Physicists invent a new way to search for dark matter using lasers
Japanese physicists devise technology to discover axion dark matter.
- Physicists from the University of Tokyo plan to use lasers to discover axions.
- Axions are theoretical particles that may be components of dark matter.
- Dark matter is a mysterious substance that may compose up to 27% of the universe.
Japanese physicists propose modifications to existing equipment that could allow them to pinpoint axions, hypothetical particles that may be components of dark matter. Dark matter, a mysterious theoretical substance that is thought to make up about 27% of all matter in the universe, is yet to be directly observed.
The scientists hope to track down the elusive axions using experiments with lasers.
The difficulty in finding dark matter is that it is made of, as many physicists think, weakly interacting massive particles or WIMPs, produced in the early Universe. While we haven't figured out how to spot these particles directly, interacting with regular matter, but we've been able to predict their existence by the gravitational effects they have throughout the universe.
The celebrated Large Hadron Collider in Switzerland has been used to search for WIMPs, and now a new approach from Japan hopes to use the KAGRA Observatory to discover dark matter by tracking down axions.
KAGRA stands for the Kamioka Gravitational Wave Detector. This first major gravitational wave observatory in Asia is located deep under a mountain of the Kamioka mine in Japan's Gifu Prefecture.
The Assistant Professor Yuta Michimura from the Department of Physics at the University of Tokyo, which runs the KAGRA project, explained that because axions are light and don't interact with normal matter, they are good candidates for dark matter.
Interestingly, he also quantified how much dark matter is there, saying the amount of it inside our planet would weigh as much as a squirrel —
"We don't know the mass of axions, but we usually think it has a mass less than that of electrons, " said Michimura. "Our universe is filled with dark matter and it's estimated there are 500 grams of dark matter within the Earth, about the mass of a squirrel."
The proposed instrument that would hunt for axion dark matter.
Credit: 2019 Nagano et al | University of Tokyo Institute for Cosmic Ray Research
As you can imagine, spotting such particles is no easy task. Physicists have to figure out ways that can make the particles reveal themselves through their signatures.
Koji Nagano, a graduate student at the Institute for Cosmic Ray Research at the University of Tokyo, says that their models show that axions affect light polarization, which describes the geometrical orientation of oscillating electromagnetic waves.
Their method of finding axions relies on this finding.
"This polarization modulation can be enhanced if the light is reflected back and forth many times in an optical cavity composed of two parallel mirrors apart from each other, " further expounds their approach Nagano.
The best examples of such cavities, says the researcher, are the long tunnels of gravitational-wave observatories.
"There is overwhelming astrophysical and cosmological evidence that dark matter exists, but the question "What is dark matter?" is one of the biggest outstanding problems in modern physics," said Nagano. "If we can detect axions and say for sure they are dark matter, it would be a truly exciting event indeed. It's what physicists like us dream for."
The team proposes plans to inexpensively modify existing observatories like KAGRA or the Laser Interferometer Gravitational-Wave Observatory (LIGO) in the U.S. to search for the axions. The plan, according to Michimura, would be to add "polarization optics in front of photodiode sensors in gravitational-wave detectors."
The idea's additional benefit is that it doesn't require building entirely new facilities. Upgrading gravitational wave labs would not hamper their original missions — looking for gravitational waves. But the new functionality would open a new chapter in the search for dark matter.
The study involved Koji Nagano, Tomohiro Fujita, Yuta Michimura, and Ippei Obata.
Check out the their paper "Axion Dark Matter Search with Interferometric Gravitational Wave Detectors" in the journal Physical Review Letters.
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Welcome to the world's newest motorsport: manned multicopter races that exceed speeds of 100 mph.
- Airspeeder is a company that aims to put on high-speed races featuring electric flying vehicles.
- The so-called Speeders are able to fly at speeds of up to 120 mph.
- The motorsport aims to help advance the electric vertical take-off and landing (eVTOL) sector, which could usher in the age of air taxis.
Credit: Airspeeder<p>To prevent crashes, Airspeeder is working with the companies Acronis and Teknov8 to develop "high-speed collision avoidance" systems for its Speeders.</p><p style="margin-left: 20px;">"As they compete, Speeders will utilise cutting-edge LiDAR and Machine Vision technology to ensure close but safe racing, with defined and digitally governed no-fly areas surrounding spectators and officials," Airspeeder wrote in a <a href="https://airspeeder.com/news/2020/9/7/airspeeder-worlds-first-flying-electric-car-racing-series-partners-with-cyber-protection-leader-acronis-34g4k" target="_blank">blog post</a>.</p>
Credit: Airspeeder<p>Beyond motorsports, Airspeeder hopes to help advance the electric vertical take-off and landing (eVTOL) sector. This sector is where companies like <a href="https://www.ainonline.com/aviation-news/business-aviation/2020-01-07/hyundai-and-uber-announce-evtol-air-taxi-partnership" target="_blank">Uber, Hyundai</a>, and Airbus are working to develop air taxis, which could someday take the ridesharing industry into the skies. By 2040, the autonomous urban aircraft industry could be worth $1.5 trillion, according to a <a href="https://www.morganstanley.com/ideas/autonomous-aircraft" target="_blank">2019 report</a> from Morgan Stanley.</p><p>Still, many technical and regulatory hurdles remain. Matt Pearson, Airspeeder's founder and CEO, thinks the futuristic motorsport will help to not only speed up that process, but also pave the way for self-driving cars.</p>
Astronomers spot an object heading into Earth orbit.
