You're Technically HOTTER Than The Sun (with XKCD!)

[@TurkMan35]

never thought i'd learn a pickupline from a physics channel "you're hotter than the sun, there's just not enough of you" lol

[@TurkMan35]

@@benbaselet2026 dude no way i'm using that on a random girl :D

[@ayushrawal7436]

@@TurkMan35 you can use that as an ice breaker in a group of people

[@S.h-comma.to.the.top-Dynasty]

And don’t forget the line that quickly followed “but we were talking about Uranus”

[@Thunderpulse]

Continues with “we were talking about (your anus) which is big”

[@6884]

be careful to avoid girls with body/eating disorders (not body-eating disorders)

[@tomdiderot4344]

He definitely knew what he was doing when he wrote, “We were talking about Uranus, which there is a lot of and would get really, really hot…”.

[@mal2ksc]

Almost all "yo mama" jokes can be recycled as "Uranus" jokes.

[@panda4247]

There is a song Uranus by Nanowar Of Steel. Check it out

[@cybercritterowo]

They even put "Uranus (Big)" they definitely knew

[@zes7215]

wrr

[@NJ-wb1cz]

I'm blushing

[@InverseOfficial]

"We were talking about Uranus, which there is a lot of" well that sounds lovely

[@gilsonfeydyt6978]

"Uranus' shockwave would reach and destroy us"

[@travcollier]

Now part of my brain is frantically trying to make that into a verse to Baby Got Back... Stupid brain

[@Hector.Pulido]

Thanks i was looking for this comment

[@Mithorium]

Thanks, I grew it myself

[@mattia_carciola]

Being hotter than the sun that's good news

[@j_sum1]

There are 7 elements named after bodies in the solar system. You forgot selenium and helium.

[@YunxiaoChu]

How about tellurium

[@InvalidOS]

a helium sun would expand a lot, and a selenium moon would probably be incredibly stinky

[@__nog642]

@@InvalidOS Why and how would it be stinky?

[@InvalidOS]

@@__nog642 selenium and its compounds are known to have a strong odor. it's below sulfur on the periodic table, and sulfur is also known for being stinky

[@glonkfpv]

it's an awful smell, especially if you get into 40s and 50s era electronics. I've got an old radio that has a selenium rectifier that if it pops, will make an awful smell. RCA radio, from 1958 - can't recall the model number

[@schwi5425]

Fun fact: Tellurium is named after the Latin word “tellus” meaning Earth so you can also include the Earth on that list at the beginning. We’d probably also die pretty much immediately

[@T.h.e.T.i.n.o]

is'nt Latin for Earth Terra? or dose "Tellus" Spicificly mean The planet? Edit: well i guess your probebly right becourse Tellus has "us" as an ending... terra dosnt meening one is in Nominative and the Other one isnt so your probebly correct

[@schwi5425]

@@T.h.e.T.i.n.o Theyre synonyms so they both mean Earth

[@cuckoophendula8211]

I guess if we wanted to get extra fancy, each planet / Roman God happens to be represented by a metal in alchemy. Mercury is the obvious one, but they have Venus being copper, Mars being iron, Jupiter being tin, and Saturn being lead for some reason (while the "planets" moon is silver and the sun is gold). Note that this was before the planets Uranus, Neptune and Pluto were discovered and neither were the elements that were named after them.

[@T.h.e.T.i.n.o]

@@schwi5425 well Earth and Earth also meen the same but one is a Planet the other is dirt. i thought mabey Terra then Spisificly meens dirt or something

[@schwi5425]

@@cuckoophendula8211 I suppose you’re right but none of those (with the exception of mercury) are actually named after the planet. Still, it would be interesting to see how a much denser Jupiter would affect the solar system

[@justfrankjustdank2538]

wait, youre not the same person?

[@chresse214]

The first "what if" book is definitely upon the most hilarious things i've read in my life. Can absolutely reccomend it. It's worth every penny.

[@ayzmmo]

Minute physics published a book ?

[@TranquilReindeer98]

@@ayzmmo The first "What If?" (and upcoming second one) was written by Randall Munroe, creator of the XKCD web comic

[@Mossprite21]

@@ayzmmo xkcd wrote “what if?” (really good btw, preorder the second book)

[@cyrilio]

I love the audiobook! It’s definitely a good one

[@ayzmmo]

@@TranquilReindeer98 Thx that's cool I'll have a look

[@physicsbutawesome]

3:16 the author's picture... legend.

