Ocean Waves

Waves are everywhere! They come in many different mediums and on different scales: electromagnetic waves (radio waves, visible light, Xrays), sound waves, vibrations on a guitar string and – ocean waves!

I’ve been thinking about ocean waves after I started taking a surfing class. So far, thinking about the physics of surfing has been much more pleasant than thinking about its dangers, like stepping on a sting-ray, getting hit by a surfboard, or getting pulled out to see by a rip current and drowning. These things scare me. I like to think that being scared of everything is just the tradeoff for having a vivid imagination, but anyways, I digress.

How do ocean waves work? To start a wave you need an initial energy source, and for the ocean that is the wind. A wind that blows in the same direction over a long distance at high speed can generate massive waves. The wind pulls against the surface of the water and transfers energy that builds up into waves.

They travel across the ocean and break where the ocean floor rises towards the shore. The rising ocean floor will slow down the water moving beneath the wave due to friction. The top of the wave will not slow down as much because it doesn’t come into direct contact with the ocean floor. The result is that the top of the wave travels faster than the water moving beneath it, causing the wave to rise up and curl forward. Eventually the wave becomes unstable and breaks on the shore.

*one step above a napkin doodle

This is the area where the wave smashes into you in sprays of salty sea water unless you jump the wave or ride over it on your surfboard. If you are like me this is also the area where you get stuck when you see a big wave rolling towards you and think, "I don't need to go out any further."

Actually catching a wave is much more fun than trying to get over them unscathed. They tell me that in order to do that, you have to paddle a lot! You can catch a wave when you are paddling at the same speed as the wave (you need momentum to ride a wave).

That’s a very basic overview (no Laplacians here). There is more physics involved including tides, but for now, it’s about time I posted something already!  

Report from the Festival

This past Saturday I went to Expo Day for the San Diego Science Festival. There was a big turn out for the event at Petco Park. Science organizations set up booths to share information through activities and demos, mostly geared towards kids.

I like the idea of the festival: represent science in San Diego and involve the public for free.

Most of the booths had very simple activities for the kids. That didn't stop me and my friend from participating, though (c'mon, the flier says the festival is for kids ages 3 – 93). We poked sticks through balloons without popping them, made DNA necklaces, looked at amphibians and reptiles, and solved a math problem for good measure.

The booths made a complete loop around the stadium. Because there were so many booths and people, you could only spend a short time at each one. While the festival promises to “excite your mind”, the crowds and the short activities didn't provide enough oomph to "excite my mind". Even if you gear it towards kids, you can still make something intellectually engaging for adults, too. But there was some exciting eye candy, like robots, can launchers, and plasma tubes.

Some people were great at explaining their demo to you, and others were...not so great. At science museums I always see the bicycle wheel gyroscope demo. A person stands on a turning platform and holds an upright, spinning bicycle wheel. When she tilts the wheel to the right, she and the platform turn to the right (and vice versa to the left). I had never actually done it, so I hopped on the platform and took the wheel. A couple middle school students were in charge of the demo, so I asked one of the girls why I can use the wheel to turn myself. She knew that it had something to do with spinning the wheel, but she admitted she didn't know what happens when you tilt the wheel. (What happens: conservation of angular momentum. When you tilt the wheel, you change the direction of its angular momentum. The wheel correspondingly exerts a force on you and you begin to turn in the direction that conserves angular momentum.)

If there's anything to be improved: maybe they could offer free workshops to provide something more in depth. Also, the booths were poorly organized. If they were organized by category (i.e. physics and astronomy, the environment, health, biotech...), it would be much easier to pinpoint what interests you and go there. The booths were scattered all over the place, but if they were also physically organized by category, you could find what interests you and hit up the booths that way.

That said, there was great representation and turn out. Just having all of these organizations readily available is a good start. I had a good time. This year my friend and I just volunteered at the information booth, but next year it would be fun to be at one of the actual booths interacting with everyone.

Numb3rs

Did you know that 31 million plastic bottles can be produced from 17 million barrels of oil?

Really. You don't believe me? What's that, you did the math?

Ok, you got me, I lied. If what I said was true, that would be one barrel of oil to make 2 plastic bottles. Pretty absurd, right? Actually, one barrel of oil makes 2,000 plastic bottles. That sounds better, doesn't it? What I meant to say was that 31 billion plastic bottles can be produced from 17 million barrels of oil.

That was a mistake published in the LA Times. And according to another LA Times article, "the million-billion mistake is among the most common in journalism." The article goes on to lament that the collective numeric literacy rate in America is "appallingly low".

I agree that most people do not have a good feel for numbers. Take simple quantitative estimations: how many feet is one block? How many liters of water fill up your bath tub? How tall is the tree in front of your house? In basic physics classes they try to teach you to get a feel for orders of magnitude and size. The problem is that up until taking those physics classes, I perhaps got most of my experience back in the second grade when I guessed how many jelly beans were in a jar.

