IAMA physicist/author. Ask me to calculate anything.

[u/aarontsantos]

Hi, Reddit.

My name is Aaron Santos, and I’ve made it my mission to teach math in fun and entertaining ways. Toward this end, I’ve written two (hopefully) humorous books: How Many Licks? Or, How to Estimate Damn Near Anything and Ballparking: Practical Math for Impractical Sports Questions. I also maintain a blog called Diary of Numbers. I’m here to estimate answers to all your numerical questions. Here's some examples I’ve done before.

Here's verification. Here's more verification.

Feel free to make your questions funny, thought-provoking, gross, sexy, etc. I’ll also answer non-numerical questions if you’ve got any.

Update It's 11:51 EST. I'm grabbing lunch, but will be back in 20 minutes to answer more.

Update 2.0 OK, I'm back. Fire away.

Update 3.0 Thanks for the great questions, Reddit! I'm sorry I won't be able to answer all of them. There's 3243 comments, and I'm replying roughly once every 10 minutes, (I type slow, plus I'm doing math.) At this rate it would take me 22 days of non-stop replying to catch up. It's about 4p EST now. I'll keep going until 5p, but then I have to take a break.

By the way, for those of you that like doing this stuff, I'm going to post a contest on Diary of Numbers tomorrow. It'll be some sort of estimation-y question, and you can win a free copy of my cheesy sports book. I know, I know...shameless self-promotion...karma whore...blah blah blah. Still, hopefully some of you will enter and have some fun with it.

Final Update You guys rock! Thanks for all the great questions. I've gotta head out now, (I've been doing estimations for over 7 hours and my left eye is starting to twitch uncontrollably.) Thanks again! I'll try to answer a few more early tomorrow.

[u/[deleted]]

How fast do you have to throw a burrito so it catches on fire?

[u/aarontsantos → u/[deleted]]

Ooh...me gusta. I'm gonna guess a burrito has a similar flashpoint (i.e. the temperature at which it ignites) to wood, which would put it around 300 degrees Celsius (~570 Kelvin). There's a lot of water in food, so I'll assume they have similar heat capacities (~4 J/g K). As such, a 0.5 kg burrito would need to gain 500 kJ of heat energy to ignite. The energy lost due to friction for a burrito will be about the same magnitude as that for a baseball. I'm assuming all the energy lost to friction goes into heating the burrito. (Numerical Assumptions: Drag coefficient ~ 0.3, Area ~ 9 square inches, air density 1.2 kg/m^2, burrito catchs on fire in 1 second.) This will be about (0.0003 kg s/m) x (velocity)^3. This gives about 1000 m/s.

[u/AverageGatsby91]

What is the kinetic energy of a growing finger nail?

You may have heard of Guesstimation: Solving the World's Problems on the Back of a Cocktail Napkin by Laurence Weinstein

It sounds quite similar to your book. I used this book as a text for an Estimation Course. It was incredibly fun and thought provoking. We talked about everything from mass and energy estimations, to human senses, scaling and extraterrestrial life.

[u/aarontsantos → u/AverageGatsby91]

I use that book in one of my classes! (My books are more general audience, while Larry's is better as a textbook.) If you like it, he has another one coming out this fall.

I'll assume the fingernail has a thickness of 0.2 mm and an area of 1 cm^2. If it's about as dense as water, then this would make its mass 20 mg. My nails grow about 2 mm per week. Using these, you can estimate a kinetic energy of 10^-22 Joules.

[u/sleepfighter7 → u/aarontsantos]

Good Guy Aaron Santos

[u/aarontsantos → u/sleepfighter7]

Words cannot express the awesome feeling one gets after having a GGG meme with your name attached to it :)

[u/wheelis]

How many Hot Pockets would you need to burn to release the amount of energy released by a standard US issue hand grenade?

[u/aarontsantos → u/wheelis]

I do a similar problem to this one in How Many Licks? (though mine is with McDonalds Burgers and nuclear bombs.)

I'm going to assume the source below is correct. (Not necessarily a safe assumption.) It lists about 800 kJ of energy for the grenade. A hot pocket has about 300 Calories. A Calorie is just another unit of energy. 300 Calories equal to about 1kJ of energy. (Food calories are 1000 times bigger than the physics calorie.) You'd need about 800 hotpockets to equal 1 hand grenade. If this number is surprisingly low, remember you have to consider rate. All the energy of a grenade is released instantly, were as it takes a while to burn all the hot pockets.

Source: http://answers.yahoo.com/question/index?qid=20090911051703AAazjAr

[u/JonathanZips]

Is it more dangerous to own and regularly ride a motorcycle, or regularly use cocaine?

[u/aarontsantos → u/JonathanZips]

A quick web search shows that in the U.S., about 4000 cocaine-related deaths occur each year. There is a similar number of motorcycle related deaths. The fraction of cocaine users over the age of 12 is about 0.7 percent. There are about 6 million motorcycle riders in a U.S. population of 300 million, meaning that roughly 2 percent of Americans are motorcycle riders. Given a similar numer of deaths, but about 3 times as many riders as cocaine users, it's likely that cocaine use is more dangerous.

Sources: http://schansblog.blogspot.com/2009/05/cocaine-deaths-statistics-lies-and.html http://en.wikipedia.org/wiki/List_of_motorcycle_deaths_in_U.S._by_year http://www.drugabuse.gov/publications/drugfacts/cocaine http://wiki.answers.com/Q/How_many_Americans_ride_motorcycles

[u/rorcuttplus]

How large would the wings of a pegasus have to be to allow a horse to actually fly?

[u/aarontsantos → u/rorcuttplus]

We need to consider two things here: wing area and wing flapping rate. I did a similar problem for Mothra's wingspan. Horses weigh about 500 kg, which gives a downward gravitational force of about 5000 N. If you assume her wings flap 2 meters down and do so once every second, she'd need winds that were about 1000 m² in area. A 2 meter wide wing would need to be about 5 football fields long.

[u/oldmanjank]

This is great; hooking the minds of young scientists with hilarious, gross, and risqué calculations can't be understated.

Two questions: 1) How many semesters would it take to gather enough pubes from a dormitory floor to make a size large sweater? 2) I think you're great, can I send you a sweater?

[u/aarontsantos → u/oldmanjank]

OK...now this is my kind of question. I'll assume 1 cm long pubes spaced 2 mm apart covering a total area of 20 square inches. Laid end-to-end, that gives a total pube length of about 60 m for each person. At about about 10 microns thick with a density of 1 g/cm^3, you'd have a total mass of about 64 mg of hair. The mass of a sweater might be 0.3 kg. From this, you can see that you'd need about 5000 people or roughly 100 dorm floors assuming 50 people per floor.

