Dec 10, 2022
Physicists measure the fine structure constant directly for the first time
Posted by Paul Battista in category: physics
New technique could lead to clearer tests of whether this fundamental constant is truly constant.
New technique could lead to clearer tests of whether this fundamental constant is truly constant.
Clues to a black hole’s origins can be found in the way it spins. This is especially true for binaries, in which two black holes circle close together before merging. The spin and tilt of the respective black holes just before they merge can reveal whether the invisible giants arose from a quiet galactic disk or a more dynamic cluster of stars.
Astronomers are hoping to tease out which of these origin stories is more likely by analyzing the 69 confirmed binaries detected to date. But a new study finds that for now, the current catalog of binaries is not enough to reveal anything fundamental about how black holes form.
In a study appearing today in the journal Astronomy and Astrophysics, MIT physicists show that when all the known binaries and their spins are worked into models of black hole formation, the conclusions can look very different, depending on the particular model used to interpret the data.
Thanks to a cool physics trick, flares from a nearby star can heat a planet from the inside, powering plate tectonics.
What we call laws of physics are often just mathematical descriptions of some part of nature. Ultimate physical laws probably don’t exist and physics is all the better for it, says theoretical physicist Sankar Das Sarma.
Until now, it was thought they came from massive star collapses.
Astrophysicists around the world may be shocked to learn that long gamma-ray bursts (GRBs) do not solely come from the collapse of massive stars. A new study by astrophysicists at Northwestern University upends the long-standing belief, uncovering new evidence that at least some long GRBs can result from neutron star mergers, which were previously believed to produce only short GRBs, the university’s publication reported.
It all began in December 2021 when the team detected a 50-second-long GRB (any GRB longer than 2 seconds is considered ‘long’).
Continue reading “New information about long gamma-rays shatters astrophysicists’ theory” »
Gas clouds across the universe are known to absorb the light produced by distant massive celestial objects, known as quasars. This light manifests as the so-called Lyman alpha forest, a dense structure composed of absorption lines that can be observed using spectroscopy tools.
Over the past decades, astrophysicists have been assessing the value of these absorption lines as a tool to better understand the universe and the relationships between cosmological objects. The Lyman alpha forest could also potentially aid the ongoing search for dark matter, offering an additional tool to test theoretical predictions and models.
Researchers at University of Nottingham, Tel-Aviv University, New York University, and the Institute for Fundamental Physics of the Universe in Trieste have recently compared low-redshift Lyman alpha forest observations to hydrodynamical simulations of the intergalactic medium and dark matter made up of dark photons, a renowned dark matter candidate.
Recently, I learned about the World Nobel Peace Summit — fascinating. Young people can go there, mingle with Nobel Peace Laureates, network and share ideas.
Amma introduces the concept of two types of education: one that allows you to earn a living and another to attain a happy, fulfilled life. Modern education should focus on not just academic skills but a culture of human rights and peaceful coexistence of peoples, the ethics of non-violence. Too often, education is propelled by vanity and the desire for individual success. Over and over, it is just competition, pressure, and a vast amount of information pumped into one’s head without instilling the habit of exploring the future consequences of one’s actions. Imagine a good physics student who becomes a scientist just to invent a bomb that could destroy the whole world. We want a child to fulfill their potential — but stay aware of the outcomes of their choices at individual and societal levels. Ethics allows one to maintain this balance. As a society, we may want to establish ethical think tanks that simulate the future and guide us as we develop new technologies and community practices.
JB: Should the ways of peaceful coexistence be taught starting from pre-school age and reinforced over the years?
Continue reading “How Nobel Peace Laureates Inspire Youth To Believe In Themselves” »
In the philosophy of mind, the multiple realizability thesis contends that a single mental kind (property, state, event) can be realized by many distinct physical kinds. A common example is pain. Many philosophers have asserted that a wide variety of physical properties, states, or events, sharing no features in common at that level of description, can all realize the same pain. This thesis served as a premise in the most influential argument against early theories that identified mental states with brain states (psychoneural, or mind-brain identity theories). It also served in early arguments for functionalism. Nonreductive physicalists later adopted this premise and these arguments (usually without alteration) to challenge all varieties of psychophysical reductionism. The argument was even used to challenge the functionalism it initially was offered to support. Reductionists (and other critics) quickly offered a number of responses, initially attacking either the anti-reductionist or anti-identity conclusion from the multiple realizability premise, or advocating accounts of the reduction relation that accommodated multiple realizability. More recently it has become fashionable to attack the multiple realizability premise itself. Most recently the first book-length treatment of multiple realizability and its philosophical import has appeared.
This entry proceeds mostly chronologically, to indicate the historical development of the topic. Its principle focus is on philosophy of mind and cognitive science, but it also indicates the more recent shift in emphasis to concerns in the metaphysics of science more generally. It is worth mentioning at the outset that multiple realizability has been claimed in physics (e.g., Batterman 2000), biochemistry (Tahko forthcoming) and synthetic biology (Koskinen 2019a, b). After more than fifty years of detailed philosophical discussion there still seems to be no end in sight for novel ideas about this persistent concern.
The first scientific results from the new Facility for Rare Isotope Beams (FRIB) at Michigan State University have been unveiled by physicists in the US. Heather Crawford at Lawrence Berkeley National Laboratory and colleagues have synthesized new neutron-rich isotopes of three different elements. Each nuclei is near the neutron drip line and the team has measured the isotopes’ lifetimes for the first time. The research provides a taste of how physicists will use FRIB to study exotic nuclei.
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Costing $730m, FRIB opened earlier this year with the aim of expanding our knowledge of nuclear physics by creating thousands of new isotopes for scientists to study. FRIB comprises a superconducting linear accelerator that can create high-intensity beams of just about every stable isotope. These nuclei are fired at targets, creating unstable isotopes that are collected to form beams – allowing the isotopes to be studied.