Scientist figures out how to move our sun to avoid space collisions
An astrophysicist proposes new designs for stellar engines that can move a solar system.
05 January, 2020
Credit: CapnHack, via energyphysics.wikispaces.com.
- An astrophysicist proposes two new designs for stellar engines.
- The engines would be able to move our sun and whole solar systems.
- Moving the sun would be necessary to avoid collisions with supernovas and other space catastrophes.
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<p>Advancing space travel generally involves building more powerful and efficient engines for space vehicles like rockets or shuttles. But what if instead of an individual spacecraft, you took our whole solar system on a ride through the galaxy by moving the sun? Such is the not-too-modest proposal of nuclear astrophysicist <strong>Matthew Caplan</strong> from Illinois State University. He published his designs for stellar engines in the December 2019 issue of the peer-reviewed journal <em>Acta Astronautica.</em><br></p><p>In the paper, Caplan envisions two stellar engine designs, with one of them based on the idea of encapsulating the sun in a megastructure that would take advantage of its energy. Another engine would make use of a giant sail to move the solar system by about <strong>50 light years</strong> during the course of a million years. </p>
<p>Why would anyone even want to do this? One big reason would be to move the solar system if we're anticipating running into a mega-explosion from a supernova or some such cataclysmic scenario. Of course, we'd need to be way more ahead technologically for any such endeavor.<br></p><p>If you were to be moving the solar system, the convenient thing is that theoretically everything inside it would move along at the same time. Being pulled by the sun's gravity would keep the contents of the system in consistent orbit. </p><p>One of the stellar engine designs involves a thin mirror-like solar sail, like the <a href="https://www.popularmechanics.com/space/deep-space/a10885/the-shkadov-thruster-or-how-to-move-an-entire-solar-system-17000392/" target="_blank">“Shkladov thruster".</a> The reflective material would be thinner than a red blood cell. The sail would be positioned over the poles of the sun and would not be orbiting. It would be important to install it in such a way that it won't interfere with the Earth's temperature. This would also affect the direction in which we'd be steering the solar system.</p>
How a Supernova Could Nuke Us
<div class="rm-shortcode" data-media_id="ftiLvL41" data-player_id="FvQKszTI" data-rm-shortcode-id="56a462ca76420f3c5f5369666950fc72"> <div id="botr_ftiLvL41_FvQKszTI_div" class="jwplayer-media" data-jwplayer-video-src="https://content.jwplatform.com/players/ftiLvL41-FvQKszTI.js"> <img src="https://cdn.jwplayer.com/thumbs/ftiLvL41-1920.jpg" class="jwplayer-media-preview" /> </div> <script src="https://content.jwplatform.com/players/ftiLvL41-FvQKszTI.js"></script> </div> <p>A nearby star system may “go supernova".</p><p>Thrust for the sail design would be created by solar radiation reflecting onto the mega-mirror. This is definitely not the fastest way to travel, with the sun being pushed along at the rate of <strong>100 light-year in 230 million years.</strong> That's actually not fast enough to get out of the way of a supernova explosion, admits Caplan. <br></p><p>What would work better is a speedier “active" thruster, called the<strong> “Caplan thruster</strong>" by <em>Kurzgesagt</em>, which initially approached Caplan to design such engines. It would be propelled by thermonuclear blasts of photon particles. This thruster is a modified version of the <a href="https://en.wikipedia.org/wiki/Bussard_ramjet" target="_blank">“Bussard ramjet,"</a> conceptualized in the 1960s, which works on fusion energy. The engine would need millions of tons of fuel per second to function, creating fusion from matter it collects in the solar wind by utilizing a giant electromagnetic field. More energy would also be gathered by a <a href="https://en.wikipedia.org/wiki/Dyson_sphere" target="_blank">Dyson sphere</a> megastructure, built around the sun. </p><p>Caplan imagines the engine having two jets, with one using hydrogen pointed at the sun, to prevent colliding with it, and another, employing helium, directed away from the star. This would cause net momentum, like from a tug boat, and move the thruster forward. </p><p>The astrophysicist calculates this type of thruster would be fast enough to escape a supernova. It could also redirect the galactic orbit of our solar system in as little as <strong>10 million years.</strong> </p>
<p style="margin-left: 20px;">"A stellar engine produces a small net acceleration of the star, not large enough to disrupt the planetary system on short timescales, but sufficiently large to deflect the star and planetary system in its galactic orbit by many light-years given millions of years," <a href="https://www.sciencedirect.com/science/article/abs/pii/S0094576519312457?via%3Dihub" target="_blank">wrote</a> Caplan in the paper. <br></p><p>If it appears that talking about millions of years is impractical and too long a stretch of time, keep in mind that a different time scale applies in space and what is being proposed is for much more accomplished civilizations than ours. Caplan thinks “a catastrophe such as a supernova could likely be predicted millions of years in advance, at a minimum, for an advanced civilization with detailed understanding of star formation and the supernova mechanism."</p><p><a href="https://www.sciencedirect.com/science/article/abs/pii/S0094576519312457?via%3Dihub" target="_blank">Check out his new paper here.</a></p>
How to Move the Sun: Stellar Engines
<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="6fcbb1b3c1c323bd045aac634f4f75cb"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/v3y8AIEX_dU?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p> Check out the explanatory video from <em>Kurzgesagt</em> for more information.</p>
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Do aliens exist? If they did, would we know?
