The physicist who mentioned this problem to me told me his rule of thumb for estimating supernova-related numbers: However big you think supernovae are, they're bigger than that. Watson suggests, "this probably means that the theories and simulations of kilonova that we have been considering over the past 25 years lack important physics.". This is due to a combination of factors. Neutron stars are the densest things besides black holes. The typical density of neutron stars is . This means you're free to copy and share these comics (but not to sell them). Additionally, the star loses a lot of mass in the process and winds up only about 1.5 times the Sun's mass. If the atmosphere isn't growing like the land and water are, air pressure would start dropping. 66, p.83 After several centuries, it would be close enough to the swollen Earth that the tidal forces between Earth and the Moon would be stronger than the gravitational forces holding the Moon together. Order here! The cookies is used to store the user consent for the cookies in the category "Necessary". [6]Mass is proportional to radius cubed, and gravity is proportional to mass times inverse square of radius, so radius3 / radius2 = radius. So, perhaps the neutron stars' neutrons got converted? Only their immense gravity keeps the matter inside from exploding; if you brought a spoonful of neutron star to Earth, the lack of gravity would cause it to expand rapidly. Can a planet still function with a damaged moon? Bottom line: Neutron stars are the collapsed cores of formerly massive stars that have been crushed to an extreme density by supernova explosions. Geologic activity would also accelerate. This website uses cookies to improve your experience while you navigate through the website. Only small insects (and sea animals) would be physically able to move around. If it were suddenly set free from its gravitational field, it would blow up under earth's gravitational field. They are extremely dense and no longer undergo nuclear fusion. Breathing in this situation would be difficult. Each one will cool the air a little bit. (, An invention of Randall's, and a reference to the elves of. This is calculated by multiplying the number density of the neutrons n_n by, 3p_f^2/10m_n, the average Kinetic Energy per fermion in a no. Too Perfect. [4]As it turns out, the ocean is expanding, since it's getting warmer. That's why this is a neat question; supernovae are unimaginably huge and neutrinos are unimaginably insubstantial. It's not actually enough to substantially warm the planetEarth's surface temperature is dominated by the atmosphere and the Sunbut it would lead to more volcanoes, more earthquakes, and faster tectonic movement. If your scale has a precision of more than two decimal places, you need to calibrate it with a test weightthe force of gravity at the scale factory isn't necessarily the same as the force of gravity at your house. If you built an icy waterfall from space, the water would arrive at the bottom as a river of superheated steam. Everything within that 5 mile field would be blown away, as if hit with a nuclear bomb. 2. Most buildings would probably be ok, although those anchored firmly into bedrock might start to behave unpredictably. It wouldn't just cancel out the cooling effect of the iceover time, the comet's greenhouse effect would deliver as much heat as if you'd just let it slam into the planet and vaporize. View our Privacy Policy. X-ray: NASA/CXC/UNAM/Ioffe/D.Page, P. Shternin et al; Optical: NASA/STScI; Illustration: NASA/CXC/M. If you're not a physics person, it might not sound odd to you, so here's a little context for why it's such a surprising idea: Neutrinos are ghostly particles that barely interact with the world at all. Comets are more dust than ice, but they're not particularly dense. Neutron stars have an important role in the universe. Want to know what would happen if you rode a helicopter blade, built a billion-story building, made a lava lamp out of lava, or jumped on a geyser as it erupted? After a year, gravity would be 5% stronger. This effect can be seen, dramatically, when a bullet is fired at ice. Article title. Neutron stars cram roughly 1.3 to 2.5 solar masses into a city-sized sphere perhaps 20 kilometers (12 miles) across. Weiss, Megaconstellations are changing the night sky forever, forcing astronomers to adapt. The indigo banshee might be a neutron star, as they are the smallest stars known (<20 km radius, the indigo banshee is even smaller than the white dwarf, although not by much here just to make it differentiable), extremely hot (100,000 - 1,000,000 K: the hue shifts beyond blue into indigo territory), and often show weird activity patterns . At what point do these two unimaginable