Once a week.
Subscribe to our weekly newsletter.
New simulations show how supermassive black holes form
Researchers from Japan add a new wrinkle to a popular theory and set the stage for the formation of monstrous black holes.
- A new theory takes the direct-collapse theory explaining the creation of supermassive black holes around which galaxies turn ones step further.
- The advance is made possible by a super-powerful computer, ATERUI II.
- The new theory is the first that accounts for the likely assortment of heavy elements in early-universe gas clouds.
It seems that pretty much every galaxy we see is spinning around a supermassive black hole. When we say "supermassive," we mean BIG: Each is about 100,000 to tens of billions times the mass of our Sun. Serving as the loci around which our galaxies twirl, they're clearly important to maintaining the universal structures we see. It would be nice to know how they form. We have a pretty good idea how normally-huge-but-not-massive black holes form, but as for the supermassive larger versions, not so much. It's a supermassive missing piece of the universe puzzle.
Now, in research published in Monthly Notices of the Astronomical Society, astrophysicists at Tohoku University in Japan reveal that they may have solved the riddle, supported by new computer simulations that show how supermassive black holes come to be.
The direct collapse theories
Glowing gas and dark dust within the Large Magellanic Cloud
Image source: ESA/Hubble and NASA
The favored theory about the birth of supermassive black holes up to now has been the "direct-collapse" theory. The theory proposes a solution to a cosmic riddle: Supermassive black holes seem to have been born a mere 690 million years after the Big Bang, not nearly long enough for the standard normal black hole genesis scenario to have played out, and on such a large scale. There are two versions of the direct-collapse theory.
One version proposes that if enough gas comes together in a supermassive gravitationally bound cloud, it can eventually collapse into a black hole, which, thanks the cosmic background-radiation-free nature of the very early universe, could then quickly pull in enough matter to go supermassive in a relatively short period of time.
According to astrophysicist Shantanu Basu of Western University in London, Ontario, this would only have been possible in the first 800 million years or so of the universe. "The black holes are formed over a duration of only about 150 million years and grow rapidly during this time," Basu told Live Science in the summer of 2019. "The ones that form in the early part of the 150-million-year time window can increase their mass by a factor of 10 thousand." Basu was lead author of research published last summer in Astrophysical Journal Letters that presented computer models showing this version of direct-collapse is possible.
Another version of the theory suggests that the giant gas cloud collapses into a supermassive star first, which then collapses into a black hole, which then — presumably again thanks to the state of the early universe — sucks up enough matter to go supermassive quickly.
There's a problem with either direct-collapse theory, however, beyond its relatively narrow time window. Previous models show it working only with pristine gas clouds comprised of hydrogen and helium. Other, heavier elements — carbon and oxygen, for example — break the models, causing the giant gas cloud to break up into smaller gas clouds that eventually form separate stars, end of story. No supermassive black hole, and not even a supermassive star for the second flavor of the direct-collapse theory.
A new model
Image source: NAOJ
Japan's National Astronomical Observatory has a supercomputer named "ATERUI II" that was commissioned in 2018. The Tohoku University research team, led by postdoctoral fellow Sunmyon Chon, used ATERUI II to run high-resolution, 3D, long-term simulations to verify a new version of the direct-collapse idea that makes sense even with gas clouds containing heavy elements.
Chon and his team propose that, yes, supermassive gas clouds with heavy elements do break up into smaller gas clouds that wind up forming smaller stars. However, they assert that's not the end of the story.
The scientists say that post-explosion, there remains a tremendous inward pull toward the center of the ex-cloud that drags in all those smaller stars, eventually causing them to grow into a single supermassive star, 10,000 times larger than the Sun. This is a star big enough to produce the supermassive black holes we see when it finally collapses in on itself.
"This is the first time that we have shown the formation of such a large black hole precursor in clouds enriched in heavy-elements," says Chon, adding, "We believe that the giant star thus formed will continue to grow and evolve into a giant black hole."
Modeling the behavior of an expanded number of elements within the cloud while faithfully carrying forward those models through the violent breakup of the cloud and its aftermath requires such high computational overhead that only a computer as advanced as ATERUI II could pull off.
