from the world's big
Researchers create a device to test a 50-year-old physics theory from the famed Roger Penrose.
- Scientists prove a 50-year-old physics theory by Roger Penrose.
- The theory explains how energy could be harvested from black holes by advanced aliens.
- Researchers from the University of Glasgow twisted sound waves to show that the effect Penrose described is real.
Check out how the researchers explain their work<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="18cab22ba8605e6eaba8784df05eeb1d"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/ES2VxhRAkUM?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
The set-up of the experiment.
Credit: University of Glasgow
Astronomers spot periodic lights coming from near the black hole at the center of our galaxy.
- Astronomers in Japan observe periodic lights coming from the region near the black hole at the center of our galaxy.
- The twinkling may be produced by hot spots in the accretion disk around the black hole.
- The mysterious region studied features extreme gravity.
Michio Kaku: A Black Hole in Our Own Backyard<div class="rm-shortcode" data-media_id="9LfqUfA6" data-player_id="FvQKszTI" data-rm-shortcode-id="629fe1f106ae179ccabcf1667d201e9b"> <div id="botr_9LfqUfA6_FvQKszTI_div" class="jwplayer-media" data-jwplayer-video-src="https://content.jwplatform.com/players/9LfqUfA6-FvQKszTI.js"> <img src="https://cdn.jwplayer.com/thumbs/9LfqUfA6-1920.jpg" class="jwplayer-media-preview" /> </div> <script src="https://content.jwplatform.com/players/9LfqUfA6-FvQKszTI.js"></script> </div>
The outer edges of a black hole might be "fuzzy" instead of neat and smooth.
- A recent study analyzed observations of gravitational waves, first observed in 2015.
- The data suggests, according to the researchers, that black holes aren't bounded by smooth event horizons, but rather by a sort of quantum fuzz, which would fit with the idea of Hawking radiation.
- If confirmed, the findings could help scientists better understand how general relativity fits with quantum mechanics.
ESO, ESA/Hubble, M. Kornmesser<p>In the 1970s, Stephen Hawking famously proposed that black holes aren't truly "black." In simplified terms, the theoretical physicist reasoned that, due to quantum mechanics, black holes actually emit tiny amounts of black-body radiation, and therefore have a non-zero temperature. So, contrary to Einstein's view that black holes are neatly defined and are not surrounded by loose materials, Hawking radiation suggests that black holes are actually surrounded by quantum "fuzz" that consists of particles that escape the gravitational pull.</p><p>"If the quantum fuzz responsible for Hawking radiation does exist around black holes, gravitational waves could bounce off of it, which would create smaller gravitational wave signals following the main gravitational collision event, similar to repeating echoes," Afshordi said.</p>
Credit: NASA's Goddard Space Flight Center/Jeremy Schnittman<p>A new study from Afshordi and co-author Jahed Abedi could provide evidence of these signals, called gravitational wave "echoes." Their analysis examined data collected by the <a href="http://www.virgo-gw.eu/" target="_blank">LIGO and Virgo gravitational wave detectors</a>, which in 2015 detected the first direct observation of gravitational waves from the collision of two distant neutron stars. The results, at least according to the researchers' interpretation, showed relatively small "echo" waves following the initial collision event.</p><p>"The time delay we expect (and observe) for our echoes ... can only be explained if some quantum structure sits just outside their event horizons," Afshordi told <em><a href="https://www.livescience.com/black-hole-echoes-unsettle-einstein-relativity.html" target="_blank">Live Science</a>.</em></p>
Afshordi et al.<p>Scientists have long studied black holes in an effort to better understand fundamental physical laws of the universe, especially since the introduction of Hawking radiation. The idea highlighted the extent to which general relativity and quantum mechanics conflict with each other. </p><p>Everywhere — even in a vacuum, like an event horizon — pairs of so-called <a href="https://www.scientificamerican.com/article/something-from-nothing-vacuum-can-yield-flashes-of-light/" target="_blank">"virtual particles"</a> briefly pop in and out of existence. One particle in the pair has positive mass, the other negative. Hawking imagined a scenario in which a pair of particles emerged near the event horizon, and the positive particle had just enough energy to escape the black hole, while the negative one fell in.</p><p>Over time, this process would lead black holes to evaporate and vanish, given that the particle absorbed had a negative mass. It would also lead to some interesting <a href="https://en.wikipedia.org/wiki/Black_hole_information_paradox#Recent_developments" target="_blank">paradoxes</a>.</p><p>For example, quantum mechanics predicts that particles would be able to escape a black hole. This idea suggests that black holes eventually die, which would theoretically mean that the physical information within a black hole also dies. This violates a key idea in quantum mechanics which is that physical information can't be destroyed.</p><p>The exact nature of black holes remains a mystery. If confirmed, the recent discovery could help scientists better fuse these two models of the universe. Still, some researchers are skeptical of the recent findings.</p><p>"It is not the first claim of this nature coming from this group," Maximiliano Isi, an astrophysicist at MIT, <a href="https://www.livescience.com/black-hole-echoes-unsettle-einstein-relativity.html" target="_blank">told</a> Live Science. "Unfortunately, other groups have been unable to reproduce their results, and not for lack of trying."</p><p>Isi noted that other papers examined the same data, but failed to find echoes. Afshordi told <em>Galaxy Daily</em>:</p><p>"Our results are still tentative because there is a very small chance that what we see is due to random noise in the detectors, but this chance becomes less likely as we find more examples. Now that scientists know what we're looking for, we can look for more examples, and have a much more robust confirmation of these signals. Such a confirmation would be the first direct probe of the quantum structure of space-time."</p>
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.