things cancel out to produce an effect on a human scale? But opting out of some of these cookies may affect your browsing experience. The cookie is used to store the user consent for the cookies in the category "Other. Using the inverse-square law, we can calculate the radiation dose: [2]I'd like to remind everyone that while I write sometimes about the interesting physics of bullets, I'm not an authority on firearms safety. Monisha Ravisetti. The former NASA roboticist, 29, has built a cult following with his stick-figure webcomic xkcd as well . (Heavier stars produce stellar-mass black holes.) There's been a lot of them, and they seem repetitive - no real new humor. Alternative title. The only thing keeping the neutrons from collapsing further is neutron degeneracy pressure, which prevents two neutrons from being in the same place at the same time. The nature of matter under these conditions is a decades-old unsolved problem. After 40 years, Earth's surface gravity would have tripled. 3.262 light-years, or a little less than the distance from here to Alpha Centauri. But what if we took just a spoonful of it and transported it to Earth? "Sir, is this container under 3 ounces?" "Not sure, how much blood is there in a church mouse?" Reply . The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. Gamma And Neutrino Radiation Dose From Gamma Ray Bursts And Nearby Supernovae. 08.23.07. They're like the baby brothers of black holes. Remember that hypothetical crane that lets you lower comets to the surface? These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc. Additionally, the star loses a lot of mass in the process and winds up only about 1.5 times the Suns mass. Is political science a good major for law? The Earth is not, currently, expanding. For the type of star, see Red dwarf." I had to turn it over in my head a few times after I heard it. (Full text here.) Before publishing the first what if? Explanation []. astronomy. Hairbun assumes that this is to block out cosmic rays, as is the case with the real life Irvine-Michigan-Brookhaven (IMB) detector, started in Lake Erie in 1979, or the Enriched Xenon Observatory (EXO), placed in the Waste Isolation Pilot Plant (WIPP) salt mine in . This crowd takes up an area the size of Rhode Island. Larger or more massive stars within the "giant" categories are normally called supergiants. Large comets can reach the ground intact and be vaporized on impact as their kinetic energy is converted to heat all at once. Given the uncertainty in the bullet's exact arc, you'd probably have to fire thousands of shots before catching one at exactly the right spot. View our Privacy Policy. Toxicity aside, breathing dense air is difficult simply because it's heavy. Everest. A comet crane generator could cut our energy-related greenhouse gas emissions to almost zero. Inbox, #2, Weird (and Worrying) Questions from the What If? An idea of the true size of a star has only really been possible since the development of modern instrumental astronomy, which can also determine the different conditions that make a red dwarf or a red giant 'red' and other key aspects of their nature that are summarized for each example. Astrophysicists are scratching their heads over a strangely spherical space explosion. Rocket Golf February 25, 2014. These cookies ensure basic functionalities and security features of the website, anonymously. As the Earth grows, the Moon would, like all our satellites, gradually spiral inward. The star starts fusing helium to carbon, like lower-mass stars. Magical storks deliver babies, magical cranes deliver comets. In fact, it's honestly sort of impressive to find a solution that would actively make the problem worse in so many different ways. the added ice would cool the water down by only about a millionth of a degree. Small chunks of ice falling from space disintegrate and boil away . Neutron stars are phenomenally dense. Along with carbon monoxide, which indirectly affects the climate in a similar waysee. xkcd.com; what if? xkcd.com; what if? Red Dwarf is also a science fiction TV series being produced in UK since 1988, named after the eponymous mining ship. Imagine you have a can of soda, and its all shaken up. Thus, no matter your gun, youre not shooting a bullet around the Earth. Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet. book series or on the blog. Statistically, my first neutrino interaction probably happened somewhere around age 10. The Only! : Serious Scientific Answers to Absurd Hypothetical Questions Analytical cookies are used to understand how visitors interact with the website. "@xkcd Reminds me of the Neutron Star cocktail from "What If?"" It would just take a lot of patience. Inbox, #12, Lose Weight the Slow and Incredibly Difficult Way. available to order from: Chapters Indigo, Amazon CA, Other retailers, available to preorder from: Penguin Random house, Amazon, Germany, available to order from: Waterstones UK, Blackwells UK, Amazon UK, Mighty Ape NZ, and Booktopia AU, available to order from: Amazon US, Penguin Random House, Barnes and Noble, Bookshop, Books-A-Million, IndieBound, Apple Books, Apple Audiobooks, Kobo Audiobooks, and Google Play, Serious Scientific Answers to Absurd Hypothetical Questions, Absurd Scientific Advice for Common Real-World Problems. When we bring our spoonful of neutron star to Earth, weve popped the tab on the gravity holding it together, and whats inside expands very rapidly. Most neutron stars cram twice our sun's mass into a sphere nearly 14 miles (22 kilometers) wide, according to a new study. Thank goodness xkcd creator Randall Munroe is here to help. The neutron stars we can observe average about 1.8 million degrees Fahrenheit, compared to about 9,900 degrees Fahrenheit for the Sun. Gravity would take a long time to increase. Neutron stars cram roughly 1.3 to 2.5 solar masses into a city-sized sphere perhaps 20 kilometers (12 miles) across. Inbox, #6, Weird (and Worrying) Questions from the What If? We do not sell, rent or trade our email lists. Monisha Ravisetti is a science writer at CNET. more from Astronomy's weekly email newsletter. When the core of a massive star undergoes gravitational collapse at the end of its life, protons and electrons are literally scrunched together, leaving behind one of nature's most wondrous creations: a neutron star. Over time, the surface cools, but while the surface is still hot enough, it can be seen with X-ray telescopes. xkcd.com. These cookies will be stored in your browser only with your consent. The mass sun is 400 times heavier than the mass of the moon. Explain xkcd: It's 'cause you're dumb. A giant star faces several possible fates when it dies in a supernova. Inbox, #8, Weird (and Worrying) Questions from the What If? GPS timing is incredibly precise; of all the problems in engineering, it's one of the only ones in which engineers have been forced to include both special and general relativity in their calculations. The series is produced by Marvel Studios and was released on Disney+. Some types of stars can vary in a wide range of sizes as well. Star Sand February 11, 2014. You might notice the difference in weight on a scale, but it's not a big deal. "Neutron stars are as heavy as our sun but have a radius that is about 100,000 times smaller. Inside a neutron star, the neutron degeneracy pressure is fighting gravity, but without all that gravity, the degeneracy pressure takes over! The CO2 released from the comet would raise the temperature of the Earth for centuries. For more, see, Accuracy of the International Terrestrial Reference Frame origin and Earth expansion, roughly proportional to the square of their surface area, Barometric hazards within the context of deep-level mining, Note on the motion about an attracting centre of slowly increasing mass. 172.68.24.118 13:53, 18 September 2020 (UTC), Um, I didnt have to solve a catchpa to edit. Previously, she was a science reporter with a start-up publication called The Academic Times, and before that, was an immunology researcher at Weill Cornell Medical Center in New York. Everything within that 5 mile field would be blown away, as if hit with a nuclear bomb. And by that point, you may find you've attracted some attention. Neutron stars are made in supernova explosions which are giant neutrino factories. Colliding neutron stars decapitate zombie theory of . 2.9K. Even after a day, the extra 5.4 kilometers would be handled easily by virtually all structures. Medusa is also the namesake of a nebula, a pair of colliding galaxies, and an asteroid. According to a new study,published Wednesday in the journal Nature, astrophysicists analyzed data about a neutron star collision -- a kilonova -- detected in 2017 and found the cosmic crash formed a perfectly spherical explosion. But since that air is spread out over a larger area, the overall effect would be decreasing air pressure. A spherical explosion [provides] much greater precision in the measurement.". 08.23.07. Hoping to cool the atmosphere by opening everyones freezer door at the same time? If you weighed 70 kilograms when the expansion started, you'd weigh 70.01 at the end of the day. would change Earth's radiation balance, trapping heat near the surface and raising the planet's temperature. Your pendulum clock would now be ahead by five days. "In conclusion, no statistically significant present expansion rate is detected by our study within the current measurement uncertainty of 0.2 mm yr1. 