Lifeboat Foundation

Three Super-Earths and two Super-Mercuries, a type of planet that is extraordinarily rare and distinct, haʋe Ƅeen found in a star systeм Ƅy astronoмers. Super-Mercuries are so uncoммon—only eight haʋe Ƅeen found so far—that they are extreмely rare.

ESPRESSO’s spectrograph detected two ‘super-Mercury’ worlds in the star systeм HD 23472. Astronoмers haʋe discoʋered that these planets are extreмely rare. This study, puƄlished in Astronoмy &aмp; Astrophysics, looked at how the coмposition of tiny planets ʋaries with planet position, teмperature, and star attriƄutes.

The reason for oƄserʋing this planetary systeм, according to Susana Barros, a researcher at the Institute of Astrophysics e Ciências do Espaço (IA) who led the project, is to characterise the coмposition of sмall planets and to study the transition Ƅetween haʋing an atмosphere and not haʋing an atмosphere.

For the first time, an international team of researchers, including those from the University of Tokyo’s Institute for Solid State Physics, has demonstrated a switch, analogous to a transistor, made from a single molecule called fullerene.

By using a carefully tuned laser pulse, the researchers are able to use fullerene to switch the path of an incoming electron in a predictable way. This switching process can be three to six orders of magnitude faster than switches in microchips, depending on the laser pulses used. Fullerene switches in a network could produce a computer beyond what is possible with electronic transistors, and they could also lead to unprecedented levels of resolution in microscopic imaging devices.

More than 70 years ago, physicists discovered that molecules emit electrons in the presence of electric fields, and later on, in certain wavelengths of light. The electron emissions created patterns that enticed curiosity but eluded explanation. This has changed thanks to a new theoretical analysis, the ramification of which could not only lead to new high-tech applications, but also improve our ability to scrutinize the physical world itself.

How the Big Bang gave us time, explained by theoretical physicist Sean Carroll.

Up next, The Universe in 90 minutes: Time, free will, God, & more ► https://youtu.be/tM4sLmt1Ui8

Continue reading “The mind-bending physics of time | Sean Carroll” »

Six massive galaxies discovered in the early universe are upending what scientists previously understood about the origins of galaxies in the universe.

“These objects are way more massive than anyone expected,” said Joel Leja, assistant professor of astronomy and astrophysics at Penn State, who modeled light from these galaxies. “We expected only to find tiny, young, baby galaxies at this point in time, but we’ve discovered galaxies as mature as our own in what was previously understood to be the dawn of the universe.”

Using the first dataset released from NASA’s James Webb Space Telescope, the international team of scientists discovered objects as mature as the Milky Way when the universe was only 3% of its current age, about 500–700 million years after the Big Bang. The telescope is equipped with infrared-sensing instruments capable of detecting light that was emitted by the most ancient stars and galaxies. Essentially, the telescope allows scientists to see back in time roughly 13.5 billion years, near the beginning of the universe as we know it, Leja explained.

😗

Observations of supermassive black holes at the centers of galaxies point to a likely source of dark energy – the ‘missing’ 70% of the Universe.

Continue reading “First Evidence that Black Holes are the Source of Dark Energy” »

When two black holes collide into each other to form a new bigger black hole, they violently roil spacetime around them, sending ripples, called gravitational waves, outward in all directions. Previous studies of black hole collisions modeled the behavior of the gravitational waves using what is known as linear math, which means that the gravitational waves rippling outward did not influence, or interact, with each other. Now, a new analysis has modeled the same collisions in more detail and revealed so-called nonlinear effects.

“Nonlinear effects are what happens when waves on the beach crest and crash,” says Keefe Mitman, a Caltech graduate student who works with Saul Teukolsky (Ph. D. ‘74), the Robinson Professor of Theoretical Astrophysics at Caltech with a joint appointment at Cornell University.

“The waves interact and influence each other rather than ride along by themselves. With something as violent as a black hole merger, we expected these effects but had not seen them in our models until now. New methods for extracting the waveforms from our simulations have made it possible to see the nonlinearities.”

The James Webb Space Telescope (JWST) is still doing its job — and doing it very well. Released today, this image shows the arms of barred spiral galaxy NGC 1,433 teeming with young stars that can be seen affecting the clouds of gas and dust around them. The image was taken as part of the Physics at High Angular resolution in Nearby Galaxies (PHANGS) collaboration, of which more than 100 researchers around the world are a part.

One of the James Webb Space Telescope’s first science programs is to image 19 spiral galaxies for PHANGS with its Mid-Infrared Instrument (MIRI), which is capable of seeing through gas and dust clouds that are impenetrable with other types of imaging.

A combined team of physicists from Harvard University and Northwestern University has found the most precise value yet for the magnetic moment of an electron. In their paper published in the journal Physical Review Letters, the group describes the methods they used to measure properties of an electron and implications of the new precision.

The magnetic moment of an electron, also known as the electron magnetic dipole moment, results from its electric and spin properties. Of all the elementary properties that have been studied, it is the one that has been the most precisely measured, and also the most accurately verified.

Measuring the magnetic moment of an electron to ever higher standards of accuracy is important because physicists believe that at some point, such measurements will help to complete the standard model of physics. In this new effort, the research group has measured the magnetic moment to a precision twice that of any other effort—the last best effort was 14 years ago.

I explore the reduction of thermodynamics to statistical mechanics by treating the former as a control theory: a theory of which transitions between states can be induced on a system (assumed to obey some known underlying dynamics) by means of operations from a fixed list. I recover the results of standard thermodynamics in this framework on the assumption that the available operations do not include measurements which affect subsequent choices of operations. I then relax this assumption and use the framework to consider the vexed questions of Maxwell’s demon and Landauer’s principle. Throughout I assume rather than prove the basic irreversibility features of statistical mechanics, taking care to distinguish them from the conceptually distinct assumptions of thermodynamics proper.

Annual UWO Philosophy of Physics Conference.
Thermodynamics as a Resource Theory: Foundational and Philosophical Implications.
June 20–22, 2018
http://philphysics.uwo.ca.
David Wallace, University of Southern California.

Continue reading “David Wallace: Thermodynamics as control theory” »