Supernovae[4]"Supernovas" is also fine. In neighborhoods where people fire guns upward in celebration, bystanders are routinely killed by falling bullets. The life of super-Earths: how the hunt for alien worlds and artificial cells will revolutionize life on our planet. Some types of stars can vary in a wide range of sizes as well. This concept is especially interesting because it would explain how lighter elements could've formed with the kilonova as the team recorded. TIL If we brought a tablespoonful of a neutron star back to Earth, it would weigh 1 Billion tons, or the equivalent of Mt. [1]Less often if you're a child, since you have fewer atoms to be hit. [3]If you want to be mean to first-year calculus students, you can ask them to take the derivative of ln(x)e dx. You'd probably notice the weight gain, and you'd definitely notice the failure of roads, bridges, power lines, satellites, and undersea cables. When would the Earth eventually become a black hole? But since that air is spread out over a larger area, the overall effect would be decreasing air pressure. They are responsible for, A real star type. . I've seen quite a bit of that on this page. Shortly after 8:41 a.m. EDT on Aug. 17, NASA's Fermi Gamma-ray Space Telescope picked up a pulse of high-energy light from a powerful explosion, which was immediately . comics from xkcd. After 40 years, Earth's surface gravity would have tripled. 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. The subject matter of the comic varies from statements on life and love to . After a month, the Earth would have expanded by 26 kilometersan increase of 0.4%and its mass would have increased by 1.2%. Most of the Earth's heat is provided by radioactive decay of minerals in the crust and mantle,[12]Although some radioactive elements, like uranium, are heavy, they get squeezed out of the lower layers because their atoms don't mesh well with the rock lattices at those depths. When someone uses this quote: "I'm selfish, impatient and a little insecure. However, if you have a very precise pendulum clock, you might notice something oddby the end of the day, it would be three seconds ahead of where it should be. Inbox, #6, Weird (and Worrying) Questions from the What If? The #1 New York Timesbestselling author of What If? A bigger projectile can go further. The phrase "lethal dose of neutrino radiation" is a weird one. Before you go on a cosmic road trip, feed the residents of New York City to a T. rex, or fill every church with bananas, be sure to consult this practical guide for impractical ideas. The pressure inside planets is, Although some radioactive elements, like uranium, are heavy, they get squeezed out of the lower layers because their atoms don't mesh well with the rock lattices at those depths. If you observed a supernova from 1 AU awayand you somehow avoided being being incinerated, vaporized, and converted to some type of exotic plasmaeven the flood of ghostly neutrinos would be dense enough to kill you. I make mistakes, I am out of control and at times hard to handle. Neutron stars are phenomenally dense. 2: Additional Serious Scientific Answers to Absurd Hypothetical Questions is out! Most other clocks would keep working fine. Plate tectonics play a key role in stabilizing the Earth's climate, and planets smaller than Earth (like Mars) don't have enough internal heat to sustain long-term geologic activity. articles, published either in Randall Munroe's What If? View our Privacy Policy. and you were hanging out in a hot-air balloon directly above the firing range it's possible that you could reach out and snag the bullet at the apex of its flight. Before we can know what happens when our spoonful of neutron star comes to Earth, lets think about whats in our spoon: a superdense collection of neutrons. It's a shame humans wouldn't live this long, because at this point, something really neat would happen. How do I get rid of whiteheads on my nose naturally? "Knowing what the shape is, is crucial here, because if you have an object that is not spherical, it emits differently, depending on your sight angle. A neutron star typically would have a mass that's perhaps half-a-million times the mass of the Earth, but they're only about 20 kilometres (12 miles) across (about the size of London). Maybe its time for a brief introduction to thermodynamics. But if you can't handle me at my worst, then you sure as hell don't deserve me at my best.". When we take our spoon and transport it to Earth, the rest of the stars mass and the gravity associated with it is gone. The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional". In true xkcd tradition, this is taken beyond reality. This means you're free to copy and share these comics (but not to sell them). Use the fact that a Neutron Star has about 1.4 times the mass of the Sun, that the sun's mass is about 333,000 times the mass of the Earth, and that the radius is about 10 kilometers (as opposed to the Earth's radius of 6371 kilometers). book, articles were posted weekly.. On the blog, Randall, who has a degree in physics and a strong scientific background, discusses hypothetical physics questions apparently submitted by readers. And apols again to the first explained who seemed to appreciate their submission as only a placeholder so I overwrote rather than integrated. The reason you don't notice the neutrino flood is that neutrinos hardly interact with ordinary matter at all. . xkcd.com; what if? 