Friday, February 27, 2009

Speedy Recovery

A close friend of a close friend had successful brain surgery this week.
Today’s Table Talk is dedicated to Noah Eiytan ben Sarah Penina -
May he have a “refuah sheleima”, a speedy recovery.
To dedicate a future Table Talk, send an email.

Some people see miracles in complexity. Others see miracles in simplicity.

Please watch these four videos, and email me – what do you see?

Question for your table: Is art to enhance our lives, or are our lives to enhance our art?

Shabbat Shalom

Friday, February 20, 2009

Rules, Rules

Do you ever feel like your day is going the same direction as the market?

Many school teachers avoid hands-on learning activities because they are afraid of chaos. My experience yesterday proves them right and wrong.

About once a month I spend the afternoon in my son’s school helping science teachers. Yesterday I co-taught two classes and brought demonstrations into two others.

If I were grading myself, I’d get an A for the first session, a B for the second, C for the third and D for the last. A real bear market day.

What made the difference?

The first two groups were 5th graders. They’re learning about magnets and electricity. Last week, they got to test out magnets on all kinds of objects to find out what kinds of materials are attracted to a magnet and what kinds are not. This time, we showed them the cool trick of putting 2 donut magnets on a pen with opposite polarity so that the top one levitates. What makes that happen? There is an invisible force. You can’t see it, but if you push down on the top magnet, you can feel it. We then talked about the biggest magnet in the world – the earth itself. I asked them if they think the earth’s magnetic field is strong enough to attract an iron nail or a small magnet. They made their predictions, then we tested them out with nails and magnets suspended by thread. They made a compass!

There was some chaos, but the rules and the worksheet, and my discipline as a teacher, kept everything together and the kids walked out with a sense of accomplishment and learning.

In the next class, the teacher had asked me that morning to show a DVD I have from Harvard called “Life Inside the Cell”. If you want to see why teachers are clamoring for this awesome video, watch it here.

I raced from classroom #2 over to the AV room, wheeled this giant TV with built-in DVD player over to his classroom, and with great anticipation beaming from the faces of those 7th graders, the TV monitor said, “BAD DVD”. I felt like a kid being reprimanded.

Fortunately, I had my laptop with me, with a full charge on the battery, so did a Julia Childish switcheroo and without missing a beat pulled it out and popped in the disk. The problem was that a 12” laptop screen is slightly less than ideal for classroom use. Or more than slightly.

I give myself a C because I should have made absolutely sure the DVD would work before agreeing to the demo. In the end, we found someone more tech savvy than I who promised to make a new DVD that he can use next week.

In the last class, it was basically a total disaster. I probably deserve an F, but because I went to Stanford I got hooked on grade inflation.

I had told the teacher that I have a great activity with mini globes and a light bulb to help the sixth graders visualize how the seasons change.

My mistake was to come in at the end of the period rather than the beginning and not to have the two things that made the first two classes so successful: a detailed plan and a worksheet.

It was uncontrollable chaos. Half the boys were not following directions, they were talking instead of listening, all the things that boys do. My gut reaction was that they were not being respectful, but in truth I blame myself. And it was not a case of “better than nothing”. Better to wait and do it on a different day.

I personally like rules and structure when I feel that they are for my own good. Does any sane adult object to seatbelt laws? How about the rule that you have to stop at a red light? How about “don’t speak lashon hara”? How about “be truthful and honest all the time”?

Shabbat Shalom

PS - here's your weekly tangential music vid:

Friday, February 13, 2009

Lucky Strikes

Mathematician Harold Gans made the following calculations:

Ehud Barak stated on January 5, 2009 that 125 Grad-Katyusha missiles "fell on populated areas" of Beersheva, Ashkelon and Ashdod.

Dr. Gans states that he obtained satellite photos and calculated that buildings cover 40% of space in populated areas of these three cities (39.7%, according to the email).

One would expect that if 126 rockets were fell on populated areas, and 40% of the populated areas had buildings, that 50 rockets (40%) would have hit buildings. Barak's announcement stated that only 2% (3 rockets) hit buildings.

If you expect 50 hits, and only 3 actually hit, this seems extraordinarily low. Dr. Gans estimates the odds against this happening as a gazillion to one, or whatever you call a 1 followed by 17 zeros. The calculations for that probability are provided below.

What do you think?


"I assume it's probably correct. The odds would certainly be minuscule.

The logic is something like this. In the numerator you have the number of ways you can have 1, 2 or 3 missiles landing on the buildings with the associated probabilities. For simplicity, let's assume there is a .4 probability of hitting a building and a .6 probability of missing the buildings.

There are 125 ways only 1 missile lands on buildings. (125 x 124 divided by 2) ways 2 of the missiles hit a building, etc.

125 x .4 x (.6 to the 124th power) +

[(125 x 124) / 2] x (.4 to the 2nd power) x (.6 to the 123rd power) +

[(125 x 124 x 123) / 6] x (.4 to the 3rd power) x (.6 to the 122nd power).

Now in the denominator you have the above cases plus all the other possibilities: 4,5,6.......................or 125 missiles hitting a building.""

Question for your Table
– What’s the difference between “extraordinary good luck” and “miraculous”? Eye of the beholder?

Shabbat Shalom


Friday, February 06, 2009

Imagine Santa Dressed Like a Rabbi

In memory of Rabbi Yisroel Noah ben Yitzchak Matisyahu Weinberg z’tzl, who left this world yesterday in Jerusalem.

Imagine Santa dressed like a rabbi.

He’s happy, funny, and sharp as a tack.

He says to you, “What would you rather be, rich or happy?”

The question is too easy, you suspect a trap. But you decide to play his game. “Happy,” you say.

“Fine. So what if I told you, come spend three months with me in my yeshiva and I’ll teach you how to be happy. Are you interested?”

“Uh...” now you feel the trap. Spending three months in yeshiva was definitely not on your agenda for this summer – or any summer. It would be a major deviation from your plans.

“I see you’re hesitating. What if I offered you 20,000 dollars. Then would it be worth three months of your time?”

Suddenly three months doesn’t sound so long.

“Gotcha!” the rabbi exclaims, pointing at you with a big smile and chuckle.

You wince. He got you.

“That’s what everyone says. Everyone says they want to be happy. But they don’t think about what they’re saying. They’re just saying the words that they know they’re supposed to say. But if they really felt that being happy was more important than being rich, they would spend at least as much time finding out how to be happy as they spend trying to get rich.”

Rabbi Noah Weinberg took everyone to task: from the most secular to the most orthodox, if they weren’t living a thoughtful, purposeful life, he challenged them to think and to analyze, and to live with wisdom not by rote.

He was larger than life, in same historic category of the late Lubavitcher Rebbe and others who directly or indirectly impacted hundreds of thousands of lives.

Here’s one of his students, Rebecca Shore:

Shabbat Shalom