Lifeboat Foundation

Interstellar dust captures a significant fraction of elements heavier than helium in the solid state and is an indispensable component both in theory and observations of galaxy evolution.

Dust emission is generally the primary coolant of the interstellar medium (ISM) and facilitates the gravitational collapse and fragmentation of gas clouds from which stars form, while altering the emission spectrum of galaxies from ultraviolet (UV) to far-infrared wavelengths through the reprocessing of starlight. However, the astrophysical origin of various types of dust grains remains an open question, especially in the early Universe.

Here we report direct evidence for the presence of carbonaceous grains from the detection of the broad UV absorption feature around 2175A˚ in deep near-infrared spectra of galaxies up to the first billion years of cosmic time, at a redshift (z) of ∼7. This dust attenuation feature has previously only been observed spectroscopically in older, more evolved galaxies at redshifts of z3. The carbonaceous grains giving rise to this feature are often thought to be produced on timescales of hundreds of millions of years by asymptotic giant branch (AGB) stars. Our results suggest a more rapid production scenario, likely in supernova (SN) ejecta.

The trouble starts when they attempt to beam up from a planet during an ion storm. Something goes wrong. They appear aboard the Enterprise, but things are askew: Crew members greet the captain with Nazi-style salutes, and First Officer Spock sports a goatee. Observing these small but significant differences, Kirk muses that the crew has materialized in “a parallel universe coexisting with ours on another dimensional plane.”

These days, one parallel universe is hardly enough for science fiction. Instead, it seems the entire multiverse is having its Hollywood moment. Films like Doctor Strange in the Multiverse of Madness and Everything Everywhere All at Once entice the viewer with multiple versions of various characters and a dizzying array of alternate realities. Though they’re not particularly heavy on the physics, these films are definitely latching onto something. The idea of the multiverse — the provocative notion that our universe is just one of many— has fully cemented itself in mainstream pop culture. (Or, at least, in the current phase of the Marvel Cinematic Universe.) Its appeal as a storytelling device is obvious. Just as time travel allowed Marty McFly to experience different timelines in the Back to the Future series, multiverse tales allow characters to explore a multitude of worlds with varying degrees of similarity to our own, as well as altered versions of themselves.

While Hollywood can’t seem to get enough of the multiverse, it remains deeply controversial among scientists. Ask a prominent physicist whether they believe in a multitude of universes beyond our own, and you’ll get either a resounding yes or a vehement no, depending on whom you encounter. Advocates on the two sides show no mercy toward each other in their books, on their blogs, and, of course, on Twitter. But physicists didn’t pull the idea out of thin air — rather, several distinct lines of reasoning seem to point to the multiverse’s existence, bolstering the idea’s merit. Sabine Hossenfelder, a theoretical physicist at the Frankfurt Institute for Advanced Studies, has called the multiverse “the most controversial idea in physics.”

Observations of galaxy growth can be explained if the black holes at their centre contain dark energy, pointing to a possible role in the universe’s expansion.

Massive black holes could be the source of dark energy and the accelerating expansion of the universe, according to observations of ancient, dormant galaxies with black holes at their centre.

The laws of physics suggest that gravity should cause the universe to contract, but a mysterious force, which physicists call dark energy, seems to be counteracting this and making the universe expand at an accelerating rate.

The discovery of gravitational waves (GWs) in the system has shown that this prediction made by Einstein 107 years ago is true. The findings also resulted in a revolution in the world of astronomy.

What Are Gravitational Waves?

Continue reading “Einstein’s 107-year-old Theory on Gravitational Waves Is True; What Are These Forces of the Universe?” »

Black holes are the source of dark energy, the mysterious force behind the accelerating expansion of the universe, says a new study. This claim comes from an international team that compared growth rates of black holes in different galaxies. The team concluded that the spread of the masses observed could be explained by black holes bearing cores of ‘dark energy’, a report by the Guardian said.

Seventeen researchers in nine countries shared their findings in two papers published in The Astrophysical Journal and The Astrophysical Journal Letters. One of the researchers, Duncan Farrah from the University of Hawaii, said, “We propose that black holes are the source for dark energy.” Farrah added that this dark energy is produced when the normal matter is compressed during the death and collapse of large stars, the Guardian report added.

The researchers said the findings could be explained if black holes grow as the universe expands. They said that observations found black holes expanding 10 orders of magnitude in mass across most of cosmic history.

When neutron stars collide they produce an explosion that is, contrary to what was believed until recently, shaped like a perfect sphere. Although how this is possible is still a mystery, the discovery may provide a new key to fundamental physics and to measuring the age of the universe. The discovery was made by astrophysicists from the University of Copenhagen and has just been published in the journal Nature.

Kilonovae—the giant explosions that occur when two neutron stars orbit each other and finally collide—are responsible for creating both great and small things in the universe, from black holes to the atoms in the gold ring on your finger and the iodine in our bodies. They give rise to the most extreme physical conditions in the universe, and it is under these extreme conditions that the universe creates the heaviest elements of the periodic table, such as gold, platinum and uranium.

But there is still a great deal we do not know about this violent phenomenon. When a kilonova was detected at 140 million light-years away in 2017, it was the first time scientists could gather detailed data. Scientists around the world are still interpreting the data from this colossal explosion, including Albert Sneppen and Darach Watson from the University of Copenhagen, who made a surprising discovery.

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

The measurements from ancient and dormant galaxies show black holes growing more than expected, aligning with a phenomenon predicted in Einstein’s theory of gravity. The result potentially means nothing new has to be added to our picture of the universe to account for dark energy: black holes combined with Einstein’s gravity are the source.

Continue reading “Scientists find first evidence that black holes are the source of dark energy” »

Over 50 percent of high-mass stars reside in multiple star systems. But due to their complex orbital interactions, physicists have a difficult time understanding just how stable and long-lived these systems are. Recently a team of astronomers applied machine learning techniques to simulations of multiple star systems and found a new way that stars in such systems can arrange themselves.

Classical mechanics has a notorious problem known as the three-body problem. While Newton’s laws of gravity can easily handle calculations of the forces between two objects and their subsequent evolution, there is no known analytic solution when you include a third massive object. In response to that problem, physicists over the centuries have developed various approximation schemes to study these kinds of systems, concluding that the vast majority of possible three-object arrangements are unstable.

But it turns out that there are a lot of multiple-star systems out there in the galaxy. Indeed, over half of all massive stars belong to at least a binary pair, and many of them belong to triple or quadruple star systems. Obviously, the systems last a long time. Otherwise, they would have flung themselves apart a long time ago before we had a chance to observe them. But because of the limitations of our tools, we have difficulty assessing how these systems organize themselves and what stable orbit options exist.

Source of Dark Energy is black holes combined with Einstein’s gravity — experts Result potentially means nothing new has to be added to our picture of Universe It makes up most of the universe, yet hardly anything is known about the so-called Dark Energy that envelopes us. The unusual ‘something’ – one of the great mysteries of cosmology – is believed to be an unknown force that is pushing things apart more strongly than gravity and causing the universe’s expansion to accelerate.