We still don't have proof of intelligent life beyond that on Earth.
13 August, 2019
- One of the biggest questions is whether we are alone in the universe — could there be other intelligent life, besides us, out there? Currently, we don't have any evidence aliens exist.
- There may have been a chance for a civilization to start billions of years before life began on Earth — one that is far more advanced, technologically speaking, than us. However, they're not making it very obvious. We have no proof of this.
- If such an advanced civilization exists, though, it probably relies on solar energy to fuels its everyday activities.
Magnetic north isn’t even close to where it used to be
You won't notice much of a difference unless you're north of the 55th parallel, though.
07 February, 2019
(Kirk Geisler/hobbit/Shutterstock/Big Think)
- Magnetic north has recently been moving north from Canada to Russia in a cold hurry.
- It's moving about 33 miles a year instead of the usual 7 miles.
- World navigation models had to updated ahead of schedule to catch up with it.
<p>If you're reading this as you travel the arctic, odds are you're probably already a bit confused. Your compass has been, well, strange, lately. That's because magnetic north has been moving. Quickly. It's never been stationary, but recently it's been moving around 485 feet northward toward Siberia every day. That's about 33 miles per year, as opposed to the average 7 miles a year between 1831 and the 1990s, when its pace quickened.</p><p>Fortunately, experts say that if you're south of the 55th parallel, you won't notice much of a difference. However, for national defense agencies, commercial airlines, and others that rely on knowing what their compasses are pointing at, it's a much bigger deal. That's why the <a href="https://www.ncei.noaa.gov/news/world-magnetic-model-out-cycle-release" target="_blank" data-vivaldi-spatnav-clickable="1">World Magnetic Model</a> — a set of online reference calculators, software, and technical details — had to be updated recently ahead of schedule instead of waiting for the next planned revision in 2020.</p>
North, north, and north
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTE2MjQ5MC9vcmlnaW4uZ2lmIiwiZXhwaXJlc19hdCI6MTYzODEwOTk0N30.SD7sUcv5s1GoxAng0TTdtfhT-5xV2K_2pXHsS9BxtYU/img.gif?width=980" id="12c8a" class="rm-shortcode" data-rm-shortcode-id="bd173f5f3a2619d67820e11a25dcc248" data-rm-shortcode-name="rebelmouse-image" />Image source: Pyty / Shutterstock
<p>There are actually three flavors of north, and they're all in different places.</p> <ul> <li><em>Magnetic north</em> — is defined as the location on the Earth's surface where all of its magnetic lines point straight downward. If you look at a compass while you're there, the needle attempts to dip down; that's why it's also called the "dip pole." Magnetic north is always on the move in response to the constant motion of electrical charges in the Earth's liquid outer mantle, which produces Earth's magnetic field.<span></span></li></ul><ul><li><em>Geomagnetic north</em> — is the northern focus of the Earth's magnetosphere, up in the stratosphere. It moves, too, but not nearly as much, since shifts in the Earth's magnetic field are more smoothed-out up there than on the ground. Its location is pretty stable, <a href="http://wdc.kugi.kyoto-u.ac.jp/poles/polesexp.html" target="_blank" data-vivaldi-spatnav-clickable="1">located</a> above and off the northwest coast of Greenland.<span></span></li></ul><ul> <li><em>True north</em>, or <em>geographic north</em> — is the northern terminus of our lines of longitude. It's located in the middle of the Arctic Ocean.</li> </ul>What’s the hurry?
