David Appell

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 ...

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 ...

Stars near the center of our galaxy are acting kind of weird. Dark matter may be the explanation.

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 ...

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 ...

A new analysis of data collected on Venus more than 30 years ago suggests the planet may currently be volcanically active.

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 ...

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 ...

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 ...

Could it be that human existence depends on gravitational waves? Some key elements in our biological makeup may come from astrophysical events that occur because gravitational waves exist, a research team headed by John R. ...

In dim light a cat sees much better than you do, as do dogs and nocturnal animals. That's because the structure of a cat's eye has a tapetum lucidum, a mirror-like layer immediately behind the retina. Light entering the eye ...

Odd things can happen when a wave meets a boundary. In the ocean, tsunami waves that are hardly noticeable in deep water can become quite large at the continental shelf and shore, as the waves slow and their mass moves upward.

Gravitationally speaking, the universe is a noisy place. A hodgepodge of gravitational waves from unknown sources streams unpredictably around space, including possibly from the early universe.

Three years ago, the stock price of the company GameStop soared over 1,625% in just a week. While it's been speculated the primary cause was unprecedented, organized action among Reddit users using a trading strategy known ...

Astrophysicists studying a popular exoplanet in its star's habitable zone have found that electric currents in the planet's upper atmosphere could create sufficient heating to expand the atmosphere enough that it leaves the ...