[LEAPSECS] props for talks?

[Rob Seaman]

Eric Fort wrote:


> Somewhat depends upon the intended audience


Undergraduate physics/astronomy students.


> but the following items come to mind


Great list!  Thanks.


> and I'll finish with 2 references from which to pick more.


I don't think I saw these.  Would welcome references of all sorts!


> The props chosen might also depend somewhat at to what "the presented philosophy of what time is" is.


I doubt I need to belabor my philosophy here :-)  Abstract is:

	http://astro4.ast.villanova.edu/aprsa/?q=node/38

Will talk about the meaning of the word "synodic".  Also issues from the 2nd edition of Dave Mills' book, "Computer Network Time Synchronization: The Network Time Protocol on Earth and in Space", e.g., http://www.eecis.udel.edu/~mills/ipin.html


> Various calendars (Myan, Hebrew, Julian, Gregorian, etc. illustrating their significance


Does anybody know of a web page or app that compares several calendars?  Perhaps some sort of game/puzzle?


> Telescope/transit/sextant - translate where you are to when it is.


The department has a Wild T-4 theodolite.  As an aside, when I visited Danny Hillis at Applied Minds, a Wild T-4 was the first thing I saw upon walking into his office.  I may have been his first visitor to exclaim, "I've used one of those!"


> marine chronometer


This was my alma mater and we learned about Harrison's clocks in our history of astronomy course.  I have no idea what they teach them these days :-)

Tony Finch wrote:


> And you should mention Noether's Theorem, which says that conservation of momentum and energy are a consequence of this invariant.


Sean Carroll was a student a few years after I graduated.  I think I'll refrain from poaching on his philosophy :-)

Poul-Henning Kamp wrote:


> Next pull out your HP5370B, tell them what it does, show them how to read the display, demonstrate it with two switches which you press in rapid order.  Attach two scope-probes, measure the speed of light along a foot

> of the wire.

>    ...

> The reason this is such a dramatic demonstration, is that people hear about speed of light only in context of imense distances: plants, spaceships or fibre-optics around the globe.


Excellent idea!  This is surely possible locally and I'll see about borrowing the setup if I give the talk again.  Light-time corrections are bread-and-butter for the variable star work they do at Villanova, but I'm not eager to carry electronics on the airplane.

Rob