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTE2MjUzMC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxOTEyMjgwNn0.kzhzoWnDITtIG0u_h-gx_8x6dVNMPpjPMmIvx3-YQQ0/img.jpg?width=980" id="dea99" class="rm-shortcode" data-rm-shortcode-id="a1eee701aef6ee6142209f89593e0273" data-rm-shortcode-name="rebelmouse-image" />Image source: Johan Swanepoel / Shutterstock
<p>The suddenly accelerating movement of magnetic north has scientists wondering what's up — not because there's any danger we're aware of — because its behavior is one of the few opportunities they have to catch a glimpse of the dynamics inside the earth's molten outer core.</p><p>The most prominent theory is that the speed-up is being driven by, as <a href="https://www.nature.com/articles/d41586-019-00007-1" target="_blank" data-vivaldi-spatnav-clickable="1"><em>Nature</em></a> puts it, "liquid iron sloshing within the planet's core." Giant streams of molten iron and nickel continually twist and swirl in the outer core, a pressure cooker that can reach 9,000° F in temperature. The iron is the source of the magnetic fields that comprise the Earth's magnetosphere. The magnetosphere is the barrier that keeps us protected from destructive ultraviolet solar radiation — its existence keeps Earth habitable. Planets with no magnetic barrier are unable to hold onto their atmosphere. Mars lost its magnetosphere 4.2 billion years ago. </p><p>Geophysicist <a href="https://environment.leeds.ac.uk/see/staff/1381/dr-phil-livermore" target="_blank" data-vivaldi-spatnav-clickable="1">Phil Livermore</a> made the case at an <a href="https://fallmeeting.agu.org/2018/" target="_blank" data-vivaldi-spatnav-clickable="1">American Geophysical Union meeting</a> in Fall 2018 that what we're seeing is the latest action in an ongoing tug of war between two magnetic fields down in the swirling outer core. One is under Siberia, and one is under Canada. Historically, the Canadian field has been winning, keeping magnetic north in Canada. However, there's been a shift, he tells <a href="https://www.nationalgeographic.com/science/2019/02/magnetic-north-update-navigation-maps/" target="_blank" data-vivaldi-spatnav-clickable="1"><em>National Geographic</em></a>, "The Siberian patch looks like it's winning the battle. It's sort of pulling the magnetic field all the way across to its side of the geographic pole."</p><p>Some scientists think that the acceleration may be an early sign that Earth's magnetic poles are about to flip, something that happens every every 200,000 to 300,000 years. Others see no evidence of that. Plus, flips occur over thousands of years, so there'd be no cause for alarm anyway.</p>Keeping an eye on magnetic north
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTE2MjUxMi9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyNjA0MDIyNn0.ASCHuzAA5dhXJHynroj6LxT8KRlGayzp15Jm1BRtX-U/img.jpg?width=980" id="6d0da" class="rm-shortcode" data-rm-shortcode-id="818173f506740fdeeb7e6348bea3778d" data-rm-shortcode-name="rebelmouse-image" />Earth's magnetic lithosphere mapped by Swarm. Image source: ESA
<p>The position of magnetic north is tracked by the European Space Agency's three <a href="https://www.esa.int/Our_Activities/Observing_the_Earth/Swarm/About_the_launch" target="_blank" data-vivaldi-spatnav-clickable="1">Swarm</a> satellites orbiting the Earth about 15 times a day — the satellites' readings are continually checked against ground readings to assess the pole's movements. Every five years, until now, at least, scientists have updated the math in the World Magnetic Model, whose goal is to "ensure safe navigation for military applications, commercial airlines, search and rescue operations, and others operating around the North Pole."</p><p>Given how things like this tend to play out over geologic time, it would surprise no one if more frequent model updates will be needed going forward.</p>
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Scientists Propose the Existence of a Giant New Space Object
A new study by planetary scientists proposes a giant new space object which could have formed the Earth and the moon.
23 May, 2017
A molten Planet. Credit: NASA/JPL-Caltech.