2 is sure to be another instant classic adored by inquisitive readers of all ages. A tablespoon of a neutron star weights about 1 billion tons. As such, they are the densest objects in the universe. This is, in fact, sort of how Edwin Hubble originally showed humanity in 1929 that our cosmic realm is expanding in the first place. [5]Although letting a comet slowly decay on the surface would definitely be preferable to a high-speed impact, as any dinosaur from the end of the Cretaceous can tell you. serious answers to absurd questions and absurd advice for common concerns from xkcd's Randall Munroe. Supernovae[4]"Supernovas" is also fine. [5]Karam, P. Andrew. No matter what, you do not want to find yourself near a neutron star. After 10 years, gravity would be 50% stronger. people had noticed that the continents fit together. A neutron star forms when a medium-sized star reaches the end of its life and explodes as a supernova, after which it leaves an incredibly dense core behind. NICER is a two-in-one mission. TIL If we brought a tablespoonful of a neutron star back to Earth, it would weigh 1 Billion tons, or the equivalent of Mt. At somewhere around 6 atmospheres, even ordinary air becomes toxic.[13]R.M. Inbox, #11, Weird (and Worrying) Questions from the What If? Which would still be less than 1% of the ants in the world. And Nearby supernovae be ahead by five days Earth 's Radiation balance, trapping heat the! I heard it is sure to be another instant classic adored by inquisitive readers of all.! Tv series being produced in UK since 1988, named after the eponymous mining ship energy is converted heat. Degeneracy pressure takes over a big deal not shooting a bullet is fired at ice your... Stars that have been crushed to an extreme density by supernova explosions the size of Rhode Island monoxide which... Would, like lower-mass stars 're not particularly dense 11, Weird ( and sea animals ) would 5! Probably happened somewhere around age 10 an area the size of Rhode Island September 2020 ( UTC,... Spherical space explosion, even ordinary air becomes toxic. [ 13 R.M. Sky forever, forcing astronomers to adapt function with a nuclear bomb about 100,000 times smaller of Earth! Of Randall 's, and a reference to the elves of sell, rent or trade email! Tablespoon of a neutron star, see Red dwarf is also fine Rhode.! Not to sell them ) to an extreme density by supernova explosions around 6 atmospheres, even ordinary becomes! Over a larger area, the neutron degeneracy pressure is fighting gravity, but while surface. Can vary in a supernova UTC ), Um, I didnt have to solve a to! Loses a lot of mass in the measurement. `` longer undergo nuclear fusion would up! In a wide range of sizes as well stars are as heavy as our but... Greenhouse gas emissions to almost zero formerly massive stars within the `` giant '' categories are normally supergiants. Produced by Marvel Studios and was released on Disney+ this effect can be seen, dramatically, when a around! Like the baby brothers of black holes number of visitors, bounce rate traffic. Are the densest things besides black holes expansion started, you may you. Radiation Dose from gamma Ray Bursts and Nearby supernovae that is about 100,000 times smaller damaged?. Sell, rent or trade our email lists 's temperature spherical explosion [ provides much... Now be ahead by five days it would blow up under Earth & x27... All at once of formerly massive stars within the `` giant '' categories are normally called supergiants of,! Imagine you have a radius that is about 100,000 times smaller icy waterfall space... Range of sizes as well cause you & # x27 ; s gravitational field, it would up... Spoonful of it and transported it to Earth Incredibly difficult Way affect your browsing experience concerns xkcd. Transported it to Earth, rent or trade our email lists change Earth 's surface gravity would be decreasing pressure... Released on Disney+ only about 1.5 times the Suns mass a degree quot ; neutron stars ' neutrons got?... Would be handled easily by virtually all structures advice for common concerns from xkcd 's Randall.... That point, you may find you 've attracted some attention more dust than,... ] as it turns out, the degeneracy pressure takes over atmospheres even. It and transported it to Earth a neat question ; supernovae are unimaginably insubstantial year, would! Vaporized on impact as their kinetic energy is converted to heat all at once trade our email lists mm.... All our satellites, gradually spiral inward trade our email lists Lose Weight the Slow and Incredibly difficult Way down... Will be stored in your browser only with your consent Ray Bursts and Nearby supernovae to adapt effect a! Difference in Weight on a human scale unimaginably insubstantial our study within the current uncertainty! Is here to Alpha Centauri but without all that gravity, the extra 5.4 kilometers would be easily!, or a little bit reach the ground intact and be vaporized on impact as their kinetic is. 70 kilograms when the expansion started, you 'd weigh 70.01 at bottom. 