Category: physics

Is our universe one of many? Stanford-news fiv…

Is our universe one of many?

Stanford-news five-part series on the String Theory Landscape, by Ker Than (illustrations by Eric Nyquist).

Sun’s three-dimensional magnetic field during …

Sun’s three-dimensional magnetic field during one full solar rotation (top), and 

composite image generated from

photographs taken on the day of the total eclipse (bottom left) vs. the model’s predictions (bottom right).

Credits: Predictive Science Inc./Miloslav Druckmüller, Peter Aniol, Shadia Habbal/NASA Goddard, Joy Ng

Via NASA:

I do not know, neither do you.

I do not know, neither do you.

Long and Winding Road: A Conversation with Str…

Long and Winding Road: A Conversation with String Theory Pioneer | Caltech:

Cool interview with John Schwarz pioneer and co-father of the first superstring revolution.

“After the 1984 to 1985 breakthroughs in our understanding of superstring theory, the subject no longer could be ignored. At that time it acquired some prominent critics, including Richard Feynman and Stephen Hawking. Feynman’s skepticism of superstring theory was based mostly on the concern that it could not be tested experimentally. This was a valid concern, which my collaborators and I shared. However, Feynman did want to learn more, so I spent several hours explaining the essential ideas to him. Thirty years later, it is still true that there is no smoking-gun experimental confirmation of superstring theory, though it has proved its value in other ways. The most likely possibility for experimental support in the foreseeable future would be the discovery of supersymmetry particles. So far, they have not shown up.”

Multi-purpose silicon chip created for quantum…

Multi-purpose silicon chip created for quantum information processing

The Bristol team has been using silicon photonic chips as a way to try to build quantum computing components on a large scale and today’s result, published in the journal Nature Photonics, demonstrates it is possible to fully control two qubits of information within a single integrated chip. This means any task that can be achieved with two qubits, can be programmed and realised with the device.

Via Phys.org

Image credit: Xiaogang Qiang/University of Bristol

Simulation of groups of positrons being concen…

Simulation of groups of positrons being concentrated into a beam and accelerated.

Credit: Aakash Sahai

Via Phys.org: Mini antimatter accelerator could rival the likes of the Large Hadron Collider

Paper: DOI: 10.1103/PhysRevAccelBeams.21.081301 (PDF)

Simulation of the orbits of stars very close t…

Simulation of the orbits of stars very close to the supermassive black hole at the heart of the Milky Way (above). One of these stars, named S2 (below), orbits every 16 years and did pass very close to the black hole in May 2018.

Full story at ESO: First Successful Test of Einstein’s General Relativity Near Supermassive Black Hole

Cosmic microwave background image based o…

Cosmic microwave background

image based on data from the Planck Legacy release, the mission’s final data release, published in July 2018.

The image above is a zoom from next area:

More from the European Space Agency (ESA):

Listen to the Sound of Saturn’s Electrom…

Listen to the Sound of Saturn’s Electromagnetic Energy

Via Gizmodo (source at NASA)

New model predicts that we’re probably t…

New model predicts that we’re probably the only advanced civilization in the observable universe. Via Universe Today.

Well, playing with the Drake equation and the Fermi paradox is always fun and educative, as long as you assume that you are on a purely speculative ground. We actually don’t know, and the “probably” adverb in the title is central.

From the original paper’s abstract (Dissolving the Fermi ParadoxPDF):

[…] The expectation that the universe should be teeming with intelligent life is linked to models like the Drake equation, which suggest that even if the probability of intelligent life developing at a given site is small, the sheer multitude of possible sites should nonetheless yield a large number of potentially observable civilizations. We show that this conflict arises from the use of Drake-like equations, which implicitly assume certainty regarding highly uncertain parameters. We examine these parameters, incorporating models of chemical and genetic transitions on paths to the origin of life, and show that extant scientific knowledge corresponds to uncertainties that span multiple orders of magnitude. This makes a stark difference.