Being able to develop a theory that takes into account, for the first time, the likely complexity of early-universe gas clouds makes the Tohoku University idea the most complete, plausible explanation of the universe's mysterious supermassive black holes. Kazuyuki Omukai, also of Tohoku University says, "Our new model is able to explain the origin of more black holes than the previous studies, and this result leads to a unified understanding of the origin of supermassive black holes."
- Astronomers prove we orbit a black hole - Big Think ›
- NASA observes a black hole feasting on a star - Big Think ›
- You'll Never Guess What a Supermassive Black Hole's Favorite ... ›
- Scientists discover first 'intermediate-mass' black hole - Big Think ›
- Scientists discover first 'intermediate-mass' black hole - Big Think ›
How would the ability to genetically customize children change society? Sci-fi author Eugene Clark explores the future on our horizon in Volume I of the "Genetic Pressure" series.
- A new sci-fi book series called "Genetic Pressure" explores the scientific and moral implications of a world with a burgeoning designer baby industry.
- It's currently illegal to implant genetically edited human embryos in most nations, but designer babies may someday become widespread.
- While gene-editing technology could help humans eliminate genetic diseases, some in the scientific community fear it may also usher in a new era of eugenics.
Tribalism and discrimination<p>One question the "Genetic Pressure" series explores: What would tribalism and discrimination look like in a world with designer babies? As designer babies grow up, they could be noticeably different from other people, potentially being smarter, more attractive and healthier. This could breed resentment between the groups—as it does in the series.</p><p>"[Designer babies] slowly find that 'everyone else,' and even their own parents, becomes less and less tolerable," author Eugene Clark told Big Think. "Meanwhile, everyone else slowly feels threatened by the designer babies."</p><p>For example, one character in the series who was born a designer baby faces discrimination and harassment from "normal people"—they call her "soulless" and say she was "made in a factory," a "consumer product." </p><p>Would such divisions emerge in the real world? The answer may depend on who's able to afford designer baby services. If it's only the ultra-wealthy, then it's easy to imagine how being a designer baby could be seen by society as a kind of hyper-privilege, which designer babies would have to reckon with. </p><p>Even if people from all socioeconomic backgrounds can someday afford designer babies, people born designer babies may struggle with tough existential questions: Can they ever take full credit for things they achieve, or were they born with an unfair advantage? To what extent should they spend their lives helping the less fortunate? </p>
Sexuality dilemmas<p>Sexuality presents another set of thorny questions. If a designer baby industry someday allows people to optimize humans for attractiveness, designer babies could grow up to find themselves surrounded by ultra-attractive people. That may not sound like a big problem.</p><p>But consider that, if designer babies someday become the standard way to have children, there'd necessarily be a years-long gap in which only some people are having designer babies. Meanwhile, the rest of society would be having children the old-fashioned way. So, in terms of attractiveness, society could see increasingly apparent disparities in physical appearances between the two groups. "Normal people" could begin to seem increasingly ugly.</p><p>But ultra-attractive people who were born designer babies could face problems, too. One could be the loss of body image. </p><p>When designer babies grow up in the "Genetic Pressure" series, men look like all the other men, and women look like all the other women. This homogeneity of physical appearance occurs because parents of designer babies start following trends, all choosing similar traits for their children: tall, athletic build, olive skin, etc. </p><p>Sure, facial traits remain relatively unique, but everyone's more or less equally attractive. And this causes strange changes to sexual preferences.</p><p>"In a society of sexual equals, they start looking for other differentiators," he said, noting that violet-colored eyes become a rare trait that genetically engineered humans find especially attractive in the series.</p><p>But what about sexual relationships between genetically engineered humans and "normal" people? In the "Genetic Pressure" series, many "normal" people want to have kids with (or at least have sex with) genetically engineered humans. But a minority of engineered humans oppose breeding with "normal" people, and this leads to an ideology that considers engineered humans to be racially supreme. </p>
