James' World 2

Click the link below the picture

.

In 1974, Stephen Hawking calculated that black holes’ secrets die with them. Random quantum jitter on the spherical outer boundary, or “event horizon,” of a black hole will cause the hole to radiate particles and slowly shrink to nothing. Any record of the star whose violent contraction formed the black hole — and whatever else got swallowed up after — then seemed to be permanently lost.

Hawking’s calculation posed a paradox — the infamous “black hole information paradox” — that has motivated research in fundamental physics ever since. On the one hand, quantum mechanics, the rulebook for particles, says that information about particles’ past states gets carried forward as they evolve — a bedrock principle called “unitarity.” But black holes take their cues from general relativity, the theory that space and time form a bendy fabric and gravity is the fabric’s curves. Hawking had tried to apply quantum mechanics to particles near a black hole’s periphery and saw unitarity break down.

So do evaporating black holes really destroy information, meaning unitarity is not a true principle of nature? Or does information escape as a black hole evaporates? Solving the information paradox quickly came to be seen as a route to discovering the truth, quantum theory of gravity, which general relativity approximates well everywhere except black holes.

.

Netta Engelhardt puzzles over the fates of black holes in her office at the Massachusetts Institute of Technology.  Ira Khan for Quanta Magazine

.

.

Click the link below for the article:

.

__________________________________________

Click the link below the picture

.

There’s a trailer out for a new science fiction film called Moonfall, to be released in early 2022, in which the moon is about to crash into Earth. It features several shots of a reddish moon hovering extremely close to the planet, crumbling apart while sucking the oceans toward it, the debris flying into spacecraft and mountains. It doesn’t actually show a collision—you know, it’s just a trailer and they don’t want to spoil everything.

This isn’t the first movie to stretch the bounds of believable physics. (Remember Sharknado?) But just because it’s science fiction doesn’t mean it’s totally wrong. That’s why I’m here: I’m going to go over the actual physics that would apply if the moon ever got too close to us.

How Could the Moon Crash Into Earth?

According to the movie’s official IMDB entry, “a mysterious force knocks the moon from its orbit,” precipitating its plunge toward Earth. That’s not a lot to go on. Would there really be a way to make that happen?

Let’s start with a basic model of how the planet and its satellite act on each other. A gravitational force pulls Earth and the moon toward each other. This force depends on the mass of both objects and has a magnitude inversely proportional to the square of the distance between the centers of the two bodies.

.

Photograph: Nasa

.

.

Click the link below for the article:

.

__________________________________________

Click the link below the picture

.

What is it, at a fundamental level, that makes up the universe? When we ask this question, we typically think about starting with things that we directly observe — things like stars, planets, humans, gas, dust, plasma, and other forms of the matter we know — and dividing them up until you reach something that is indivisible. Although we originally thought that atoms would be these “uncuttable” things, we soon discovered they could be further divided: into electrons and atomic nuclei, which themselves are composed of quarks and gluons.

As we mastered the laws of physics and began to manipulate these subatomic particles, we gained the ability to accelerate and collide them, enabling the creation of a wide slew of particles and antiparticles: everything described by the Standard Model of particle physics. And yet, if we add up the sum total of all of these forms of matter, including photons, neutrinos, and everything that does not compose atoms, we fall far short of what is needed to describe our universe. Two additional components are necessary: dark matter and dark energy. Moreover, although we fully expect there to be a particle responsible for dark matter, that is not the case at all for dark energy.

.

There is a large suite of scientific evidence that supports the picture of the expanding Universe and the Big Bang, complete with dark energy. The late-time accelerated expansion doesn’t strictly conserve energy, but the presence of a new component to the Universe, known as dark energy, is required to explain what we observe. (Credit: NASA / GSFC)

.

.

Click the link below for the article:

.

__________________________________________

Click the link below the picture

.

The list of mycologists whose names are known beyond their fungal field is short, and at its apex is Paul Stamets. Educated in, and a longtime resident of, the mossy, moldy, mushy Pacific Northwest region, Stamets has made numerous contributions over the past several decades— perhaps the best summation of which can be found in his 2005 book Mycelium Running: How Mushrooms Can Help Save the World. But now he is looking beyond Earth to discover new ways that mushrooms can help with the exploration of space.

In a new “astromycological” venture launched in conjunction with NASA, Stamets and various research teams are studying how fungi can be leveraged to build extraterrestrial habitats and perhaps someday even terraform planets. This is not the first time Stamets’s career has intersected with speculative space science. He also recently received an honor that many researchers would consider only slightly less hallowed than a Nobel Prize: the distinction of having a Star Trek character named after him.

Scientific American spoke with Stamets about the out-of-this-world implications for the emerging field of astromycology.

.

Paul Stamets. Credit: Trav Williams Broken Banjo Photography

.

.

Click the link below for the article:

.

__________________________________________

Click the link below the picture

.

As the world’s top climate scientists released a report full of warnings this week, they kept insisting that the world still has a chance to avoid the worst effects of climate change.

“It is still possible to forestall most of the dire impacts, but it really requires unprecedented transformational change,” said Ko Barrett, vice-chair of the Intergovernmental Panel on Climate Change. “The idea that there still is a pathway forward, I think, is a point that should give us some hope.”

That hopeful pathway, in which dangerous changes to the world’s climate eventually stop, is the product of giant computer simulations of the world economy. They’re called integrated assessment models. There are half a dozen major versions of them: four developed in Europe, one in Japan, and one in the U.S., at Pacific Northwest National Laboratory.

“What we mostly are doing, is trying to explore what is needed to meet the Paris goals,” says Detlef van Vuuren, at the Netherlands Environmental Assessment Agency, which developed one of the models.

.

.

.

Click the link below for the article:

.

__________________________________________

Click the link below the picture

.

Two intriguing signals spotted in a small gravitational-wave detector could represent all kinds of exotic phenomena — from new physics to dark matter interacting with black holes to vibrations from near the beginning of the universe. But, because of the experiment’s novelty, researchers are being cautious about claiming a discovery of any kind. 

Facilities such as the Laser Interferometer Gravitational-Wave Observatory (LIGO) use gigantic laser-driven detectors to look for enormous ripples in the fabric of space-time known as gravitational waves. These come from the collisions of black holes and neutron stars out in the distant universe, which are events so powerful they shake space-time and send out surges with wavelengths measured in hundreds of miles.

Long before these huge observatories were built, scientists suspected that gravitational waves of such sizes existed because they knew that black holes and neutron stars should sometimes crash together, Michael Tobar, a physicist at the University of Western Australia in Perth, told Live Science.

.

Gravitational waves are giant ripples in the fabric of space-time. (Image credit: Shutterstock)

.

.

Click the link below for the article:

.

__________________________________________