Another day, another conference. From Dragon*Con, I crossed half-way across the country to Chicago to attend the 119th Meeting of the Astronomical Society of the Pacific on “EPO and a Changing World.” This morning I’m sitting in a session presented by astronaut George “Pinky” Nelson (the astronaut who repaired Solar Max) on things that need to happen for education to be made more effective. He is focusing largely (and I feel correctly) on the need to support our teachers by providing them training, content, and infrastructure.

Intriguing comment of the day: “We should only teach a geometric explanation of the lunar phases. Let’s pick a grade, say 5th grade, and only teach the lunar phases there. Think about multiplication of 2-digit numbers – they do that in the 3rd grade. Let’s teach lunar phases in 5th grade.” This particular comment caught my attention because I am personally annoyed at how much time in astronomy classes in all grades are spent learning lunar phases. The cosmos is a huge place with lots of amazing detail waiting to be learned. Let’s move beyond celestial motions and lunar phases to study the stars themselves and the universe of galaxies they orbit within.

Throughout his talk, Nelson stressed that we need to train educators in both teaching strategies based on how people learn and we need to train them in the content. We do a fairly good job providing them with training in pedagogy, but if you look at the standard elementary-education curriculum, the amount of content in specific subjects is very limited. Once their initial college education is complete, teachers must continue learning on their own and through continuing education programs. That alone, however, isn’t enough. When we give them course materials, we can’t expect them simply know how to teach what we give them, but instead we need to provide them all the background material as well. In an example, he (using his hands) indicated that the student materials for one particular activity is only 1inch (~2.5 cm) thick, while the teacher material is more like a 8 inches (~20cm) thick. This teacher packet saves the teacher from needing to spend time googling and in the library and pre-vets the good materials and puts it straight into the hands of the people who need it most.

We also need to rethink how we are teaching our teachers. We can’t stick them in general lecture-based, giant survey courses in science and expect them to learn what they need to learn to effectively teach astronomy or any other science. This is a two-fold problem. 1) Lecture isn’t an effective way to teach anyone anything – we learn best in cooperative learning environments where people learn by doing and discussing, and I suspect most lecturers will yell at classroom members who are doing or discussing while lecture is in progress. This stifles learning. 2) Elementary school classrooms do use activity-based learning, and if we teach teachers using lectures and expect them to use activities, we aren’t teaching them by example. This is very disconnected. By teaching teachers using activities, discussions, and small amounts of lecture (you can’t get away from it entirely), we can teach them more effectively, and give them examples of things they can do in their classrooms.

As the EPO community puts on our weekend workshops and our outreach materials, we need to put all these pieces together. This website certainly isn’t there – a blog is very much a lecture, although the comment role seems to do a good job encouraging “after class” dialogue. Astronomy Cast is in the same boat. This talk directly challenged people like me to find ways to encourage people like you to not just “listen” to content, but to also reach out and regularly do astronomy through projects like Galaxy Zoo.

Good speakers can be problematic: they leave me wishing I had more time to do more.

Okay, so that last one is an exaggeration. As far as I know, human babies and the CMB have nothing in common. The remark about the Oort Cloud, however, may not always be as far fetched as it sounds. A group of scientists working at the Harvard-Smithsonian Center for Astrophysics, and lead by David Babich, have theorized a new technique for determining the mass distribution in the Oort cloud using distortions in the Cosmic Microwave Background.

According to the theories of Babich and his team, if you observe the light of the CMB through the Oort cloud, the intensity you detect is related to both how much CMB light is blocked by Oort cloud objects (which are so small and so far away that you can look through them the way you look though a cloud of fine dust), and to how much light the Oort cloud objects emit at the color being observed (in this case, the dust you are looking though is made of glow in the dark paint). If the Oort cloud isn’t symmetrical, any distortions may be visible as anisotropies in the light of the CMB.

