US nuclear-fusion lab enters new era: achieving ‘ignition’ over and over

This year, the US National Ignition Facility (NIF) has lived up to its name by achieving ignition using lasers — not once, but four times. Ignition is a nuclear reaction that creates more energy than it consumes, similar to the hydrogen-fusion process that powers the Sun.

DeepMind AI outdoes human mathematicians on unsolved problem

An artificial intelligence (AI) system, called FunSearch, has improved on mathematicians’ previous solutions to problems inspired by the card game Set. Until now, researchers have used AI to solve mathematics problems with known solutions. This time, FunSearch went further than what had already been solved by humans in combinatorics, a field of mathematics that studies how to count the possible arrangements of sets containing finitely many objects.

Australian Indigenous genomes are highly diverse and unlike those anywhere else

Australian Indigenous communities are some of the most genetically distinct people on the planet, with the highest rate of genetic variation outside groups in Africa. A new pair of studies sought permission from 159 Indigenous Australians to add their genetic data to global databases, and found that as much as 12% of structural variants — variations that are at least 50 base pairs in size — are unique to these communities.

‘Biocomputer’ combines lab-grown brain tissue with electronic hardware

A computer that combines laboratory-grown human brain cells with conventional circuits can complete tasks such as voice recognition. Researchers trained the system on 240 recordings of eight people speaking. A machine-learning algorithm decoded the mini brain’s neural activity pattern to identify voices, with 78% accuracy. The technology could one day be integrated into artificial-intelligence systems or used to study neurological disorders.

Quantum-computing approach uses single molecules as qubits for first time

Physicists have used lasers as ‘optical tweezers’ to position molecules so precisely that the molecules can be used as qubits to process quantum information. Pairs of calcium monofluoride molecules were gingerly manoeuvred so that they became entangled and behaved as a single collective quantum system. The molecules were cooled to close to absolute zero, making them almost completely still. When their rotation was completely stopped, they represented the ‘0’ state of the qubit. Meanwhile, molecules allowed to rotate with just one quantum of rotational momentum represented the ‘1’ state. Molecules have some advantages over other qubit candidates, such as atoms. For example, molecules could be pushed into service as ‘qutrits’, which have three possible states: −1, 0 and +1.

‘Wobbly spacetime’ may help resolve contradictory physics theories

A new attempt to reconcile the physics of the very big and very small offers up a testable prediction: time itself might be ‘wobbly’. Physicists have long sought a unifying theory that integrates the spectacularly successful — but mathematically incompatible — general theory of relativity and quantum theory. The “postquantum theory of classical gravity” suggests that space-time is smooth and continuous, not ‘quantised’ into discrete chunks. But it has fluctuations — which could be revealed by precise table-top mass measurements.

Blogger Comments:

This theory is based on misunderstandings such as 'time flows' (dimensions don't flow, processes unfold) and 'curved spacetime' (it is the geodesic trajectory in space that is curved, not spacetime).

Gravitational waves from giant black-hole collision reveal long-sought ‘ringing’

Researchers have found the first evidence that ‘ringing’ vibrations are produced by colliding black holes. Newly merged black holes are lopsided, but quickly settle into the lowest-energy shape, a sphere. In the same way that a bell rings with specific frequencies determined by its shape, the stabilising black hole ‘rings down’, and radiates gravitational waves with frequencies that are determined by its mass and spin. A reanalysis of data from the largest black-hole merger ever detected, in 2019, indicates that it produced a black hole 250 times the mass of the Sun — much more massive than the original analysis suggested.

Dolphins feel electric fields

Bottlenose dolphins (Tursiops truncatus) can sense electricity using the pits left behind when the whiskers they are born with fall out. “Everybody thought these structures are vestigial — so without any function,” said zoologist and study co-author Guido Dehnhardt. His team trained two captive dolphins to place their snouts near submerged electrodes and swim away when they detected an electric field. The researchers found that the dolphins’ sensitivity to electricity was similar to that of platypuses. Electroreception could help the animals to find fish hiding in sand on the sea floor or to navigate the ocean using Earth’s magnetic field.

Tiny robots made from human cells heal damaged tissue

Using cells from the human windpipe, scientists have developed tiny self-propelling robots that might have therapeutic properties. When researchers placed the ‘anthrobots’ on a layer of neural tissue that had been scratched, the neurones underneath completely healed within three days. This suggests the potential for personalised regenerative medicine, say the researchers.