[@robertwallace5498]

All of Randall Munroe's books and comics are amazing, definitely worth a read

[@samhanna2349]

what if. highly recommend this book

[@snailracer5260]

‘How to’ and ‘thing explainer’ are also great

[@mustang1912]

This is wrong, the blast would have far too little energy to affect the earth.

[@scaper8]

@@snailracer5260 The dedication in _Thing Explainer_ makes me tear up every time. For those not in the know, he wrote the book using only the 500 (I think?) most common words in the English language. This includes the dedication, which was to "strong, pretty ring wearer." It was always so beautiful, somehow, to describe his wife in simple, childlike words. I don't know, it just gets me everytime.

[@noneofyourbusiness4133]

I’m so fucking mad he doesn’t put them on the blog anymore god fuckinf damn it

[@lexinwonderland5741]

Two of my favorites collaborating! I've been keeping up with XKCD for at least a decade now, it's a relic of the old internet/academic/nerd culture and it makes me so happy that Randall is still active!!

[@namenamename390]

Fun fact: Uranium was called uranium because at the time, the planet had several competing names and the guy who discovered the element named it this way to support the name Uranus for the planet.

[@ASmolPotatoOntheInternet]

Should have been named King George tbh.

[@ragnkja]

@@ASmolPotatoOntheInternet George’s Star.

[@Volvith]

@@ASmolPotatoOntheInternet Yes but there's significantly less butt jokes you can make involving King George. :)

[@meirl5700]

@@ASmolPotatoOntheInternet CGP grey enjoyer detected

[@burnv06]

Some men just want to watch the world burn.

[@Syuvinya]

Randall Monroe's What If?, How To, and Thing Explainer are some of the best science non-fictions I've read. Will definitely give What If? 2 a read!

[@EPMTUNES]

Xkcd and minute physics is a crossover my 2013 self has been waiting for for years, thank you both

[@MuzikBike]

wasn't there another one earlier? I think it was about rockets

[@hellomynameisjoenl]

@@MuzikBike There was definitely one about a lava moat.

[@TlalocTemporal]

@@hellomynameisjoenl -- That was for the other XKCD book series, Thing Explainer (the Up Goer Five), and How To (make a lava moat)

[@authorinthedark]

"how to make a lava moat" and "how to go to space" are two of their older collabs

[@PunnamarajVinayakTejas]

Is it because of the stick figures?

[@QelerQr]

"we were talking about uranus which there is a lot of and which gets really really hot"

[@AustinLi-ux9qs]

yall stop spamming about uranus jokes

[@natetwehues2428]

Most What Ifs can be summarized as "this doesn't end well."

[@timothymclean]

If it ended well, it wouldn't be worth talking about.

[@1224chrisng]

the ending one from the last version is fine, he talked about a -10 magnitude earthquake, which would be smaller than a truck driving by

[@just-a-fnf-fan]

ok

[@oworandom]

@@1224chrisng aint a trunk magnitude much more stronger though? I remembered the -10 one is literally the feather touching the ground at this point

[@musicexams5258]

@@oworandom -10 was a mote of dust landing on a table 0 was pretty funny because it's a football team charging into your house for some reason they just hate your house?

[@MacElMasMancoDeTodos]

"You're technically hotter than the Sun, but just there's not enough of you" *People without limbs:*

[@svahn1]

"In a sense, you are hotter than the Sun. There's just not as much of you." Killer pickup line, thanks.

[@hokage102364]

I've been gleefully sharing the fun fact that humans give off more heat than the Sun per square inch and that the Sun is only hotter than us since it's so much bigger than us since I was like 6. I think I learned that in some random science trivia book. This is actually nerdier lol.

[@I-Maser]

I dont understand how this should work, could you explain further? Since in the video he says a chunck of the Suns *core* , but since the core undergoes fusion i cant see how this should give of less heat than a human. The surface of the sun however makes some sense

[@evannibbe9375]

Change that to “per cubic inch”

[@I-Maser]

@@evannibbe9375 well how exactly is a human body able to give of more heat per cubic inch than the suns core, which is literally undergoing fusion?

