As you know I have a Science in the News section to each day’s talk in my University of Tampa Physics 125 class. Last week and next, my students are studying “The Universe”, and I have been telling them about the Cosmic Distance Ladder. This is an overlapping sequence of methods that astronomers use to measure the literally astronomical distances necessary to understand the universe.
I find it easy to locate major news stories, either from the world of science or from current events, that connect to each lecture. In this post, I’m pasting in two of my view graphs for next Monday’s and Tuesday’s sections: Science in the News: Women in Science.
For a new post, here are two slides from my Science in the News for Physics 125.
Take a look at the first PowerPoint slide below.
The left-most curve shows the brightness variation of a certain type of variable star. You can see that it gets brighter and dimmer and brighter again with a period of a few days. It turns out that if you had a bunch of these variable stars at the same distance you’d observe that the brighter the star, the longer it takes to brighten and dim and brighten again. Thus, if you see one of these stars, and you measure how long it takes to brighten and dim, you can estimate how far away it is by comparing its brightness, as you see it, with what you know is the actual brightness, if it were to be at that “all at the same distance.”
Henrietta Swan Leavitt discovered this relationship, the right-most curve, about a hundred years ago, while she worked as an “astronomical computer” at the Harvard Observatory. You can read about these women, the “computers”, in the second item linked below. It’s an interesting account.
This particular discovery of hers was the key to Edwin Hubble’s proof that the Andromeda Galaxy was 2 ½ million light years away, outside of the Milky Way, and that was key to his discovery of the expansion of the Universe.
Henrietta Leavitt’s boss, astronomer William Henry Pickering, had an unusually broad-minded and enlightened attitude toward scientific women, but she was doing her work in Boston at the same time as Emmy Noether could not get a regular academic appointment at Gottingen, even though the famous David Hilbert tried to get one for her.
In the second slide, after the link to the article about the “computers”, is a link to a worthwhile interview with Prof. C. Megan Urry, newly appointed the Chair of the Physics Department at MIT. She is an important researcher in the science of black holes. Read about the difficulties she faced during her career because she is a woman.
Here’s the link to the first article: Astronomical “computers”.
Here’s the link to the second article: Interview with Urry .
Here’s a picture of Henrietta Leavitt, which I copied from the Wikipedia article about her. She died at 53, and while Pickering, her director, credited her work in published papers, she did not receive the renown due her until after her death.