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Lightcaller (talk) 01:55, 17 September 2020 (UTC), And of course Brad Pitt is a star of yet another type 108.162.215.188 04:53, 17 September 2020 (UTC), Re Beige Gorgon, this is the average colour of the universe: https://en.wikipedia.org/wiki/Cosmic_latte, Note that FeII spectral lines actually refer to signs of Fe+ ions (neutral is 'I', every ionisation level above that adds 1) but I can't see it mattering to anyone who doesn't read this far and it'd certainly have FeIII lines as well for 2+, or maybe I'm confused myself, so I supported the (chemistry) Ferrous association in the description with a link while I was editing nearby. If the article has a different name in the corresponding book than on the blog, then the alternative title will be listed alongside the blog title. and more Earth means more heat. This means that when a particle accelerator (which produces neutrinos) wants to send a neutrino beam to a detector somewhere else in the world, all it has to do is point the beam at the detectoreven if it's on the other side of the Earth! where m is the mass of the neutron and h is Planck's constant. is a blog hosted on the xkcd.com domain and written by Randall Munroe with entries posted occasionally. This would be similar to the situation on Earth billions of years ago, when we had more radioactive material and thus a hotter mantle. At some point, our growing Earth would reach the point where adding more mass causes it to contract, rather than expand. 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. That size implies a black hole can often swallow a neutron star whole. Overwhelmingly Large Telescope xkcd comics i enjoy . But without it, we go nowhere.\" Carl SaganIf you enjoy What If, make sure to check out our other channel \"Underknown\": https://www.youtube.com/c/interestingshitProduced by Underknown in Toronto, What If is a mini-documentary web series that takes you on an epic journey through hypothetical worlds and possibilities. 2: Additional Serious Scientific Answers to Absurd Hypothetical Questions is out! Most of our infrastructure would have collapsed. You get the point. -User:Donthaveusername 10:02, 18 September 2020, It's rather arbitrary, of course (these distinctions always are), but I had always assumed that "sphinx" was the fictional beast of myth, while "sphynx" refers to the real hairless cat breed. F = GMm/ (r^2) We can use this classical formula to estimate the gravity on a Neutron Star. Not as quickly as you might think. His stick-figure drawings about science, technology, language, and love have an enormous, dedicated following, as do his deeply researched answers to his fans' strangest questions. All human structures will stay. At this point, the star is simply getting . But harvesting orbital energy like this is a neat idea! [11]Sasselov, Dimitar D.. A tablespoon of neutron star weighs more than 1 billion tons (900 billion kg) the weight of Mount Everest. astronomy. On the other hand, if the atmosphere is also expanding, surface air pressure would rise. Red dwarf: 0.09-0.5 R; 0.07-0.3 M, 1500-4000 K, 0.00001-0.05 L. Surprisingly, most skyscrapers would hold up fine under much higher gravity. But what if we took just a spoonful of it and transpo. Inbox, #2, Weird (and Worrying) Questions from the What If? shooter is at sea level and catcher is up a mountain at the extreme range of the gun. Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. The detonation of a hydrogen bomb pressed against your eyeball? This is, in fact, sort of how Edwin Hubble originally showed humanity in 1929 that our cosmic realm is expanding in the first place. Before publishing the first what if? This cookie is set by GDPR Cookie Consent plugin. A neutron star forms when a main sequence star with between about eight and 20 times the Sun's mass runs out of hydrogen in its core. and gently set the comet in the ocean. The millions of people around the world who read and loved What If? This channel runs preposter. Everest would no longer be in the "death zone". This is the type of star that. We can use the Doppler effect to measure the orbital motion of a pulsar. what if? Outer space is a lot higher up than Niagara Falls,[citation needed] so the plunge down into the atmosphere at the bottom of Earth's gravity well adds a lot more than 0.1 degrees worth of heat. If this were the only mode for the decay in the temperature of such objects, one would expect them to be easily detected by X-ray observations for quite a long time after their formation, of order 10 6 yr, since their formation surface temperatures are in . Once its nuclear fuel is consumed, the . would change Earth's radiation balance, trapping heat near the surface and raising the planet's temperature. In that case, the birth of the black hole may be very energetic.". After 10 years, gravity would be 50% stronger. How close would you have to be to a supernova to get a lethal dose of neutrino radiation? Since the volume expands faster than the surface area, the overall heat flowing out per square meter will increase. Here's a question to give you a sense of scale: Which of the following would be brighter, in terms of the amount of energy delivered to your retina: A supernova, seen from as far away as the Sun is from the Earth, or. Filled with bonkers science, boundless curiosity, and Randalls signature stick-figure comics, What If? Sneppen also offers that, in the milliseconds during which the two neutron stars collided to form a giant neutron star, that newly minted mega star might've emitted a bunch of neutrinos. We also use third-party cookies that help us analyze and understand how you use this website. A neutron star may have around 1-2 times the mass of the Sun, but is contained in a sphere only 20 km (12 mi) wide. Statistically, my first neutrino interaction probably happened somewhere around age 10. Reminds me of an XKCD joke. Using the inverse-square law, we can calculate the radiation dose: So, here's a thought: What would you expect to happen if we took two vicious neutron stars and smashed them together? The "bullet catch" is a common magic trick in which a magician appears to catch a fired bullet in mid-flightoften between their teeth. 