Articles by David Appell
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.
Phys.org / A device to sort photon states could be useful for quantum optical computer circuits
To build light-based quantum technologies, scientists and engineers need the ability to generate and manipulate photons as individuals or a few at a time. To build such quantum photonic logic gates that might be used in an ...
Phys.org / Using a gamma ray burst to search for violations of Einstein's relativity postulates
Einstein's theory of relativity is based on two assumptions, or postulates. The first is that the laws of physics look the same to everyone traveling in a straight line with no acceleration.
Phys.org / Using atomic excitations to measure the rotation of spacetime
How would atoms behave near a supermassive object? We know how atoms behave in extremely weak gravity like that at the Earth's surface: They can be excited from a lower energy level to a higher one when an electron absorbs ...
Phys.org / In the hunt for alien life, is man truly 'the measure of all things?'
Enrico Fermi's lunchtime question at wartime Los Alamos, "Where is everybody?" has been both a gift and a problem to scientists ever since. Known as "Fermi's Paradox," it simply asks, why, since life on Earth is ubiquitous ...
Phys.org / Test of a prototype quantum internet runs under New York City for half a month
To introduce quantum networks into the marketplace, engineers must overcome the fragility of entangled states in a fiber cable and ensure the efficiency of signal delivery. Now, scientists at Qunnect Inc. in Brooklyn, New ...
Phys.org / A maximally entangled quantum state with a fixed spectrum does not exist in the presence of noise, mathematician claims
For more than 20 years, quantum researchers have wondered whether a quantum system can have maximum entanglement in the presence of noise. A mathematician from Spain recently answered the question: No.
Phys.org / Corrected sunspot records show the Maunder minimum did not end abruptly
How accurate are past records of sunspots? In a new study published in The Astrophysical Journal, a team of multinational researchers examined the historical record and found that after the unusual period of almost no sunspots, ...
Phys.org / Photon entanglement could explain the rapid brain signals behind consciousness
Understanding the nature of consciousness is one of the hardest problems in science. Some scientists have suggested that quantum mechanics, and in particular quantum entanglement, is the key to unraveling the phenomenon.
Phys.org / Study reports dim odds for finding alien civilizations
Are there any advanced alien civilizations elsewhere in our galaxy? We don't know. All we do know is that there is at least one. Should we be optimistic or pessimistic about finding others?
