# Tag Info

4

The software part is easy: it uses standard ASCII characters so the source code can be universally applied. "Engineering Logic" has its own variations,but notice that "addition" is similar to "OR" and "multiplication" is similar to "AND" when dealing with base-2 numbers -- and that Boolean logic is ...

1

A reference to deep pre-history and quaternions is interesting but it can be very misleading to imply the present tense. Quaternions are not used in anything remotely contemporary - math or physics. They have some residual use in game development but much more in pseudo-theoretic quibbles (to claim that Cartesian coordinates have intrinsic problems - ...

16

This usage of $\mathbf i$, $\mathbf j$, and $\mathbf k$ is not specific to physics. It is also used in mathematics, specifically when teaching linear algebra or multivariable calculus in $\mathbf R^3$ as well as group theory for the quaternion group $Q_8 = \{\pm 1, \pm i, \pm j, \pm k\}$. The notation came from the use of the letters $i$, $j$, and $k$ in ...

3

I was one of those secretaries that knew how to use those beasts. In fact, I used a manual typewriter (not a Selectric) to type these formulas for the 30 chemists I worked for at General Tire in the U.S. Our typewriters were outfitted with a holder. I had boxes of individual keys for each of those Greek letters, etc. To create the formula, I picked out ...

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