Other Resources My Cup of Joe » What's your favorite equation? Rss Feed  
Moderators: k9car363, the bear, DerekL, alicefoeller Reply
 
 
of 3
 
 
2014-03-01 6:43 PM
in reply to: tech_geezer

User image

Pro
5755
50005001001002525
Subject: RE: What's your favorite equation?

Originally posted by tech_geezer

Originally posted by BrianRunsPhilly

F=ma. Applies to so many things in life.

I like the time-dependent case for Schroedinger's equation too, because it is simple and yet QM was the hardest class I've ever taken.

 

 

I remember struggling with quantum mechanics until I learned that physics just used entirely different symbols for operations than I was used to in math classes.  They abstracted the symbols down to a level that nothing meaningful was left, much as the version of Schroedinger's equation you wrote.  I started writing stuff out in my version of the equations, which were much longer, and I began to understand it.  

Interesting thing, I went into engineering after undergrad.  Since that time, I have never used Schroedinger's equation, not even once.  I haven't even needed to know it even for background.  I use Newton's equation every day.   It says a lot about engineering versus physics.  Of course, I prefer to write it as F=m*(d^2/dt)x.

I haven't done the math since grad school, but use QM quite often as implemented in molecular dynamics software. It's funny how some people can grasp math when it's used, but struggle in the abstract. I'm one of them. Got terrible grades in Algebra, Calc, etc. but aced Physics, Physical Biochemistry, etc.



2014-03-02 8:07 AM
in reply to: BrianRunsPhilly

User image

Elite
4547
2000200050025
Subject: RE: What's your favorite equation?
How 'bout a shout out to
p=mv.

You've gotta love how momentum is represented by p!

2014-03-02 9:32 AM
in reply to: ChineseDemocracy

User image

Veteran
976
500100100100100252525
New Hampshire
Subject: RE: What's your favorite equation?
I do HVAC Engineering, so I'd say typical ones for figuring out BTU's or maybe grains of moisture use a psychometric chart. I use the same equation manipulated a dozen different ways every day. I love going and talking to kids in high school and college and telling them I actually use math on a daily basis.
2014-03-03 11:20 AM
in reply to: jonD81

User image

Pro
5755
50005001001002525
Subject: RE: What's your favorite equation?
2014-03-03 11:27 AM
in reply to: donw

User image

Regular
866
5001001001002525
Central Coast, CA
Subject: RE: What's your favorite equation?

Originally posted by donw

Ideal gas law ... PV=nRT In high school chemistry it blew me away when I learned that the number of molecules was the same for any gas at a given volume, pressure and temperature.

This has stuck with me since high school chemistry since it's silly to "say" as "piv-nert".

2014-03-03 11:37 AM
in reply to: BrianRunsPhilly

User image

Elite
4344
2000200010010010025
Subject: RE: What's your favorite equation?

Originally posted by BrianRunsPhilly

? = :-) (4/3)πtc

explanation found here

I don't know astrophysics and general field theory well enough to get all the jokes but I got a bit of it.  Fun stuff.  It is on Stanfield's official page at SLAC so I would guess it was dated 4/1 of some year.

TW



2014-03-03 1:25 PM
in reply to: tech_geezer

User image

Sensei
Sin City
Subject: RE: What's your favorite equation?

"m v squared over two g" always sounds poetic to me for some reason.

F=G m1m2/r2.

I always liked all formulas for motion/force/energy/friction.  Physics/statics/dynamic stuff.

2014-03-04 7:25 AM
in reply to: Kido

User image

Elite
4344
2000200010010010025
Subject: RE: What's your favorite equation?

Originally posted by Kido

"m v squared over two g" always sounds poetic to me for some reason.

F=G m1m2/r2.

I always liked all formulas for motion/force/energy/friction.  Physics/statics/dynamic stuff.

They have a wonderful symmetry and poetry.  

Under action of a constant force the motion proceeds along a path that increases the distance folded against itself.

To each according to its mass and in inverse measure of its proximity each to the other at the same time.

In Archimedes' and Aristotle's time, equations were written in natural language without symbols of todays expressions.  Algebraic notation was not invented until the late Renaissance. The advance of science was thus aided by the underlying artistry and poetry in the physics.

TW

 

2014-03-04 12:49 PM
in reply to: tech_geezer

User image

Member
432
10010010010025
Calgary, AB
Subject: RE: What's your favorite equation?

Originally posted by tech_geezer

What do you BTers think about one of the equations from the article?