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 . Lightcaller (talk) 01:55, 17 September 2020 (UTC), Wat. The comic's tagline describes it as "a webcomic of romance, sarcasm, math, and language". Stars like our Sun leave behind white dwarfs: Earth-size remnants of the original star's core. 4 min . A normal star of that mass would be more than 1 million miles(1.6 million km) across. What about our roads and bridges? This cookie is set by GDPR Cookie Consent plugin. Inbox, #8, Weird (and Worrying) Questions from the What If? While you might not notice the increased gravity just yet, you'd notice the expansion. e.g. Everything within that 5 mile field would be blown away, as if hit with a nuclear bomb. However, a suitably tough baseball glove might be able to snag it. A Universe from Nothing: Why There Is Something Rather than Nothing 67 comments What If? Can a job not hire you because of anxiety? Monisha Ravisetti is a science writer at CNET. When our sun enters this phase in a few billion years, it will consume Mercury, Venus, and possibly the Earth. Various ideas were put forward to explain this, including the idea that the ocean basins were rifts that opened in the surface of a previously-smooth Earth as it expanded. And indeed, it is by nine orders of magnitude. So while you could lift a spoonful of Sun, you cant lift a spoonful of neutron star. 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. That's why this is a neat question; supernovae are unimaginably huge and neutrinos are unimaginably insubstantial. At this point, even the strongest humans would only be able to walk with great difficulty. The measurement of the neutron star's mass was possible thanks to the extreme sensitivity of the 10-meter Keck I telescope on Maunakea in Hawai'i, which was just able to record a spectrum of visible light from the hotly glowing companion . Neutron stars pack their mass inside a 20-kilometer (12.4 miles) diameter. As he consistently demonstrates, you can learn a lot from examining how the world might work in very specific extreme circumstances. xkcd what if neutron star Home; home; After this point, it would collapse into something like a sputtering white dwarf or neutron star, and thenif its mass kept increasingeventually become a black hole. At somewhere around 6 atmospheres, even ordinary air becomes toxic.[13]R.M. Where are the best places to see the 2023 and 2024 solar eclipses? As such, they are the densest objects in the universe. This is a good thing to keep in mind if you buy a digital scale. How do I minimise waste on a flight? 0:52. 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. The CO2 released from the comet would raise the temperature of the Earth for centuries. And by that point, you may find you've attracted some attention. Gravity varies by this much between different cities already. This cookie is set by GDPR Cookie Consent plugin. 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. The mass of the sun is 1.989 10 30 kg while the mass of the moon is 7,348 * 10 22 kg. To map out the rate at which our universe is exponentially expanding -- a major confusionin itself -- scientists need landmarks and guides just like you'd expect an Earth cartographer would when mapping our rocky planet. Serious Scientific Answers to Absurd Hypothetical Questions, Absurd Scientific Advice for Common Real-World Problems, More Serious Scientific Answers to Absurd Hypothetical Questions, 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. Look at your handthere are about a trillion neutrinos from the Sun passing through it every second. A real star type. Millions of people visit xkcd.com each week to read Randall Munroe's iconic webcomic. As the Earth started expanding, you'd feel a slight jolt, and might even lose your balance for a moment. Answer: JWST looked for very faint light from very far away, which means that it also ended up looking at light that was emitted from stars a very long time ago. Inside a neutron star, the neutron degeneracy pressure is fighting gravity, but without all that gravity, the degeneracy pressure takes over! 2.3 AU is a little more than the distance between the Sun and Mars. More active plate tectonics might be good for life. Additionally, the star loses a lot of mass in the process and winds up only about 1.5 times the Suns mass. 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. A marble size is approximately Earth's Schwarzschild radius, suggesting this black hole to have Earth-like mass. It's like the idiom "knock me over with a feather" or the phrase "football stadium filled to the brim with ants". The way seafloor spreading and magnetic pole reversal neatly confirmed each other is one of my favorite examples of scientific discovery at work. Planning to ride a fire pole from the moon back to Earth? Sure, it would release a little CO2, but it would be nothing compared to the pollution from our current sources of energy. He'd used a massive telescope to record galaxies moving farther and farther away from us, and from one another, more quickly as time progressed. Too Perfect. is based on his blog of the same name that answers unusual science questions from readers in a light-hearted way that is scientifically grounded. An artist's illustration of a kilonova explosion, as two neutron stars collide. There are no purely vertical cliffs that are that tall, so you'd need to fire the bullet at an angle, and it would have significant sideways speed at the top of its arc. Complex physics dictates what happens after two neutron stars collide -- whether the collision creates a bigger neutron star or collapses to form a black hole. A neutron star isn't as dense as a black hole . The cause of the collapse would be the expanding ground below them, not the increased gravity. If you built an icy waterfall from space, the water would arrive at the bottom as a river of superheated steam. The dynamics of really huge rocky planets aren't often analyzed, since there's no obvious way that they could form; anything that large will have enough gravity to gather hydrogen and helium during planet formation and become a gas giant. Spice up your small talk with the latest tech news, products and reviews. These stellar beasts, made mostly of neutrons, are basically ultra-dense cosmic corpses roaming around space and, with incomprehensibly strong gravitational fields, torturing everything in their paths. When she's not at her desk, she's trying (and failing) to raise her online chess rating. A blur, mostly. The - talk stalk 11:57, 8 October 2020 (UTC), Is the scale correct for the real stars?