[@alexsiemers7898]

@@I-Maser it’s likely that the sun, even with as dense as the core is, can only go through so much fusion per unit volume, and once again it’s just the immense size of the core that gives it the energy output we know. I did some “”basic”” math just based on the solar output measured at earth’s surface (~1.4kw/m^2), used that to get the sun’s total output (surface area of a sphere the size of earth’s orbit, multiplied by that energy per square meter) and found that a solar core twice the diameter of earth would average 8 watts of energy per cubic _meter._

[@I-Maser]

@@alexsiemers7898 so the sun is producing more energy than a human, but cant give it off as fast as we do, cause it can only radiate heat away, unlike us who can also give heat of to the Air. Right?

[@harizaka]

"In a sense, you are hotter than the Sun-there’s just not as much of you. But we were talking about UrAnus... "

[@cosmoss007]

lol

[@iveriiver]

Which there is alot of

[@resurgam_b7]

I would absolutely support having all... okay most, of the "What If" scenarios narrated and animated by you. That would be a splendid binge watch, the natural evolution to the binge read of XKCD's website that I do every couple years :D

[@6884]

I gifted a copy of What If (1) to my then-PhD-supervisor. The fact that he didn't seem to have enjoyed it much was indeed a dire warning of what came next.

[@SupersuMC]

Don't leave us hanging: what came next‽

[@Vezail]

We need to know by Monday!

[@uncreative369]

What came next?

[@collectorguy3919]

I'd guess he found a lot wrong with the book and that created work for the PhD candidates

[@alexandreocadiz9967]

I supposed that him not liking the book was a warning that the supervisor was cruel and a terrible boss

[@A_Loyalist]

Sun people (as defined as human sized chunks of the core of the sun) are cooler than me, but I'm hotter.

[@JojoDrs_]

When I see xkcd, I always think of his "what if" chapters like the periodic table as a wall or the relativistic baseball Then I look at the title of this video and I strongly agree with one of the first sentences of this video: "This is not going to end well."

[@mads_in_zero]

When an XKCD "what if" opens with a "we are going to have a problem" type message, you know it'll be catastrophic.

[@HyperBirbN3rd]

At the start of one What If 2 chapter it’s all like "This is actually surprisingly reasonable by What If standards" and goes on to describe how many people would get killed ("only" about 10)

[@robertjarman3703]

@@HyperBirbN3rd Which one was that? I have a copy of What If II but I forget which chapter.

[@HyperBirbN3rd]

@@robertjarman3703 I forgor :( and I don’t have a copy because I got one from the library back when it was just published and practically memorized it 🤓 Maybe the lava lamp?

[@atomictheprotogen6816]

We need some crazy collaboration between kurzgesagt, vsauce, veritasium, and minutephysics

[@TheOtherSteel]

If Mercury were suddenly made of mercury, wouldn't it immediately begin to boil? Being frozen solid on the dark side, vapor on the sunny side, and liquid in between, I would think that would cause enormous stress.

[@fakestory1753]

And those mercury vapor will eventually reach earth

[@KuK137]

There is actually pretty big band between molten and boiling points of Mercury so as long as we can get some convection going on, no part of it would be frozen. Though, surface of Mercury gets above boiling point temperature so you'd see Mercury clouds soon (which would probably shield the surface somewhat). Though, Mercury is pretty shiny, maybe it would deflect enough radiation to lower surface temperature? Also, the element is 3x denser than the planet, which would mean planet shrinking by a lot if we keep mass in transition...

[@oliviapg]

It wouldn’t reach earth, it would just stay in its orbit

[@fakestory1753]

@@oliviapg but solar wind..

[@MarsJenkar]

@@fakestory1753 I'm no physicist, but I don't think solar wind would exert enough force on mercury vapor to have much of an effect. Even if it did have an effect, it would take a _long_ time to cross the 50-plus million mile gulf to Earth's orbit.

[@a.bergstrom7172]

I’ve loved Randall‘a books for a long time now. Nice to finally see some of them get recognized. I’d get the books they go into a lot of detail and are absolutely worth it.

[@aster2790]

1:50 I am confident that this line was not accidental

[@997_99]

🤣

[@AaronRotenberg]

I assume anyone pronouncing "Uranus" with the stress on the second syllable is trying to make a double entendre.

[@zxcucruma5433]

Uranus(big)

[@mayhair]

How else would you word it?