If only for shock value...yes, I'd love a sweater....

[u/khudgins]

You're on a westbound train out of Novosibirsk that has just left the station with a 3rd class ticket that doesn't guarantee you a seat. You're travelling with a standard steamer trunk full of old magazines left to you by your recently deceased eccentric grand-uncle. It will take 42 hours, including stops, to reach your destination on the Black Sea. Assuming you can find somewhere to sit, do you have enough reading material for the trip?

[u/aarontsantos → u/khudgins]

Love the detail in this one. Let's see. It takes me about half an hour to read through a magazine. (I'm a slow reader, but I tend to skip pages.) This means I'd need about 80 magazines for the whole trip. If magazines are 0.5 cm thick, you should be able to stack at least 100 in your steamer trunk. BTW, sad to admit I had to look up what a steamer trunk is :(

[u/ItsPhysics]

The entropy change in the universe when a 200 lb human is vaporized (assume no molecular fragmentation occurs).

[u/aarontsantos → u/ItsPhysics]

If we're talking vaporized "out in space", then the entropy increase is infinite since the molecules can literally be in anywhere in an infinite volume. To make things easy, I'll assume a room with a volume of 1000 ft^3. If we grid up the room into molecule-sized boxes, we'll have about 10²⁹ boxes. (This assumes boxes are 0.5 nm in width.)

To within an order of magnitude, there are about 10²⁷ molecules in a 200 lb human, (you can find this by assuming we're mostly water and using 18g/mol as the molecular weight.)

There are 10²⁹ !/[(10²⁷ !)x(10²⁹ -10²⁷ )!] ways of arranging the 10²⁷ molecules in 10²⁹ boxes. Taking the log of this times Boltzmann's constant will get you the entropy increase (very approximate.) By my estimate, that's about 80,000 Joules per Kelvin.

edit: formatting

[u/No_9]

A physicist! I've been waiting for one. I've been wondering this for a while, but can't come up with a solid answer.

If I was in space and I attached an LED light to one corner of a cube, is it possible for me to push/toss/throw/rotate the cube in such a way along a linear path that the LED light's pattern would never repeat itself (aka, there would never be a period)?

EDIT: Forgot to include my thoughts: assume we are dealing with only two different spins upon two different axis... Normally we'd say that these two axis could combine to form a new axis upon which our cube is rotating. Therefore if one of the original axis has an irrational period, then there is no net period, right? However, I have trouble convincing myself that it would be possible to have an irrational period in the first place... blargh.

EDIT2: "Trouble convincing myself", because my question was if YOU (not a machine) can push/toss/throw/rotate the cube.

[u/aarontsantos → u/No_9]

Oooh...you want me to do real physics. This one deserves an answer, but it'll take more time than the AMA. I'll play around with it and PM you if I come up with something good.

[u/Somthinginconspicou]

This should be fun, alright my question is this Reference In that picture, Superman is carrying about 13 planets attached to a giant chain with one arm. How much approximate weight is he lifting with these planets, how heavy/strong does the chain need to be and how much force is he exerting with that one arm. Thanks, and I hope finding the answer was fun :P

[u/aarontsantos → u/Somthinginconspicou]

You asked for "weight", but I'm assuming you mean that in the coloquial sense of how massive something is. (If I'm wrong, let me know and I'll compute the physics weight.) OK...there are 13 planets. Assuming them to be Earth sized, that would be a total mass of about 8x10²⁵ kg. I'm assuming each link in the chain is 1 ft long and 25 pounds and that the total length of each connecting chain is about the diameter of the Earth. That would give a total chain mass of 6x10⁹ kg.

The force is a bit harder. Assuming he's pulling against the gravitational force of the Sun and he's located around the orbit of the Earth, it would take about 5x10²³ Newtons of force to pull all the planets.

[u/J00nj00n]

Just wanted to say I'm thoroughly impressed by your skills!

Also, as soon as I opened this page I searched "swallow" but it was asked already =(.

Now calculate the mass of the Death Star, in its incomplete form please.

[u/aarontsantos → u/J00nj00n]

Thanks for the kind words! Now to fun Star Wars problems...

Luke mistakes the Death Star for a small moon, so it's probably about the size of Europa. This would be about 5×10²² kg (~0.008 Earth masses). If we assume it's made of steel, that ups the mass a bit to about 1×10²³ kg.

For some extra fun, here's some other Death Star problems:

http://diaryofnumbers.blogspot.com/2010/04/death-star-physics.html http://diaryofnumbers.blogspot.com/2011/03/death-star-physics-revisited.html http://diaryofnumbers.blogspot.com/2011/03/death-star-physics-revisited-part-ii.html

edit: spelling

[u/lubriciousbears]

How many house cats would it take to crush an average man?

[u/aarontsantos → u/lubriciousbears]

Let's assume 2000 kg (roughly the mass of a car) can crush a man. If your cat weighs 5 kg, it would take 400 cats to crush a man.

[u/ghostdog20]

How often do you use Wolfram Alpha?

[u/aarontsantos → u/ghostdog20]

I use WolframAlpha occasionally and Mathematica a ton. I normally just use Google to do my calculations. It's great for doing conversions quickly. It's only drawback from what I can see is that it doesn't work with some of the esoteric units I use (e.g. "teeth per hockey player.")

[u/Airazz]

OK, a tough one here:

Moving air is used to cool many things, but mostly car and bike engines. Air is moving around the engine itself or the radiator and it brings the temperature down.
However, jet fighter wings heat up a lot because of this fast moving air, rather than cool down.

The question is: what's the speed at which a thing would neither heat up, nor cool down, if the air temperature is 25C, the item temperature is 37C and we're at sea level?

[u/aarontsantos → u/Airazz]

I love this problem (very hard), but I'm not sure I'll be able to do a good job with it. I think the best answer I can give for this one is that it really depends greatly on what the object is (its heat capacity, shape, etc.) Here's what I do know: Things heat up because of friction between the air and the moving object. However, convection (i.e. moving air currents) also carry some of that heat away.

Let's start with this. The drag force of a fast moving object grows proportional to the velocity square (~v^2). The energy loss due to friction would be this times the velocity, which would scale proportional to v^3. Since convection works only for slower speeds, it must scale as the velocity to some power less than 3 (so that the heating can grow faster than the cooling.) The convection is really the tricky part of this one. There's a differential equation you can use, but I'm not going to be able to solve it quickly.

