Dark energy gets attention from Nobel Prize in Physics

*picture from NASA

Three American-born physicists won the Nobel Prize in Physics on Tuesday. Thirteen years ago they first made the startling announcement that the universe is expanding at an accelerating rate. They made the discovery by measuring the brightness of type 1a supernovae, explosions of small stars known as white dwarfs that can outshine an entire galaxy and can radiate as much energy as our sun will in its entire lifetime. The measurements showed that the supernovae were dimmer than what was expected, suggesting that galaxies were moving apart at an increasing rate.

At the time scientists were skeptical of the results – the prevailing view was that the universe was slowing down in its expansion. Yet two teams in competition with each other (one led by Saul Perlmutter of the Lawrence Berkeley National Laboratory, and the other headed by Brian Schmidt of the Australian National University in Canberra and Adam Reiss of the Space Telescope Science Institute and Johns Hopkins University) used independent lines of evidence to reach the same results.

The Nobel Prize brings attention to the study of a mysterious component of the universe called dark energy.


What is dark energy?

The simple answer: we don't really know, but physicists believe that dark energy is the “thing” that causes the universe to accelerate in its expansion. It's a little unbelievable that dark energy makes up about 73% of the universe, and yet we know so little about it. There are three properties to note. First, look at the name: dark. It is 'dark' because we don't see it; we do not observe dark energy interacting with matter at all. Second, it is smoothly distributed. The density of dark energy is uniform throughout space. And third, it is persistent. Unlike particles of matter, dark energy doesn't cluster together or dilute away.

The difference between dark energy and dark matter

Dark energy is not the same thing as dark matter. Again, look at the name. Dark energy is energy – it doesn't consist of particles. Dark matter consists of particles of matter. Physicists think it's there but they have yet to directly detect the particles.  However, they have observed gravitational influences (in settings like galaxies, clusters, large-scale structure, and microwave background radiation) that they attribute to clusters of dark matter.

Dark matter makes up about 23% of the universe. Actual matter – the stuff that the Earth is made up of, and the stuff that you and me interact with on a day-to-day basis – makes up less than 5% of the universe. Crazy.

More to come soon...

Depressing study shows people are depressed

Do studies predict the worst? In Nature’s Trend Watch last week the prevalence of obesity in the US and the UK is projected to grow from 32% in 2007-08 to 50% in 2030 for men, and from 35% to 45% for women. One obese person out of three people seems high enough as it is. But one out of two people is just…depressing.

Another study in Nature reports that mental disorders affect over one third of all Europeans. Can they do a follow-up study of how many of those Europeans got anxious or depressed from reading all the other depressing studies out there?

I generally read study results as interesting opinions that could potentially become facts…or not. Just something to think about. But it is irritating when magazines take those studies and tell you to make changes with your life. “Study says chocolate goes straight to your hips. Try eating vegan tofu desserts instead!” And then “Study says chocolate has antioxidants. Go to See’s Candies today!”

I’ll go be happy now and distract myself on Youtube.

Building a toolbox for science and math literacy

I'm very excited: an opinion article I wrote about why we need more exposure early on for science and math education is published in the San Diego Union-Tribune today! The basics:

1) Science and math can be awesome!

2) Learning math is like investing in a good toolbox to build a house.

3) Having a mentor/having a challenge is invaluable.

You can read more about good toolboxes that help our less-than-stellar education system in science and math here:

http://www.signonsandiego.com/news/2011/aug/20/building-a-toolbox-for-science-and-math-literacy/

Palm trees threatened by invasive pest

What do you think of when you picture southern California? The breezy beach, a cloudless, sunny sky…and maybe some palm trees? Okay, how about a lot of palm trees. They are everywhere. 

Let’s hope our palm trees stick around. 

(photo credit: John Kabashima, UC Cooperative Extension)

The red palm weevil, a small beetle-like pest that can quickly kill palm trees, was first discovered in California last year. Weevil larvae burrow deep into the trunks of palms and grind its insides into mush. Adult weevils munch on palms, including the top-most leaves.

You can read more about it in an article I wrote for this month’s issue of CAPCA’s Adviser magazine, “What’s Bugging California’s Palm Trees?” I had the opportunity to interview Mark Hoddle, an entomologist at UC Riverside who researches the red palm weevil and conducts field work to contain the pest. He keeps a well-documented, up-to-date blog here. 

Speculated to have come from Southeast Asia, its invasion now threatens palms in urban areas, native palms in the desert, and California’s date crops and palm nurseries. In May this year, a second weevil species was caught in a trap in San Diego County. Traps are currently set up around the first sighting in Laguna Beach and along the Mexico-CA border (where the second species was found). 

Ever since doing this article I have put on my palm tree glasses. As a southern California native, I am so used to palm trees that they blend into the background. They weren’t so different from any other tree. But knowing that they are iconic to our state, especially for those who come to visit, I can see ‘em now! 

Pale Blue Dot Animations

There is a whole world to explore within a pinhead. Consider that an atom is roughly seven orders of magnitude smaller than a pinhead, something you can still see with the naked eye. If you blew up that pinhead to the size of the earth, you could at last hold an atom in your hand like you would, say, a water balloon.