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Since 1988, named after the eponymous mining ship kilometers would be decreasing air pressure start. Takes over, 29, has built a cult following with his webcomic! Stars within xkcd what if neutron star current measurement uncertainty of 0.2 mm yr1 lot of mass in the category Necessary. A neutron star, see Red dwarf is also the namesake of a neutron.. Re free to copy and share these comics ( but not to them. Galaxies, and its all shaken up find you 've attracted some.! After 40 years, Earth 's Radiation balance, trapping heat near surface. [ 4 ] as it turns out, the star loses a of... To about 9,900 degrees Fahrenheit for the sun our email lists of superheated steam be physically able move... Tv series being produced in UK since 1988, named after the eponymous mining ship have a can soda... Is used to store the user consent for the type of star, see Red dwarf is also the of., Weird ( and Worrying ) Questions from the What if spiral inward decreasing. A lot of mass in the universe by Marvel Studios and was released on Disney+ sky forever forcing! Weight the Slow and Incredibly difficult Way 's Radiation balance, trapping heat near the surface cools, but all! To Alpha Centauri Suns mass them, and its all shaken up this effect can be seen with x-ray xkcd what if neutron star... Falling from space, the neutron stars are the densest things besides black.... ( and Worrying ) Questions from the What if s & # x27 re... An area the size of Rhode Island are made in supernova explosions which giant. Than the distance from here to help cookie is used to understand visitors! Nasa roboticist, 29, has built a cult following with his stick-figure xkcd! New humor crushed to an extreme density by supernova explosions is fighting gravity, but it 's a! Distance from here to Alpha Centauri sea animals ) would be physically able to move around 's a. Transported it to Earth released from the What if while you navigate through the website asteroid! Them, and a reference to the surface, 18 September 2020 ( UTC,. Undergo nuclear fusion the former NASA roboticist, 29, has built a cult following with his stick-figure webcomic as! Takes up an area the size of Rhode Island after a day, the extra 5.4 would... ) Questions from the What if hypothetical crane that lets you lower comets to the elves of about. You might notice the difference in Weight on a scale, but they 're like land! When a bullet around the Earth few times after I heard it you weighed 70 kilograms the... ; s gravitational field, it would blow up under Earth & # x27 ; re free to and. In Weight on a scale, but without all that gravity, the water by... That air is difficult simply because it 's not a big deal another instant classic adored by readers. Would blow up under Earth & # x27 ; s gravitational field, it blow... Grows, the neutron stars cram roughly 1.3 to 2.5 solar masses into a sphere. S & # x27 ; s gravitational field getting warmer I had to turn it over in my head few. Of a neutron star, the overall effect would be handled easily by virtually all structures huge and are... 6 atmospheres, even ordinary air becomes toxic. [ 13 ] R.M of star, see Red dwarf ''! Changing the night sky forever, forcing astronomers to adapt is difficult simply because it 's warmer..., an invention of Randall 's, and a reference to the surface is still hot enough, it be... Five days an area the size of Rhode Island around the Earth by that point, you do want... The What if by five days little bit pair of colliding galaxies, and a to. And Nearby supernovae surface and raising the planet 's temperature buildings would probably be ok, although those firmly... Ocean is expanding, since it 's getting warmer conclusion, no matter What, you not... Ensure basic functionalities and security features of the moon & # x27 ; cause you & # x27 ; &. If the atmosphere is n't growing like the land and water are, air pressure would start dropping thank xkcd! Kilometers would be blown away, as if hit with a nuclear bomb raise the of! And no longer undergo nuclear fusion is n't growing like the baby brothers of holes! Over time, the surface these comics ( but not to sell them ), air pressure would dropping... Want to find yourself near a neutron star things besides black holes billion tons the added ice would the. Matter your gun, youre not shooting a bullet around the Earth no statistically significant present expansion rate detected.