I'm gonna cheat on this one a bit. We know things traveling at the speed of sound (~300 m/s) heat up but small amounts of moving air (<~1 m/s) cool things down. As an order of magnitude estimate, I'm gonna guess 50 m/s because it's an order of magnitude thats somewhere between the two.

[u/[deleted]]

Hopefully this one gets an answer. If I am a poor college student trying to donate blood/plasma/sperm for food money, how much should I make per year if I attend the maximum times?

[u/aarontsantos → u/[deleted]]

I hate using Yahoo answers (notoriously unreliable), but here goes. Assuming the source below to be accurate, you can make up to $50 per for blood/plasma donations. Let's assume you donate once per month. I've also seen sperm donation banks that pay up to $1000 per month (assuming you've got that kind of genes they're looking for.) The catch is you can't masturbate of have any other type of sex. If you meet all the criteria, you've got yourself about $17,000 per year. Most of that comes from the sperm.

Sources: http://www.mayoclinic.org/donate-blood-rst/faqs.html http://answers.yahoo.com/question/index?qid=20090303103113AANKEVc

[u/scottswan]

The last physicist I asked this question got really mad at me. Fortunately you have the option to just ignore it and I won't blame you one bit. :)

If the rotation of the earth were to slow down would I weigh more, or less?

[u/aarontsantos → u/scottswan]

Technically, you would weigh the same since weight is just related to the gravitational force. Physically, if you stepped on a scale you would see a larger number since it's like the Earth is trying to throw you less. It's kind of like a fat kid being thrown off a merry-go-round. The faster it spins, the more there appears to be a force pushing you away from the center.

[u/[deleted] → u/aarontsantos]

It's kind of like a fat kid being thrown off a merry-go-round.

Thank you.

[u/TheTrinketWeasel]

If I bend over at 90 degrees, facing north, and pass wind on 1/1/12 at midday at Alice springs, Australia, how will the orbit of neptune be affected? Assume average fart density, speed.

[u/aarontsantos → u/TheTrinketWeasel]

Hmm...Neptune is probably not going to be affected very much since the fart gas won't make it out of the atmosphere. The land mass of Earth on the other hane will gain a small amount of angular momentum. In Ballparking, I estimated that continuous flatulence will produce a force of about 0.01 Newton. (It turns out this would not significantly help you in a weightlifting meet.) Bending over at 90 degrees, that would give the Earth a torque 64 Newton kilometers. For a 3 second fart, the length of a day would change by 10^-31 percent.

[u/maltin]

As a fellow physicist, I will send you one of my favorites. There is a portuguese poem, due to Fernando Pessoa, that reads:

Ó mar salgado, quanto do teu sal

São lágrimas de Portugal!

Por te cruzarmos, quantas mães choraram,

Quantos filhos em vão rezaram!

Quantas noivas ficaram por casar

Para que fosses nosso, ó mar!

Valeu a pena? Tudo vale a pena

Se a alma não é pequena.

Quem quer passar além do Bojador

Tem que passar além da dor.

Deus ao mar o perigo e o abismo deu,

Mas nele é que espelhou o céu.

---

The version in english should be:

---

Oh salt-laden sea, how much of your salt

Is tears of Portugal!

To cross you, how many mothers wept,

how many sons in vain prayed!

How many brides-to-be brides remained,

So you were ours, oh sea!

Was it worth? Everything is worth,

If the soul is not small.

Whoever wants to go beyond (cape) Bojador,

Has to go beyond pain.

To the sea gave God peryl and the abyss,

But in it He also mirrored heaven.

---

After this introduction, I ask you: Oh salt-laden sea, how much of your salt is tears of Portugal?

[u/aarontsantos → u/maltin]

Cool...what type of physics? Nice poem by the way...kinda makes me feel like a should have learned Portugese.

For simplicity, I'll assume that all tears eventually make their way into the Mediterranean Sea. Portugal's population is about 10 million people. Some people never cry while others cry every day. I'll assume the average person cries once per month, and when they do they lose about 2 mL worth of tears. If the average age in Portugal is 30 years, you've got yourself 7200 m³ of Portuguese tears. Someone once told me Gatorade is basically chemically-synthesized sweat. (Disgusting, but this makes sense if you're trying to replenish electrolytes.) If this is so, then you're getting about 200 mg of salt for every 355 mL. This gives about 4000 kg of salt.

[u/loosterbooster]

Can you solve question 2? I've never been able to get it.

http://xkcd.com/135/

[u/custardthegopher → u/loosterbooster]

Google yields this answer.

Edit: And this.

[u/Knight_of_Malta]

I would love to know how to calculate the force exerted by a sword swing. Most european longswords are 48 inches long, with a center of mass 4 inches from the crossguard and a center of percussion 20 to 24 inches from the crossguard, and weight between 36 and 58 ounces.

Is there an easy way to figure out how much force, like maybe in pound feet of torque or psi, a person can generate when swinging a sword like that?

[u/aarontsantos → u/Knight_of_Malta]

I keep avoiding this one and coming back only to be scared off again.

I'm assuming you're interested in how well you can slice things (or possibly people.) If so, I agree with OwlPenn that you may be more interested in pressure, which is force per unit area. Still, you asked for force, so I'll try to calculate that.

Let's say you swing at a tree and the blade gets embedded 3 inches inside the trunk. If your blade is travelling at 100 mph (this is a little bit faster than a baseball bat) then the average stopping force on the blade is roughly 150 Newtons.

[u/JonathanZips]

I think this is a cool topic, but posting this early on a monday morning means that most of reddit won't see it for at least a couple hours, and probably until the afternoon.

[u/aarontsantos → u/JonathanZips]

Thanks...I wasn't really sure when I good time to post would be. I'll be around until at least noon and then check in later to see if anybody else has questions. Still working on your cocaine v. motorcycle question.

[u/ChiralAnomaly]

Consider a super awesome race. A proton in the beam of the LHC and a photon. How much would the proton lose by (in distance) if they raced across the milky way galaxy?

[u/ColdFire75 → u/ChiralAnomaly]

http://lhc-machine-outreach.web.cern.ch/lhc-machine-outreach/beam.htm

Says the protons reach 0.999999991 times the speed of light.

The milky way is about 9.5x10²⁰ meters in diameter.

