Bus Bomb diagram

[Wrench Profile]

Zaba - thank you, I was right! I think your educated husband was too - there is a distinction between the arrows directing attention to the items, and the one showing the direction of rotation.

Meaning the rotational arrow has a tail on it because it has no "starting point" like the others?

[duckking2001 Profile]

::puts on skeptics hat::

How unique are these symbols and terms? Could it just be a case of engineers seeing engineering stuff because that's how they look at things? In other words are they specifically engineering symbols and terms, or more general impressions that engineers might say could be applied?

[traveller1st Profile]

I'm not buying the idea that that's a skeptic's hat.

[smithy Profile]

Meaning the rotational arrow has a tail on it because it has no "starting point" like the others?

Yes, I think so mate.

Duckky, I agree with Trav, I think that's an Engineers hat not a skeptics one!

In respect to your "colored by a viewpoint" question though, which is a good one, I think using the dot-dash lines to show a centre line is an (engineering) drawing convention used most in orthographic (or multiple view) renderings everywhere, undoubtedly.
And it's not applied correctly by Z., here, but does imply he'd had some training in technical drawing at some point.
I think that's about it.
Was it commonly taught in U.S. High Schools of the period?
While I'm hijacking and generally messing up this thread, I wasn't taught about Radians at school and I wonder if you were, Trav. (Asked for Wrench's benefit!)

[traveller1st Profile]

Nope I wasn't. Although that doesn't mean it wasn't taught, just not at me. There was advanced maths, which I didn't take and or wasn't good enough for so it may have been part of that. Don't know.

[Wrench Profile]

I took quite a bit of math: geometry, calculus, trig, algebra... All forgotten now, best I can do is figure out the tip. Radians sounds vaguely familiar. And that's another point to ponder, would a 40 year old Z who learned this stuff in his teens still remember it and use it 20+ years later without being in a related field of work at some point?

I don't ever recall learning the segmented center line and other drawing related things we've discussed. If it was a general education subject I must have been sick that week.

[duckking2001 Profile]

Note to forum Admins: Need more hats.

The thing that I never bought about the "Radian Theory" was that even though you and I may never have heard of one before, there really isn't anything to show that Z knew anything about mathematics. He just said the word "radian".

I'd say that it's not at all beyond the realm of possibility that he could have heard the word and found out what it meant and knew less about it than anyone on here who wouldn't have known about if it wasn't for Zodiac.

But anyway...

I think we've established with a good deal of probability that Z had some technical knowledge beyond what could be called general information. The question is whether this is specific enough to narrow it down to one field that really tells us something about the guy.

[Wrench Profile]

To be considered in the mix is the very use of Mt. Diablo in the bus bomb plot, it being an "Initial Point" used in surveying.

http://www.mdshs.org/

Also something I never knew despite being a Bay Area native. It's possible he conjured all this up from layman's knowledge, the use of Mt. Diablo, magnetic north, radians etc. as part of his 'where's the bomb' game, but I think these drawing items help support the idea he may indeed have been in some related field.

But would Z slip up, not knowing this would be suspected?

[traveller1st Profile]

Here is a page from Videocity magazine. Morf discovered this researching the equinox letter. I found this page trawling through the PDF archives for the mag and noted some zync in it. Most notable the use of the word radian.

VOLUME1NR4_0067.jpg [ 220.06 KiB | Viewed 296 times ]

Here's the link to the mag's archive page. This article was actually part of a Callifornia submissions section in the issue it appeared in.

http://www.radicalsoftware.org/e/browse.html

[Zabagliona Profile]

...Mechanical drawing was a common elective in US high schools in the 1950's and 1960's...His HS math would have likely involved the use of radiansat some point....He also could have used/learned these things in the military....