Fun Science-y Ideas 5

[kacarrol]

I was going to resurrect this thread: thread730-288029 but it was closed to comments. I just wanted to add one more idea that I stumbled across the other day: calculating Pi by throwing frozen hotdogs (because, frankly, who doesn't want to throw hot dogs, pun intended!).

http://www.wikihow.com/Calculate-Pi-by-Throwing-Frozen-Hot-Dogs

Regards,
K

 

[JohnRBaker]

Sounds like something Enrico Fermi would have come up with as he was famous for being able to quickly devise ways to measure things using everyday objects. For example, just before the first test of the atomic bomb in New Mexico in 1945 Oppenheimer wanted to get a quick estimate of the strength of the blast and didn't want to wait for the hours or even days that it might take using the data that was going to be collected by the various instruments surrounding the blast area. So it's reported that Fermi took a bunch of pieces of wood of different sizes and set up a row of them sticking out of the ground near the bunker but in clear view of the blast site and based on which ones were knocked over versus which ones were not, he was able to calculate the energy released to within something like 10% of the actual number, which was good enough for Oppenheimer.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[kacarrol]

John,

Actually I was just about to put up another post here, and included in that list is "Fermi Questions".

Without further ado, see this website for a whole list of activities:

http://www.physics.uwo.ca/science_olympics/events/index.html

K

 

[JohnRBaker]

It's sad, but since the advent of the handheld calculator and the demise of slide rules, at least in my opinion, engineers have begun to lose the ability to quickly estimate results. After all, when using a slide rule we had to at least know where in the order-of-magnitude was the answer going to fall otherwise we wouldn't know where to place the decimal point.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[jgailla]

John,
I'm young enough to have never used a slide rule in anger. All hand held calculators in college. I expect myself and engineers under me (and over me) to know when something is off by an order of magnitude.

 

[JohnRBaker]

One can only hope

BTW, if you ever feel you'd like to learn how to use a slide rule but you either won't or can't find a place to buy one, they now have cell-phone app's for that. On my iPhone I have the 'Virtual Slide Rule' app from Gushiku Studios LLC. And if your skills are a bit rusty, they even include tutorials showing you how to use a slide rule.

Or you could just go online:

http://www.antiquark.com/sliderule/sim/virtual-slide-rule.html

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[MintJulep]

Fermi Estimation:

https://what-if.xkcd.com/84/

 

[kacarrol]

Star to both MintJulep (I love xkcd but haven't kept on top of reading it) and JohnRBaker (I have always wanted to learn to use a slide rule!).

I've also never used a slide rule (obviously, from my first sentence) but I've had no issues with estimating orders of magnitude. I know this "skill" was covered in several grade school topics, and sure came in handy when writing exams! Of course it's handy for on the job too.

 

[moltenmetal]

xkcd rocks! That was very entertaining. Order or half-order of magnitude estimates are a wonderful and regrettably, terribly underused tool. David Mackay makes good use of them in his book "Renewable Energy- Without the Hot Air". Bill Banholzer's paper that I've linked to on other threads is also a good user of this sort of screening analysis to sort out the fundamental feasibility of marketing/tech development claims made to investors.