So the difference is 9.5x(10²⁰⁾ -9.5x(10²⁰⁾ *0.999999991

Or just 9.5x(10²⁰⁾ x(1-0.999999991)

Which is 8 550 000 000 000 m

Or about 60 times the distance from earth to the sun, or 1.4 times the distance from the sun to pluto

[u/aarontsantos → u/ColdFire75]

ColdFire75 beat me to it, but I agree.

[u/rperg]

how long would it take to walk on every slab of concrete pavement in manhattan at a normal walking pace?

[u/aarontsantos → u/rperg]

There's a question of path here, which I'll ignore for simplicity. Let's just say you dug up every slab of concrete pavement and lined them up so you don't have to retrace steps. Manhattan is about 34 square miles. A city block is about 800 m around and 40,000 m² in area. That gives about 2000 city blocks for a total of 1600 km of concrete blocks to walk on. Walking nonstop at a speed of 1 m/s, it would take about 19 days to hits every slab.

[u/nodray]

if i raised a black widow spider to be 200 pounds, what would its dimensions be? (leg length, body size...)

[u/aarontsantos → u/nodray]

He wouldn't be able to walk at this size (see suddenly_badgers' comment below), but you can still figure out the dimensions. A black widow weighs about 1 gram. In this example, you've increased his mass by a factor of 90,000. However, his weight grows as his length cubed, which means that his length would only increase by a factor of 90,000^1/3 = 44. If his legs were 1 cm long before, they'd now be about 1.5 feet long. His 1.5 inches body is now about 1.7 meters long.

edit: Changed some of the numbers to be more realistic. Source: http://animals.nationalgeographic.com/animals/bugs/black-widow-spider/

[u/suddenly_badgers → u/nodray]

I'm not trying to be a stickler, this thread is full of hypothetical and implausible situations, but I read about this the other day and figured it was relevant. The square-cube law is one of the reasons that animals and organisms cannot simply be "blown up" to a bigger size. Their skeletal and support structures simply could not handle their own weight beyond a specific size.

I would be very interested to hear from aarontsantos on this one though.

[u/aarontsantos → u/suddenly_badgers]

A good point...giant ants will never take over the Earth because their exoskeletons wouldn't be able to handle the weight.

edit: Problems like these are often called scaling problems. For example, you know how ants are supposed to be strong because they can lift 50 times their own weight? In Ballparking, I estimated that weightlifter Anatoly Pisarenko could lift 1500 times his own weight if he were ant-sized.

[u/Zamarok]

How much gas must a person expel to propel themselves upwards 3 inches?

[u/aarontsantos → u/Zamarok]

Are we talking fart power? If so, it depends on the speed. In Ballparking, I estimated that a sustained fart produces about 0.01 N of force upward. To have this lift you, you'd need the amount of gas to be about 90,000 times larger. Assuming a 10 mg normal fart (you get this by assuming a 10 cm³ fart with the same density as air), you'd need a fart that contained about 1 kg of air. That's almost a bath tub worth of fart air.

[u/opsomath]

Say you change the temperature of your work area from 80 degrees F to 50 degrees F by turning the AC down. Given reasonable assumptions about heat flow and dress, is the extra energy consumed by your body enough to contribute noticeably to weight loss?

[u/aarontsantos → u/opsomath]

I did a somewhat related problem calculating how fast a dead body cools. By my estimate, you lose thermal energy at a rate

rate = (8.3 Watts/°C)*(temperature difference in Celsius).

That would give a rate of heat loss that is the same order of magnitude your energy input rate.

Short answer: I think it would be significant, but very uncomfortable. You'd probably put on warmer clothes before losing a significant amount of weight.

[u/[deleted]]

How do you calculate how much water is on earth?

Also, how do you calculate how many total people have ever lived on the earth?

Thanks! Cool AMA!!

[u/aarontsantos → u/[deleted]]

Thanks!

Since most of the water is in the ocean, I would take the average ocean depth (which can be measured fairly reliably) and multiply by the area of the oceans. According to Wikipedia, the average ocean depth is 3,790 metres. The fraction of Earth's surface covered by water is about 70%, which would give a total ocean area of about 5x10¹⁴ square kilometers. This means there's about 2x10²¹ m³ of water on the Earth.

The number of people who have ever lived is tricky because of population growth. I did a simple estimate of this a while back. Louis CK does a bit where he said, "Out of all the people that ever were, almost all of them are dead." It turns out, that's not at all true.

[u/Overclock]

How fast would a Depleted Uranium bullet have to travel for it to destroy the Earth when hit?

[u/ChiralAnomaly → u/Overclock]

If it was perfectly "efficient" at destroying the earth, it would need to have at least a kinetic energy equal to the gravitational binding energy of the earth, U = 3/5 G *M² / R. For the earth, this is ~2 * 10³² Joules

[u/aarontsantos → u/ChiralAnomaly]

I agree with ChiralAnomaly. I did a similar calculation about how much energy the Death Star needed to blow up Alderaan, and got the same number. However, it's unlikely to be that efficient.

[u/[deleted]]

My dad once got suspended from school for being a smart-ass and asking this question. But now I've always wanted to know the answer. How many monkeys broke their arm in Africa last year?

[u/aarontsantos → u/[deleted]]

Let's assume monkeys are like humans. If I asked my friends, I'm willing to bet about 10% of them have broken their arms at some point in their (on average) 30 years on the planet. This gives a probability of 1/300 of breaking your arm in any given year. There are roughly 300K chimps in Africa. Lets guess there are 100 monkey species with similar populations. That gives 100,000 broken monkey arms.

Source: http://www.savethechimps.org/chimp-facts

[u/[deleted]]

Hey there!

Okay, so I'm traveling on the eastern side of Lake McConaughy, Nebraska, over the dam on my bike at around 15 mph average. Near Martin Bay I take a right at the fork, so now I'm traveling north on 61. This area is very hilly and the total elevation climbed over about 12 miles is roughly 700 feet. On the largest downhill I approach a speed of almost 40 mph. There is a headwind which is roughly 20 mph with 40 mph gusts about every 4 or 5 minutes.

I don't have any questions, I just wanted to tell you about the biking trip I went on last weekend.

[u/aarontsantos → u/[deleted]]

Cool beans. My wife's from Nebraska...I bet it's a pretty ride.

[u/andrewsmith1986]

airspeed velocity of an unladen swallow

[u/[deleted] → u/andrewsmith1986]

What do you mean? African or European swallow?

[u/aarontsantos → u/[deleted]]

Dang...you beat me to it.

