A tribute to a great African-American planetary scientist

[ This blog is dedicated to tracking my most recent publications. Subscribe to the feed to keep up with all the science stories I write! ]

Meet Claudia Alexander, NASA Badass Who Never Got Her Due

In a field dominated by white men, Claudia Alexander was a pioneer

For The Daily Beast:

Comet 67P/Churyumov—Gerasimenko is a tiny world of ice and rock, just 5 kilometers long. The comet is shaped vaguely like a rubber duck, with steep cliffs and other prominent features that stand much taller in relation to the size of the world. One of remarkable features is a twin set of sharp “horns” on the head of the rubber duck, known now as C. Alexander Gate.

Claudia Alexander served as project scientist for the Rosetta mission, which is orbiting Comet 67P. Until her death in July, she helped lead the United States side of the project, coordinating the various scientific and engineering aspects of the mission. Last week, her colleagues named the C. Alexander Gate in her honor and memory, with her European Space Agency counterpart Matt Taylor making the announcement.

Alexander is the first, and so far only, African-American woman to achieve such a prestigious position on a space mission, and she did it twice: once for the Galileo spacecraft to Jupiter and again for the Rosetta probe to Comet 67P. In fact, she was also the youngest ever appointed when she was picked at age 40 to be the final project scientist for the Galileo mission in 2000. [Read the rest at The Daily Beast….]

Advertisements

Emmy Noether and her wonderful theorem

[ This blog is dedicated to tracking my most recent publications. Subscribe to the feed to keep up with all the science stories I write! ]

Mathematician to know: Emmy Noether

Noether’s theorem is a thread woven into the fabric of the science

For Symmetry Magazine:

We are able to understand the world because it is predictable. If we drop a rubber ball, it falls down rather than flying up. But more specifically: if we drop the same ball from the same height over and over again, we know it will hit the ground with the same speed every time (within vagaries of air currents). That repeatability is a huge part of what makes physics effective.

The repeatability of the ball experiment is an example of what physicists call “the law of conservation of energy.” An equivalent way to put it is to say the force of gravity doesn’t change in strength from moment to moment.

The connection between those ways of thinking is a simple example of a deep principle called Noether’s theorem: Wherever a symmetry of nature exists, there is a conservation law attached to it, and vice versa. The theorem is named for arguably the greatest 20th century mathematician: Emmy Noether.

So who was the mathematician behind Noether’s theorem? [Read the rest at Symmetry…]

Of symmetries, the strong force and Helen Quinn

[ I am reviving the Bowler Hat Science blog as a quick way to link all my new publications. Subscribe to the feed to keep up with all my stories! ]

Of symmetries, the strong force and Helen Quinn

From Symmetry:

Modern theoretical physicists spend much of their time examining the symmetries governing particles and their interactions. Researchers describe these principles mathematically and test them with sophisticated experiments, leading to profound insights about how the universe works.

For example, understanding symmetries in nature allowed physicists to predict the flow of electricity through materials and the shape of protons. Spotting imperfect symmetries led to the discovery of the Higgs boson.

One researcher who has used an understanding of symmetry in nature to make great strides in theoretical physics is Helen Quinn. Over the course of her career, she has helped shape the modern Standard Model of particles and interactions— and outlined some of its limitations. With various collaborators, she has worked to establish the deep mathematical connection between the fundamental forces of nature, pondered solutions to the mysterious asymmetry between matter and antimatter in the cosmos and helped describe properties of the particle known as the charm quark before it was discovered experimentally. [Read more at Symmetry…]

(Since my weekly round-up experiment seems to have failed horribly, I’m going to try to go back to linking and summarizing individual articles I’ve written around the web on this blog. We’ll see if I keep it up!)

The great physicist Chien-Shiung Wu in 1958. [Credit: Smithsonian Institution]

The great physicist Chien-Shiung Wu in 1958. [Credit: Smithsonian Institution]

Chien-Shiung Wu is one of those physicists that everyone should know about, but not enough do. A veteran of the Manhattan Project, she went on to become the world’s expert on beta decay: the process by which an atomic nucleus changes into another element, emitting an electron (or positron) in the process. In the 1950s, she realized beta decay would be a way to test a fascinating new theory of the weak force, which predicted that there should be a fundamental asymmetry between processes occurring in different directions. Her experiment was the first observation of parity violation, which opened up a wealth of new results, leading ultimately to the discovery of the Higgs boson.

For Double X Science, I commemorated this discovery, explaining why it’s important and how weird it is. It would seem that the laws of physics shouldn’t depend on which direction a process occurs, yet that’s the way the Universe works!

Wu realized she could test this idea in the lab after discussions with her colleagues Tsung-Dao Lee and Chen-Ning Yang, who laid the theoretical groundwork for understanding the weak force. She recruited Henry Boorse, Mark Zemansky, and Ernest Ambler, who were skilled at experiments at very low temperatures. It’s a great illustration of the collaborative nature of science: Lee and Yang provided theoretical knowledge, but needed Wu to design and perform the experiment; Wu in her turn brought in experts in low-temperature physics to provide expertise in an area unfamiliar to her. (On a more sour note, Lee and Yang won the Nobel Prize for the discovery of parity violation, but Wu and her fellow lab workers were passed over.) [Read more…]

Madame Wu and the backward Universe

Double X Science chemistry editor Adrienne Roehrich started a new podcast series, discussing stories of the week. Her first cohost was…me! We talked about important women in biochemistry, the size of protons, the science of procrastination, and cosmic rays—all in 15 minutes.

You can download the podcast from the Double X site, or subscribe through Feedburner. Adrienne is also working on listing our content on iTunes; I’ll update when that happens. Update: the podcast is now available on iTunes!

Procrastination and protons

Ada Lovelace, 1815-1852 [Credit: Wikipedia]

For Ada Lovelace Day, I compiled a list of many of the best science writers I know:

Last year, I celebrated Emmy Noether, perhaps the greatest mathematician of the 20th century. This year (largely because I’m swamped with other work), I’m stealing a great idea from Ed Yong, and celebrating living writers who are my friends, colleagues, and influences. This list is in no particular order, isn’t anywhere close to complete, and has some overlap with Ed’s list. My main criteria are that these are writers I read regularly, so their interests mix with mine to some degree. (Writers marked with an asterisk* are people I have met in Real Life, whatever that signifies.) Leave your own favorites and influences in the comments! [Read more….]

Happy Ada Lovelace Day!