Minimoons<p>Scientists have confirmed just two prior minimoons. One was <a href="https://en.wikipedia.org/wiki/2006_RH120" target="_blank">2006 RH120</a>, which orbited us from September 2006 to June 2007. The other was <a href="https://en.wikipedia.org/wiki/2020_CD3" target="_blank">2020 CD3</a>, which got stuck in the 2015–2016 timeframe, and is believed to gotten away in May 2020.</p><p>2020 SO, the new kid on the block, is expected to arrive in October 2020 and pop out of orbit in May 2021.</p><div id="37962" class="rm-shortcode" data-rm-shortcode-id="f4c0fc8a2cba6536ea4cd960ebed3e6e"><blockquote class="twitter-tweet twitter-custom-tweet" data-twitter-tweet-id="1307729521869611008" data-partner="rebelmouse"><div style="margin:1em 0">Asteroid 2020 SO may get captured by Earth from Oct 2020 - May 2021. Current nominal trajectory shows shows capture… https://t.co/F5utxRvN6Z</div> — Tony Dunn (@Tony Dunn)<a href="https://twitter.com/tony873004/statuses/1307729521869611008">1600621989.0</a></blockquote></div>
Identifying 2020 SO<p>The first clue 2020 SO isn't your ordinary asteroid is its exceptionally low velocity. It's traveling much more slowly that a typical asteroid — their <a href="https://www.lpi.usra.edu/exploration/training/illustrations/craterMechanics/" target="_blank">average rate of travel</a> <a href="https://www.lpi.usra.edu/exploration/training/illustrations/craterMechanics/" target="_blank" rel="noopener noreferrer"></a>is 18 kilometers (58,000 feet) per second. Even <a href="https://en.wikipedia.org/wiki/Moon_rock" target="_blank">moon rocks</a> sent careening into Earth orbit by impacts on the lunar surface outpace pokey 2020 SO.</p><p>For another thing, 2020 SO has an orbital path very similar to Earth's, lasting about one Earth year. It's also just slightly less circular than our own orbit, from which it's barely tilted off-axis.</p><p>So, what is it? <a href="https://cneos.jpl.nasa.gov/ca/" target="_blank">NASA estimates</a> that the object has dimensions very reminiscent of a discarded Centaur rocket stage from the <a href="https://en.wikipedia.org/wiki/Surveyor_2" target="_blank" rel="noopener noreferrer">Surveyor 2 mission</a> that landed an unmanned craft on the moon. Back in the day, rocket stages were jettisoned as craft were aimed toward their desired position. This stuff, if released high enough, remains in space. It appears that this Centaur rocket, launched in September 1966, is now making its way back homeward, at least for a little bit.</p><p>When 2020 SO arrives at its closest point in December, the rocket is expected to be about 50,000 kilometers from Earth. Its next closest approach is much further: 220,000 kilometers, in February 2010.</p><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQzMDk3NC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyODg1MTQ1MX0.HGknDwqp0GmeuczKY_AS7vrPG7KMFUc_XO95tNoI2xo/img.jpg?width=980" id="e5cda" class="rm-shortcode" data-rm-shortcode-id="85eb1f790d8c3ee5b261f7ba13eaa5e1" data-rm-shortcode-name="rebelmouse-image" alt="Centaur rocket stage" />
Centaur rocket stage
What we may be able to learn<p>Earthly space programs being as young as they are, scientists would love to know what's happened to our rocket during a half century in space.</p><p>While 2020 SO won't get close enough to drop into our atmosphere, its slow progress has scientists hopeful that they'll still get some kind of a decent look at it.</p><p>Spectroscopy may be able to reveal what the rocket's surface is like now — has any of its paint survived, for example? Of course, being out in space, it's likely to have been hit by lots of dust and micrometeorites, so the current state of its surfaces is also of interest. Experts are curious to know how reflective the rocket is at this point, valuable information that can help planners of future long-term missions anticipate how well a craft out in space for extended periods will remain able to reflect sunlight.</p>
From cryonics to time travel, here are some of the (highly speculative) methods that might someday be used to bring people back to life.
- Alexey Turchin and Maxim Chernyakov, researchers belonging to the transhumanism movement, wrote a paper outlining the main ways technology might someday make resurrection possible.
- The methods are highly speculative, ranging from cryonics to digital reconstruction of individual personalities.
- Surveys suggest most people would not choose to live forever if given the option.
