Lifeboat Foundation

Gravity has shaped our cosmos. Its attractive influence turned tiny differences in the amount of matter present in the early universe into the sprawling strands of galaxies we see today. A new study using data from the Dark Energy Spectroscopic Instrument (DESI) has traced how this cosmic structure grew over the past 11 billion years, providing the most precise test to date of gravity at very large scales.

DESI is an international collaboration of more than 900 researchers from over 70 institutions around the world and is managed by the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab).

Continue reading “New DESI data shed light on gravity’s pull in the universe” »

Astronomers at the University of Toronto (U of T) have discovered the first pairs of white dwarf and main sequence stars—” dead” remnants and “living” stars—in young star clusters. Described in a new study published in The Astrophysical Journal, this breakthrough offers new insights into an extreme phase of stellar evolution, and one of the biggest mysteries in astrophysics.

Scientists can now begin to bridge the gap between the earliest and final stages of binary star systems—two stars that orbit a shared center of gravity—to further our understanding of how stars form, how galaxies evolve, and how most elements on the periodic table were created. This discovery could also help explain cosmic events like supernova explosions and gravitational waves, since binaries containing one or more of these compact dead stars are thought to be the origin of such phenomena.

Most stars exist in binary systems. In fact, nearly half of all stars similar to our sun have at least one companion star. These paired stars usually differ in size, with one star often being more massive than the other. Though one might be tempted to assume that these stars evolve at the same rate, more massive stars tend to live shorter lives and go through the stages of stellar evolution much faster than their lower mass companions.

Astounding simulation shows magnetic fields create fluffy, not flat, accretion disks around supermassive black holes, altering our understanding of black hole dynamics.

A team of astrophysicists from Caltech has achieved a groundbreaking milestone by simulating the journey of primordial gas from the early universe to its incorporation into a disk of material feeding a supermassive black hole. This innovative simulation challenges theories about these disks that have persisted since the 1970s and opens new doors for understanding the growth and evolution of black holes and galaxies.

Continue reading “Caltech Astrophysicists Flip Black Hole Theories With Stunning New Simulations” »

Then, in the 1980s, neutrinos from this supernova were picked up by the Irvine-Michigan-Brookhaven detector deep underground in Ohio. The discovery marked one of the first measurements of neutrinos from beyond our solar system, helped kickstart the field of observational neutrino astronomy, and provided a starting point that next-generation neutrino detectors continue to build on.

But the discovery was also lucky: The detector was built primarily to study proton decay, rather than neutrinos. “When you build a new detector with new capabilities, you’re sensitive to things that you never expected,” says Henry Sobel, a physics professor at the University of California, Irvine, and one of IMB’s original collaborators. The unexpected supernova would shape the legacy of IMB, which was recently recognized as an APS Historic Site for its role in neutrino science.

In the mid-1970s, teams of physicists were racing to build detectors that could measure proton decay, a hypothesized phenomenon that would confirm Howard Georgi and Sheldon Glashow’s new Grand Unified Theory, one that sought to unite three of the four fundamental forces of nature. The winner emerged in Painesville, Ohio, a small city northeast of Cleveland: The IMB detector, the world’s first kiloton-scale nucleon decay detector, began collecting data in 1982.

Researchers use the H.E.S.S. Observatory to overcome the challenge of detecting high-energy cosmic-ray electrons and positrons, revealing their likely origins close to our solar system through advanced data analysis techniques.

The Universe is filled with extreme environments, from the coldest regions to the most energetic sources imaginable. These conditions give rise to extraordinary objects like supernova remnants, pulsars, and active galactic nuclei, which emit charged particles and gamma rays with energies far exceeding those produced by the nuclear fusion processes in stars—by several orders of magnitude.

Challenges in Cosmic Ray Detection.

Black holes are one of the most enigmatic stellar objects. While best known for swallowing up their surroundings into a gravity pit from which nothing can escape, they can also shoot off powerful jets of charged particles, leading to explosive bursts of gamma rays that can release more energy in mere seconds than our sun will emit in its entire lifetime.

For such a spectacular event to occur, a black hole needs to carry a powerful magnetic field. Where this magnetism comes from, however, has been a long-standing mystery.

Using calculations of black hole formation, scientists at the Flatiron Institute and their collaborators have finally found the origin of those magnetic fields: the collapsing parent stars of the black holes themselves. The researchers report their results November 18 in The Astrophysical Journal Letters.

Recent research by a student-faculty team at Colgate University unlocks new clues that could radically change the world’s understanding of the origin of dark matter.

Assistant Professor of Physics and Astronomy Cosmin Ilie and Richard Casey have explored an idea put forth by two scientists at the University of Texas at Austin, Katherine Freese and Martin Winkler, suggesting that dark matter may have originated from a separate “Dark Big Bang,” occurring shortly after the birth of the universe.

It is widely accepted that all the matter filling our universe (including dark matter) originated from one major event—the Big Bang. This corresponds to the end of the cosmic inflation period, when the vacuum energy that drove the very brief extreme expansion initial phase of our universe was converted into a hot plasma of radiation and particles.

Dutch astrophysicists have observed the collision of two neutron stars, capturing unprecedented data that offers new insights into the formation of black holes.

The team, based at the Niels Bohr Institute at the University of Copenhagen, documented the birth of the smallest black hole ever recorded through their observations. Their findings, published in Astronomy and Astrophysics, illuminate the immense cosmic forces at play and how such events have shaped the universe and the creation of atoms.

The multiverse offers no escape from our reality—which might be a very good thing.

By George Musser

As memes go, it wasn’t particularly viral. But for a couple of hours on the morning of November 6, the term “darkest timeline” trended in Google searches, and several physicists posted musings on social media about whether we were actually in it. All the probabilities expressed in opinion polls and prediction markets had collapsed into a single definite outcome, and history went from “what might be” to “that just happened.” The two sides in this hyperpolarized U.S. presidential election had agreed on practically nothing—save for their shared belief that its outcome would be a fateful choice between two diverging trajectories for our world.