[@TheWorldsLargestOven]

How the f*ck are you supposed to pronounce it? Uunars? Sunaru? Urineus?

[@mothman7786]

Haven't checked in with Munroe in ages, glad to hear he's still active for crazy thought experiments

[@stephen3164]

“The blast from Uranus…” - oh, my family already knows that’s deadly! 🤣

[@bluey-next777]

2:27 *Insert the blue crab music meme here*

[@bluey-next777]

2:40 NOT AGAIN!

[@xborak2]

"Unfortunately, the night sky - and human eyes - would get a little harder to find" best comment

[@aaaaaattttttt5596]

What does it mean

[@thaddeusgenhelm8979]

@@aaaaaattttttt5596 It was alluding to the upcoming explosion of Neptune that would obliterate all humans (and therefore make human eyes hard to find) and the stripping away of Earth's atmosphere, etc. making the night sky as a we consider it also similarly absent (also the lack of human eyes to observe it would also add to the difficulty!)

[@DreadEnder]

1:49 this is why the name was changed

[@T4gProd]

I love living in a timeline where pretty much two of my favorite science communicators collaborate.

[@cube2fox]

Favorite stick figure creators

[@chlorine4567]

⑨

[@koshmeji]

Happy Chiruno Day

[@EdKolis]

What next? Neil deGrasse Tyson and Bill Nye? William Shatner and Mark Hamill?

[@naaha6709]

thank you for the compliment

[@marc-andreservant201]

Let's see... Pluto has a radius of 1,188 km, which corresponds to a mass of 1.398*10^23 kg. This is 2.19*10^22 times the amount of plutonium in the Nagasaki bomb, which had a yield of 20 kilotonnes of TNT. Assuming the explosion would be proportionally bigger, this comes out to 4.37*10^23 kt, or a ball of TNT 73,200 times the mass of the Earth. Amazingly, this is still 8 orders of magnitude weaker than a supernova.

[@pedronunes3063]

It's the old rule, imagine any absurd explosion and compare to a supernova, the supernova wins.

[@patrickmccurry1563]

@@pedronunes3063 Hypernova. Black hole merger.

[@chemplay866]

@@patrickmccurry1563 Cheesburger

[@pepero_sadpepmijt_form6322]

@@chemplay866 😨

[@HeroDarkStorn]

@@patrickmccurry1563 He said "imagine", not "name". If you imagine a Hypernova, you probably won't come anywhere near a nova. My favorite approach to the scale of supernova, courtesy of What-if: "Put the strongest nuke against you eye, and replace the sun with a supernova. Which is brighter? The supernova. By 9 orders of magnitude."

[@smugbowkid9919]

Randall Munroe is such a great comedian, and actually educates me through comedy. It’s super epic, I love his books and his comics.

[@alexheyman4588]

Would the shockwave from a Plutonium-241 Pluto be powerful enough to melt the entire Earth like that? I'm just wondering because Pluto is a lot smaller than Uranus or Neptune and orbits farther away, at least on average. (Considering that the power of the shockwave would fall off with the square of the distance traveled, would its effect on Earth vary meaningfully depending on where in Pluto's eccentric orbit it happened to be when turned to Plutonium-241?)

[@15Redstones]

Couldn't find information for Pu-241, but for 239 Earth would be blasted with about 30 days worth of solar radiation in a few seconds.

[@arcan762]

@@15Redstones what if pluto was on the other side of the sun to us at the time?

[@chrisdevine4848]

I am skeptical too. Happy to stand corrected, but I want to see the maths! (But certainly cannot be bothered to do it myself!) :)

[@mattdombrowski8435]

I'm not mathey enough to give a real answer, but I am mathey enough enough to give you an order of magnitude guesstimate. So, according to Google, the tsar bomba had about 1% the luminosity of the sun for a brief moment with a core mass of 64 kg. The mass of pluto is 10^22 kg. If we assume this scales linearly (which is probably an underestimate because a planetary mass would coincidentally mimic some of the ways we boost yields), it would momentarily reach roughly 10^18 % the luminosity of the sun at 1 AU from Pluto. Pluto is 30-ish AU away, which would roughly bring that down to roughly 10^16 % solar luminosity for an instant.