 

ei*pi+1=0

Its got five essential mathematical constants, 0, 1, pi, i, and e; plus it is so improbable.  Sort of cool for that. I am more apt to use the related identity

ei*x=cos x + i*sin x

TW

 

 

I was gonna vote for that one!  (ei*pi+1=0)

Also a fan of infinite equations --     1 + 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + ... = 2.   

2014-03-04 7:40 PM
in reply to: Hoos

User image

Master
2380
2000100100100252525
Beijing
Subject: RE: What's your favorite equation?

Work = Fd

F = ma

a = g (force of gravity)

Work = mgd.

mgd = beer. (miller genuine draft

Work = Beer.

 

 

2014-03-04 8:14 PM
in reply to: tech_geezer

User image

Regular
243
10010025
Subject: RE: What's your favorite equation?
From college: F=ma and you can't push a rope

Used a nice one today: T = F(P/2(pi) + Db * Kf/2cos(angle) +Dn*Kf/2)
- Torque required to load a bolt to a specific force


2014-03-05 6:51 AM
in reply to: scottinPA

User image

Champion
9407
500020002000100100100100
Montague Gold Mines, Nova Scotia
Subject: RE: What's your favorite equation?
Hard to choose but I've always enjoyed the simple elegance and profound implications of:



Shane
2014-03-05 9:14 AM
in reply to: tech_geezer

User image

Veteran
361
1001001002525
Colorful Colorado
Subject: RE: What's your favorite equation?
Definitely the Riemann Zeta function. Its so spooky in its connection to things.
2014-03-05 9:52 AM
in reply to: rockymtnhigh

User image

Deep in the Heart of Texas
Subject: RE: What's your favorite equation?

C6H12O6    ====>   2(CH3CH2OH) + 2(CO2

 

 

2014-03-05 10:05 AM
in reply to: rockymtnhigh

User image

Elite
4344
2000200010010010025
Subject: RE: What's your favorite equation?

Originally posted by rockymtnhigh Definitely the Riemann Zeta function. Its so spooky in its connection to things.

I just used the Riemann Zeta in a derivation to evaluate an infinite series that came up in an equation for bending. I had never heard of it before. Where else does it show up?

TW

2014-03-05 10:09 AM
in reply to: Hook'em

User image

Elite
4344
2000200010010010025
Subject: RE: What's your favorite equation?

Originally posted by Hook'em

C6H12O6    ====>   2(CH3CH2OH) + 2(CO2

 

 

Cheers! (raises glass)

TW



2014-03-05 10:14 AM
in reply to: gsmacleod

User image

Elite
4344
2000200010010010025
Subject: RE: What's your favorite equation?

Originally posted by gsmacleod Hard to choose but I've always enjoyed the simple elegance and profound implications of: Shane

At the speeds I personally go, this one is irrelevant.

2014-03-06 7:17 AM
in reply to: 0

User image

Champion
9407
500020002000100100100100
Montague Gold Mines, Nova Scotia
Subject: RE: What's your favorite equation?
Originally posted by tech_geezer

Originally posted by gsmacleod Hard to choose but I've always enjoyed the simple elegance and profound implications of: Shane

At the speeds I personally go, this one is irrelevant.




More time training, less time posting about favourite equations

That is certainly part of the elegance of the Lorentz factor for me; how something so insignificant at classical speeds can have such profound consequences as one approaches the speed of light.

I've also always enjoyed:



Shane


Edited by gsmacleod 2014-03-06 7:18 AM
2014-03-06 8:29 AM
in reply to: gsmacleod

User image

Elite
4344
2000200010010010025
Subject: RE: What's your favorite equation?

Originally posted by gsmacleod
Originally posted by tech_geezer

Originally posted by gsmacleod Hard to choose but I've always enjoyed the simple elegance and profound implications of: Shane

At the speeds I personally go, this one is irrelevant.

More time training, less time posting about favourite equations That is certainly part of the elegance of the Lorentz factor for me; how something so insignificant at classical speeds can have such profound consequences as one approaches the speed of light. I've also always enjoyed: Shane

What I remember about learning the wave equation was the amazing use of what seemed to be an artificial, purely mathematical construct of imaginary numbers to represent fundamental real physics.  When you think about it, all numbers, math, and formulas are abstractions of the real thing.  That we can make the association between the abstract thing and the real thing is the amazing part.

2014-03-06 9:05 AM
in reply to: tech_geezer

User image

Veteran
361
1001001002525
Colorful Colorado
Subject: RE: What's your favorite equation?
Originally posted by tech_geezer

Originally posted by rockymtnhigh Definitely the Riemann Zeta function. Its so spooky in its connection to things.

I just used the Riemann Zeta in a derivation to evaluate an infinite series that came up in an equation for bending. I had never heard of it before. Where else does it show up?

