Teaching in 2012-2013

Meteors, Meteorites and Asteroids

Sun, 17 Feb 2013 19:19:51 -0500

#phywi #stwei

Been an interesting week, skywise. We had that asteroid, 2012DA14, approach earth on Friday. I was sitting in a conference session Friday afternoon and at 2:25 I strained to hear or feel something for about 10 minutes, but, of course, I didn’t. An asteroid is pretty much anything orbiting the sun that’s smaller than a planet. This is a large range. Friday’s asteroid was a teensy fraction of the size of the earth, even though that’s still pretty huge. Little wonder I didn’t feel anything.

When something enters our atmosphere and glows in the sky, we call it a meteor. An asteroid can be a meteor. Most meteors are smaller than 2012DA14. A meteor that actually strikes the earth is a meteorite.

The meteorite that landed in Siberia Friday had a radius of about one meter, according to the estimates I’ve seen, though nobody’s sure, exactly. That works out to a weight of about 10 tons, which amounts more or less to 3.5 rhinos or 2 Hummers. It’s iron, and you certainly wouldn’t want to be hit by it, coming down as it did, with a velocity of about 16,000 m/s.

The asteroid, 2012 DA14 has a radius of about 25 m, and while neither the asteroid nor the meteorite is all that spherical, using an estimated radius helps compare their sizes. The volume of a sphere is proportional to r^3, so the asteroid had a volume (and weight) that was about 15,600 times bigger than that of the meteorite. Little wonder that nobody saw the meteorite coming.

Asteroid 2012 DA14

Sun, 10 Feb 2013 07:22:00 -0500

#phywi #stwei

Asteroid 2012 DA14 is an irregularly shaped rock measuring abut 45 meters across, about half a football field. It has a mass of about 150 million kg, about 330 million pounds. It is moving at 7820 m/s relative to earth, more than 17,000 miles per hour. This is more than 20 times the speed of sound. The asteroid will pass earth at a distance of about 5.4 earth radii from the center of the earth, about 17,000 miles from the surface. This distance is within the circle traced out by many weather satellites, close indeed. Nobody knows exactly what the asteroid is made of; we may learn more of that as it passes.

Closest approach will occur Friday, 02.15, at about 2:30 PM EST. This is during the time of test08 for my period H class. Ponder that, briefly. The asteroid is way too small to affect the earth’s orbit or tides. It is certainly large enough to cause immense damage if it were to strike earth. Some estimate that an area of radius 15 miles or so would be completely destroyed. Earth collides with asteroids this size an estimated once in more than 1000 years. The last one is believed to have occured in Siberia, in 1908. There is no chance, given its orbit, that 2012 DA14 will strike earth.

2012 DA14 was discovered on Feb 23, 2012. The “2012” part of the name refers to the year of its discovery. ”D” refers to the half-month of discovery, the fourth half-month of the year. ”14” refers to 14x25 =350, and “A” refers to the number 1. This asteroid was the 351st discovered during the fourth half-month of 2012. That is the naming system astronomers use. You may call it whatever you want, but no one will know what you are talking about.

The Power of a Hot Body

Mon, 31 Dec 2012 09:30:43 -0500

#phywi Happy New Year everyone!

http://nyti.ms/VrL7F3

I thought I just had to share that with you. Here’s a note that might (I hope) raise more questions than it answers.

http://bit.ly/10EBSF5

Questions, questions

Mon, 24 Dec 2012 12:22:38 -0500

Asking questions is as important to students as it is to reporters and ambitious business professionals. Study well.

http://bit.ly/U49OGv

The value of struggle

Mon, 03 Dec 2012 10:56:17 -0500

#phywi #stwei Please take 10 minutes to watch this video. We’ll discuss it a little in class tomorrow. How does it pertain to our work?

http://n.pr/SfoleO

A Teen Engineer in Africa

Wed, 21 Nov 2012 12:09:55 -0500

#phywi #stwei “For quite many years Sierra Leone and many other African countries received aid, but it does not necessarily get us anywhere. We’re not looking into the future. We’re not designing our own future. Unless we have a host of young people who can think at any given point that here is a challenge, that here is a problem, that here is an opportunity to solve it, there won’t be a steep growth in national development.”

-David Sengheh, from Sierra Leone, an MIT PhD candidate, about Kelvin Doe, also from Sierra Leone, at age 15 a guest developer at MIT.

Read and watch: http://bit.ly/TdKpd6

Social Media in Healthcare, and Teaching?

Tue, 09 Oct 2012 06:22:49 -0400

This could be more important than ACA. Plus, nobody can repeal it. What does it suggest about teaching?

http://well.blogs.nytimes.com/2012/10/08/texting-the-teenage-patient/?hpw

Oatmeal

Tue, 09 Oct 2012 06:21:21 -0400

Back to work today after Columbus day weekend. Tried cooking oatmeal with apple cider instead of water. Delish! Why didn’t someone tell me?

John Gurdon wins Nobel Prize in Medicine and Physiology

Mon, 08 Oct 2012 16:23:10 -0400

#phywi #stwei According to the New York Times, Dr. Gurdon’s high school biology teacher wrote: “I believe Gurdon has ideas about becoming a scientist; on his present showing this is quite ridiculous. If he can’t learn simple biological facts he would have no chance of doing the work of a specialist, and it would be a sheer waste of time, both on his part and of those who would have to teach him.”

I don’t believe that of any of my students, even those who start slowly in one of my classes. There is just no way of knowing how a student will grow intellectually while he or she is still in high school.

Needless to say (but being a high school teacher, I will say it anyway) Dr. Gurdon worked long and hard to pursue his dream. And now he is a world famous biologist and a Nobel Laureate. How fabulous is that!

SelTopPhy Course Blog

Wed, 22 Aug 2012 05:14:38 -0400

#stwei All materials for our course will be posted here.

www.stwei.tumblr.com

Physics Course Blog

Wed, 22 Aug 2012 05:12:07 -0400

All materials for our course will be posted here:

www.phywi.tumblr.com

Sasha DiGiulian #phywi #stwei

Sun, 29 Jan 2012 12:20:36 -0500

Don’t miss this. http://vimeo.com/33306702

How to Have a Good Idea #stwei #phywi

Mon, 16 Jan 2012 11:48:48 -0500

See http://www.edge.org/ for their collection of short essays from some very interesting people in response to their question of the year: What is your favorite deep, elegant or beautiful explanation? Highly recommended.