How much flow and volume from urination do you need to levitate your whole body for two seconds off the floor?

[honeymustardgas@lemmy.world]

That would be a challenge to find out. Because I would look for the material with the minimum durability, not just a metal tank, lol. Like what is the weakest material that can still withstand this type of thing.

[sbv@sh.itjust.works]

Flipped inside out, even.

[stinky@redlemmy.com]

Silicone Rubber

Polyurethane (PU) Elastomers

Thermoplastic Elastomers (TPEs)

or traditional latex rubber

[tokenboomer@lemmy.world]

Comments are locked. This question has been answered.

[jeinzi@discuss.tchncs.de]

Aerospace engineer here. To levitate, the force of the exhausted mass flow (F=ṁv) has to equal the pull of gravity (F=mg) on your body.
The gravity of earth is g=9.81N/kg. Wikipedia says the average body mass is 62kg. It also says the bladder capacity of an adult is about 400ml, and I'll assume the density to be 1kg/l. You want to levitate for 2 seconds, so your mass flow needs to be ṁ=0.4kg/2s=0.2kg/s.
If you rearrange the equation, you get v=mg/ṁ=62kg9.81N/kg/(0.2kg/s)=3041m/s.

So if you manage to pee with a velocity of about 3km/s, you can levitate for 2 seconds with an average sized bladder.

To achive that, your "exhaust" must be clenched to a diameter of about 0.29mm. This gives a cross-section of 0.66mm² or 6.6*10^-8m². Multiply that with the velocity of 3041m/s and you again get your flow of 0.2l/s.

Of course, during those 2 seconds you loose mass and therefore, earth's pull on you gets less and you start to accelerate. We can use the rocket equation to calculate your final velocity to 3041m/s*ln(62kg/61.6kg)=19.7m/s

You'll end up flying into the ceiling at about 71km/h and probably die. This could be avoided if you had very precise control over your bladder and would continously reduce your pee velocity.

[bradorsomething@ttrpg.network]

Will the density of my pee affect this?

[jeinzi@discuss.tchncs.de]

Yes, higher density means you exhaust more mass during those 2s, and therefore you don't have to pee so fast.

[ultragigagigantic@lemmy.ml]

Fuck yeah science

[ininewcrow@lemmy.ca]

Beautiful, I was waiting for an engineer to do the calculations .... so in layman's terms, clench your urethra, push your bladder as hard as unhumanly as possible and hope to everything that is holy that your entire urinary tract doesn't explode before your urine leaves your body.

[chuckleslord@lemmy.world]

It's not a question of if your urinary tract will explode, but where.

[ininewcrow@lemmy.ca]

I guess we'll have to keep experimenting to determine which parts need the reinforcing in order to achieve our goal of two second levitation

[crackhappy@lemmy.world]

frantically starts drinking heavy water

[iamanurd@midwest.social]

According to one of my favorite shorts of all time, the answer is “I don’t know”

[bradorsomething@ttrpg.network]

I remember learning a bladder begins to spasm at 600mL, so we could actually use this spastic pressure to help us levitate. In this paper, I propose…

[bjoern_tantau@swg-empire.de]

I implemented a realistic physics simulation that answers this question for Diarrhea.

[zoop@beehaw.org]

This was exactly what I thought of when I saw the post! I'm glad you saw this and shared your work here. It's awesome and it makes me so happy.

[zoop@beehaw.org]

What a fun way to find out my bladder capacity is around three times the average at least. Connective tissue disorders are whack. Now I've just gotta work on the other factors so I can piss-levitate longer than everyone else! I'll be unstoppable!!

[tempermentalanomaly@lemmy.world]

we can rebuild him we have the technology

[scipitie@lemmy.dbzer0.com]

But reinforcement makes you heavier and you're back to the drawing board!

It might be easier to first chop arms and legs off to save the excess weigh.lt.

[tetris11@lemmy.ml]

wow I just checked out the source, and as a physicist I can verify that some of those fluid dynamic models you implemented are very cutting edge