[@flykiller]

Pluto: 1.303e22 kg, 1.854 g/cm^3 Plutonium-241: 19.84 g/cm^3, Decays on average with 5.23 keV or 2.09 MJ/gram Plutonium-241 planet would be 1.394e23 kg and would explode (assuming Plutonium-241 explodes entirely with average decay energy) with 2.9e32 Joules. Pluto is on average 40 AU away from us so at that distance energy of the explosion per area would be 645 kJ/m^2. This is equivalent to being 2.8 km away from the Hiroshima nuke (in space). We are getting this energy from the sun per ~8 minutes. It doesn't seem that much but it can be because of wrong reaction energy. I could only find this value for 241 isotope.

[@Calthecool]

What If? 1 is my favorite book of all time, definitely ordering What If? 2 ASAP.

[@caffiend81]

I am actually a little shocked that any of the outer planets exploding would produce enough energy to melt the Earth given the vast distances combined with the inverse square law, and the lack of a medium for a pressure wave (though I understand that the expanding gas and debris are still a thing). But, I trust Randall Munroe's ability to calculate these things so... 🤣Damn!

[@WaluigiisthekingASmith]

There's some fun fermi calculations you can do. 1 au is 8 light minutes. is 10^8 * 10^3 is 10^11 meters. The mass of a planet is something on the order of 10^25 kg and the density of a gas planet is about 1 g/cm^3 or 1000 kg/m^3. That means the volume is ~ 10^22 m^3 (I'm assuming the replacement is by volume and not by mass. Since neptunium etc are so dense it actually is important). The distance to the outer planets is probably about 10 au so the area of equal flux is (10^12)^2*4 pi = 10^25 m^2. I don't know the amount of energy in a fission nuke per cubic meter of input material so I'm just going to wildly guess 10^12 to 10^15 joules. Even if I did know I'm almost certain I would still be way off because of weirdness in scaling. Anyway, 10^12 * 10^22/10^25 = 10^9 joules per square meter which I bet would be enough to kill everyone on the planet . Looking up online, little boy only used ~ 63 kg of uranium so, in one nice Wolfram alpha formula, here's the actual answer www.wolframalpha.com/input?i=%28Neptune+volume+*+density+of+neptunium+*+yield+of+little+boy%2F%2863+kg+%28Neptune+average+distance%5E2*4*pi%29%29%29 Not enough to destroy the earth but certainly enough to kill everyone on it.

[@KuK137]

@@WaluigiisthekingASmith Actually it wouldn't all fuse because the planet would blow up sooner dispersing the material. This is huge problem even in atomic bombs with a few kg of material (and why we need to compress it with explosives to keep the fission reaction from blowing up the core), it would be vastly worse in planet sized core. You'd have a radioactive asteroid field that would use up most energy on dispersing the planet and very little of it on radiation and shockwave...

[@djinn666]

​@@KuK137 I wouldn't be so sure of that. Compression increases fission rate, so in the process of being blown apart, the surface material would be compressed and undergo fission too. With an astronomical amount of material, inertia alone might be enough for fission to complete.

[@mdab121]

The distance to Neptune is 30 AU.

[@entcraft44]

@@WaluigiisthekingASmith The amount of fissile material used in construction does not equal the amount of fissile material that actually gets split. From the 63kg less than a kilogram actually reacted. For a planet-sized core there are (probably) factors which will increase and factors which will decrease the efficiency. I think it will be higher because of the much better inertial confinement and much higher neutron flux in all but the outermost layers of the planet. The exact things that will happen are complicated to predict. You are correct with "weirdness in scaling". But you are probably at most two orders of magnitude away from the real answer.

[@dariocardajoli6831]

Love xkcd's comics this was a must watch !

[@alexmacdonald1998]

My take away from this is that radioactive elements should be treated like potential roommates: pick the most stable one! Any choice is potentially toxic and may contaminate your stuff, but at least a more stable isotope has less likely hood of having a critical meltdown while you are visiting family during Christmas holidays. Just remember that while uranium can appear stable because it does not appear active, this often means it has lost its job and is not actively seeking another and thus will be short come rent day. Similarly, Plutonium frequently goes through what seems to be a non explosive romantic partner transfer, but then ends up getting a cat whose litter box never gets cleaned.

[@thedownwardmachine]

Thank you for letting me know about this book. I’ve been waiting years for it. When the first one came out, I enjoyed it so much that I was sad when I got to the end and immediately re-read it.

