Comic Info:

My company does a fair bit of R and D and it's really fun. It's amazing how much work can go into answering a simple question... and sometimes the best answer you can come up with is "maybe...?"



Sidhekin's picture

Sorry, was the "definitely less than eight" intentional?

Unless we're talking fractional tubes (whoah!), "seven" would do. Unless, unless he meant "definitely no more than eight"?

(What, you thought I was going to complain about "less" vs "fewer"?)

fues's picture

But it might be six!

Sidhekin's picture

Worst case might be six? Why bring in eight, then?

Rashkavar's picture

Adds a 1.3 Factor of Safety. Depends on how critical the function of the device is. If it's very critical, I'd go with 9 or 10 tubes (3x3 array or 2x5), since that bumps things up a bit more. Less critical, 7 (packs nicely in a hex-pack) since you're not risking as much by pushing down the FS.

If it breaking means people die, more like 20 or so. Or you can go with the Brooklyn Bridge's factor of safety and use 36 tubes, if you're designing it for use by the public for a hundred plus years.

Kiptoke's picture

The answer was apparently so interesting, or took so long, that literally half the people changed shirt colors.

Pierre Lebeaupin's picture
Pierre Lebeaupin

Funny; reminded me of this story, where Richard Feynman, working on the Connection Machine, determined the optimal number of buffers to use in routing would be 5, but using differential equations. His analysis was distrusted and they attempted to go with 7 as suggested by a more conventional (for computer architecture), discrete analysis, but the chips with 7 buffers turned out to be too big to manufacture efficiently (for reasons presumably unrelated to either analysis), so they thought they'd rely on Feynman's work and reduced the number of buffers to 5, and the computer working with the chips such manufactured turned out to work OK.

Rashkavar's picture

In honor of this event, the US government even created a new agency, the ATF - Always Trust Feynman.

The organization you normally think of as the ATF is actually the BATFE. They just shorten the acronym because the US believes in the Rule of Three, as noted by its obsession with 3 letter acronyms for agencies. (CIA, NSA, FBI, ATF,...)

(In case text strips the humor from this, the only true statement here is that the proper acronym for the ATF should be the BATFE - Bureau of Alcohol, Tobacco, Firearms and Explosives....or for something more pronouncable, the Boat-fae)

sleadley's picture

Given time, engineers can do quantified qualification really well. If you don't have time to do it right, give the favorite SWAG of a friend of mine, "X, plus or minus 2 dB." (Caveat emptor, only attempt this with quantities that don't normally scale exponentially.)

Jam's picture

Books and Cons oh MY

HEY EVERYONE did you hear that I'm still alive somehow!? I have a new book! You can get it!

I'm customizing orders RIGHT NOW, every waking moment when I'm not attending thousands of conventions or working that full time job thing that I do. I was already at Emerald and FanExpo before I even had time to think about making this blog.  Next you will find me at:

Calgary Expo: Apr 25-27 (not the Thursday)

TCAF (Toronto): May 10-11

VANCAF (Vancouver): May 25-26

These events will be phenominal!! The last ones are FREE to attend! COME SAY HI :D

"But Jam will you be at _____??" I don't know! Probably not, nothing else for the year is planned or confirmed. I might throw something onto the list for fall but definitely not for summer. ALRIGHT, that's all, I have to get back to everything SEE YOU SOON!

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