Five new ways to catch gravitational waves

Scientists are developing ways to spot those ripples in space-time that are invisible to current gravitational-wave-hunting facilities such as LIGO.

1. Ultra-long waves could be detected over many years by measuring the distance between Earth and stars called pulsars.
2. Telescopes are searching for patterns in the cosmic microwave background that would have been imprinted by gravitational waves in the early universe.
3. Observing atoms as they drop down a 1km-tall pipe could reveal waves coming from black hole collisions.
4. Desktop detectors for speculative high-frequency waves could reveal exotic physics right after the Big Bang.
5. A radical idea for spotting gravity waves involves putting a diamond crystal into quantum superposition — something that has never been demonstrated.

‘Fantastic’ particle could be most energetic neutrino ever detected

An observatory in the depths of the Mediterranean Sea has spotted what could be the most energetic neutrino ever detected — “a fantastic event”, says physicist Francis Halzen. Neutrinos are tiny subatomic particles that travel at nearly the speed of light and are thought to come from cataclysmic cosmic events, such as a growth spurt of a supermassive black hole. For now, the team is staying quiet about the direction the neutrino came from to avoid tipping off competitors about its origin.

A common misunderstanding about wave-particle duality

It’s an all-too-common misconception to think of light, electrons and other quantum entities as shape-shifters that can sometimes be waves, and other times particles, says science writer Philip Ball. Recent experiments that were widely reported as showing ‘particles morphing into waves’ reveal the problems of using classical concepts to describe quantum mechanics, he explains. “Wave-particle duality is not a property of the quantum world, but a flawed classical analogy for it.”

Astronomers detect sudden awakening of black hole 1m times mass of sun

A black hole that’s more than one million times more massive than the Sun has suddenly woken up at the centre of a distant galaxy, dubbed SDSS1335+0728. The stirring black hole might be the culprit behind the galaxy’s unusual brightening, which has had scientists scratching their heads since 2019. The surge in light output is probably due to the presence of an active galactic nucleus, which occurs when a black hole begins chewing through the material that surrounds it.

Measuring the forces that sculpt embryos

Scientists are finding new ways to measure how squeezing, stretching, pushing and pulling forces shape the development of every tissue in the body. Tiny oil-encapsulated droplets can sense stresses inside live embryos and optical tweezers can push and pull cell membranes or organelles. Some researchers are developing contact-free alternatives such as the ‘foambryo’ algorithm, which models embryos as foams of bubble-like cells.

How the ‘mind’s eye’ calls up visual memories from the brain

Vivid memories that flash into the mind’s eye might be made in the primary visual cortex, the same area of the brain that processes raw visual input from the eyes. A study in monkeys suggests that neurons there display a different activity pattern when images are conjured up from memory compared with real-time vision. Some researchers say that other areas, such as the prefrontal cortex, are more likely to be the seat of the ‘mind’s eye’.

Do elephants have names for each other?

Elephants seem to use proper names to address their fellows. Scientists used machine learning to analyse 469 deep rumbles made by wild female African savannah elephants (Loxodonta africana) and their families in Kenya. They found patterns that indicate that calls are specific to individuals. The researchers also played recorded calls to elephants out in the field and watched how the animals responded.

Fire pits offer glimpse into Neanderthal life

Ancient hearths reveal that generations of Neanderthals regularly visited a rugged river valley in Spain over a period of around 200 years. Previous work estimated that Homo neanderthalensis made these fires around 52,000 years ago — plus or minus a few thousand years. Researchers dramatically narrowed down this timeframe by analysing traces of Earth’s changing magnetic field preserved in the fire pits’ minerals. The oldest and youngest of the hearths were last lit at least 200 years apart, with decades-long intervals between the use of different hearths.

Physicists coax molecules into exotic quantum state — ending decades-long quest

A decades-long quest to create a Bose–Einstein condensate from molecules is finally over. Physicists cooled sodium-caesium molecules until they were almost stationary — which, thanks to Heisenberg’s uncertainty principle, meant their positions were so uncertain that they became indistinguishable and formed a single gigantic quantum state. Physicists have forced atoms into this bizarre state of matter since 1995, but molecules are much harder to cool. The key was using microwave fields to keep heat-generating collisions between molecules under control.

Biggest genome ever found

A species of fork fern, Tmesipteris oblanceolata, has the biggest genome ever recorded. It contains 160 billion base pairs — 11 billion more than the previous record holder, the flowering plant Paris japonica, and 50 times more than the human genome. It’s not known why the fern evolved that way, or how it accesses the relatively small proportion of DNA that is actually useful.