Archive for the ‘Articles’ Category.

Geometry Group 2019

1. Perelman’s stunning proof of the million-dollar Poincaré Conjecture needed to consider not just manifolds but “manifolds with density” (like the density in physics you integrate to compute mass). Yet much of the basic geometry of such spaces remains unexplored. Recent results after Chambers ([8], [10]) show in various cases that if balls about the origin minimize perimeter for given volume if they are stable. Major open cases include hyperbolic space with radial density [9]. For a log-concave radial density such as e-1/r, isoperimetric curves probably pass through the origin, like the isoperimetric circles for density rp [4]. Double bubble in plane with density rp would be interesting. See references [1-11] below.

Continue reading ‘Geometry Group 2019’ »

On Construction Using Construction Tools of Finite Size

Nat Sothanaphan wrote this article as a high school student in 2011.

On Construction Using Construction Tools of Finite Size

Passing Michaels Yields Top

Today in Easton sitting East I bid Michaels 2S after 1S-P-1N, showing hearts and diamonds, and my mom passed! We made 2S for a near top.

The Urinal Problem

Nat Sothanaphan wrote this article in Grade 12.

Urinal Problem

Is Making 6N Better Than Making 7N?

Playing at the Bethlehem Bridge Club with Frank Kuebler November 20, 2017, I was North in 6N. It’s 100% on the diamond lead if you’re careful. You can’t go to the board with the Heart Ace to take the club finesse because if it loses you lose a club and a heart (although as the cards lie you’d make 7N here). You can’t even lay down the Club Ace , lest an opponent with four Clubs holds up and cuts your communications (although as the cards lie you’d make 7N here). The guaranteed line is to lose a club and keep the Ace to access the spades in hand.

6S at the Toronto Bridge Club

On July 17, 2017, at the Toronto Bridge Club, my partner Paul Selick and I got to 6S by me in the East. After South played HJ on the second Heart, which I ruffed in dummy, I played for a 3-3 Heart break (which would let me make 7) and went down 1.  Greg Lawler pointed me to the best line: draw trump, overtake the Diamond King with the Ace, and take the Heart finesse. It loses, but a ruffing finesse brings home the Hearts. Note that this line also works if North has both Heart honors, as long as Hearts are no worse than 4-2.

A Squeeze at the Penultimate Trump

On the pictured hand 13 at the Pembury Bridge Club in Pittsfield MA on Wednesday June 14, 2017, as East I made 3S, losing a trick in each suit. After ducking the heart lead and winning the continuation, I could have made 4 by reaching a position with DA5 and H7 in my hand, DJ8 and CJ on the board, and South down to HQ and DQT. Leading my heart endplays South in Diamonds. Peter Winkler explained to me how to make 4 on a Club lead (the previous endplay cannot afford a club loser). After losing e.g. a Club, a Heart, and a Spade, play Spades from dummy, coming down to S53, DJ84 in dummy. Now on the penultimate spade, come down to DAK, Hxx in hand, and South cannot protect both Diamonds and Hearts. (If North leads a Diamond when he gets in with a Club, East will be left with the HA as the second entry to hand. Play Spades in a way to prevent North from getting in to lead Diamonds twice. Curiously, when they start with Hearts, you need to play Spades the other way to prevent South from giving North a Heart ruff.)

Amazing AMS spring sectional in Pullman WA

I just attended an amazing constellation of events around the AMS spring sectional meeting Saturday/Sunday April 22-23, 2017, in Pullman, Washington, organized by Kevin Vixie of Washington State University.

The meeting was preceded by a day on Data Science, with an incredible variety of short talks every 15 minutes, interspersed with discussion periods. Continue reading ‘Amazing AMS spring sectional in Pullman WA’ »

The Life of an Adjunct

Guest post by Donna Kalinowsky

Dear Community College President,

Perhaps you do not know what life is like for an adjunct. When I started here in 1992 or so, I made about $9000 per year. Even then, that was not much. I was eligible for Section 8 housing, food stamps, fuel assistance, Medicaid, head start for my kids, access to local food pantries, Christmas Elf programs for children’s gifts, and the Earned Income credit. Thanks to these things, I was able to raise 4 children, ages 29, 27, 14 and 9. Continue reading ‘The Life of an Adjunct’ »

Retirement Book

screen-shot-2016-11-15-at-8-14-53-amHeartfelt thanks to Brooks Foehl/Alumni Office and especially to my students for their kind remembrances upon my retirement: