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The discovery of the accelerated expansion of the Universe has often been attributed to the force known as dark energy. An intriguing new theory was put forward last year to explain this mysterious force; black holes could be the cause of dark energy! The theory goes on to suggest as more black holes form in the Universe, the stronger the pressure from dark energy. A survey from the Dark Energy Spectroscopic Instrument (DESI) seems to support the theory. The data from the first year of operation shows the density of dark energy increases over time and seems to correlate with the number and mass of black holes! 

Cast your mind back 4 billion years to the beginning of the Universe. Just after the Big Bang, the moment when the Universe popped into existence, there was a brief period when the Universe expanded faster than the speed of light. Before you argue that nothing can travel faster than the speed of light we are talking of the very fabric of space and time expanding faster than the speed of light. The speed of light limit relates to travel through the fabric of space, not the fabric of space itself! This was the inflationary period. 

This illustration shows the “arrow of time” from the Big Bang to the present cosmological epoch. Credit: NASA

The energy that drove the expansion in the early Universe shared similarities with dark energy, the repulsive force that seems to permeate the Universe and is driving the current day accelerated expansion of the Universe.

What is dark energy though? It is thought to make up around 68% of the Universe and, unlike normal matter and energy seems to have a repulsive force rather than attractive. The repulsive nature was first inferred from observations in the late 1990’s when astronomers deduced the rate of acceleration when observing distant supernova. As to the nature of dark energy, no-one really knows what it is or what it comes from, that is, until now. 

Artist’s illustration of a bright and powerful supernova explosion. (Credit: NASA/CXC/M.Weiss)

A team of researchers from the University of Michigan and other institutions have published a paper in the Journal of Cosmology and Astroparticle Physics. In their paper they propose that black holes are the source of dark energy. Professor Gregory Tarle said ‘Where in the later Universe do we see gravity as strong as it was at the beginning of the Universe?’ The answer, Tarle goes on to describe is the centre of black holes. Tarle and team propose that what happened during the inflation period runs in reverse during the collapse of a massive star. When this happens, the matter could conceivably become dark energy. 

The team have used data from the Dark Energy Spectroscopic Instrument (DESI) which is mounted upon the 4m Mayall telescope at Kitt Peak National Observatory. The instrument is essentially 5,000 computer controlled fibre optics which cover an area of the sky equal to about 8 square degrees. The evidence of dark energy is achieved by studying tens of millions of galaxies. The galaxies are so far way their light takes billions of years to reach us. We can use the information to determine how fast the Universe is expanding with unprecedented precision. 

Stu Harris works on assembling the focal plane for the Dark Energy Spectroscopic Instrument (DESI), which involves hundreds of thousands of parts, at Lawrence Berkeley National Laboratory on Wednesday, 6 December, 2017 in Berkeley, Calif.

The data shows evidence that dark energy has increased with time. This is not perhaps in itself surprising but it seems to accurately mirror the increase in black holes over time too. Now that DESI is operational, more observations are required to hunt down the black holes and try to quantify their growth over time to see if there really is merit in this new exciting hypothesis. 

Source : Evidence mounts for dark energy from black holes

The post The Connection Between Black Holes and Dark Energy is Getting Stronger appeared first on Universe Today.

A bird flu virus that has been circulating in dairy cattle for months has now been found in a pig in the US for the first time, raising the risk of the virus evolving to become more dangerous to people

Inside a hunk of a material called a semimetal, scientists have uncovered signatures of bizarre particles that sometimes move like they have no mass, but at other times move just like a very massive particle

Soil is full of an uncountable number of viruses, and scientists are only beginning to understand just how substantial their role in the carbon cycle may be

If there are alien civilizations in the Universe, some of them could be super advanced. So advanced that they can rip apart planets and create vast shells surrounding a star to capture all its energy. These Dyson spheres should be detectable by modern telescopes. Occasionally astronomers find an object that resembles such an alien megastructure, but so far, they’ve all turned out to be natural objects. As best we can tell, there are no Dyson spheres out there.

And when you think about it, building a Dyson sphere is the cosmic endgame of a capitalist dystopia. In the never-ending quest to capture and consume every last bit of energy, your civilization rips worlds asunder, moving heaven and earth to create an orbitally unstable, unlivable engine. If you can traverse light-years and transform planets, why not just move Earth-like planets and moons into a star’s habitable zone and have a nice cluster of comfy planets to live on? If this kind of stellar-punk civilization is out there, could astronomers detect it? This is the question behind a study on the arXiv.

The authors begin by noting that when Freeman Dyson proposed the idea in 1960, our solar system was the only known planetary system. Star systems were thought to be rare at the time, but now we know better. Most stars have planets, and even our solar system has a dozen water-rich moons that could be made habitable with a shift of their orbits and a bit of terraforming. Since this would be much easier than building a Dyson sphere, the authors argue that modified systems should be much more common. The only question is how to detect them.

One way would be to look for planetary systems that don’t seem to have formed naturally. For example, if you find a system with a dozen worlds in a star’s habitable zone and few other planets, that isn’t likely to have happened by chance. Less obvious would be to look for systems that are orbitally unusual. Perhaps the planets have orbital resonances that aren’t stable in the long term, or have unusually perfect orbits. Maybe the chemical composition of some worlds don’t match that of the system as a whole. Anything that stands out might be worth a closer look.

Using lasers to change a planet’s orbit. Credit: Narasimha, et al

Another way would be to look for signs of systems under construction. The authors note that planets could be moved or captured slowly over time using high-power directional lasers to accelerate them. Stray light from those lasers would be visible across light years. If we detect monochromatic laser light coming from a potentially habitable star, it could be aliens building a better home.

It’s not likely that we’ll find this kind of evidence, but the idea is no stranger than those of giant alien megastructures. Besides, it’s fun to think about just how many habitable planets you could pack into a single star system. It turns out to be quite a lot!

Reference: Narasimha, Raghav, Margarita Safonova, and C. Sivaram. “Making Habitable Worlds: Planets Versus Megastructures.” arXiv preprint arXiv:2309.06562 (2023).

The post Will Advanced Civilizations Build Habitable Planets or Dyson Spheres appeared first on Universe Today.

Enough landmines are buried underground worldwide to circle Earth twice at the equator, but the identification and removal of these explosives is costly and time-consuming. New research could help solve the problem.

Biomedical engineers have invented a 3D printing system, or bioprinter, capable of fabricating structures that closely mimic the diverse tissues in the human body, from soft brain tissue to harder materials like cartilage and bone.

SURD, an algorithm, reveals causal links in complex systems. Applications may include forecasting climate to projecting population growth to designing efficient aircraft.

Despite ongoing efforts to curb CO2 emissions with electric and hybrid vehicles, other forms of transportation remain significant contributors of greenhouse gases. To address this issue, old technologies are being revamped to make them greener, such as the reintroduction of sailing vessels in shipping and new uses for hydrogen in aviation. Now, researchers have used computer modeling to study the feasibility and challenges of hydrogen-powered aviation.

Singlet fission (SF) is an exciton amplification phenomenon in which two triplet excitons are generated from a singlet exciton produced by the absorption of a single photon in chromophores. A team of researchers has demonstrated that SF can be promoted by introducing chirality and controlling chromophore orientation and arrangement. Their innovative study is expected to promote diverse applications in energy science, quantum, and information materials science, photocatalysis, solar cells, and life science.

A new method for determining causality gives scientists a more holistic view of the causal role that contributing factors play within just about any system.

Teams of astronomers used the combined power of NASA's Hubble and James Webb space telescopes to revisit the legendary Vega disk.

Researchers found that a 12-week therapeutic virtual yoga program for chronic low back pain can be a feasible, safe and effective treatment option.

Microplastics have been steadily increasing in freshwater environments for decades and are directly tied to rising global plastic production since the 1950s, according to a new study by an interdisciplinary team. The findings provide insight into how microplastics move and spread in freshwater environments, which could be important for creating long-term solutions to reduce pollution, the researchers said.

Well, I’ll be. The group of interns at the left-wing The Nation have objected to the magazine’s recent endorsement of Kamala Harris and published their gripes. Now why would that happen? We all know that many editors and reporters at the Washington Post objected to the paper’s failure to endorse Kamala Harris, but this kind of reversal is unexpected.  Well, sort of—unless you know how “progressive” young Leftists are beginning to change journalism.

So why the beefing? It’s Israel, Jake!

Here, from the “activism” section of the magazine (!), is the long gripe by The Nation‘s interns (click to read for free):

An excerpt giving the tenor of their rage:

We, The Nation’s current interns, find this endorsement unearned and disappointing. We have a different interpretation of the magazine’s abolitionist legacy, one that says a publication committed to justice must refrain from endorsing a person signing off on genocide. We do not support Donald Trump, but to champion Harris at this moment is to ignore the atrocities that are being carried out with weapons supplied by the Biden-Harris administration.

The Nation’s endorsement notes that on foreign policy the “positive case [for Harris] is harder to make,” adding that “she has failed so far to offer anything more substantive to the millions of Americans…desperate for an end to America’s unconditional support for Israel’s brutal war on Gaza.” Yet it goes on to endorse her anyway—implying that domestic concerns are somehow more important. We disagree. On the grounds of Gaza alone, Harris should not have received The Nation’s endorsement.

In the 12 weeks since she effectively became the Democratic nominee, Harris has failed to differentiate her policies from Joe Biden’s blank-check support for genocide. Instead, she repeats the same bland pronouncements about the need for a ceasefire and uses the same passive-voice support for the idea of Palestinian “freedom and self-determination.” Again and again, she has been asked by Palestinian, Arab, and Muslim voters, along with a broad coalition of Democrats of conscience, to offer an alternative, and again and again she has refused. She would not even allow a pre-vetted Palestinian supporter of hers to speak at theDemocratic National Convention.

We have watched this abdication of moral responsibility by the Democratic nominee with a growing sense of dismay. As young journalists, we think of our colleagues in Gaza. Israel has killed more than 175 journalists in Gaza since last October—and right now, with US support and the Western media’s indifference, Israel is effectively issuing hit lists of reporters in Gaza. During the last year, The Nation has published dispatches from Palestinian journalists, from 14-year-old Lujayn to the journalist Mohammed Mhawish, both of whom have survived air strikes, most likely from US-made weapons. We cannot advocate for a person who is complicit in the murders of fellow journalists and the bombing of colleagues whose pieces we have fact-checked.

Even when they try to leaven  Harris’s position as a perpetrator of genocide with her “good” domestic policies, they can’t resist bringing up Gaza again and again:

Harris, for instance, promises to provide tax credits to families with newborns and to sign a law to restore the right to abortion nationwide. Yet her commitment to the welfare of children doesn’t extend to the more than 17,000 kids killed in Gaza, hundreds of whom died from inadequate postnatal care like incubators. She will fight for reproductive care in the United States, but in Gaza, tens of thousands of mothers have or will give birth without access to doctors, pain relief, hospitals, or food and water.

Harris also pledges to strengthen our healthcare system. But in Gaza, as many as 1,000 healthcare workers have been killed, 30 of 36 hospitals have been damaged or destroyed, and fewer than half are even partially functional. People routinely die from the blockade of basic sanitary equipment, ordinary medicines, and vaccines.

Harris’s plans to relieve the housing crisis in the United States ring hollow next to her support for Israel’s destruction of homes in Gaza, the West Bank, and Lebanon. With the Biden-Harris administration’s full knowledge and aid, 90 percent of Gazans have been forcibly displaced, and hundreds of thousands of homes have been damaged and destroyed. Nor has the administration done anything to stop the demolitions of houses and illegal expansion of settlements in the West Bank.

So who do the interns think the magazine should endorse for President? Nobody, of course. It’s curious that the Washinton Post would get slammed for not endorsing anybody, but the interns haven’t been slammed (or so I’ve seen) for the same action. Of course accusing Israel of genocide is perfectly okay with the “progressive” Left. One more bit from this execrable whine:

There will be people wondering whom we would endorse, if not Harris. Our answer is that we choose not to endorse any party’s candidate for president. We know that a second Trump presidency would be a disaster, but we believe that we cannot vote our way out of this genocide. And while some of us will be voting for president in November—and some of us will not—we all reject the idea that democracy will be safe under a Harris administration.

This is, to my mind, ridiculous, and exemplifies the Jew-hatred that is permeating young people and gradually working its way up into journalism, government, and corporations.  You don’t have to be a rocket scientist to realize that, in fact, the genocide is on the side of Hamas, which put into words (and acts repeatedly on) its desire to eliminate Israel. It is Hamas that deliberately tries to kill Jewish civilians, while Israel does its best to avoid killing civilians (its ratio of civilians killed to terrorist fighters killed is one of the lowest of modern times). Does Hamas warn Israeli civilians to get out of the way when it fires a rocket? No, it wants to kill civilians. It targets civilians, both with rockets and, of course, personally, as the October 7 massacre and subsequent acts of terrorism attest.

And, of course, we all know that part of Hamas’s strategy is to ensure that Gazan civilians get killed as a way of winning the world’s sympathy. They do this by embedding their fighters and rocket launchers among civilians and even in hospitals and humanitarian zones.  That guarantees not only that civilians will die as “collateral damage” (I hate that phrase, since all non-combatant human life should be preserved), but also that journalists, who have to be close to the action, will die as well. As the saying goes—and you know it’s true—”If Hamas put down its weapons, the war would be over. If Israel put down its weapons, all the Jews would be killed and Israel would disappear.” The reason Israel sustains fewer casualties is that it has more weapons than do the Palestinians as well as defense systems against rockets fired by Islamist terrorists.

I regard it as a touchstone of ignorance (willful ignorance, not simply “failure to know”) when someone accuses Israel of genocide when it’s palpably clear that Israel is not engaged in a program of eliminating all Palestinians, whose population has grown rapidly in the last decade. And of course where are the accusations of genocide against Hamas? I haven’t heard any lately, except, perhaps, by Israelis, but even then I can’t think of any.

I can’t print here what I think of these ignorant interns since this is a family-friendly site. Just let me say that I hope to Ceiling Cat that they don’t take over journalism and politics. Harris is already weakening American support of Israel by repeatedly calling for a cease-fire, which if effected now, would simply allow Hamas to regroup and continue perpetrating terrorism. If I were a paper and had to endorse a candidate (of course I don’t think papers should be endorsing candidates), it would of course be Harris. But to withhold that approbation because of a supposed “genocide” is sheer stupidity.

The abiding sin of the interns is their failure to blame Hamas rather than Israel for the deaths of Gazan civilians.  If beginning in 2005, a subset of Palestinians was not intent on killing Jews and getting rid of Israel, Gaza would now be a Mediterranean paradise, rich and full of big-spending tourists and beach resorts.

Alan Turing's theories about computation seem to have a startling consequence, placing hard limits on how fast or slow any physical process in the universe can grow

DNA analysis suggests Pando, a quaking aspen in Utah with thousands of stems connected by their roots, is between 16,000 and 81,000 years old

All day yesterday I was making my way back to Chicago from Ivins, Utah: first, a two-hour drive to Las Vegas, then a two-hour wait in the airport, with the flashing and music of slot machines IN THE WAITING AREA, and finally a four-hour flight back home. I am exhausted. Which is to say: posting will be very light today—if there is any.

But on the way home I read Salman Rushdie’s latest book, Knife: Meditations After An Attempted Murder, which came out in April. Click the screenshot below to go to the Amazon site. I have to say that the cover is wonderfully designed given the contents:

It’s a short (200-page) account of the attempted murder of Rushdie on August 12, 2022 by accused perp Hadi Matar, a Lebanese-American likely trying to fulfill the fatwa issued on Rushdie in 1989 by the Ayatollah Khomeini.  The Ayatollah considered Rushdie’s book The Satanic Verses as anti-Muslim blasphemy, and called for the author’s assassination. A $3 million bounty accompanied the fatwa. Rushdie went into hiding, but several people connected with the book were killed.

Finally, after 33 years, the fatwa was fulfilled when Matar ran at Rushdie as the author was about to address a Chautauqua, New York audience about the need for a “safe space” for politically demonized writers.  Matar apparently stabbed Rushdie 15 times in the neck, eye, chest, and hand, blinding him in one eye and rendering his left hand largely useless. For several days Rushdie hovered between life and death, but thanks to expert trauma care, he survived. His eye remains but its sightless, and his hand is only minimally useful. But, Rushdie avers, he was largely saved by the love of his (fifth) wife, the African-American poet Rachel Eliza Griffiths. In many ways the book is a paean to Griffiths, who was by his side the whole way, and the description of their mutual love is quite moving.

Rushdie, as you see from this book, is back in action, and on to another novel. I have read only one of his, but it was a corker: Midnight’s Children, which I picked up for a pittance in a used-book stall in New Delhi. I was mesmerized by the novel, which won not only a Booker Prize, but the “Booker of the Bookers“, an award for the 25th anniversary of the Prize. In other words, it was judged the best of the 25 Booker winners.  I’ve read a fair number of Booker-Prize winners, and think Rushdie’s award was well deserved. Midnight’s Children is a great classic, a magical-realism account centered on the partition of India in 1947. PLEASE read it if you haven’t.

Sad to say, that is the only novel of Rushdie’s I’ve read, and I must catch up. He’s written about 20 of them, apparently of varying quality, including an earlier autobiography called Joseph Anton, dealing with his post-fatwa journey. But I hear some of the novels are gems, and I must get to them.  He’s a likely future winner of the Nobel Prize for Literature, which I think has been delayed only because Stockholm fears Muslim backlash if Rushdie wins.

As for Knife, it’s a gripping short read and the details of Rushdie’s assault and subsequent recovery make the book one that’s hard to put down. I recommend it highly for a short read and for those interested in Rushdie.  A fair amount of the last part of the book is a fictionalized dialogue between Rushdie and his assailant, which changes the pace of the book substantially. At first I didn’t like this bit, but the more I read it, the more I enjoyed it. It is, I suppose, a way for Rushdie to come to terms with Matar and his attack, trying to suss out why a New Jersey resident would knife the writer after so many years.

Below is a Wikipedia photo of the post-attack Rushdie. He decided not to have his eye removed but rather to hide it with a dark lens in his glasses. He does have macular degeneration in his other eye, and fears above all that he will go blind. But it looks as though they’ve stabilized his condition:

Elena Ternovaja, CC BY-SA 3.0, via Wikimedia Commons

Matar, by the way, is still awaiting trial. They delayed it because his public defender argued that Rushdie’s published account was essential for Matar’s defense.

Just under 5 per cent of the Wikipedia pages in English that have been published since ChatGPT's release seem to include AI-written content

Meanwhile, in Dobrzyn, Hili has a message for us all:

A: What are you thinking about?
Hili: About hope in hopelessness.
A: And what is your conclusion?
Hili: That it requires intelligence, knowledge and craftiness.

Ja: O czym myślisz?
Hili: O nadziei w beznadziejności.
Ja: I jaki wniosek?
Hili: Wymaga inteligencji, wiedzy i przebiegłości.