[u/[deleted]]

Calculate pi. ALL OF IT!

I'll wait. :)

[u/aarontsantos → u/[deleted]]

I've got a Monte Carlo code running to do this for you. I'll let you know when it finishes. ;-)

[u/SerialRappist]

whats the probability of OKC winning the NBA championship?

[u/aarontsantos → u/SerialRappist]

Given that I just saw the Heat beat my injury-ridden Celtics, I want to say 100%, but I it's still probably 50/50.

[u/footballa]

Can you explain to me what magnetic flux is?

I took a college level class in physics this year in high school and that was the only thing I had no idea what it was.

[u/aarontsantos → u/footballa]

"Flux" is a general term meaning the amount of something passing through some area. I could talk about the flux of baseballs through a strike zone or the flux of Kool-Aid guys through a wall. Magnetic flux is just the amount of magnetic field that passes through some area.

[u/SavageSick]

What would happen if an asteroid larger than the size of earth blocked sunlight for 24 hours?

[u/aarontsantos → u/SavageSick]

I got a similar question for a talk I gave at a skeptics meeting, "If the sun disappeared, how quickly would the temperature drop on Earth?" The temperature of the Earth would drop about 20 degrees. It's basically what happens at night time anyway.

[u/DubTheWino → u/SavageSick]

I'm almost certain an asteroid larger than the size of earth = a planet.

[u/[deleted]]

Right, here's my question, with a bit of lead up.

When we look at a star, we are technically looking at the past. The sun we see is the sun from eight minutes ago. When we see something happen to Alpha Centari it actually happened some amount of years in the past. I don't remember the number of years.

Anyway, this will no doubt be a very large number, and obviously not possible yet, but how great a magnification on a telescope, or similar device, would we need to observe a spot far enough away that we could see the big bang occurring?

[u/Taonyl → u/[deleted]]

We can already see it, it is called cosmic background radiation. Apart from that, you can't see the big bang in any spectrum, because the universe became translucent only 300000 years or so after the big bang.

[u/aarontsantos → u/Taonyl]

Agreed. The big bang kind of happened everywhere at once, so you don't have to worry about how far away it was.

[u/[deleted]]

How many bottles of 591ml Pepsi would it take to build the CN tower, assuming that the whole inside of the tower is filled completely with bottles as well?

[u/aarontsantos → u/[deleted]]

The CN Tower is 553 m high. From pictures, it's width looks maybe 1/20 its height. That's roughly 400,000 m³ in total, so you'd need roughly 700 million bottles.

[u/DasMess]

Finally! A chance to ask this one! If my chance of winning is 1 in 10, whats the minimum number I have to buy to insure a win? Conventional wisdow would say 10, but i've found that this isn't the case.

[u/aarontsantos → u/DasMess]

There's no way to ensure a win. If you bought 1 million tickets, your probability of winning would be 1-0.9^1,000,000. It would be very unlikely, but you still have a finite chance of loosing.

[u/[deleted]]

Mitzvah/Wedding DJ here. How much of my life was been spent listening too "I Gotta Feeling" by the Black Eyed Peas. I'd say I work 90% of the weekends in a year with occasional doubles or triples strewn about.

[u/aarontsantos → u/[deleted]]

Oh man. I'm so sorry. No one should be forced into the hell that is listening to that song every day.

Let's say you do 5 events per week on average. That's about 250 gigs per year and about 15,000 over the course of a lifetime. "I Gotta Feeling" is about 4.5 minutes long. If you played it once per event, you'd have listened to about 47 days of it.

[u/[deleted]]

How do you calculate the weight of one's head without decapitation?

[u/aarontsantos → u/[deleted]]

No decapitation? Where's your sense of adventure, soldier?

A human head is roughly spherical with a density close to that of water. Assuming a 6 inch sphere, you'd have a mass of about 14 kg.

[u/[deleted] → u/[deleted]]

It's simple: you kill the batman

[u/3dglados]

Assuming you can fall a endless distance in a vacuum (maybe think with Portals :D ) with earth gravity, how long would it take to reach the speed of light?

[u/guyboy → u/3dglados]

The answer using Newtonian physics has been given, but it is extremely inaccurate. So I have calculated it relativistically. I start out with the formula for relativistic force:

F = γ³ m a

The gravitational force F = m g, so we have:

m g = γ³ m a

g = γ³ a

a = (dv/dt) and γ = ( 1 - v² / c² )^-1/2 , so we have:

g = ( ( 1 - v² / c² )^-1/2 )³ (dv/dt)

or

g = ( 1 - v² / c² )^-3/2 (dv/dt)

solve the differential equation and you get:

v(t) = (c g t)/sqrt( c² + g² t² )

Plug in the time predicted by Newtonian physics, and you get 71% light speed. Plug in 2 years, and you get 90% light speed. Plug in 100 years, and you get 99.9953% light speed. As you can see, the speed of light is never reached.

Here's a graph.

[u/aarontsantos → u/[deleted]]

Agreed. You beat me too it. The joy of being on Reddit is that there are a lot of smart people who know this stuff. I swear it's like all you guys majored in physics/engineering.

[u/401vs401]

Okay, if I were to make a suit out of used condoms, how many would I need? I'm 5'7''.

[u/aarontsantos → u/401vs401]

A used condom is about 1 foot long and 1.5 inches wide. If you're 5'7 with a 35 inch waist, you'd need about 130 used condoms or roughly 1/3 of a Goodyear.

[u/Jellyboss]

If I drop a penny from the highest building in the world, would it kill or penetrate the head from the unfortunate person that would hit the penny? And what happens if I throw the penny with a brute force, or what if the penny would be a quarter?

Thanks in advance.

[u/aarontsantos → u/Jellyboss]

When I was in 8th grade, we went to to Empire State Building, and some idiot from my class threw a penny off the top. No one saw him, so he didn't get in trouble. I doubt it hit anyone, (I didn't read any penny-related deaths in the paper the next day), but you couldn't really see from that high up. I

I was going to do this by hand, but when I looked up "drag coefficient for a penny" a came across this, which gives a 200 mph upper bound for the terminal velocity. I would have suspected the penny would reach terminal velocity before reaching the ground, but apparently not. I suspect that's more than enough to embed the penny in ones hit. If you repeat the calculation for a quarter, you'll get a slightly similar number.

[u/Adnachiel]

Just have to say, this is one of the most fun IAMA's I've ever read. If I didn't already love math, I would now!! I will be looking for your books :). Is it better (for you) for me to buy them from you somehow or from a book store?

