Physics Phriday - It is a Time Machine

From Jack van Ryswyck:
You know it's funny you should mention that. The other day I suddenly saw Mike vanish before my very eyes, desk chair and all. Left in his place was a box shaped area of seemingly totally empty space, filled with absolutely nothing but some strange looking radiation.

Two seconds later Mike suddenly reappeared, looking very normal. In fact, looking rather exactly like he had at the moment he vanished. He then looked at me as if I had done something totally strange.

He told me that he had not seen anything vanish at all, but to him it looked like I instantaneously had shifted position and facial expression, as if I were an old time movie that had skipped a few frames. We then noticed that the atomic clocks that we had coincidentally been carrying were inexplicably off by 2 seconds. We had just synchronized them earlier that morning, but now his was 2 seconds behind mine.

Some time later a very similar thing happened, but this time a part of his desk chair stayed behind when Mike and the rest of his chair vanished. The remaining part of his chair just got cut clean off and fell to the floor. Mike and the rest of the chair reappeared two seconds later, though the chair did not reassemble. He said that he saw part of his chair suddenly teleported to the floor instantly.

Then the other day Josh and I were passing juggling balls when the same thing happened again. Suddenly everything in the box shaped area vanished, and many copies of a juggle ball appeared, all moving in a parallel direction. I then found myself tossing a juggle ball into the box. Oddly enough it happened to have the same colour as all the copies, and by some mysterious coincidence it was moving in just the same direction. Two seconds later all but one of the balls disappeared, and everything else reappeared. At the far side of the box, one juggle ball flew off. The net effect was just as if I had thrown the ball across the box incredibly fast. Impossibly fast really.

The next time it happened I saw the empty box appear filled with many copies of about one-third of a juggle ball. All but one of them were moving in a parallel direction away from me, but the nearest copy seemed to be moving towards me. In self defense I grabbed the juggle ball nearest to me, which happened to be the same colour, and as a makeshift missile defense system I threw it against the partial juggle ball that was moving menacingly towards me. They collided. The partial ball got knocked into a trajectory parallel to all the others. My defense missile ball got nudged back towards me. Then all the partial balls disappeared, except one that flew off at the far side. My defense missile ball was suddenly missing about a third of it. The remainder fell to the floor. The part that fell to the floor on the other side of the box seemed to fit it exactly.

Weird.

Probability and "Man from the South"

A few nights ago I read Roald Dahl's "Man from the South", which brings to mind Dahl (surely no relation of Borges' Dahlmann) as a combination of Poe, Borges and O. Henry, and surely no writer of children's books. A RocketFuel colleague, Ari, pointed out a Hitchcock movie based on the story, which I might get around to watching some nice and bright sunny Saturday morning. To tranquilize myself after reading the rather macabre tale at night, I fell to thinking about some rather interesting probability questions based on the events described.

I want to give you the chance to read the story first, and I really hope, post your own questions, before I raise my questions in a blog in a couple of days. Then, a few days later, I'll give my solutions, which, because of possible differing assumptions, may be different from yours. I'll also add the takes of people who talk to me about it.

Yet another RFI colleague, Jack, referred me to a wikipedia article and pointed out that I was not the first to start thinking about probability motivated by games of chance. Late by a whisker again, Jeeves, dash it all!

Letter to Amherst Bee about ACSD math teaching

“Data shows math textbook doesn’t hurt scores” (June 23, 2010) http://www.amherstbee.com/news/2010-06-23/Front_Page/Data_shows_math_textbook_doesnt_hurt_scores.html shows nothing of the sort.

The school district has no data for years prior to use of the mentioned text – Math Investigations, so no comparison can be made.

All data presented were based on the NYS test, which the state Education Dept. itself admits has been lowering thresholds for “mastery level” for years. The district's own longitudinal data shows a drop of 2% “mastery” per year of exposure to MI at Amherst, while NYS and Erie county averaged 2% per year increases! For Maths 3,4,5: at the end of 4 years, Amherst finishes at the bottom of all 5 neighboring districts.

Ms. Lavin's vociferous claims of children's and teachers' “increased ... ability to think, ...understanding and ...confidence” have no basis in reality.

Dr. Carosella's “ (The Adminstration's) ...statements do not support that MI is a bad program ...” makes me proud to have a Board member with such incredibly high standards.

The relative high performance of ACSD students (and the difference between SDS and Windermere) can be attributed to the socio-economic status of the parents, and there is no way to attribute it to MI.

A US Dept. of Education 2009 study found that MI is “the least effective” of 4 curricula and found a 9 - 12%-ile drop attributable to MI. 40 of 70 school districts touted as “successes” by the publisher of MI dropped the program within two years and 24 have funding that obligates the use of MI.

Your ostensibly neutral reporter, Mr. Nagy, displays a bias towards the Administration and no understanding of the issues or the Math involved.

For a comprehensive pedagogical and mathematics based critique of MI, allow me the opportunity to write an article.