Regulating designer babies<p>On a policy level, there are many open questions about how governments might legislate a world with designer babies. But it's not totally new territory, considering the West's dark history of eugenics experiments.</p><p>In the 20th century, the U.S. conducted multiple eugenics programs, including immigration restrictions based on genetic inferiority and forced sterilizations. In 1927, for example, the Supreme Court ruled that forcibly sterilizing the mentally handicapped didn't violate the Constitution. Supreme Court Justice Oliver Wendall Holmes wrote, "… three generations of imbeciles are enough." </p><p>After the Holocaust, eugenics programs became increasingly taboo and regulated in the U.S. (though some states continued forced sterilizations <a href="https://www.uvm.edu/~lkaelber/eugenics/" target="_blank">into the 1970s</a>). In recent years, some policymakers and scientists have expressed concerns about how gene-editing technologies could reanimate the eugenics nightmares of the 20th century. </p><p>Currently, the U.S. doesn't explicitly ban human germline genetic editing on the federal level, but a combination of laws effectively render it <a href="https://academic.oup.com/jlb/advance-article/doi/10.1093/jlb/lsaa006/5841599#204481018" target="_blank" rel="noopener noreferrer">illegal to implant a genetically modified embryo</a>. Part of the reason is that scientists still aren't sure of the unintended consequences of new gene-editing technologies. </p><p>But there are also concerns that these technologies could usher in a new era of eugenics. After all, the function of a designer baby industry, like the one in the "Genetic Pressure" series, wouldn't necessarily be limited to eliminating genetic diseases; it could also work to increase the occurrence of "desirable" traits. </p><p>If the industry did that, it'd effectively signal that the <em>opposites of those traits are undesirable. </em>As the International Bioethics Committee <a href="https://academic.oup.com/jlb/advance-article/doi/10.1093/jlb/lsaa006/5841599#204481018" target="_blank" rel="noopener noreferrer">wrote</a>, this would "jeopardize the inherent and therefore equal dignity of all human beings and renew eugenics, disguised as the fulfillment of the wish for a better, improved life."</p><p><em>"Genetic Pressure Volume I: Baby Steps"</em><em> by Eugene Clark is <a href="http://bigth.ink/38VhJn3" target="_blank">available now.</a></em></p>
A leading British space scientist thinks there is life under the ice sheets of Europa.
- A British scientist named Professor Monica Grady recently came out in support of extraterrestrial life on Europa.
- Europa, the sixth largest moon in the solar system, may have favorable conditions for life under its miles of ice.
- The moon is one of Jupiter's 79.
Neil deGrasse Tyson wants to go ice fishing on Europa<div class="rm-shortcode" data-media_id="GLGsRX7e" data-player_id="FvQKszTI" data-rm-shortcode-id="f4790eb8f0515e036b24c4195299df28"> <div id="botr_GLGsRX7e_FvQKszTI_div" class="jwplayer-media" data-jwplayer-video-src="https://content.jwplatform.com/players/GLGsRX7e-FvQKszTI.js"> <img src="https://cdn.jwplayer.com/thumbs/GLGsRX7e-1920.jpg" class="jwplayer-media-preview" /> </div> <script src="https://content.jwplatform.com/players/GLGsRX7e-FvQKszTI.js"></script> </div>
Water Vapor Above Europa’s Surface Deteced for First Time<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="9c4abc8473e1b89170cc8941beeb1f2d"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/WQ-E1lnSOzc?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
Dr. Katie Mack explains what dark energy is and two ways it could one day destroy the universe.
- The universe is expanding faster and faster. Whether this acceleration will end in a Big Rip or will reverse and contract into a Big Crunch is not yet understood, and neither is the invisible force causing that expansion: dark energy.
- Physicist Dr. Katie Mack explains the difference between dark matter, dark energy, and phantom dark energy, and shares what scientists think the mysterious force is, its effect on space, and how, billions of years from now, it could cause peak cosmic destruction.
- The Big Rip seems more probable than a Big Crunch at this point in time, but scientists still have much to learn before they can determine the ultimate fate of the universe. "If we figure out what [dark energy is] doing, if we figure out what it's made of, how it's going to change in the future, then we will have a much better idea for how the universe will end," says Mack.
A unique exoplanet without clouds or haze was found by astrophysicists from Harvard and Smithsonian.
- Astronomers from Harvard and Smithsonian find a very rare "hot Jupiter" exoplanet without clouds or haze.
- Such planets were formed differently from others and offer unique research opportunities.
- Only one other such exoplanet was found previously.
Munazza Alam – a graduate student at the Center for Astrophysics | Harvard & Smithsonian.
Credit: Jackie Faherty