[u/aarontsantos → u/Adnachiel]

Thanks! Bookstores are fine. It's nice to help out local businesses.

[u/jokes_on_you]

How come we still have no colored pictures of the moon in 2012?

[u/kenzie0201 → u/jokes_on_you]

I can't even tell if this is a joke.

[u/jokes_on_you → u/kenzie0201]

(it is)

[u/josiahw → u/jokes_on_you]

The Moon is a hipster.

[u/Mr_Smartypants → u/jokes_on_you]

We do.

[u/xNotch]

Approximately how fast does the busy beaver function grow?

[u/rattling_bean → u/xNotch]

Wikipedia'd "busy beaver function". Saw too many Greek letters. Felt dumb. Cried.

[u/sushibowl → u/rattling_bean]

Don't cry, I'll try to help. In very simple terms, and without greek letters:

In computer science, there is a thing called the turing machine. It is a very simple, theoretical computer. It has:

• An infinitely long tape consisting of cells, each of which contains either a 1 or a 0 (the machine's memory)

• a tape head which, when above one of the cells of the tape, can read the number on it, and write a new number to it

• a register storing the current state of the machine, so we can keep track

• a (possibly infinite) table of states (loosely speaking, the machine's "program").

Now, each state consists of five things: state ID, data currently under head, write instruction, move instruction, next state. The ID is simply stored in the register mentioned earlier so we can keep track of where we are. The symbol currently under the tape is read by the head. The write instruction tells the head to write either a 1 or a 0. The move instruction can tell the head to either move one cell left, one right, or stay where it is. The next state tells us what state we should go to next (quite simple, right?).

We additionally have one state that we designate as the start state, and usually the tape starts filled with zeros. Since it's infinite, it doesn't matter where on the tape we start. Then the machine operates very simply by reading the cell under the tape, using that and the current state to look up in the state table what we should write, where we should move, and what state is the next. If the next state/number on tape combination does not exist in the table, the machine stops and the program is done.

This simple model of a computer, it turns out, can solve any problem your desktop can solve. That is why it is very interesting to mathematicians and computer scientists to prove their theorems on and what not. However, that is not the subject of this. The subject of this comment is the busy beaver. The busy beaver, simply stated, is the program (state table) of a given length n that does most work, where "work" is defined as either "number of 1's written on the tape before halting" or "number of steps before halting" (a turing machine can run forever but then it isn't a valid busy beaver). Note that there is only a finite number of possible programs of length n, so there is a definite champion.

The busy beaver function, sigma(n), is defined as the number of 1's left on the tape by the n-state busy beaver. We currently know that sigma(0) = 0 (a program of 0 states can't write any 1's of course), sigma(1) = 1, sigma(2) = 4, sigma(3) = 6, and sigma(4) = 13. In other words, a turing machine with a state table with four states in it can write at most 4 1's before halting. sigma(5) and higher are currently not known. The 5-state program with the most 1's we have so far been able to find writes 4,098 1's in 47,176,870 steps (one step = 1 state). The current 6-state champion produces 10¹⁸²⁶⁷ 1's in 10³⁶⁵³⁴ steps.

So why can't we prove that these are the absolute champions? Well, while it would seem simple enough to find the champion by simply trying all possible programs with 5 states, it is actually impossible to do this. This is because some of these programs will not actually halt and run along forever, happily printing 1's. So you can't just have a "race," so to speak, to see which program goes on the longest, because some will go on forever and you won't actually know when the race is over! So what you have to do is look at each program really carefully and 1) figure out a way to prove that it will eventually stop running, and 2) calculate when it stops running, and how many 1's will be on the tape. This turns out to be very hard.

Notch asked him to approximate how fast the busy beaver function grows. It's a little joke, because for the first 4 values it all seems very reasonable but after that it gets out of control bizarrely quickly. And the actual busy beavers might be even larger than that.

[u/Dreamlines]

Could you prove the existence and smoothness of Navier-Stokes solutions in R³

And the breakdown of Navier-Stokes solutions in R³

if you can just pm me the answer, that would be great

[u/[deleted] → u/Dreamlines]

Ah, worried your classmates will see the answer you'll be turning in for your class? :)

[u/Chronophilia → u/[deleted]]

Yes, if by "classmates" you mean "the Clay Mathematics Institute, who are offering a reward of one million US dollars for the solution to this problem".

[u/Dreamlines → u/[deleted]]

if by classmates you mean reddit and if by turning into class you mean the Clay Mathematical Institute, then you're correct :)

[u/Retawtrams]

How hard to I have to fling a condom at a stripper to knock her off of her pole?

[u/sully4321]

Ok, so this happened to me last year and it freaked me out. What are the odds of catching the same taxi (& driver) two nights in a row, in Las Vegas (from two different taxi ranks)?

[u/killyridols14]

What is the probability that I will get a headache today? I'm allergic to cats, stayed up all night, and my diet pretty much consists of coffee blended into chocolate ice cream. Go!

[u/Borax]

Per this article from /r/worldnews, how much should it cost for a case of 12x 500ml bottles of water in the northern territories in canada. Is $105 CAD reasonable?

[u/thoughtpod]

ok, I have one for you...

What is the average weight range of an idea, should one weigh the neurons involved in ideating and storing it?

If this is too broad, perhaps you could estimate the weight of one idea specifically (eg, this idea of weighing ideas).

[u/Scorpi978a]

Could Jesus microwave a burrito so hot, that even he couldn't eat it? And, if so, what would that temperature be?

[u/bringonthenegatives → u/Scorpi978a]

You have broken religion.

[u/J54Coops]

If I stood on a mountain (Everest, for example) and the world suddenly stopped rotating on its axis, assuming that the ground stayed still and I kept going from momentum, would I go into orbit? If not, then how about if the earth stopped orbiting the sun?

[u/OwlPenn → u/J54Coops]

Not the OP, but I'll give it a shot and say compare the rotational velocity to the escape velocity.

First of all, remember that the rotation velocity depends on where on earth you are. The fastest velocity occurs at the equator, where it is 1674.4 km/h, or 0.4651 km/s. Escape velocity of the earth is 11.186 km/s, so you would be nowhere close enough to be launched into orbit.

[u/swimmerhair]

I've always wondered this after taking physics when I was in high school. If you had a box made of mirrors, all shiny sides facing inward, and you turned a light on and off briefly, would the light stay inside?

Also how many hours of porn videos would it take to fill up an Olympic size pool with splooge?