Immortality and identity<p>The paper defines life as a "continued stream of subjective experiences" and death as the permanent end of that stream. Immortality, to them, is a "life stream without end," and resurrection is the "continuation of that same stream of experiences after an arbitrarily long gap."</p><p>Another key clarification is the identity problem: How would you know that a downloaded copy of yourself really was going to be <em>you? </em>Couldn't it just be a convincing yet incomplete and fundamentally distinct representation of your brain?</p><p>If you believe that your copy is not <em>you</em>, that implies you believe there's something more to your identity than the (currently) quantifiable information contained within your brain and body, according to the researchers. In other words, your "informational identity" does not constitute your true identity.</p><p>In this scenario, there must exist what the researchers call a "non-informational identity carrier" (NIIC). This could be something like a "soul." It could be "qualia," which are the unmeasurable "subjective experiences which could be unique to every person." Or maybe it doesn't exist at all.</p><p>It's no matter: The researchers say resurrection, in some form, should be possible in either scenario.</p><p style="margin-left: 20px;">"If no 'soul' exist[s], resurrection is possible via information preservation; if soul[s] exist, resurrection is possible via returning of the "soul" into the new body. But some forms of NIIC are also very fragile and mortal, like continuity," the researchers noted.</p><p style="margin-left: 20px;">"The problem of the nature of human identity could be solved by future superintelligent AI, but for now it cannot be definitively solved. This means that we should try to preserve as much identity as possible and not refuse any approaches to life extension and resurrection even if they contradict our intuitions about identity, as our notions of identity could change later."</p>
Potential resurrection methods<p>Turchin and Chernyakov outline seven broad categories of potential resurrection methods, ranked from the most plausible to most speculative.<br></p><p>The first category includes methods practiced while the person is alive, like cryonics, plastination, and preserving brain tissue through processes like chemical fixation. The researchers noted that there have been "suggestions that the claustrum, hypothalamus, or even a single neuron is the neural correlate of consciousness," so it may be possible to preserve just that part of a person, and later implant it into another organism.</p><p>Other methods get far stranger. For example, one method includes super-intelligent AI that uses a <a href="https://en.wikipedia.org/wiki/Dyson_sphere#:~:text=A%20Dyson%20sphere%20is%20a,percentage%20of%20its%20power%20output." target="_blank">Dyson sphere</a> to harness the power of the sun to "power enormous calculation engines" that would "reconstruct" people who collected a sufficient amount of data on their identities.</p>
Turchin<p style="margin-left: 20px;">"The main idea of a resurrection-simulation is that if one takes the DNA of a past person and subjects it to the same developmental condition, as well as correcting the development based on some known outcomes, it is possible to create a model of a past person which is very close to the original," the researchers wrote.</p><p style="margin-left: 20px;">"DNA samples of most people who lived in past 1 to 2 centuries could be extracted via global archeology. After the moment of death, the simulated person is moved into some form of the afterlife, perhaps similar to his religious expectations, where he meets his relatives."</p><p>Delving further into sci-fi territory, another resurrection method would use time-travel technology.</p><p style="margin-left: 20px;">"If there will at some point be technology that allows travel to the past, then our future descendants will be able to directly save people dying in the past by collecting their brains at the moment of death and replacing them with replicas," the paper states.</p><p>How? Sending tiny robots back in time.</p><p style="margin-left: 20px;">"A nanorobot could be sent several billion years before now, where it could secretly replicate and sow nanotech within all living being[s] without affecting the course of history. At the moment of death, such nanorobots could be activated to collect data about the brain and preserve it somewhere until its future resurrection; thus, there would be no need for forward time travel."</p>
Pixabay<p>The paper <a href="https://www.academia.edu/36998733/Classification_of_the_approaches_to_the_technological_resurrection" target="_blank">goes on to outline some more resurrection methods</a>, including ones that involve parallel worlds, aliens, and clones, along with a good, old-fashioned possibility: God exists and one day he resurrects us. </p><p>In short, it's all extremely speculative.</p><p>But the aim of the paper was to catalogue known potential ways humans might be able to cheat death. For Turchin, that's not some far-off project: In addition to studying global risks and transhumanism, the Russian researcher heads the <a href="http://immortality-roadmap.com/" target="_blank">Immortality Roadmap</a>, which, similar to the 2018 paper, outlines various ways in which we might someday achieve immortality.</p><p>Although it may take centuries before humans come close to "digital immortality," Turchin believes that life-extension technology could allow some modern people to survive long enough to see it happen. </p><p>Want a shot at being among them? Beyond the obvious, like staying healthy, the Immortality Roadmap suggests you start collecting extensive data on yourself: diaries, video recordings, DNA information, EEGs, complex creative objects — all of which could someday be used to digitally "reconstruct" your identity.</p>But odds are you're not interested. Although Turchin and other scientists are bent on finding ways to avoid death and extend life indefinitely, <a href="https://www.theguardian.com/uk/2011/may/16/dying-still-taboo-subject-poll" target="_blank" rel="noopener noreferrer">surveys</a> <a href="https://quillette.com/2018/03/02/would-you-opt-for-immortality/" target="_blank" rel="noopener noreferrer">repeatedly</a> <a href="https://www.cbsnews.com/news/60-minutesvanity-fair-poll-the-afterlife/" target="_blank" rel="noopener noreferrer">show</a> that most people would not opt to live forever if given the choice.