Why do they call it a "minute of angle"?

[Ramone]

The thing I found interesting when I learned about this is that ' Minute of Arc' predates minute as a measure of time...

When clock makers added a hand to clocks to sub divide hours, they divided the clock face by 60, which naturally lead to calling these divisions " minutes ", and when they divided that further, " seconds " were the obvious choice.

Some great reading about clocks, clock making, and it's critical role in navigation:
https://www.amazon.com/Illustrated-...UTF8&qid=1481637097&sr=1-3&keywords=Longitude

 

[Ramone]

Aside from the history of math and UOMs ....
who has a good method to memorize and apply ballistic correction and/or range estimation on the fly.
I am talking simple enough w/o a calculator or cheat card. Please share it.
Or perhaps this belongs on a different thread. ??

No one, really. My best method is to develop a really good dope card, and memorize the 'breaks' in come ups vs range for that particular rifle with that specific cartridge.

 

[1stmarine]

No one, really. My best method is to develop a really good dope card, and memorize the 'breaks' in come ups vs range for that particular rifle with that specific cartridge.

That is a pretty common and efficient way to manage it.
Drop is always the easiest one as gravity doesn't change but wind is more involved when we define a method that works in both axis.
I am curious about what simplified formulas and methods people use including w/o the need to memorize long tables.
This will never replace the math and/or computer but the idea is that it should get you on the target or close to it quickly.

 

[JohnKSa]

,

Bigger stuff and stopping rifles, it matters how the bullet handles bone and thick hide.

One assumes that "bigger stuff and stopping rifles" implies the bullets will be solids in which case expansion is meaningless. Penetration figures are still valuable. Not because they necessarily replicate the performance against heavy bones and thick hides but because they allow the comparison of one cartridge to another. Assuming that the bullets don't deform/expand/fail and when discussing bullets in the very large dangerous game category, the one that penetrates the farthest in gel should still penetrate the farthest through heavy bone and hide. In other words, even if the gel figure isn't representative, the RELATIVE performance in gel should still be informative.

When clock makers added a hand to clocks to sub divide hours, they divided the clock face by 60, which naturally lead to calling these divisions " minutes ", and when they divided that further, " seconds " were the obvious choice.

Interesting bit of trivia. The first clocks had only hour hands. When clocks with minute hands became available, the minute hand was, at least at first, commonly called the second hand since it was not the first hand.