David Waller

A tear jerker for nerds

Last night I watched the movie "Contact" on TV. It is the second time I have seen it, but I thoroughly enjoyed watching it again. Jodie Foster plays a radio-astronomer who is a member of SETI (Search for Extra-terrestrial Intelligence). Naturally, she gets lucky and discovers a message from an alien intelligence.

Despite the stereotype about science-geeks loving science-fiction, I usually don't care for science fiction. "Contact" is a stand-out exception though. The original story was written by Carl Sagan, who was a real-life astronomer. Having a real scientist write the story probably helped since it avoids the usual pitfalls of crap sci-fi by having the science part correct and minimal and by focussing on the human aspects of the story.

That said, my favourite part of the movie is when Jodie Foster's character first discovers the radio signals from outer space. She quickly realizes that the radio pulses represent numbers: 2, 3, 5, 7, 11, 13... As soon as her character said "2, 3, 5, 7...". I yelled out, "Primes! Prime numbers! They're prime numbers!!!" I got so excited I forgot for a moment I was watching a movie. My excitement quickly turned very emotional - I felt like crying.

Maybe it's my lack of sleep from being on graveyard shifts at SNO for the last week. Or maybe I'm just a big softie for dramatized scientific discoveries. As if that wasn't bad enough, another scene later in the movie had me tearing up again: Jodie Foster witnesses the early stages in the formation of a solar system. She is overcome by the beauty she sees and suggests that a poet would make a better space explorer than a scientist since a poet would be better at conveying the beauty of the Universe.

There are more "overt" dramatic moments (tragedy, romance) in the movie that I imagine are supposed to elicit emotional responses. Interestingly, they didn't do much for me. For me, they couldn't compete with the movie's portayal of the emotional power of scientific discovery. I guess that's pretty strong evidence that I am in the right line of work.

I have yet to make a big scientific discovery in my career. I hope I can have that good fortune in the future. Until then, I will be happy to live vicariously through the fictional discoveries of imaginary people.

Is a faster electron a heavier electron?

Here's a recent question from the Einstein's Big Idea blog. It's a question that frequently gets asked about E=mc^2...

Somu Selvaraj asks:
According to quantum theory of light,it contains the packets of quanta called photons.When electromagnetic waves like X-rays,gama rays,incident on the surface of certain metals the electrons on them absorbs that energy and are ejected and that electrons are called photo electrons. My question is 'if the electrons get the energy from the light whether the mass of the will increase or not? here the according to Einstein,
     E=mc2
if it absorbs that energy would the mass of the electron differs or not.

The answer is "yes" the electron's mass really does increase.  Let's pretend you are sitting in a lab watching the metal. After the electron absorbs the packet of electromagetic energy ( = photon), its total energy increases. Normally, we tend to talk about the electron as having had its kinetic energy (roughly, the energy of motion) increased by this absorption. Since the kinetic energy and therefore the total energy of the electron has increased, according to E = mc^2, the mass must also have increased.

Because the kinetic energy has increased, the velocity has also increased. In general, whenever an object increases its velocity, its "relativistic" mass increases. If it were to stop (lose all its kinetic energy) its mass would return to its minimum, called its rest mass.   The rest mass is always the same, but the mass is only equal to the rest mass if the object is resting!

For everyday objects like cars or bicycles, the velocities are much too slow for the effects of Einstein's theory of relativity (E=mc^2) to be noticeable, but for subatomic particles, it's not too hard to make them move fast enough for relativity to be very important. Particle physicists deal with relativistic particles everyday!

Accepting and rewarding Einstein

These two questions were posted a couple of days ago by one of our readers of the Einstein's Big Idea blog. I will take a stab at them!

Eduardo Avaria of Chile asks:

Was a part of Einstein's geniusness his obstination in "guesing" that he had the right and everybody else, even newton, and the entire physic scene was wrong (in his photon theory as an example)?

And as a secondary question, i want to know why the physicist comunity take so long to give cientists the recognitions they deserve. Why Einstein had to wait till 1921 to get the nobel prize he deserved since 1904? Or the photelectric effect was only a "touchable screen" to award him for his marvelous job?

I'll address the first question first. I wouldn't say that Einstein was "guessing" at his equations for relativity, etc. Despite his reputation as being "not very good at math", he was still quite decent at it by most people's standards! He used conceptual and mathematical reasoning to arrive at many of his big discoveries - including E = mc^2. He could back up his claims with solid mathematics.

It is important to stand by your work to make it stick, but he wouldn't have stood by his work with much conviction if it wasn't supported by solid reasoning and math.