The key to understanding this result is understanding that warm objects give off light in a variety of colors. The hotter an object is, the shorter the wavelength of the light – the bluer the light. The colder an object, the longer or redder the light will be. Humans, for instance, give off the most light in infrared. That doesn’t mean we give off all our light in any one specific wavelength of infrared. Rather, we give off most of our light in one shade of color, but there is light of a variety of colors coming from our warm bodies, even in the darkest of rooms (although some colors, like green, aren’t emitted in numbers enough higher than zero to matter).

The CMB is basically a perfect black body with a temperature of 2.728 Kelvin. It is located at essentially infinity in all direction. It is a perfect background light. This team theorizes that objects in the Oort Cloud should have temperatures related to their distances, such that an object at 1000 AU would have a temperature of 8.5 K and nearer objects would be hotter while farther objects are colder (think of the temperatures of rocks illuminated by a camp fire. The same physics describes the heat of the rocks and of the objects in the Oort Cloud. These temperatures are very similar, and the same technology that can be used to detect the CMB will also detect the heat signature of Oort cloud objects.

So, while the 2.728 K CMB and 8.5 K Oort cloud objects both emit microwave light, the light doesn’t peak at the exact same color, although there is overlap. Despite the amazing precision that WMAP and other missions have already mapped the CMB, their accuracies weren’t sufficient to test this theory, but this is something that future missions, like Planck, may be able to. Any distortions in the Oort cloud that are found will point to past encounters with stars. As our Solar System passes near other stars on its orbit through the galaxy, the Oort cloud gets distorted and these distortions trigger long period comets.

Good theories, in my mind, are defined as theories come in to forms. There are those, relativity, that put existing observations together in a new way that leads to deeper understanding and understanding of previous mysteries, while also making predictions. There are also good theories that look at the universe and apply existing knowledge to predict future discoveries we can’t get to through more common means. This set of papers falls in that second category. This isn’t theory for the sake of pretty math – this is theory that defines how to build a better mouse trap.

That silly little kid in me wishes I had been on that airplane. They could actually hear the fragments burning up.

Should I worry about meteors when I fly? Nope. And doing stats can be fun.
Time for some back of the envelope calculations. Say that 2 asteroids a year crash through the atmosphere like the one seen by this flight. This is a total guesstimate. I’m sure a real number is out there somewhere, but I’m feeling lazy. Let’s say those two estimated asteroids turned meteorites spend roughly 30 seconds falling in bits and pieces through airplane altitudes. That would be 1 minute a year out of 365.24d*24hr/d*60min/hr = 525949 minutes/year. So, the probability of an asteroid going through the atmosphere at any one moment is 1 in 525949.

Now, that falling piece of rock broke up and splatted through the atmosphere over an area of roughly 100 square kilometers. Assuming the plane is at a cruising altitude around 35,000 ft (10.7 km) above our Earth (radius = 6,378.1 km), there is a total area of 4 pi r^2 = 512,918,602 square km. So, the probability that one particular plane will be within that 100 square km is 1 in 5,129,186.

Put together the probability that at any given half minute in time a plane will be at in the particular 100 square km region is those two probabilities multiplied together: 1 in 2,697,690,256,973.

Now, that assumes there is one plane hanging out flying. I tried to find out how many planes are flying at any given moment and failed. According to the National Air Traffic Controllers Associationroughly 87,000 flights a day fly over the US alone. Based on that, I’m going to make a wild guess that at any given moment there are probably an average of 10,000 flights some where. They aren’t evenly distributed. For instance, you’ll get more flights over the East Coast instead of over Antarctica. I’m going to ignore that however, to get a worst case approximation. Let’s say those guesstimated 10,000 flights are distributed evenly over the planet. That gives us a 1 in 269,769,025 (likely severely exaggerated) chance that an airplane will get hit by a meteor.

So, yeah, I’m not worried

Now, I have to admit that stats is one of those places where I periodically leave out details. If anyone knows what I left out, please leave a comment.