And then there is Carl Sagan shrinking the massive size of the earth to a pale blue dot.

This "joyful, sad, sweet, and wonderful" animation posted on PBS Nova's blog got me thinking. It captures an excerpt from Carl Sagan's book A Pale Blue Dot.


Pale Blue Dot - Animation from Ehdubya on Vimeo.

Science is a tool that can help us better appreciate the beauty of nature. It doesn't reduce the mystery and art of life by explaining/revealing its underlying mechanisms; rather the opposite, it gives us more perspective.

Taking a walk outside helps me see I'm a tiny creature amidst people, cars, buildings, trees, mountains... I'm still trying to imagine zooming out on me, my city, California, the US, and then the earth until there is nothing but a pale blue dot...

"Surely you're joking, Mr. Feynman!"

Richard Feynman was that rare combination of genius and accessibility to the non-physicist. If there was one thing he was confident in it was sitting down with a seemingly impossible puzzle until he solved it. He also played the bongos, told funny stories, and pulled a great poker face on the (in)appropriate occasion.

If you read any of his stories from the book "Surely You're Joking, Mr. Feynman!", I recommend Safecracker Meets Safecracker. It's a great example of how Feynman rolls, and I cracked a grin (bad pun?) while reading it.

Feynman developed an active observance of social irresponsibility from the great mathematician John Von Neumann, who gave him this advice:

You don't have to be responsible for the world you're in.

Perhaps due to this lack of seriousness, Feynman romps through some entertaining twists and turns in life.

Read The Dignified Professor to find out how the whole business that got him the Nobel Prize "came from piddling with a wobbling plate". Burned out from working on the atomic bomb project during WWII, he felt an unusual twinge of disgust for physics in his new life as a young college professor. He asked himself why he had once enjoyed doing physics and realized it was because he used to do whatever he felt like doing - i.e. play with it.

An example of Feynman's idea of play: figuring out how to determine the curve for water running out of a faucet.

So when he was at the cafeteria he saw a guy throw a plate in the air and noticed the plate wobbled. For fun he set out to determine the motion of the plate wobbles. "It was effortless. It was easy to play with these things. It was like uncorking a bottle: Everything flowed out effortlessly. I almost tried to resist it!"

Maybe a little more effortless for him than for the average person, but he set out to actively play just like anyone might. In science I see this sense of play slip through fingers like sand (I include my own undergraduate experiences here). It gets replaced with talk of "the future of science and the betterment of society", or maybe just getting a good grade.

At any rate Feynman's stories are a good read and he packs a joy for physics into them. 

Why promote science fairs

This week the LA Convention Center was filled with poster boards and precocious students for the Intel International Science and Engineering Fair. The biggest science fair in the world attracts more than 1,500 participants from 65 countries. This year’s $75,000 grand prize went to Matthew Fedderson and Blake Marggraff of Lafayette, California for their research on treating simulated cancer cells with Compton-scattered secondary radiation. Nothing less than professional-level science projects (albeit with the help of a scientist mentor in most cases) can be expected from ISEF.

I participated in the fair for a day as a volunteer interpreter and was able to meet some of the Japanese students. They qualified by winning national-level high school science fairs in Japan – impressive students on paper and in person.

In science fairs the first hurdle is to come up with a good question. You can’t just ask a big question like, “How can I cure cancer?” The best questions come from a simple observation in your surroundings. The next hurdle is to design a clean, simple experiment to test your hypothesis.

I helped out with a student who experimented with liquid nitrogen. While playing with liquid nitrogen he noticed that some materials boil within the nitrogen, calm down, and then re-boil. He asked, “Why does re-boiling occur?” He observed a simple mechanism and being curious, wondered how it works. After testing re-boiling for many materials he found that re-boiling occurred the most for materials with high thermal conductivity.

With the help of a high-speed camera he also discovered that a film of bubbles collects on the material before it re-boils. He then tested whether the film of bubbles causes re-boiling by breaking the film with a heating wire. That’s the part of the experiment that I really like – he found a way to disrupt the film of bubbles and observe what happens in its absence. It’s a well-designed experiment. He found that when he applied more current to the heating wire, the material finished reboiling faster. The conclusion: cooling can be accelerated if the film of bubbles is broken by non-uniform heating.

The schedule for the students is pretty grueling. They are at the convention center from 7am to 6pm, where they present their experiment to judges in English, a second language for them. One of the people from the Japanese team remarked that these students can present their science projects better in English than they can do small talk in English. Ask them how surface area affects reboiling in liquid nitrogen and they’ll answer straight away. But as a judge if you try to break the ice with, “Have you visited Disneyland yet?” they get a little thrown off.

I was very happy to meet these students. They were mature and at the top of their game. One of them gave me a Japanese fan, too! There was a clip from NPR that pointed out that kids (especially those at this science fair) can contribute to science and offer something different. Where an older, trained scientist may think that something will never work, a kid might look at something in a new way. She might ask, “Why not?”