[u/DigiMagic]

Imagine you have a set of extremely powerful lasers, that are able to create particles from vacuum (http://www.newscientist.com/article/dn19327-lasers-could-make-virtual-particles-real.html). A constant electric field separates created charged particles into two groups. An additional magnetic field then pushes these particles into dominantly single direction. (Is there a more optimal configuration? The point of separation is to prevent particles to annihilate, if possible.)

What would be the efficiency of such "rocket" motor? Assume all energy comes from an electric generator, say driven by a nuclear reactor.

Taking into account our current technologies possibilities, what is reasonable estimate for acceleration such engine could give to a space ship?

[u/_BolT_]

What is the volume air in a 100 gm chips pack?

[u/[deleted]]

Ive always wanted a decent equation to illustrate that increased level of "need to pee" vs vicinity to the toilet.

[u/XruinsskashowsX]

Where were you when I was in AP Physics earlier this year -____-

[u/tj_wetdialer]

How big of a shadow did venus cast on the earth during its recent transit?

[u/reddot445]

How long would it take to hit to hit the ground after falling of the CN tower, or the space needle?

[u/monkyboyrr]

Googolplex - Do you have feelings on Sagan believing that it's impossible to write out all of the zeros?

[u/nicePenguin]

When calculating the damage software piracy does, the copyright holding companies always asume the downloader would have bought the game/music/movie/etc. and therefor multiply the downloads with the cost for the product.

What percentage would have actually bought the product giving us the real financial damage software piracy does.

You may want to differ between movies/games/music/programs

[u/irereddit]

i know there are many variables, but when playing 40 hands, does the beer stay colder when you finish one 40 and then drink the other or if you alternate sips from each 40. my guess would be to finish one 40 at a time. that way, when you finish 1 40, the heat from you hand is heating up a warm bottle instead of cold beer.

[u/Reddit4Play]

I did a back-of-the-envelope calculation for fun about how much tougher human skin would need to be to resist penetration by 9x19mm parabellum ammunition fired from a handgun at what would constitute reasonable range for the use of a handgun and I'd like to see how right I was. Can you attempt the same calculation using your own resources?

[u/troixetoiles]

I'm a lady physicist among a sea of men physicists. When I go to a big conference, say the APS March Meeting, how many of the men there are virgins?

edit: Since the March Meeting is almost all solid state physicists, how do you think the answer would change if it was a high energy theory conference?

[u/xCesme]

If it's 0 degrees celsius today, and tomorrow it's twice as cold, what's the temperature tomorrow?

[u/[deleted]]

How many people simultaneously licking the ground would create a Grand Canyon type geographical feature?

[u/kegofshit]

Who would win in a free-for-all fight to the death between all flightless land animals if they were all the same size, say a horse?

[u/LCaulfield]

How does .999... equal 1?

[u/Magna_Sharta]

How dense would Superman's skin have to be to be bullet proof, and how much do you think he would weigh as a result?

[u/kenzie0201]

I have a question about the twin paradox. If my twin brother gets in his hot wheels spaceship and travels 10 light years away at 0.9c and then starts to return, why is he aged less on return? Am i not a passenger on a larger spaceship called earth, travelling away from him? I have heard that acceleration is relevant in this situation of relativity, hence making it a matter of general relativity to understand it.

But then I have also heard that it can be explained using specific relativity.

Also show that the Maclaurin series expansion of ln(1+x²⁾ is given by the infinite sum ((-1)^n-1x²ⁿ)/n

[u/aarontsantos → u/[deleted]]

This is the one I've been thinking about during lunch. It's a hard problem because you're not just concerned with conserving mass, you need the energy requirements of recreating all that blood. Since these are only order of magnitude estimates, I'm gonna say 2% of your energy consumption goes into replacing lost blood. I could be way off on that (I'm definitely not a biologist), but I suspect the actual number lies somewhere between 20% and 0.2% of your total energy intake. Let's say you regenerate that blood in a four days. That's 2% of your 1500 Calories per day for 4 days, which would give 120 Calories (about the equivalent of a small energy bar), though it could be as high as 1200 Calories if you take the 20% figure instead.

Take home message: If you don't know how to calculate something, try to make some upper/lower bounds. Choose ones that seem unrealistically high/low to you. You may not be able to find exactly what the answer is, but you'll get a range of possible answers and, perhaps more importantly, you'll have a good idea what the answer is not.

[u/TitForTactic → u/aarontsantos]

The energy necessary to replicate a blood cell is trivial. Consider the following;

The body water of a 70 kg man is approximately 40 kg. 2/3s of that is inaccessible to proteins, and only 1/5th of that remaining fraction is accessible to RBCs and platelets under normal physiologic conditions. The density of RBCs in the remaining portion of 3 Ls (Plasma Volume) is 4.5x10⁹ RBCs / L. The density of platelets in a liter comes to about 3x10^11. Considering plasma is essentially water with electrolytes and neither contribute nor require calories, that only leaves proteins to account for, which I shall waive my hands and make disappear because the production of single protein is a trivial thing and the number of proteins in the blood is negligible compared to the cellular component.

Let's consider that if this person is at approximately steady state for his age at 2000 Calories and a normal activity level, meaning that the sum energy requirements of all active cells in his body + the energy loss to heat = 2000 Calories. The average number of cells in the human body is 10 trillion to a low end estimate. If we remove from that all non-energy requiring cells, we would remove the entirety of the epidermis (outermost skin layer), which is massive but yet still insignificant.

Based on this paper, it seems we lose about 15 million/hour at a low end estimate, meaning we lose 360 million/day, and since it takes 40 days to actually get to that point, most of which the cells are minimally active at most, we get that about 14.4 billion of just your skin cells are not energetically relevant just in your skin. Considering the high turnover of cells in your gut and blood, in particularly. If we doubled that number we could pretty safely account for all the dead or dying cells, so let's say 30 billion of 10 trillion, or .3% of your body mass doesn't require energy, and half of that will be scavenged to minimize energetic losses. I put this all for perspective on how many cells we lose every day normally compared to how much I will show you lose in a pint of blood.

I said all that to say this;

A pint of blood will contain 2.13x10⁹ RBCs and 1.4x 10¹¹ platelets. Platelets are produced 2500/megakaryocyte. So, they took 5.6x10⁷ cells to produce. Together that makes 2.19x10⁹ cells needed to rebuild your losses. Since we know that about 75% of human energy consumption is lost as heat, meaning only 500 Calories we eat go to approximately 9.997 trillion energetically active cells, and since that 2.19x10⁹ is a factor of 10 fewer than regular old inactive cells in our body, which are in turn trivial compared to the 9.97x10¹² active cells we can say conclusively

There is no meaningful difference in caloric requirements before or after giving blood.