Now I'll tackle your second question: why did it take 17 years for Einstein to get the Nobel Prize in Physics?  Seventeen years is actually not that long to wait to receive a Nobel Prize! Many scientists have had to wait much longer. And some couldn't wait long enough - they died before they had been rightfully honoured. Nobel Prizes are awarded only to the living, so it's often joked that you have to have a strong constitution to win a Nobel.

More importantly, new ideas take a little while to sink in with anyone - physicists included! Even Einstein's seeming simple and profound ideas took some time to sink in. We physicists are notoriously sceptical when it comes to new ideas and love shooting them down. If, after lots of shooting, a new idea espaces unscathed, then it is deemed worthy. That's one of the best features of science - new ideas must stand up to scrutiny - most seemingly great new ideas have holes poked in them and die, but a few survive and sometimes go on to change our perception of concepts as profound as time and space.

Radioactive salt in SNO

The picture on the left is a snap shot of the SNO event display from less than five minutes ago. The roughly circular cluster of orange dots are SNO light detectors that have "seen" light inside the detector all within 20 nanoseconds of each other. The event is probably caused by a radioactive decay of radioactive salt in SNO.

What the heck is radioactive salt doing in the detector you ask? We put it in a few days ago to help understand our detector's response to other sources of radioactive background and also to understand our response to neutrons. Sodium-24 is the radioactive isotope in the salt (NaCl = sodium chloride).

Fortunately, the half-life of sodium-24 is only 15 hours, so in a couple of weeks, there will be very little radioactivity left.  The sodium-24 decays by first emitting an electron (and an anti-neutrino which we don't see). This changes the sodium-24 nucleus into a magnesium-24 nucleus in an "excited state". Basically, the new nucleus is unstable so very quickly emits two gamma rays. One of these gamma rays can sometimes split one of SNO's heavy hydrogen nuclei (the "heavy" part of SNO's heavy water) into a neutron and a proton. This neutron then sticks or "captures" onto another heavy hydrogen nucleus. This in turn produces a high energy gamma ray which is visible in the SNO detector after it scatters an electron. The electron actually emits the light which is seen by the light detectors. 

Phew! That's not so straightforward is it. My apologies - I didn't want to lie to you about what really goes on inside SNO! Basically, for these radioactive salt calibration runs, we see the result of neutrons capturing on nuclei in the detector. Seeing lots of these events helps us to understand better how our detector works. Like a piano tuner tunes a piano to get just the right sound, we are tuning SNO to make it run as well as possible.

Car shopping

Since my last blog was about a new SUV, I will continue on the same theme and write about my recent car shopping experience. 

My wife, Pam, and I decided some time ago that we would get a new vehicle sometime before Christmas. This decision was based on the imminent arrival of our second child: due in early January! Our ever-reliable and virtuous Toyota Corolla is just too small for two baby seats, two adults and a dog.  So, we decided to get a bigger car.

From the moment we decided to get a bigger car, my wife and I agreed that a big SUV was out of the question for moral/political/social reasons. For aesthetic/psychological reasons I was also opposed to getting a mini-van. That left only one real option: a wagon.

These days wagons are cool - or at least I think they are cool. Unfortunately, not many car companies make wagons. They are too busy churning out ridiculously over-priced, and profitable, SUVs. Our wagon choices were quite limited. I was excited about the new Mazda 6 wagon (partially thanks to Tommaso's old posting about his Mazda 6 wagon). Pam liked the Subaru wagons: Forester and Legacy.

Early on, we decided we would buy a used car (2-5 years old) as cars lose ~50% of their value in the first few years. You pay a very high premium to own a new car. Our old Corolla was two years old when we bought it and it has been great for us.

My initial excitement about the Mazda 6 wagon faded when I realized how expensive they are. First, they are over $30,000 new, plus they came out only a year ago so used wagons are (a) virtually impossible to find, and (b) still expensive when you find one.  We test drove a Mazda anyway - it was great to drive (sadly). Fortunately, our next choice, a Subaru, looked much more promising. The Forester in particular gets decent mileage for a larger car (10 L/100 km in the city) and it is easy to find used ones for sale.

After much shopping, we found a very good deal on a 2000 Forester with very low kilometres. It is now ours, but we haven't picked it up from the dealer yet. My wife will get to do that later in the week. I will have to wait until I am back from Sudbury to take it for a spin.

There are only two downsides to the Forester. The first is that it is not the world's most beautiful car - I thought they were really ugly before I realized that the Forester would be a good choice for us. After this realization, I managed to convince myself that they are not nearly as ugly as I originally thought - honestly - no really - honestly! 