TW




Its connected to the distribution of Prime numbers -- check out the Riemann Hypothesis: http://en.wikipedia.org/wiki/Riemann_hypothesis

And to quantum physics: http://uclmaths.org/images/a/a8/Laaksonen-qchaos-18Jan.pdf

If you're into that sort of thing, this is a pretty good book:

http://www.amazon.com/Prime-Obsession-Bernhard-Greatest-Mathematics...
2014-03-06 10:15 AM
in reply to: rockymtnhigh

User image

Extreme Veteran
2261
20001001002525
Ridgeland, Mississippi
Subject: RE: What's your favorite equation?

Anybody here deal with sorting algorithms?  Here's a cool video of some sorting algorithms visualized
http://www.youtube.com/watch?v=kPRA0W1kECg

I didn't know about the "Cocktail Shaker sort" until that video, but it definitely seems interesting.



2014-03-06 11:52 AM
in reply to: 0

User image

Melon Presser
52116
50005000500050005000500050005000500050002000100
Subject: RE: What's your favorite equation?

I miss math and science terribly.

The first is a favorite (but not the favorite) because it always got the best of me. I can still write some insane equations from memory (and I, too, took QM and advanced biochemistry), but I was never able to remember that goshdarned junior high level equation! It is very lovely, though.

The second, to me, represents everything that is both challenging and awe-inspiring about (un)reality at the quantum level.



Edited by IndoIronYanti 2014-03-06 11:57 AM




(Equations.jpg)



Attachments
----------------
Equations.jpg (11KB - 10 downloads)
2014-03-06 12:10 PM
in reply to: IndoIronYanti

User image

Extreme Veteran
2261
20001001002525
Ridgeland, Mississippi
Subject: RE: What's your favorite equation?

Eigenvectors always kicked my rear when I took Linear Algebra.  Every time I saw one I thought "well there's -5 for this test...".

 

2014-03-07 8:25 AM
in reply to: IndoIronYanti

User image

Elite
4344
2000200010010010025
Subject: RE: What's your favorite equation?

Originally posted by IndoIronYanti

I miss math and science terribly.

The first is a favorite (but not the favorite) because it always got the best of me. I can still write some insane equations from memory (and I, too, took QM and advanced biochemistry), but I was never able to remember that goshdarned junior high level equation! It is very lovely, though.

The second, to me, represents everything that is both challenging and awe-inspiring about (un)reality at the quantum level.

I'm not certain about that second one.

TW

2014-03-07 8:32 AM
in reply to: 0

User image

Elite
4344
2000200010010010025
Subject: RE: What's your favorite equation?

Originally posted by msteiner

Eigenvectors always kicked my rear when I took Linear Algebra.  Every time I saw one I thought "well there's -5 for this test...".

 

The power of linear algebra is being able to write out systems of equations with algebraic rules that are much like scalar algebra.  The analogy between scalar and matrix math allows problems to be solved by familiar techniques. The difficulty with this particular equation is that it has no counterpart in scalar algebra.  I use this one a lot to get to the connections between states in state space systems.  It is certainly worth the effort to push through on this one and see where it goes in linear system dynamics.  There are many, many analogous equations in functional analysis too.  The level of abstraction just gets deeper. 

TW



Edited by tech_geezer 2014-03-07 8:35 AM
New Thread
Other Resources My Cup of Joe » What's your favorite equation? Rss Feed  
 
 
of 3
 
 
RELATED POSTS

Favorite Physics Equation...

Started by akustix
Views: 1277 Posts: 14

2008-10-03 11:51 AM WaterDog66

What's your favorite workout song? Pages: 1 2

Started by asoul23
Views: 1803 Posts: 48

2008-01-15 9:36 PM TriAya

What's your favorite catch phrase? Pages: 1 2 3

Started by Spokes
Views: 2354 Posts: 70

2007-07-04 9:01 PM drdi

What's your favorite winter sport? Pages: 1 2

Started by AdventureBear
Views: 1193 Posts: 32

2007-02-20 8:42 AM LukeTX04

What's your favorite "new"classic/ cult movie? Pages: 1 2 3 4

Started by gullahcracker
Views: 2853 Posts: 82

2005-12-07 8:20 AM Opus
RELATED ARTICLES
date : March 5, 2009
author : mrakes1
comments : 0
Discussions on an eating plan to lose weight, lean protein sources, being hungry, recovery foods, eggs and Marni's favorite supplements.
 
date : May 6, 2008
author : Amy Kuitse
comments : 0
Discussions on long workout recovery food timing, foot numbness after a run, open water sighting, swim training for a 750m race, favorite wetsuit and the ability to do a half Ironman.