<p class="p1">Earth as we know it today was a much different place a few billion years ago. In fact, chances are, it was a giant donut-shaped mess of spinning hot vaporized rock. The researchers from Harvard University and University of California, Davis think that Earth was in the shape of an entirely new planetary object they’ve dubbed <strong>“synestia”.</strong> </p> <p class="p3"><span class="s1">The study, published in the <a href="http://onlinelibrary.wiley.com/doi/10.1002/2016JE005239/abstract" target="_blank"><span class="s2">Journal of Geophysical Research: Planets</span></a></span><span class="s3">, was carried out by the planetary scientist Sarah Stewart, a professor at Harvard, and Simon Lock, a graduate student from UC Davis, with support from NASA and the U.S. Department of Energy. </span> </p> <p class="p3"><span class="s3">The focus of the work by Stewart and Lock was on planet formation from a sort of interplanetary pinball, when giant rotating objects smashed into each other in the young Universe. These violent cataclysms produced new partially-melted and vaporized space bodies, which would eventually cool down and become the mostly spherical planets we have today.</span> </p> <blockquote><p class="p6"><span class="s3">“We looked at the statistics of giant impacts, and we found that they can form a completely new structure,” <a href="https://www.ucdavis.edu/news/synestia-new-type-planetary-object" target="_blank">said Stewart</a>.</span></p></blockquote> <p class="p7"><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xODMzOTUzNy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY2MjY2NzU3NX0.Es4OR9kdYEcT3jALzX2tcivWfdr05hJ5jcwqhTcjQRM/img.jpg?width=980" id="2e3b2" class="rm-shortcode" data-rm-shortcode-id="684ce95d7eab7c592f00b65625d39e3d" data-rm-shortcode-name="rebelmouse-image"></p> <p class="p7"><em style="color: #737d83; font-size: 13px;">This figure shows to scale a rocky planet, a molten disk/ring structure, and a synestia all with the same mass (about one Earth mass). Credit: Harvard University.</em></p> <p class="p7"><em style="color: #737d83; font-size: 13px;">How exactly would synestias form? The researchers found through modeling that when spinning planetary bodies barrel towards each other at high temperatures and with high angular momenta, their crash would actually create a totally new object of mostly vaporized rock, with the same <a href="https://www.khanacademy.org/science/physics/torque-angular-momentum/torque-tutorial/v/angular-momentum" target="_blank">angular momentum</a>. The outer layers of the vaporized planets would be in orbit around the rest of the new body. </em></p><em style="color: #737d83; font-size: 13px;"> <p class="p7">The scientists described it as an indented disk that looks like a red blood cell or a donut with the center filled in. The reason they called the planetary body they proposed “synestia” comes from “syn” which means “together” in Greek and “Hestia” - the Greek goddess of the home, hearth and architecture. </p> <p class="p1">Once formed, the synestia, like a molten cocoon, would start cooling off, condensing into a solid object in a few hundred years - a pretty short time in cosmic terms. Unless they are formed by the collision of gas giants like Jupiter - such synestias would survive in their forms much longer.</p> <p class="p7">The idea of synestias could also explain the formation of moons. While they have not been observed directly, synestias could be present in other solar systems and could be detected in the future. </p></em>
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Hey Bill Nye! What Will Happen to Earth as the Moon Drifts Away from It?
Farewell Moon, we barely knew you. Bill Nye knows the Moon is moving away from Earth 1.48 inches per year. Will it keep drifting further away, and what happens to Earth when it does?
14 November, 2016
No matter what happens to you in life, there’s one constant you can always depend on: that when night falls, the Moon will be there in the sky. Dun-dun-dun: or can you? Chris and Brendan have submitted a question to Bill Nye after discovering that the Moon is moving away from Earth 1.48 inches per year. Will it keep drifting further away, and what happens to Earth when it does?
<p>This is exactly what certain specialists at NASA’s Jet Propulsion and Applied Physics lab do all day; they calculate orbital motions and their repercussions. It’s common knowledge that the Moon exerts a gravitational force on our planet and causes tidal bulges. What’s less often taught in class is that those tidal bulges push energy back at the Moon, moving it ever so slightly into a higher orbit. </p>
<p>There’s evidence to show that the Moon used to be much closer to Earth and days were much shorter, but as the Moon slings further away and Earth’s rotation slows down, the days are getting longer and will continue to do so – but no need to panic: to give you an idea of the time scale, in 100 years from now, the day will only have increased by 2 milliseconds.</p>
<p>Eventually, billions of years from now, our planet's rotation will have slowed so much that it would take a month to complete a turn. Our oceans would freeze, the tides would be unable to bulge, and that's where it ends: the push and pull between the Earth and Moon would stop for good. </p>
<p>There’s no way we’ll be around then though, says Bill Nye, whether we evacuate this planet or wipe ourselves out or get into a galactic collision with Andromeda, so stay curious, but cool as a cucumber.</p>
<p>Bill Nye's most recent book is <a href="http://www.indiebound.org/book/9781250007148"><i>Unstoppable: Harnessing Science to Change the World</i></a>.</p><p><a href="http://www.indiebound.org/book/9781250007148"><img height="150" src="%5Cr%5Cnhttps://s3.amazonaws.com/edge-misc-assets/Book+Covers/Bill+Nye+Unstoppable" width="225"></a></p>
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