⚛️ Scientists Have Built the World’s First Nuclear Clocks. They Could Change How We Measure Time.

For decades, the world’s most precise clocks have measured time using electrons moving between quantum energy levels inside atoms.

Now, two independent teams in Vienna and Beijing have demonstrated something physicists have pursued for more than 20 years:

Clocks that measure time using the atomic nucleus itself.

And the difference could be revolutionary.

Atomic nuclei are more than 10,000 times smaller than atoms and are generally much less sensitive to external electromagnetic disturbances.

That makes nuclear transitions exceptionally promising as stable frequency references.

The challenge? Almost every nuclear transition requires enormous energies, far beyond what conventional lasers can provide.

But one isotope is special: thorium-229.

Its nucleus has an unusually low-energy excited state that can be accessed using ultraviolet laser light at approximately 148 nanometers.

Researchers embedded thorium-229 nuclei inside tiny calcium fluoride crystals and developed lasers capable of detecting their nuclear transitions.

Then came the breakthrough.

They used the nuclear transitions themselves to automatically stabilize the laser frequency.

The result: two independently demonstrated, functioning nuclear clocks.

The European system operated continuously for approximately 24 hours, achieving fractional frequency instability approaching 10⁻¹⁵ after a day of averaging.

That’s an extraordinarily small fluctuation — although today’s best optical atomic clocks are still substantially more stable.

But the most exciting application might have nothing to do with telling time.

One team has already used its nuclear clock to search for dark matter.

Some theories predict that ultralight dark matter could cause tiny oscillations in fundamental physical constants, subtly changing how atomic nuclei behave.

By comparing nuclear and atomic clocks, physicists can search for these otherwise invisible effects.

The experiment found no dark matter signal, but it established new constraints on certain theoretical models.

And this is only the beginning.

Future nuclear clocks could potentially improve satellite navigation, measure gravitational effects with extraordinary precision and test whether the fundamental constants of physics really remain constant.

For thousands of years, humanity has built better clocks to understand time.

Now we’re building clocks that might help us understand the universe itself.

#Physics #QuantumPhysics #NuclearPhysics #AtomicClocks #DarkMatter #QuantumTechnology #Science

https://www.nature.com/articles/s41586-026-11084-4

🧠 Just 10 Minutes With AI Can Make You Give Up More Easily

AI makes us faster.

But what happens when we suddenly have to think without it?

A newly peer-reviewed study involving 1,222 participants suggests something uncomfortable: after just 10–15 minutes of AI-assisted problem-solving, people performed worse on their own — and were more likely to give up.

Researchers conducted three randomized experiments involving mathematics and reading comprehension. Some participants solved problems independently, while others had access to ChatGPT. Initially, the AI-assisted group performed better. But when researchers unexpectedly removed the chatbot, the advantage disappeared. In the first experiment, participants who had used AI correctly solved just 57% of subsequent problems, compared with 73% among those who had worked independently. They also skipped nearly twice as many questions: 20% versus 11%.

The researchers identified an especially interesting pattern. Participants who used AI primarily to obtain complete answers struggled more afterward than those who used it for hints or explanations. That comparison was observational, not a separate randomized experiment, but it suggests an important distinction: AI that helps you think may be very different from AI that thinks for you.

The possible explanation is a psychological shift. When answers arrive instantly, independent effort begins to feel unnecessarily difficult. Researchers call attention to the loss of productive struggle — the mental work through which we develop skills and persistence.

Important caveat: The experiments measured immediate effects during short online tasks. They do not establish permanent cognitive damage or show that regular AI use necessarily makes people less intelligent. Whether these effects persist over weeks or months remains unknown.

But the implication is fascinating.

We may be building machines that make us extraordinarily productive while quietly changing how willing we are to solve problems ourselves.

Perhaps the smartest AI assistant isn’t the one that always gives you the answer.

It’s the one that sometimes makes you figure it out.

Would you prefer an AI that solves everything instantly — or one that occasionally forces you to think?

#AI #ChatGPT #Psychology #Neuroscience #CognitiveScience #ArtificialIntelligence #Science

https://arxiv.org/abs/2604.04721