Articles by David Appell
Phys.org / Ultrawide binary objects in the Kuiper belt may not have come from the earliest solar system, research suggests
Trying to understand the makeup and evolution of the solar system's Kuiper belt has kept researchers busy since it was hypothesized soon after the discovery of Pluto in 1930. In particular, binary pairs of objects there are ...
Phys.org / More comprehensive search for sterile neutrinos comes up empty
Particle physicists have been looking for so-called "sterile neutrinos" for a few decades now. They are a hypothesized particle that would have a tiny mass like the three known neutrinos but would not interact by the weak ...
Phys.org / Hints of a 'neutrino fog' could complicate efforts to detect dark matter
As if searching for dark matter isn't difficult enough already, physicists may have detected another hurdle known as a "neutrino fog" from solar neutrinos streaming through Earth.
Phys.org / A novel state of thorium opens the possibility for a nuclear clock
Why are there atomic clocks but no nuclear clocks? After all, an atom's nucleus is typically surrounded by many electrons, so in principle it should be less susceptible to outside noise (in the form of light). A nucleus, ...
Phys.org / Constraining the body of a hydra can cause it to grow two heads
Hydra are small, invertebrate, predatory animals that live in water. They're tubular, radially symmetric and up to 10 mm long, with a head (mostly a mouth), a single, adhesive foot, and tentacles.
Phys.org / New image recognition technique for counting particles provides diffusion information
A team of scientists have invented a technique to determine the dynamics of microscopic interacting particles by using image recognition to count the number of particles in an imaginary box. By changing the size of the observation ...
Phys.org / Scientists discover a promising way to create new superheavy elements
What is the heaviest element in the universe? Are there infinitely many elements? Where and how could superheavy elements be created naturally?
Phys.org / Scientists determine the timing and duration of a major hyperthermal event in the Early Jurassic
Using high-precision dating of geologic regions, scientists have found evidence that one of the most significant warming spikes of the last 500 million years had a surprisingly short duration, about 300,000 years. And it ...
Phys.org / May 2024 super geomagnetic storm challenges current space weather prediction models
During May 2024, a series of eruption events on the sun saw the largest geomagnetic storm hit Earth in two decades. The largest since the solar storms of Halloween 2003, it occurred from May 10 to May 13, producing aurorae ...
Phys.org / Using gamma-ray bursts to probe origin of star formation excess discovered by Webb
Among its other notable achievements and puzzles, the James Webb Space Telescope (JWST) has found a larger number of bright galaxies in the distant universe than was expected. While scientists are still debating the excess, ...
Phys.org / Atmospheric oxidation and the creation of modern Mars
Like Earth, Mars was formed about 4.5 billion years ago, but its early surface was very different than today's. Mars' surface then had high rates of meteorite and asteroid impacts from the period known as the Late Heavy Bombardment. ...
Phys.org / Can the 'hard steps' in the evolutionary history of human intelligence be recast with geological thresholds?
What took so long for humans to appear on Earth? The Earth is 4.6 billion years old, and life began about 4 billion years ago, yet humans—the only intelligent, technological species we know of in the universe—have existed ...
Phys.org / Why do large electorates tend towards evenly split results?
Election polls often tighten up remarkably as the election date draws near. "Leave" (the European Union) won the UK election of May 2016 with a majority of 51.9%, but earlier the polls weren't nearly as tight—in January 2011 ...
Phys.org / Could interstellar quantum communications involve Earth or solve the Fermi paradox?
Thus far, the search for extraterrestrial intelligence (SETI) has used strategies based on classical science—listening for radio waves, telescopes watching for optical signals, telescopes in orbit scouring light from the ...
Phys.org / A fundamental magnetic property of the muon measured to unprecedented precision
Scientists have measured the magnetic moment of the muon to unprecedented precision, more than doubling the previous record.
