the seemingly impossible. By embedding a thorium atom within a highly transparent crystal and bombarding it with lasers, Hudson’s group has succeeded in getting the nucleus of the thorium atom to absorb and emit photons like electrons in an atom do. The astonishing feat is described in a paper published in the journal Physical Review Letters.
Enhanced Measurement Capabilities

This 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. The reason is that atomic electrons are influenced by many factors in their environment, which affects how they absorb and emit photons and limits their accuracy. Neutrons and protons, on the other hand, are bound and highly concentrated within the nucleus and experience less environmental disturbance.

Using the new technology, scientists may be able to determine if fundamental constants, such as the fine-structure constant which sets the strength of the force that holds atoms together, vary. Hints from astronomy suggest that the fine-structure constant might not be the same everywhere in the universe or at all points in time. Precise measurement using the nuclear clock of the fine-structure constant could completely rewrite some of these most basic laws of nature.

...

Hudson said the new technology could find uses wherever extreme precision in timekeeping is required in sensing, communications, and navigation. Existing atomic clocks based on electrons are room-sized contraptions with vacuum chambers to trap atoms and equipment associated with cooling. A thorium-based nuclear clock would be much smaller, more robust, more portable, and more accurate.

...