There’s an intriguing possibility that the emergence of conscious life is not just a coincidence, but an inevitable outcome of cosmic evolution.
AD — Go to https://ground.news/drbecky to stay fully informed with the latest Space and Science news. Subscribe through my link to get 40% off the Vantage plan for unlimited access this month only. | I often get asked how do we know dark matter exists? Which is why I’ve made a video on all the observational evidence we have before (linked below)! But occasionally I’ll get asked how do we know how much dark matter there is, which is a really fun question. There’s many different ways we can calculate this, including the ratio between normal (baryonic) and dark matter, but in this video I just wanted to highlight three different ways astrophysicists calculate this.
Here’s my previous video on all the evidence we have for dark matter — • All the evidence we have for dark mat…
My previous video on whether dark matter could be made of black holes — • Is dark matter made of black holes?
My previous video on whether black holes contain dark matter — • Do black holes contain dark matter?
My previous video on why galaxies merge if the universe is expanding — • If the Universe is expanding, then wh…
Continue reading “How do we know how much dark matter there is in the Universe?” »
On November 14, 2014, a telescope spotted a burst of light in a galaxy 570 million light-years away. It was thought to be a supernova, an arrestingly bright explosion that marks a star’s death. This week, astronomers revealed that the burst was not a supernova after all, but rather a black hole having dinner—one of…
The newfound black hole, an intense, light-trapping abyss which has been named Gaia BH3, lurks just 1,926 light-years from Earth in the Aquila constellation. (That makes it the second closest black hole to Earth after Gaia BH1, which resides at 1,500 light-years away and is three times lighter than Gaia BH3.) The so-called “sleeping giant” — so named because unlike its ilk, the dormant black hole doesn’t appear to be shredding its companion star to pieces — birthed out of the imminent collapse of a once-massive star. It is the first direct link between a black hole and a progenitor star that was deprived of metals heavier than hydrogen and helium, according to the new study published in April in the journal Astronomy and Astrophysics.
The discovery confirms a leading theory of stellar evolution that posits high-mass black holes are remnants of stars that are low on metals. Such metal-poor stars have damped mass-eroding winds compared to their metal-rich counterparts, and thus have more material available to form heavier black holes. Astronomers normally time announcements of science discoveries at the same time as data release, in this case no sooner than early 2026, but “you cannot hide this kind of discovery from the community for two years,” says Panuzzo. “It is a unique case of publication based on the preliminary data because the data is exceptional and also something that’s very interesting for the community.”
Since superfluid light exists in computers I think frankly we may already solve the theory of everything because the missing piece is infinity in all things which solves all future problems.
Thinking of spacetime as a liquid may be a helpful analogy. We often picture space and time as fundamental backdrops to the universe. But what if they are not fundamental, and built instead of smaller ingredients that exist on a deeper layer of reality that we cannot sense? If that were the case, spacetime’s properties would “emerge” from the underlying physics of its constituents, just as water’s properties emerge from the particles that comprise it. “Water is made of discrete, individual molecules, which interact with each other according to the laws of quantum mechanics, but liquid water appears continuous and flowing and transparent and refracting,” explains Ted Jacobson, a physicist at the University of Maryland, College Park. “These are all ‘emergent’ properties that cannot be found in the individual molecules, even though they ultimately derive from the properties of those molecules.”
Physicists have been considering this possibility since the 1990s in an attempt to reconcile the dominant theory of gravity on a large scale — general relativity — with the theory governing the very smallest bits of the universe—quantum mechanics. Both theories appear to work perfectly within their respective domains, but conflict with one another in situations that combine the large and small, such as black holes (extremely large mass, extremely small volume). Many physicists have tried to solve the problem by ‘quantizing’ gravity — dividing it into smaller bits, just as quantum mechanics breaks down many quantities, such as particles’ energy levels, into discrete packets. “There are many attempts to quantize gravity—string theory and loop quantum gravity are alternative approaches that can both claim to have gone a good leg forward,” says Stefano Liberati, a physicist at the International School for Advanced Studies (SISSA) in Trieste, Italy.
Continue reading “‘Superfluid spacetime’ points to unification of physics” »
Ever wonder what happens when you fall into a black hole? Now, thanks to a new, immersive visualization produced on a NASA supercomputer, viewers can plunge into the event horizon, a black hole’s point of no return.
In this visualization of a flight toward a supermassive black hole, labels highlight many of the fascinating features produced by the effects of general relativity along the way. Produced on a NASA supercomputer, the simulation tracks a camera as it approaches, briefly orbits, and then crosses the event horizon — the point of no return — of a monster black hole much like the one at the center of our galaxy. (Video: NASA’s Goddard Space Flight Center/J. Schnittman and B. Powell)
“People often ask about this, and simulating these difficult-to-imagine processes helps me connect the mathematics of relativity to actual consequences in the real universe,” said Jeremy Schnittman, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who created the visualizations. “So I simulated two different scenarios, one where a camera — a stand-in for a daring astronaut — just misses the event horizon and slingshots back out, and one where it crosses the boundary, sealing its fate.”
ALMA telescope discovered a galaxy (BRI 1335–0417) with features of a spiral galaxy, dating back 1.4 billion years after the Big Bang, beating the previous record by over a billion years.
We discuss a perturbative and non-instantaneous reheating model, adopting a generic post-inflationary scenario with an equation of state w. In particular, we explore the Higgs boson-induced reheating, assuming that it is achieved through a cubic inflaton-Higgs coupling ϕ|H|2. In the presence of such coupling, the Higgs doublet acquires a ϕ-dependent mass and a non-trivial vacuum–expectation–value that oscillates in time and breaks the Standard Model gauge symmetry. Furthermore, we demonstrate that the non-standard cosmologies and the inflaton-induced mass of the Higgs field modify the radiation production during the reheating period. This, in turn, affects the evolution of a thermal bath temperature, which has remarkable consequences for the ultraviolet freeze-in dark matter production.
A team of scientists, astrophysicists and physicists, in an experiment called BICEP2 (Background Imaging of Cosmic Extragalactic Polarisation 2), carried out over nine years at an astronomical observatory at the South Pole, reported that they had discovered undeniable traces of a much sought-after phenomenon in astrophysics: gravitational waves. It was also announced that the method used to make the discovery had provided an important confirmation of the theoretical model of Big Bang cosmology, and would allow the first moments after this primordial explosion—the moment of creation for modern astrophysics—to be studied experimentally.
When you don’t find gravitational waves…
If we imagine space and time as the surface of an ocean, gravitational waves can be thought of as ripples in that ocean. More precisely, gravitational waves are theoretical ripples in space-time, first predicted by Albert Einstein in 1916 on the basis of his general theory of relativity. Like electromagnetic waves, which are produced by the oscillation of an electric charge, it is thought that a sufficiently strong oscillation of a very massive object should produce gravitational waves, which carry energy in the form of gravitational energy.
“People often ask about this, and simulating these difficult-to-imagine processes helps me connect the mathematics of relativity to actual consequences in the real universe,” said Jeremy Schnittman, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who created the visualizations. “So I simulated two different scenarios, one where a camera — a stand-in for a daring astronaut — just misses the event horizon and slingshots back out, and one where it crosses the boundary, sealing its fate.”
