Anyone know what this means? (calculus I presume)

wooflepoof

wooflepoof

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I recently bought a shirt at the Johnson Space Center that reads:

WHAT PART OF
showequation.php

DONT YOU UNDERSTAND?

I kinda wanna understand it...any ideas? I'm assuming its referring to rockets or something so, any rocket scientists here?:p

PS I'm pretty sure i recreated it accurately but...I only learned LaTeX just to write this down
 
I believe that is finding acceleration using velocity with both polar and spherical coordinate systems.
 
Well, 3D integrals find the volume of things so it's not acceleration (that's a derivative anyway, of change in velocity or 2nd derivative of change in displacement, not a integral, if I recall). I'll look a few variables up and look at it some more to figure out what we're finding the volume of. Probably the universe. Wasn't there any text on the shirt or anything to clue you in? Why'd you buy a shirt in a language you don't speak anyway? People with Chinese tattoos get in lots of trouble for that. :p Kidding!

Edit: Dude, props for the LaTeX though!
 
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well its saying that F_8 is all that then they simplify it into the closed integral and the partial derivative times the triple integral of the rest of that so really its just saying what part of F_8 = blah don't you understand.
 
actinium said:
well its saying that F_8 is all that then they simplify it into the closed integral and the partial derivative times the triple integral of the rest of that so really its just saying what part of F_8 = blah don't you understand.
Click to expand...

I was about to say that.

:-|
 
flydiscovery said:
Well, 3D integrals find the volume of things so it's not acceleration (that's a derivative anyway, of change in velocity or 2nd derivative of change in displacement, not a integral, if I recall). I'll look a few variables up and look at it some more to figure out what we're finding the volume of. Probably the universe. Wasn't there any text on the shirt or anything to clue you in? Why'd you buy a shirt in a language you don't speak anyway? People with Chinese tattoos get in lots of trouble for that. :p Kidding!

Edit: Dude, props for the LaTeX though!
Click to expand...

The problems they give you in math class for acceleration and velocity involve single integrals, reality is often times different. Could you describe how the gravitational pulls of the sun and the planets within our solar system effect the course of comet using a single dimension? I couldn't, I'd need at least two, but most likely all three.
 
I'm certainly stuck and very curious. All I can make is this:

F_8 = some kind of volume = some kind of area that changes over time

Of course I'm probably completely off. There's just no consistency of variables across fields. I'll bet if someone knows what F_8 means and that R with the umlat means, we'll be a lot closer.

Susurrate, that may be true but I see NO indication that acceleration being looked at here. Those are clearly volume integrals. I am certain there are no polar/spherical coordinates. There's no theta for one.
 
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It means that I decided to take social sciences because I never could understand that stuff.
 
Blind_Io said:
It means that I decided to take social sciences because I never could understand that stuff.
Click to expand...

Which I can translate to mean that if I see stuff like this big or half that size while at my new school I am dropping out of comp sci and becoming a mechanic.
 
Yeah I agree with Susurrate. I'm pretty sure that's finding the area under multiple sets of curves in three dimensions, hence the calculations a guidance system makes to keep the ship from cartwheeling like a coke bottle rocket with no tailfins.
 
Essentially that is the equation for calculating trajectory when using the moon to "slingshot" back to Earth.


This post is 100% certified premium grade BS.
 
wooflepoof said:
I recently bought a shirt at the Johnson Space Center that reads:

WHAT PART OF
showequation.php

DONT YOU UNDERSTAND?

I kinda wanna understand it...any ideas? I'm assuming its referring to rockets or something so, any rocket scientists here?:p

PS I'm pretty sure i recreated it accurately but...I only learned LaTeX just to write this down
Click to expand...

Without knowing what exactly each variable stands for...
R and r are usually directional vectors, describing the position in space
omega - angular frequency
rho - density (of something)
v and V - speed and volume (in this case flipped, usually v - speed and V - volume)
beta_rho - no idea (could be anything)
A - surface area
t - time

I assume that x means cross product (in that case the vectors aren't properly marked as vectors [bold or with an arrow above them]), which gives the second integral dimension

m/s? * (density of something) * m?

but that isn't really helping.