Image source: pixelparticle/Shutterstock/Big Think<p>The team behind the new paper, <a href="https://www.ippp.dur.ac.uk/profile/jscholtz" target="_blank">Jakub Scholtz</a> of Durham University in the U.K., and <a href="https://unwin.people.uic.edu/James_Unwin.html" target="_blank">James Unwin</a> of the University of Illinois at Chicago, are concerned not just with these odd orbits, but also with a set of <a href="https://arxiv.org/abs/1707.07634" target="_blank">gravitational anomalies</a> observed by Poland's <a href="http://ogle.astrouw.edu.pl" target="_blank">Optical Gravitational Lensing Experiment</a> (OGLE). Both phenomena, the authors say, "can be simultaneously explained by a new population of astrophysical bodies with mass several times that of Earth."</p><p>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," <a href="https://www.vice.com/en_us/article/qvgz97/planet-nine-might-be-a-black-hole-from-the-dawn-of-the-universe" target="_blank">says</a> Unwin.</p><p>Intriguingly, the scientists say, the proposed PBH may ultimately be more observable than Planet 9 has proven to be, if indirectly.</p>
How a black hole could be detected<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMTY0OTIwNS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYwOTE1MTc3MX0.5ZcjgSgCNYFxmLMSVOhgRGJBXroxeDDXbc777YY9n2U/img.jpg?width=980" id="f33e7" class="rm-shortcode" data-rm-shortcode-id="0428a20d1afabaab95ddd31dc47cf885" data-rm-shortcode-name="rebelmouse-image" />
Fermi Space Telescope
Image source: NASA<p>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 <a href="https://fermi.gsfc.nasa.gov" target="_blank">Fermi Space Telescope</a> or the <a href="https://chandra.harvard.edu" target="_blank">Chandra X-ray Observatory</a> could detect. </p><p>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."</p>
Cutting it close<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMTY0OTM4MS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYwNjIzNzMxMX0.yObKSSTrm25dn3eY2YUtfhIg-1KXqJeRM-sOURqgCE4/img.jpg?width=1245&coordinates=0%2C74%2C0%2C75&height=700" id="d4ce2" class="rm-shortcode" data-rm-shortcode-id="5b7e7460af89079b36ee20665babc7fe" data-rm-shortcode-name="rebelmouse-image" />
Image source: gurzart / Shutterstock<p>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?</p><p>"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.</p>
Adding to the conversation<p> 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 <em>can't</em> be a planet," Unwin tells <a href="https://today.uic.edu/uic-physicist-suggests-there-may-be-a-black-hole-in-our-solar-system" target="_blank"><em>UIC Today</em></a>. "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."</p>
How ‘The Goblin’ may unravel the mystery of Planet Nine<div class="rm-shortcode" data-media_id="s2E7WqjE" data-player_id="FvQKszTI" data-rm-shortcode-id="4ca9824f335154179e58908ff3321286"> <div id="botr_s2E7WqjE_FvQKszTI_div" class="jwplayer-media" data-jwplayer-video-src="https://content.jwplatform.com/players/s2E7WqjE-FvQKszTI.js"> <img src="https://cdn.jwplayer.com/thumbs/s2E7WqjE-1920.jpg" class="jwplayer-media-preview" /> </div> <script src="https://content.jwplatform.com/players/s2E7WqjE-FvQKszTI.js"></script> </div>
The TESS satellite captures rare images of a cataclysmic event in a faraway galaxy.
- TESS, a NASA planet-hunting satellite takes images of a black hole shredding apart a star.
- This phenomenon, called a tidal disruption event, is very rare.
- The star was the size of our sun.