"You know, on second thought I think I'll take the bus."

You've apparently not heard of the TSA VIPR teams.

The IQR (inter-quartile range) would probably be a better measure of spread if you are going to use the median as a measure of center.

To be sure. The difficulty with IQR is that the average college sophomore has no idea what it is. I actually tried this one semester, and ended up having to teach statistics one-by-one to each student that came in complaining about his grade. It was easier, and took less of my time, to use a system that had less technical validity, but used terms with which the students were familiar, and could independently calculate.

I personally prefer that the median correspond to the center of the C range, rather than the top.

Consider it my small concession to grade inflation.

Actually, no. Anyone that mastered the material did get an "A" -- that's part of the "law of large numbers." The medians (and means, and standard deviations) of the classes varied little.

When I taught undergraduate engineering courses at a state university, I always had large classes (> 80 students), so I decided to let the law of large numbers work to my advantage. I would grade each student's work with a numerical score, and would then find the median and standard deviation of the scores for each class. The median I defined to be the threshold between "C" and "B". One standard deviation above the median became the threshold between "B" and "A", and one standard deviation below the median became the threshold between "C" and "D". Any score below two standard deviations away from the median was a failing grade.

I used the median, instead of the mean, to ensure that I never had more than half the class with an "A" or "B". After some experimentation otherwise, it seemed like one standard deviation per grade was just about right -- most students got a "B" or "C", and only the exceptional ones got an "A" or "D" (or worse).

This scheme seemed to work well, and was no more arbitrary than any other. Plus, it was deterministic, in the sense that I could tell the students on Day One how I graded. If a student got a "C", for example, it was because more than half the class did better than he did. In addition, I could justify an "A" grade to the administration, since that person performed at least one standard deviation above the median.

Um, no. "Radiation" was the word for which you were looking. "Radioactivity" refers to the particles which are emitted from nuclei as a result of nuclear instability.

There was a significant solar flare at 1832z (1:32 p.m. EST) on 7 January, that bathed the Earth with electromagnetic radiation (X-rays, UV, radio, etc.). This was an X1.2-class flare, meaning that its flux would have peaked at 1.2E(-4) watts/square meter at the Earth's surface, had our atmosphere not protected those of us on the ground from the worst of its effects. The effects of the flare itself (largely attenuation of HF radio signals over the Western Hemisphere during and shortly after the event) are over and done with.

Since this flare was caused by a particular sun spot group that remains active and unstable, Orbital Sciences was concerned about a repeat performance when the Antares' avionics were in the upper atmosphere, and therefore not protected from a second, possibly even more intense, flare that the sun spot may produce.

Concurrent with this flare was a coronal mass ejection (CME), which consists largely of protons blasted out of the sun's atmosphere (the corona). Since these particles are protons, not massless photons, they travel slower than the speed of light, and it takes them a while to get here; they are expected to arrive sometime early on 9 January UTC. However, predictions of CME particle velocity are difficult and prone to error; CMEs can arrive early.

Since the CME could be arriving while the Antares was in operation (the flight was scheduled for liftoff at 1832z on 8 January), and the performance of the rocket's avionics could not be guaranteed in that environment, when this risk was combined with the risk of another X-class flare I think they just decided that a scrub was the wiser choice.

I thought we'd been testing them in other nations' skies for a while now -- what more needs to be done?

I'm pretty sure this guy passes me every day on the way to the office.

Most 50- and 60-somethings I know think it's OK, too.

Well, actually, he's only ticketing people who use the phone to text, or send or receive Internet data traffic. Making phone calls? No problem.

I wonder what happens under Georgia law if one is making a cell phone call over VOIP, while stopped at a red light. Is that a voice call, or the use of Internet data?

Or what happens when one is on a conventional cell phone call, but has to enter additional data, like a password or to respond to an automatic answering system. Is that a move from voice to data?

What a poorly edited article. One never knows which Bell -- Genevieve or Mike -- is speaking.

This.

I well remember the first advertisement I saw for a device that "lets my friends know what I'm listening to!" I turned to my coworker and we shrugged at each other. Why would anyone want to do that? That's my business! If they're curious, they can ask; if I want them to know, I'll tell them. But geez, I would never give up my privacy like that.

We both shook our heads at the thought of the fools that would try to market such an obvious failure, and walked away. From the future, of course. But now that my coworker and I realize the error of our ways, do we now have such devices? No. Our privacy feelings haven't changed; only the world around us has (we went from agreeing with the majority to agreeing with a minority).

What color is he now?

Why do you say that? Everyone on your list is young.

Let me put it this way: Mr. Whitlock became an expert in a technology he learned in his teens, and rejected a technology that developed around him in his sixties. How receptive will you be to the state-of-the-art, game-changing technology of say, the year 2050, that makes the computer technology you have worked with your whole life, obsolete?

Indeed.

In the early 1960s I lived in a very small town -- but a town that had a library. Wandering through it one summer day (it was air conditioned!), I discovered the Science Fiction shelf. It was organized by author's last name. I decided to start on the right, and go to the left -- I was a contrarian even then -- and was unimpressed with the first selection of books I read (by authors the names of whom I have forgotten -- apparently the library didn't have any John Wyndham books). I decided to reverse my field, and start from the left.

Shazam! Poul Anderson, Isaac Asimov, Ray Bradbury, Arthur C. Clarke, . . . I was hooked for life. Heinlein and Pohl were glorious discoveries along the way. Later on, when I could afford subscriptions to Galaxy and Amazing Science Fiction, Pohl became a real favorite.

One of the very last of the greats from the Golden Era.