Could ‘Planet 9’ actually be an ancient black hole?
A new paper suggests a primordial black hole may be making things weird at the edge of our solar system.
- Though a Planet 9 has been hypothesized, we can't seem to find it, at least not yet.
- The strange orbits of distant bodies and weird gravitational anomalies beg for an explanation.
- Scientists propose a hunt for telltale gamma rays from a primordial black hole.
One of the more tantalizing mysteries of modern astronomy is figuring out just what it is that's distorting the orbits of objects out at the edge of our solar system. The most popular candidate is a large, unseen mystery planet, dubbed either "Planet 9" or "Planet X."
However, no such body's been observed.
Last June, new models from the University of Cambridge and American University of Beirut, in Lebanon, showed how there may be no need for a Planet 9 after all — a swarm of small, icy objects may be what's producing the weird orbits. A new study, however, says, nope, it is something big out there, and the reason we can't see it is that it's an ancient black hole.
Image source: pixelparticle/Shutterstock/Big Think
The team behind the new paper, Jakub Scholtz of Durham University in the U.K., and James Unwin of the University of Illinois at Chicago, are concerned not just with these odd orbits, but also with a set of gravitational anomalies observed by Poland's Optical Gravitational Lensing Experiment (OGLE). Both phenomena, the authors say, "can be simultaneously explained by a new population of astrophysical bodies with mass several times that of Earth."
Such a body might be a primordial black hole (PBH), created within the first second after the Big Bang, that's somehow been captured by our solar system. The authors consider this idea every bit as likely as a Planet 9, which would require a re-thinking of planetary formation given that it would be a free-floating member of a solar system. "A solution with an ordinary planet and a solution with an exotic compact object like a primordial black hole are very similar," says Unwin.
Intriguingly, the scientists say, the proposed PBH may ultimately be more observable than Planet 9 has proven to be, if indirectly.
How a black hole could be detected
Fermi Space Telescope
Image source: NASA
Scholtz and Unwin say confirmation of a PBH could be attained with the capture of gamma-ray signals from its microhalo composed of dark matter. While we currently have no way to directly observe dark matter, it's believed that the fatal interactions between dark matter and normal matter at the edge of the PBH would produce gamma "annihilation signals" that devices such as the Fermi Space Telescope or the Chandra X-ray Observatory could detect.
This microhalo might extend hundreds of thousands of miles from the black hole's center. "We actually expect [annihilation signals] to happen at quite a significant rate," says Unwin, "so these things have the potential to just be glowing sources in the sky."
Cutting it close
Image source: gurzart / Shutterstock
One obvious question a black hole inside our solar system would prompt is whether or not the system's planets would eventually be drawn into it. If it's located in the same area as the proposed Planet 9, it would be over 56 billion miles away from Earth. That's less than a single light year, 6 trillion miles, pretty close in astronomical terms. Should we be worried?
"For normal black holes," explains Scholtz, "you need to have at least a solar mass because it is created out of a star. These primordial black holes can be much lighter; for example, an Earth mass, or in fact, even lighter." In layman's terms, we can relax — this one would be tiny.
Adding to the conversation
The paper by Scholtz and Unwin is still under peer review and hasn't yet been published in its final form. It's a new idea, and possibly incorrect, but still worthy of consideration. "We're not saying that it can't be a planet," Unwin tells UIC Today. "We're saying it need not be a planet, and the important point is that this extends the experimental search needed to find this object we believe may be in the outer solar system."
How ‘The Goblin’ may unravel the mystery of Planet Nine
Join Radiolab's Latif Nasser at 1pm ET on Monday as he chats with Malcolm Gladwell live on Big Think.
University of Utah research finds that men are especially well suited for fisticuffs.
- With males having more upper-body mass than women, a study looks to find the reason.
- The study is based on the assumption that men have been fighters for so long that evolution has selected those best-equipped for the task.
- If men fought other men, winners would have survived and reproduced, losers not so much.
