Today, October 15th, is Ada Lovelace Day. Since 2009, it is a day set aside to learn about the many women in STEM disciplines who don't get the credit they deserve for their pioneering work in the fields of science, technology, engineering, and mathematics. The day is named for Augusta Ada King, Countess of Lovelace, who was a brilliant mathematician and wrote the world's first computer program. In 1842.

Neatorama has published quite a few articles over the years about women in science and technology. In honor of the occasion, feel free to catch up on them.

The Amazing Dr. Florence Baker dedicated her life to the health of poor people.

Josephine Cochrane developed the modern dishwasher.

A Short History of Women Inventors and Scientists.

An Ode to Great Double X-Chromosomed Scientists.

Women in Space: The Mercury 13.

Florence Nightingale’s Statistical Diagrams.

The Finkbeiner Test

The Ada Lovelace Day site has a map on which you can find further articles posted specifically for Ada Lovelace Day.

The memory of some system wit hysteresis implies some change of internal state and is not at issue with the kind of time invariance Noether's law refers to. Unless you use rules/laws that abstract away that internal state to get a description of what is going on, then you end up with a system that might not conserve energy (via exchanging it with whatever you abstracted away). Otherwise, "repeat an experiment at a different time" implies setting up everything the same, including the same starting point in whatever hysteresis effect you are dealing with.
Abusive comment hidden. (Show it anyway.)
I didn't have a chance to read the wikipedia article beyond seeing it had an introduction section. Her theorem basically amounts to there being an equivalence between certain kinds of symmetries in laws of physics and laws that state something is conserved. For example, the idea that an experiment should act the same anywhere if you recreate the same conditions, i.e. just moving everything from empty point A to empty point B, mathematically implies that momentum is conserved. Rotational symmetry, that turning things to point in a different direction doesn't change things, implies conservation of angular momentum, and being able to repeat an experiment at a different time implies conservation of energy. As long as some really basic laws of physics (basically an extension of Newton's laws) are true, then conservation of energy and the time symmetry will always be a pair, with violation of the former implying violation of the latter.
Abusive comment hidden. (Show it anyway.)
You're right: I'm confused forwards and backwards.
Abusive comment hidden. (Show it anyway.)
In my opinion, one of the deepest and most elegant theorems in physics (and potentially difficult to explain) is Noether's theorem, developed my Emmy Noether, who also made quite a few other contributions to mathematics. Although she seems to rarely come up in textbooks, as with such works named using surnames, most people wouldn't notice her first name unless they saw a footnote or an article with more emphasis on history.
Abusive comment hidden. (Show it anyway.)

Email This Post to a Friend

Separate multiple emails with a comma. Limit 5.

Success! Your email has been sent!

close window
X