Today Is ENIAC Day...Celebrate w/ a Ridge....(long/historical/boring)

Posted by: TomHill

Today Is ENIAC Day...Celebrate w/ a Ridge....(long/historical/boring) - 03-15-2019 07:59:54

Today is ENIAC (Electronic Numerical Integrator and Computer) Day, celebrating the dedication of this first computer at the Moore School of Engineering/Univ of Pennsylvania on March 15, 1946.
Johnny von Neumann was a celebrated Princeton mathematician that was heavily involved in the Manhattan Project during the War yrs. When he heard about development of the ENIAC at Moore, he instantly recognized its value to calculations for the design of a ThermoNuclear weapon. Though the ENIAC was designed to calculate firing tables for artillery shells for the USArmy, its actual first use was in the design of the Hydrogen bomb by LosAlamos scientists.
Johnny left Moore School and went to the IAS (Institute of Advanced Study) at Princeton to pursue his work on stored program computers. There, he planned to develop a machine (later called the JONIAC) based on his seminal ideas of stored program computing.
The original ENIAC was programmed by plugboard wiring. It would take several weeks of connecting wires into these plugboards to program a calculation. A little known fact is that all of these original programming was done by...women. The physicists & engineers considered it below their pay grade to actually do the programming of ENIAC. LosAlamos eventually, in the early '50's, developed their own version of the ENIAC, which Nick Metropolis labeled the MANIAC.

After serving in the War as a radar technician, Hewitt Crane went to work for IBM ('49-'52) as a computer maintenance technician. In 1952,he was tapped by von Neumann to come to the IAS. Johnny realized that to build his machine, his soldering skills were not up to the task and he needed someone good with a soldering iron (iron...not soldering gun). Hence HewCrane entered the scene. However, the hiring by Johnny at the IAS of a mere...pffffttt (in my finest Bill the Cat accent)...technician was thought to degrade the lofty principals upon which the IAS was founded. The physicists & mathematicians (including Albert Einstein and the renowned Kurt Godel) were up in arms over the hiring of Hew onto the IAS staff. Fortunately, their objections were overruled by the director of IAS, J.Robert Oppenheimer ("Oppie"), who had been the scientific director of the Manhattan Project during the war.

OK..we're getting there. After his stint at IAS, Hew then went to Calif to work for SRI (Stanford Research Institute), where he made many noteworthy contributions, including the electronic transmission of check images. In the late '50, Hew and other SRI scientists (Dave Bennion, Norm Rosen, Howard Ziedler) purchased an abandoned property high above PaloAlto on MonteBello Ridge, which had vnyds and a defunct winery. And, of course, the rest is history.

So to celebrate ENIAC Day, it is appropriate to hoist a glass of Ridge MonteBello or JimsomareZin to the memory of Hew and all these other early computer pioneers. Realizing, of course, your iPhone has within your hand the computing power that would dwarf that of the ENIAC.

Posted by: BEB

Re: Today Is ENIAC Day...Celebrate w/ a Ridge....(long/historical/boring) - 03-17-2019 05:49:57

This is fascinating! Thanks for posting, Tom.
Posted by: TomHill

So... - 03-18-2019 10:37:50

So....some of the best minds in Science (or as we call it at LosAlamos...SCIENCE) frittered away almost an hour of time this morning working this problem.

Most of them were unaware that Fri was ENIAC Day. Just no sense of history, I guess.

The ENIAC was developed for/funded by the USArmy to calculate artillery firing tables. I got to thinking about this problem this weekend & it was driving me crazy. Why would you need the ENIAC for such a simple calculation??

You are given a (presumably non-moving, a moving target would complicate the problem..but only slightly) target X miles away. You have an artillery shell that weighs W pounds. You load the cannon (not the Pacabel one, though) with enough HE (High Explosive) to put J joules of energy into the shell. What angle A do you aim your cannon to hit the target X miles away??

If you assume a point artillery shell (like we sometimes assume a spherical cow for certain purposes), the arc will describe a parabola under the Earth's gravitational field. That trajectory requires only the mere solution of a quadratic equation that you can do with a slide rule (Post or K&E are the slide rules of choice). Why would you need an ENIAC for a back-of-the-envelope calculation??

However, an artillery shell is not a point. It is a projectile that has a volume and, therefore, there is air-resistance during its flight to include in the calculation. There is also the air temperature/density that affects the air resistance, so the coefficient of friction varies. To correctly do this calculation of angle A requires the solution of a differential equation. Usually a Runge-Kutta numerical solution of this time-dependent differential equation. Hence, the need for the ENIAC. Since artillery commanders are not skilled in solutions of differential equations and have no ENIAC at their side, they need a set of tables to determine the firing angle A. So this was what the ENIAC was designed to provide the USArmy.

This group of high-level scientific types decided that in less than an hour, we could write an iPhone app that would do this calculation for these artillery commanders and free them from hauling those ENIAC-generated tables around with them out in the field. We plan to sell it for big $$'s to the USArmy.

And you all thought we had bigger problems to solve at LosAlamos!!

Posted by: R. Schiffman

Re: So... - 03-18-2019 14:26:47

Thanks for this. Very interesting.
Posted by: Paul Nelson

An alternative application - 03-18-2019 21:11:53

Very interesting historical read on the ENIAC.

As for your app idea. Would the same principles of artillary would also apply to golf?
You might find a golfing app more profitable. On the other hand, the military does like to spend a lot of money on specialized equipment. Best of luck! Haha.

Posted by: Bryan Gros

Re: So... - 05-28-2019 22:12:19

Wow. Runge-Kutta. There's a blast from the past!