Built for mayhem<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjY2NDIyMy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxMzk4NTQ2OX0.my6nML12F3fEQu3H4G0BScdqgaMZkRQHxgyj-Cmjmzk/img.jpg?width=980" id="906fc" class="rm-shortcode" data-rm-shortcode-id="dd77af7a881631355ed8972437846394" data-rm-shortcode-name="rebelmouse-image" />
Image source: Ollyy/Shutterstock<p>The researchers are, of course, talking averages here, not stating a rule: There are plenty of accomplished female pugilists, as well as lots of males who have no idea how to throw a punch.</p><p>Even so, says co-author <a href="https://www.wofford.edu/academics/majors-and-programs/biology/faculty-and-staff" target="_blank">Jeremy Morris</a> says, "The general approach to understanding why sexual dimorphism evolves is to measure the actual differences in the muscles or the skeletons of males and females of a given species, and then look at the behaviors that might be driving those differences."</p><p>Carrier has been interested in the idea that millennia of male fighting has shaped certain structures in male bodies. Previous research has reinforced his hunch:</p> <ul> <li><a href="https://jeb.biologists.org/content/216/2/236" target="_blank">When a hand is formed into a fist, its structure is self-protective</a>.</li> <li><a href="https://unews.utah.edu/flat-footed-fighters/" target="_blank">Heels planted firmly on the ground augment upper-body power</a>.</li> <li><a href="https://www.ncbi.nlm.nih.gov/pubmed/24909544" target="_blank">A study examined facial bone structure as being especially well-suited for taking a punch</a>.</li> </ul> <p>(That last one is our favorite. Do you know the German word "<a href="https://www.urbandictionary.com/define.php?term=Backpfeifengesicht" target="_blank">backpfeifengesicht</a>?" It's an adjective describing "a face that badly needs a punching.")</p><p>"One of the predictions that comes out of those," asserts Carrier, "is if we are specialized for punching, you might expect males to be particularly strong in the muscles that are associated with throwing a punch."</p>
Testing the theory<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjY2NDIzMy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYwNzMxMTE2MH0.UXJICMy57UPYUWskhK98alctOrPidJL9yxMkz3HDQrM/img.jpg?width=980" id="98718" class="rm-shortcode" data-rm-shortcode-id="b12287684ac3e740b70392e6433a6b8f" data-rm-shortcode-name="rebelmouse-image" />
Image source: Ollyy/Shutterstock<p>The researchers measured the punching — and spear-throwing — force of 20 men and 19 women. The assumption was that early humans were punchers <em>and</em> spear-throwers.</p><p>Prior to testing, each participant had filled out an activity questionnaire so that "we weren't getting couch potatoes, we were getting people that were very fit and active," says Morris.</p><p>For punching, participants operated a hand crank that required movement similar to throwing a haymaker. The purpose of the hand crank was to spare participants any damage that might be inflicted on their fists by throwing actual punches. Subjects were also measured pulling a line forward over their heads to assess their strength at throwing a spear.</p><p>Even though all of the participants, male and female, were routinely fit, the average power of males was assessed as being 162% greater than females. There were no gender differences in throwing strength recorded. Other untested, though presumably likely, hand-to-hand combat activities come to mind including tackling, clubbing, running, kicking, scratching, and biting.</p><p>Carrier's takeaway: "This is a dramatic example of sexual dimorphism that's consistent with males becoming more specialized for fighting, and males fighting in a particular way, which is throwing punches."</p>
Boys will be boys<p>It, er, strikes us as odd that, even in science fiction — hi-tech weaponry notwithstanding — the hero <em>is</em> going to wind up duking it out with some bad guy, or alien, in the climactic battle. What is it about men punching, anyway? Are they more sexually attractive? The study suggests so:</p><p style="margin-left: 20px;"><em>The results of this study add to a set of recently identified characters indicating that sexual selection on male aggressive performance has played a role in the evolution of the human musculoskeletal system and the evolution of sexual dimorphism in hominins.</em></p><p>It's tough to contribute to the gene pool after being killed in battle.</p><p>Also, while the authors aren't <em>quite</em> saying that males' historical fighting role is mandated by biology and not by social expectations, neither are they quite <em>not</em> saying it.</p><p>As Carrier explain to <a href="https://attheu.utah.edu/facultystaff/carrier-punch/" target="_blank">theU</a>: "Human nature is also characterized by avoiding violence and finding ways to be cooperative and work together, to have empathy, to care for each other, right? There are two sides to who we are as a species. If our goal is to minimize all forms of violence in the future, then understanding our tendencies and what our nature really is, is going to help."</p>
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Cool hand rebuke<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQyMTIyNy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NjY1NTYyOH0.0MCPKN3If94mYCNf3mMNrnTvJXjXN_bKLhgk9203EXk/img.jpg?width=917&coordinates=0%2C0%2C0%2C0&height=453" id="1627b" class="rm-shortcode" data-rm-shortcode-id="6d76421ba1ea0de4b09956b97e80c384" data-rm-shortcode-name="rebelmouse-image" />
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