[@felixar90]

If mercury was made of mercury, would it turn into a perfectly smooth nearly spherical mirror, and not appear brighter but be actually pretty much invisible most of the time, because of the specular reflection reflecting almost no light at earth? Also, If mercury was mercury, would it be solid, liquid or gas? Or maybe it would have a mercury cycle? It would be much more reflective, so it wouldn't be as hot, probably?

[@AmoghA]

1:01 minutephysics suggests not hold U-238 at home. Thanks for the heads up, Henry because I had a planned a sleepover with friends where would hold U-238, but now it's scrapped.

[@patrickmccurry1563]

Pitcheblende aka uraninite is a natural ore of uranium and not dangerous... if you don't keep it in your pocket all day. Weirdly plutonium is far safer as it emits only alpha radiation fully blocked by the upper dead layer of skin. As long as you don't eat or breathe it of course.

[@screwaccountnames]

The interesting thing about holding U-238 (for a short amount of time) is that you would actually be fine. You shouldn't do it for longer than a few minutes, or regularly, and you should definitely wash your hands thoroughly afterwards, but in terms of radioactivity getting into your body from just holding a lump of U-238, it's about comparable to walking through an airport security checkpoint.

[@ajax4887]

Thank you for pronouncing Uranus properly

[@GideonFrazier]

Yesss. I already have my first copy of what if and how to! I’m so excited

[@chrishill601]

I realized what was bothering me about the 'hotter than the sun' explanation, although it took me a few minutes to be able to put it into words. The definition I had in the back of my head for how hot something is, is 'a measurement/calculation of its temperature' **or** 'a measurement/calculation of its heat energy.' Very slightly different things, but I'd be ok with either. The definition they seem to be using is, 'a measurement/calculation of the amount of heat energy *being produced* by the thing.' So, although by their definition, I may be producing more heat, (by volume,) and therefore be hotter, (by volume,) than the sun; the fact that there is so much less of me, and that this isn't a new development, rather there's been a lot less of me for enough time for both me and the sun to reach equilibrium at our respective volume/surface areas, by my definition, the sun is much hotter than me, (by volume or otherwise.)

[@minerman60101]

"What If?" and "How to" were amazing, I am absolutely getting "What if? 2" and you should too

[@jimmysgameclips]

Me: "Is there a What If 2?" 3:10 "Yeeeessss!"

[@ambriz202]

just started binging xkcd's comics so this was a nice surprise

[@capitalistraven]

Lol, lucky you. It's amazing. Also the first "What If" and "Thing Explainer" and basically anything Randall touches.

[@PhoenixKrash69]

That moment when your so used to XKCD’s style that you don’t immediately realize Randall Monroe’s author photo is just his stick figure.

[@lolicantthinkofabettername3437]

1:42 so what you are saying is that if we mede a pile of humans large enough we could burn the centre person to death? (Neglecting death by shear weight ofc)

[@jannikheidemann3805]

You can produce human gas and charcoal that way. Don't try it at home, your neighbours will thank you.

[@tontobonto2073]

Bees use this tactic to kills wasps

[@peterandersson81]

Dear Randall, I am a huge fan of your work, and this is once again simply excellent! Some notes on the terminology though. Fissile nuclides are such that can be fissioned by a thermal neutrons. All fissile nuclides can support a self-sustained nuclear reaction and U-235 and Pu-239 are famous examples of such fissile nuclides. Np-237 however is not fissile. Since it has already an even number of neutrons, it is not as energetically favoured to absorbing another one, as compared to the fissile nuclides which have an odd number of neutrons. However, as you correctly shown in the video, neptunium-237 can still support a self-sustained chain reaction. The reason for this is that the fission neutrons have more than enough energy to split that nucleus, since they are not thermal to begin with. So therefore, Np-237 can indeed be used in a nuclear explosive device (or planet). This feature of the nuclide is sometimes called "fissible". Fissible nuclides can support a self-sustained chain reaction, eventhough not being fissile. It is notable however, that sometimes all of these nuclides are grouped together and called fissile, so that can be said in your defence, but it is wrong in my opinion (or at least confusing) to call them that. Finally, regarding the plutonium, most isotopes are either fissile or fissible. So it wouldn't matter much which of the isotopes you chose for pluto, from 239-242 at least, since most of them are either fissile or fissible. Although, I don't remember if your unusual pick of Pu-244 is fissible or not. Pu-244 has the longest halflife of plutonium isotopes, but it is very unusual since not produced much in the uranium fuel cycle. Sorry for the nitpicking. I really liked the video!

