A Physics Puzzle from the Kitchen (sort of)

Diagram of Puzzle

Two perfect conducting spheres are immersed in a fluid with electrical conductivity σ = 5 x 10-2 S/m. The spheres have radius r = 1 mm and are maintained a distance R = 1 m apart. A potential difference of V = 220 V is maintained between the two spheres. The fluid extends to infinity. Calculate the net current flowing between the spheres. (If you've been paying attention, you've noticed that this situation violates charge continuity.

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New CMB Results from BICEP1

Likelihood for Parameter r Calculated from BICEP1 B-mode Measurement

Last week we published new results from the BICEP1 Cosmic Microwave Background (CMB) polarization experiment. (Disclaimer: I'm a coauthor of the paper.) BICEP1 is the first in a series of experiments at the South Pole searching for the signal of cosmological Inflation in the CMB. BICEP1 took data in 2006--2008, but this is the first result to include all three years of data.

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Antarctica 2013--2014 Part 1: Preparation and PQ

South Pole

As some of you know, I'm going back to the South Pole later this year in December/January. Preparing to go to Antarctica is an intensive process. Most of it relates to preparing the measurements and instrument upgrades we plan to make there. However, there's also a medical component. Antarctica is a "harsh continent" with high altitude (the effective pressure altitude at the South Pole is around 10,500 ft.), freezing cold, extreme aridity, and limited medical facilities.

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Up Goer: "Inflation"

Inspired by xkcd's Up Goer Five, I attempted to explain my research using only the ten hundred most common English words. It was pretty hard.

I try to find out what caused the beginning of everything. We think we know what happened back in time until almost the beginning. We know it was very hot then and that everything was moving away from everything else very fast. We have a good idea that explains how it got that way. The idea is called "inflation."

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Detection of CMB B-mode Polarization by SPT

Last week, members of the South Pole Telescope (SPT) collaboration reported the first detection of B-mode polarization in the Cosmic Microwave Background (CMB). Scientists have been searching for B-mode polarization for over a decade because it offers an opportunity to study all the matter in the Universe and the cause of the Big Bang.

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Happy Independence Day

As many of you know, every Fourth of July I read the Declaration of Independence and the Constitution. Every year I'm reminded of the wisdom and foresight that went into them. Here are a few random tidbits from this year's reading:

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Antarctica 2012--2013 Part 9/9

[Note: This is the last in a series of posts adapted from emails I wrote while traveling to the South Pole for research in 2012--2013.]

This is the last entry from the South Pole. I just bag dropped for the flight back to McMurdo tomorrow (Jan. 4). The procedure here is even simpler than at McMurdo. The bag drop is at "Destination Zulu," the rear entrance of the station, so there's no need to drag bags outside. The cargo crew takes care of weighing so all you have to do is put a tag with your name on your bags and leave them there.

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New Results from AMS, Speculation on Dark Matter

Photo of AMS on International Space Station

Last month the Alpha Magnetic Spectrometer (AMS) team reported a new measurement of positrons in cosmic rays (journal article, less technical summary and commentary). The results imply that new, not yet understood physical processes are producing more positrons than expected at high energies.

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Antarctica 2012--2013 Part 8

The Race Around the World was difficult. It was only -10 or so so full ECW wasn't required. I wore my big red but only long underwear underneath and fleece pants instead of snowpants. Even like that I was too hot with the big red all zipped up. I think just a normal jacket would have been better. Some kind of mask is required because breathing cold, dry air too fast can damage your lungs.

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Antarctica 2012--2013 Part 7

There's not much time for recreation when you're working 12+ hours per day.

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