The first integral seems to be transformed using either Stoke's or Gau?' theorem, but to be sure one would have to know how beta is defined..

edit: assuming that rho is a classical density with dimension kg/m?, the equation's result has dimension kg*m/s? which means it's a force (as suggested by F_8), which means Susurrate was right all along ;)
(although it's all done in euclidean coordinates :p )



flydiscovery said:
(...)Of course I'm probably completely off. There's just no consistency of variables across fields. I'll bet if someone knows what F_8 means and that R with the umlat means, we'll be a lot closer.(...)
Click to expand...

R dot dot = second derivative (d?/dt?) of R
 
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I do believe it's a momentum flux equation for a compressible fluid... and a finite volume formulation at that!

In essence it's an equation that represents the rate of change of momentum for a volume of fluid, so is equated to the mythical F8 which is a force. More specifically it represents high speed flow where compressibility cannot be neglected.

The right hand side contains:
- First term (rho*V^2 dA) is rate of momentum flux through the surface of volume.
- Second term (d/dt*rho*V dV) is the rate of change of density inside the volume, which when multiplied by velocity becomes a momentum flux due to compressibility.

The middle bit is more interesting:
- First term is just a volume integral. Beta could be shockwave angle, which would sort of make sense as it's inviscid compressible.
- Second looks like the momentum flux for a vortex / eddie in cylindrical co-ordinates. I say looks as I ain't gonna derive it from 1st principals to check.

So yeah, it's a fluid dynamics equation.. but only one of them, it's gonna be part of a set of them that can be collectively solved numerically. There's not that much to "understand" really, it's F=ma for a volume of fluid.
 
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wooflepoof said:
I recently bought a shirt at the Johnson Space Center that reads:

WHAT PART OF
showequation.php

DONT YOU UNDERSTAND?

I kinda wanna understand it...any ideas? I'm assuming its referring to rockets or something so, any rocket scientists here?:p

PS I'm pretty sure i recreated it accurately but...I only learned LaTeX just to write this down
Click to expand...

Are you sure you got the equation down right, because the dv and dA should never be inside the bracket, unless you are saying V is a constant and should therefore be pushed out. Also they should be d^2*A and d^3v, but, it might have been left out in short hand.

The forum the equation takes, leads me to believe this might have something to do with Transport phenomena, which has a lot of application in astro physics. Something NASA would have to work with everyday.
 
alright so from reading this all Ive been able to establish is that its definitely probably not a recipe for vanilla ice cream. :p I'm surprised there have been so many responses I decided to look up some of these terms and read more into it, learning nothing that'd get me closer to the answer...but still, awesome. :thumbsup:
 
CD82 said:
Without knowing what exactly each variable stands for...
R and r are usually directional vectors, describing the position in space
omega - angular frequency
rho - density (of something)
v and V - speed and volume (in this case flipped, usually v - speed and V - volume)
beta_rho - no idea (could be anything)
A - surface area
t - time

I assume that x means cross product (in that case the vectors aren't properly marked as vectors [bold or with an arrow above them]), which gives the second integral dimension

m/s? * (density of something) * m?

but that isn't really helping.

The first integral seems to be transformed using either Stoke's or Gau?' theorem, but to be sure one would have to know how beta is defined..

edit: assuming that rho is a classical density with dimension kg/m?, the equation's result has dimension kg*m/s? which means it's a force (as suggested by F_8), which means Susurrate was right all along ;)
(although it's all done in euclidean coordinates :p )





R dot dot = second derivative (d?/dt?) of R
Click to expand...

you are right on euclidean, omega is the angular velocity though :D

So long story short F=ma
 
Susurrate said:
So long story short F=ma
Click to expand...

This was my very, very first thought but I don't see m mentioned anywhere and that's the one thing that can't really be derived through any of these integrals.
 
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