The second downside is that Subaru calls the Forester a "compact SUV". The acronym SUV makes me cringe - there's a lot of negative baggage attached to those three letters. The Forester really is a wagon though. The mileage is far better than real SUVs and it's not nearly as large or high off the ground; it's much more car-like. I'm convinced Subaru calls it an SUV just to try to sell more of them. I'm not fooled!

We should be set now. Just as long as there are no more babies... If that were to happen, maybe I could convince myself that I like mini-vans too. The mind is an amazing thing; it will do anything to minimize cognitive dissonance.

The perfect SUV for social climbers

The other day I saw a hulking SUV called the "Ascender". It's made by Isuzu. I couldn't help coming to the conclusion that the Ascender is the perfect vehicle for aspiring social climbers...

Maybe I should pitch my advertising idea to Isuzu. They could try a commercial that goes something like: "Are you desperate to climb the social ladder? Want to rise above your neighbours? Buy the new Isuzu Ascender - it's the SUV on the up and up".

Nu Yawk

In between taking care of my flu-ridden daughter and getting sick myself, my wife, Pam, and I managed to squeeze in a weekend trip to New York City. It was my first time going strictly as a tourist and Pam's first time.

We stayed with friends near Trenton, New Jersey. That saved us lots of money and meant we could visit our friends. The downside was that it took two hours each way to commute to Manhattan. We took trains to and from the city. It was great to be able to do that, but it's a shame the trains aren't faster. They move like molasses for much of the trip. I am sure the travel time could be reduced by a factor of two if the trains and/or tracks were in better shape.

We drove to NY/NJ, so our trip was truly on the cheap. It was a 7.5 hour drive from Ottawa to our friends' place in suburban New Jersey. For the most part, it was a surprisingly lovely drive through upstate New York. The drive is mostly through forests and the Appalachians. The leaves had just started to change colour at the higher altitudes. 

We had two days in Manhattan, though the first started at 4pm and the second started at 2pm due to problems with the train system (no trains could run for 8 hours). Despite our limited time, we accomplished many of our touristic goals:

1. visited the Museum of Modern Art (MoMA);
2. ate funky Japanese food for supper (Japanese-German fusion food - restaurant should have been called Axis or something like that).
3. went up Empire State Building at night. As far as tourist stops go this one was a 10/10 - especially since there was no line-up when we went - right after two hours of rain - apparently, the wait time is usually closer to two hours;
4. had lunch at nifty restaurant Chinatown (salt-baked seafood - yum!);
5. admired Brooklyn Bridge - much more beautiful than I expected;
6. visited the site of the World Trade Center - sombre;
7. visited the insanity known as Times Square - enough said;
8. went for Mexican fast food at Burritoville - surprisingly delicious;
9. saw "Rent" at Nederlander Theater - awesome!

In my opinion, that wasn't a bad little weekend away from Ottawa. Unfortunately, the flu I caught from our daughter took hold our first night in Manhattan. But, I was psyched up enough to ignore how crappy I felt until we got back to Ottawa.

Not only did we save money by driving and staying with friends, but we also ate at cheap places the whole time. NYC is a diner's paradise: great food can be found in almost any price range. I had fantasized about eating at fancy French joints like Le Bernadin or Le Cirque 2000, but ended up slumming it - and loving it - instead!

There's so much to see in that wonderful city that we will surely be back in the future. Maybe next time, Zoe will be old enough to come with us. This was our first trip without her. She stayed with my mom. Fortunately, Zoe survived without her parents, so Pam and I can look forward to more weekend getaways in the future.

Pestilence

Not much blogging lately. Too busy and too sick. My daughter Zoe started daycare three weeks ago and since then, productive time has been largely a fantasy. Zoe's first week at daycare required me to be with her for about 1/2 the week. Her first week at the daycare was an "integration" week. 

The next week, Zoe was sick. As every parent knows, daycares are Heaven on Earth for germs, viruses, bacteria, etc.. I spent a couple of days at home taking care of her. Not surprisingly, I got sick too. I stayed at home a few days last week because I felt too rotten to go into work and also because I knew my colleagues wouldn't appreciate my germs. Zoe and I were not the only casualties of her starting daycare; both my wife and mother also caught her bug.

Now, that I am almost better, I am in Sudbury again. Thank goodness I am on afternoon shifts (16:00 -> 24:00) this week instead of graveyard shifts. A week of graveyard shifts would surely have been the end of me. However, in two weeks time a have a week of graveyards...