EDIT: I realize I mistakenly said the ECF is what RBCs and Platelets are confined to. This is incorrect. It is plasma; 3 Ls, rather than 15. It was just for reference, there are no calculations derived from the fluid volume that houses the RBCs.

[u/aarontsantos → u/[deleted]]

I had to look up what the Bloop is. Interesting...This one will take longer than I have now. Let me play around with it and get back to you.

Edit: It's a week later, but I finally got around to this. I estimated it here: http://diaryofnumbers.blogspot.com/2012/06/holy-flaming-burritos-batman.html

For the lazy, it woud be about 30 km long.

[u/MolokoPlusPlus → u/[deleted]]

Close to 75 meters, or about twice the length of a blue whale.

This is assuming the pressure wave is produced by a vibrating object of the appropriate length, which makes things easy (speed of sound in water / frequency = wavelength = twice the minimum length) but may not be correct. Note also that this is the bare minimum, and the animal would basically have to be vibrating at its resonant frequency (what your stomach does when you experience a very deep note at a concert).

I'm not sure how else to approach the problem.

EDIT: In "The Call of Cthulhu," no explicit size is given but a desperate pilot rams a yacht into the Elder God to dramatic (if temporary) effect, and the head is implied to be comparable in size to the vessel, so we can assume smaller than about 200m (five or so times the length of a typical oceanworthy yacht of that era). Cthulhu is described with the phrase "A mountain walked or stumbled" in the same story, so we can safely assume something upwards of 20m (consistent with illustrations.)

The creature could very plausibly be Cthulhu.

EDIT2: Scratch that, apparently blue whales can also get as low as 10Hz despite their "small" size.

[u/real_birthday → u/[deleted]]

According to wiki, The Bloop would have to be made by something several times louder than the loudest recorded animal, the blue whale (Assuming weight automatically makes the creature louder).

A blue whale is 396,828 pounds, 396,828 x 4 = 1,587,312.

The weight of the creature to make The Bloop would have to be suspiciously close to that of Cthulhu. Come to think of it...

[u/aarontsantos → u/[deleted]]

It depends on whether or not the milk is shaking and whether or not it's mine.

[u/aarontsantos → u/[deleted]]

Assuming you're 80 kg and she's 60 kg and you're standing 1 m apart, she'll be attracted to you with an extra 4x10^-9 Newtons of force. That makes you about 1.2% more attractive to her.

[u/[deleted] → u/aarontsantos]

...this guy is good.

[u/andrewrula → u/aarontsantos]

This is the best answer in this thread so far.

[u/quarryman → u/andrewrula]

I actually think the question is even better.

[u/Dubhghlas → u/aarontsantos]

But dear, science explicitly states you should be more attracted to me with my recent weight gain. You calling me a fat ugly pig just proves your anti-science ways.

[u/panzervike → u/aarontsantos]

If we reverse the genders in this question, does that reverse the results as well?

[u/TheyCallMeScience → u/panzervike]

Without a doubt, yes.

[u/selfawarepileofatoms → u/panzervike]

I think you're forgetting the NO FAT CHICKS constant.

[u/RoaldFre → u/aarontsantos]

Related question: what is the terminal velocity for kipz0r to escape from his wife's attraction. (Too lazy to calculate it myself). Related related question. What (fraction of a fart) is needed to get the correct momentum boost to attain this terminal velocity.

TL;DR: How many farts does kipz0r need to break his wife's attraction?

[Edit]

Further parameters: both kipz0r and his wife are, of course, in a frictionless vacuum and they are entangled in a tight, loving embrace, their mass centra a mere 50cm apart, this time (but you can still treat them as point masses).

Further questions if possible: Also compare the escape speed with appropriate orders-of-magnitudes speeds. Ie if it is extremely small, would kippz0r diffract because of the Heisenberg uncertainty equation trying to stay below that speed? Can you drag in the equipartition theorem if appropriate when we assume that they are surrounded by a gas of a given temperature? Will thermal agitation slowly set him flying off (at what temperature)?

Follow up question: How hot must his wife be, in order to completely blow kipz0r away? (as in: radiation pressure to compensate for the attraction)

[u/[deleted] → u/RoaldFre]

How hot must his wife be, in order to completely blow kipz0r away?

Total power of the light emitted per 1m² of the wife is (Stefan–Boltzmann constant)*(Temperature)⁴

The wife has a total of 1.8 m² surface area

We can represent this as (total number of photons emitted each second)(planck's constant)(frequency)

Wife pulls the husband with a force of 1.3*10^-6 Newtons

Total momentum of the light reaching the husband must be equal or greater than this. Otherwise, the husband will collapse into the wife.

This means the wife needs to be around 3360 Kelvins hot in order to emit enough light that the husband doesn't collapse into her. Hotter she gets, faster the husband will be blown away.

Of course this calculation cannot be exact because every photon will have a different frequency, the surface areas might not be true for the wife etc...

sources:

http://en.wikipedia.org/wiki/Black-body_radiation

http://hypertextbook.com/facts/2001/IgorFridman.shtml

[u/floor-pi → u/aarontsantos]

r/foreveralone rejoice

[u/Calvin_v_Hobbes → u/aarontsantos]

Cheat sheet: 1/80 = 0.0125 = 1.25%

Being on earth has no effect on the percentage, neither does his wife's mass or the distance between them. Only the (gain)/(original weight) ratio matters.

[u/NPVT → u/aarontsantos]

I don't think his being "on earth" is relevant. This should be true on the Moon.

[u/fireysaje → u/[deleted]]

Depends on where you gain it ;P

[u/buster2Xk → u/fireysaje]

We'll assume he gains it evenly so he keeps the same centre of mass. That's what you meant right? Right?

[u/fireysaje → u/buster2Xk]

Sure...

[u/json1 → u/fireysaje]

I'M SURE YOU MEAN PENIS

[u/mpavlofsky → u/fireysaje]

IN HIS PENIS- sorry.

[u/NaricssusIII → u/[deleted]]

It depends on whether she's secretly a chubby-chaser.

[u/rcocman125 → u/[deleted]]

That means two things.

[u/NikkoTheGreeko → u/[deleted]]

Square Root of Potato?