There are some great visualizations of numeric quantities that I've come across. On his blog Jay Epperhart posted a cool visualization of what ONE BILLION means. And he uses the universe, with all the galaxies containing their stars and planets, to do it. Not only did I get a reference point for the number one billion, but I also got a small peek at how insignificantly small and humble Earth is. Also, xkcd has a great guide to visualizing numbers with the metric system

It's a pity that we aren't very numerically literate, because math uses numbers all the time. We're literate in English, of course, but not in the universal language that is math.

"I am convinced that the act of thinking logically cannot possibly be natural to the human mind," writes astrophysicist Neil de Grasse Tyson in his book The Sky Is Not the Limit. As math is based on the rules of logic, it is reassuring to know that for the vast majority of people, it doesn't come naturally. Like most other endeavors, it takes effort and practice to begin to appreciate the underlying beauty.

The stigma attached to math is that it is tedious and impenetrable. In his book Tyson mentions a publisher who commented that when writing a book about science, every equation included in the book will decrease the potential buyers by one half. And yes, equations are intimidating. Why make the effort if they are foreign to you?

But what if the education in America prepared us to appreciate the beauty of math, i.e. to be numerically literate? We were forced to read __________(insert tedious and boring book required for high school English) to better appreciate the English language, but we didn't get the same rigor and results to be well-versed in the language of numbers.

SD Science Festival 2010

This Saturday is Expo Day for the SD Science Festival, and I think I'm going to volunteer. I've never been to it before but it looks like fun:

The San Diego Science Festival is back! Widely known as the largest celebration of science on the West Coast, on March 20-27 the Festival is hosting dozens of countywide events promising to “excite the minds” of thousands of students and their families. As a grand finale, there will be 150+ hands on activities and stage shows at Expo Day at PETCO Park on Saturday, March 27. Check out the online calendar for complete details: http://www.sdsciencefestival.com/

How to see in 3D

I was sitting in the theater last week ready to watch my first 3D movie in the theaters, Alice in Wonderland. I looked down at my 3D glasses thinking, “Whatever happened to those red and blue glasses?” The kind you could find in a box of Captain Crunch? The glasses I was about to put on looked like geeky sunglasses. How did they work, anyway?

You might be familiar with the basics of making 3D images. It starts with how humans perceive depth.

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Physics at the Olympics

Congratulations to Yu-Na Kim, who won the Olympic gold medal in ladies' figure skating last week. I could gush on and on about Yu-Na Kim and her exquisite skating. Normal people have strengths and weaknesses, and the same goes for skaters. Some skaters have great artistry but lackluster jumps, or athletic jumping but unrefined artistry. Yu-Na Kim is very rare in that all the elements of her skating are excellent. It really isn't fair. But I love watching her.

If you were watching figure skating at the Olympics last week, you were watching physics in action! There are some very simple laws of physics at work that can make or break great skating.

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Science, Media, and Improbable Research at AAAS

This year's AAAS (American Association for the Advancement of Science) Meeting just happened to be in San Diego, so I decided to attend. Luckily, the Physics Department at UCSD had slots for students to get into the meeting for free. I don't think that many of the physics students were interested in going, though, because I applied late and got a slot!

The meeting's theme was “Bridging Science and Society”. I was mostly there to bridge myself to the rest of the science community. The National Association of Science Writers (NASW) has a mentorship program that pairs beginners with veteran science reporters. Luckily again, I was able to get a great mentor through the program and shadow her for a day. She interviewed an avid science blogger who writes on A Blog Around the Clock. He explained to me that he writes about the “meta” of science communication – that is, he reports on science reporting. During his interview he talked about the dynamics of the blogosphere. I thought it was interesting when he mentioned that a NYU journalism professor likes to spend 45 minutes composing one message on Twitter. I guess the professor likes to maximize linguistic efficiency.

In general I got the sense that within science writing and reporting, some attention has been shifting towards multimedia, like video, podcasts, photos, and the hodge-podge of media you can find online. Writers don't just write anymore; they take their own videos, they tweet and facebook people, and do whatever it takes to capture our attention when we're online. This is my impression, at least.

While at the meeting I also saw an Improbable Research show. What is improbable research, you ask? It is “research that makes people laugh and then think”. These are the guys that administer the Ig Nobel Prizes. I got to the show late, just as they were finishing up with “objects found in patients' rectums”. Huh, I think they got the order right – it does make you laugh, and then think. That was followed by research linking romantic love to obsessive compulsive disorder. That was followed by the emergency bra. It's a bra that doubles as a face mask in unexpected disasters and emergencies! You take the bra cup and apply it over your face to filter out harmful dust and chemicals in the air. The emergency bra is readily available, which is great considering that almost no one in the audience had a face mask on them. Furthermore, since we have two breasts and not one, ladies, you can save yourself and the lucky man sitting next to you! The researcher also gave a demonstration. It looked pretty effective, if you ask me.

Not to end this on an absurd note... Well, actually, yes, I will, but next time I'll be sure to have some more substantial, meaty science in the works.