[@aster2790]

Damn imagine having an almost-planet worth of nuclear ore next to you We wouldn't even start existing to die from radiation

[@samtherat6]

If Neptune was on the other side of the sun from us, would we stand a better chance?

[@johnchessant3012]

What if that random town in Sweden was made of an alloy of yttrium, terbium, erbium, and ytterbium

[@Aeropunk08]

And now XKCD has their own KZbin channel!

[@dicyanoacetylene6220]

Ok, but if we have control of exactly when the planets turn into their corresponding elements, what if we wait for Neptune to be on the other side of the sun from us? What problems arise from this? Edit: this was apparently not as clear as I thought. I was implying that we would try to use the sun to block the high energy blast wave that would've otherwise been heading directly for us. Does the destructive wave get stopped to a relatively survivable level, or does enough of it make it around the sun (do to diffraction) that it makes little difference? Or does something else happen, like yes, the initial blast is stopped by the sun, and we are close enough that whatever is able to make it around the sun still won't hit us, but it still imparted enough energy into the sun's atmosphere that it caused a coronal mass ejection that is going to hit us instead? Things like that.

[@CaTastrophy427]

Yeah I kinda wanted to know what that explosion would do to the sun, if anything

[@thaddeusgenhelm8979]

While impressive and energetic, based on my understanding of the energies in play I don't think the sun would be as impressed as us. Like, just consider that in this example the blast leaves the earth itself in one piece, if heated and without an atmosphere. If it won't even seriously disrupt our little iron ball, what's it going to do to the sun?

[@incognitoburrito6020]

Extremely rough estimation--that puts it only like twice as far away, meaning it'd only be about a quarter as bright. Unless the sun interferes somehow. With such a resounding "everyone on earth would die," I doubt it would make much difference.

[@dicyanoacetylene6220]

@@thaddeusgenhelm8979 That's kind of the point, use the sun as a blast shield so we can potentially survive a nuke the size of a planet.

[@thaddeusgenhelm8979]

@@dicyanoacetylene6220 Ahh, okay, I thought you were wondering about its implications on the sun, not the value of the sun as a shield, my mistake.

[@roadkillavenger1325]

Several years ago on a cold winter night, a man heard a noise coming from the forest behind his house. He grabbed a flashlight and pointed it at the woods. He didn't see anything at first, but suddenly he was filled with more fear than he'd ever felt before. He could hear it's...

[@Marenthyu]

What if I, too, already preordered "What if? 2"? Should be here in 5 days from now!

[@friedec3622]

Uranium are generally safe, until it reaches something called 'critical mass' 47 kilograms of Uranium clumped together can make a nice mushroom.

[@blu_223]

0:15 nice voice crack

[@slavakid5336]

i don’t hear it

[@blu_223]

​@@slavakid5336 listen carefully when he said "composed"

[@soisaus564]

Best voice crack in 2023

[@universlion]

.

[@mctooch]

HOLYYYYY VOICE CRACK

[@LDSG_A_Team]

Super excited to get the second volume! I was gifted the first one when it came out and I absolutely love every bit of it! Thanks for reminding me to buy it now that it's out :D

[@ZenZooZoo]

What a collab ❤

[@qx102]

"We were talking about Uranus, which there is a lot of" - minutephysics 2022

[@catkook543]

2:18 Might want to set an epilepsy warning for here

[@kalebbeer3526]

That has gotta be the best sponsor/ promo/ whatever you call it that i have ever seen, I'm definitely getting this for myself and i think it's the second thing I've ever been compelled to buy from a youtube sponser spot

[@uelssom]

0:01 why is the & backwards

[@AfgonYT.]

When I first watched this video, I had no idea that he had made a sequel. Eight years later, and he released the sequel to one of my favorite books on my birthday!

[@ligmanuts2015]

3:21 What if Japan disappeared? BORN IN A WORLD WITHOUT ANIMEE

[@micahphilson]

1:45 This is one of my favorite lines by Minutephysics ever. Says you're hot, then talks about Uranus, which is very big.

