Articles by David Appell
Phys.org / New technique measures superconductivity at very high pressures
In 1911, Heike Kamerlingh Onnes discovered the first superconductor, metallic mercury when cooled to a critical temperature of 4.2 Kelvin, where it conducts electricity without resistance. Ever since materials scientists ...
Phys.org / The major Atlantic current that keeps Northern Europe warm could have new variations and tipping points
Northern Europe is relatively warm given its place on the globe. For example, although north of most major Canadian cities, London is warmer than all of them (even Vancouver in British Columbia). But this warmth could disappear ...
Tech Xplore / A passive, renewable, more efficient way to extract water from the atmosphere
Freshwater scarcity affects over two billion people in the world, primarily in arid and remote regions, as well as islands and coastal areas without freshwater sources. Climate change and population growth are only making ...
Phys.org / Creation of a deep learning algorithm to detect unexpected gravitational wave events
Starting with the direct detection of gravitational waves in 2015, scientists have relied on a bit of a kludge: they can only detect those waves that match theoretical predictions, which is rather the opposite way that science ...
Phys.org / Study shows elephant trunk dexterity can be mimicked with minimal actuators
The trunk of an elephant is among the versatile appendages in the animal kingdom. Now a research team has shown that most of its dexterity can be reproduced with a model using just three "muscles." And they built a physical ...
Phys.org / The Milky Way's eROSITA bubbles are large and distant
In 2020, astronomers discovered a large hourglass-shaped structure in or near the center of our Milky Way galaxy. Dubbed "eROSITA bubbles," there have been a few different hypotheses proposed to explain their precise nature. ...
Phys.org / The surprising behavior of black holes in an expanding universe
A physicist investigating black holes has found that, in an expanding universe, Einstein's equations require that the rate of the universe's expansion at the event horizon of every black hole must be a constant, the same ...
Phys.org / Uncovering the prolonged cooling events of the Holocene
Climate changes, but not always for the same reason. Today's rapid climate change is due entirely to man. The Holocene—the last 12,000 years—has been seen as having a stable climate, with a lack of chaos that allowed humans ...
Phys.org / Dark matter could make our galaxy's innermost stars immortal
Stars near the center of our galaxy are acting kind of weird. Dark matter may be the explanation.
Phys.org / A surprising result for a group's optimal path to cooperation
What is the best way for a group of individuals to cooperate? This is a longstanding question with roots in game theory, a branch of science which uses mathematical models of how individuals should best strategize for the ...
Phys.org / Detecting 'Hawking radiation' from black holes using today's telescopes
In 1974 Stephen Hawking famously claimed that black holes should emit particles as well as absorb them. This so-called "Hawking radiation" has not yet been observed, but now a research group from Europe has found that Hawking ...
Phys.org / Recent and extensive volcanism discovered on Venus
A new analysis of data collected on Venus more than 30 years ago suggests the planet may currently be volcanically active.
Phys.org / First observation of a focused plasma wave on the sun
For the first time, scientists have observed plasma waves from a solar flare focused by a coronal hole, akin to the focusing of sound waves responsible for the Rotunda effect in architecture or the focusing of light by a ...
Tech Xplore / New, electricity-free desalination method shows promise
Researchers from The Australian National University have proposed a new method for desalinating water that avoids many of the unwanted side effects of traditional desalinating techniques and that reduces the energy required ...
Phys.org / Atmospheric 'teleconnections' sustain warm blobs in the northeast Pacific Ocean
The past 10 years have seen a series of "warm blobs" in the northeast Pacific Ocean. These marine heat waves do widespread damage to ecosystems and marine life in the area, but the mechanisms by which they develop and are ...