[@Playful_Target]

1:54 "uranus (big)" that's sus

[@nanaminaokoshi7077]

I never thought there would be "What If 2". But I was proven wrong.

[@rQuilln]

Beginning of the vid: "Spoiler alert, This doesn't end well." Most of the viewers: "Yeah, the earth doesn't end well." me at 2:46 : Yeah, they doesn't end well.

[@douglasstrother6584]

"Burnin' For You" ~ Blue Oyster Cult (1981)

[@dayhaysuper3639]

I love plutonium

[@menigmatique]

The original 'What If?' and 'How To' were some of the funniest most informative books i've ever read, preordered 'What If? 2' and definitely recommend it to anyone interested in channels like Minute Physics

[@woodrobin]

And the audio book version is read by Wil Wheaton!

[@LJCRIA]

I’m glad my favorite stick figure drawers finally collabed

[@DM-yj9qf]

indeed, there is a lot of uranus

[@dionemoolman]

I decided to calculate the luminosity of a Uranium Uranus: Uranium 238 has a density of 19000 kg per cubic metre, so given Uranus has a radius of 25 300 km the planet would have an approximate mass of 1.3*10^27 kg, making it almost as heavy as Jupiter (realistically it would be heavier due to compression near the core but I'm going to ignore that because idk how to calculate it). Uranium-238 is actually pretty bad at generating heat, generating only 100 microwatts per kg, which is actually comparable to the sun. Nonetheless, that adds up to a total heat of 1.3*10^23 watts, or 0.03% that of the sun. Which means that the energy received on earth would be 0.00008% that of the sun. Using the heat dissipation law P=AST⁴, with P being the power dissipated, A being the surface area, S being the Stefan-Boltzmann constant, and T being the surface temperature, we can estimate a temperature of about 4100 K. This means it would glow orange. It's worth noting it would be slightly dimmer than 0.00008% that of the sun because a lot more of the light would be in the infrared, but it would be compatible to a crescent moon (meaning it would definitely be visible during the day).

[@zhonghuaxiansheng]

Thanks, I know.

[@cheesemanmaster]

Thanks man, I really needed that

[@teresashinkansen9402]

Misleading tittle. The sun is hotter than any living thing, however the metabolic rate of many have more power density than the sun.

[@Zangoose_]

Best ad ever placed into a video

[@SokoBuilds]

I loved reading What If when I was still in High School, I’m in university now and my curiosity is as peaked as it was back then! Just ordered the book and can’t wait to read it. :)

[@Pwnage195]

"Uranus's shockwave would reach and destroy us." had me wheezing lmao

[@kiri101]

Now that's a sponsor I can actually get behind. Munroe's work is amazing.

[@morti7157]

So you are telling me if we would collect all the lizards……

[@JayneAllenTabangan]

1:49 ahhhhhhhhh yes the good old Uranus joke never gets olt😂😂😂😂😂😂😂😂😂😂😂😂

[@brendaninglis_333]

This collab is incredible

[@abraveastronaut]

Okay, but what if Earth was made of earth? ... ...wait.

[@CarlosBallena]

"But we were talking about Uranus..." subtle... nice!

[@Name-ot3xw]

I know, but appreciate that you recognize my greatness.

[@NStripleseven]

The “a small piece of U238 is fine, but a planet is 1000 degrees” thing is the same reason that a pile of decaying leaves gets kinda warm in the middle.

[@GasolineLicker]

“You’re hotter than the sun, there’s just not as much of you. But we are talking about ‘Uranus,’ which there IS a lot of.” thanks I’m using that as a pickup line

[@HyperHrishiHD]

No one’s ever called hot before, thanks! Except when I got a fever but yeah.

[@reach17-CH]

"We were talking about Uranus, which there is a lot of" I'll take that as a compliment

[@chickaberga2]

How does a “shock wave” from an exploding Neptune travel through space to reach Earth if there’s not a fluid medium in space for the shock wave to travel? (genuinely asking to better my physics knowledge)

[@alexsiemers7898]

It’s just the thermal energy released by the fission events. I know shock wave _technically_ implies a physical medium for the wave to move through, but that’s my guess.

[@rhealgagnon1460]

Bro the sense you make out of nonsense ,,,it's amazing 👏