Sunday, June 11, 2017

Sex Differences in Sports


Here is a run-down on male-female differences and how they might affect sports performance.

Oh, and here's one comparing athletes' bodies to average men.

The Secret History of SCUBA



Chris Lambertsen started working on underwater breathing as a teenager in the 1920s, on the beaches of the Jersey shore. He pursued this vision to become a doctor, inventor and have a few other adventures along the way.

Saturday, April 22, 2017

The Original Earth Day


Whew! If you think the future is bad now, be glad it isn't 1970.
Thirteen predictions* from Earth Day, 1970.

(more Earth Day predictionsSimon and Ehrlich's famous bet)
*(Apr'17) Mark Perry says: eighteen.

Friday, April 21, 2017

Spring 2017 Bridge Contest

The whole class was very good at making bridges this year.
(And very bad at choosing the better of two bridges.)

video 
This year's strongest bridge collapsing in slow motion.


Wednesday, April 19, 2017

Something From Nothing

One of the weirder ideas of Quantum mechanics is that empty space is not empty at all. No matter how empty you make a space, pairs of particles and and anti-particles will spontaneously come into being move around for a while, then touch each other and disappear.

Apparently physics equations predict that this could happen. We just haven't had any evidence for it...and no idea how we could possibly get evidence. A few decades ago someone suggested that if it happened close enough to a black hole one half of that particle pair could be sucked into the black hole while the other half moved away and became permanent new matter in the universe.


This year, a team from the European Southern Observatory's Very Large Telescope found visual evidence via a phenomenon called vacuum birefringence.

Synthetic Blood


Scientists in England have isolated stem cells and persuaded them to produce red blood cells. The first goal is to get them to make complicated and rare blood types.

Saturday, March 25, 2017

Farming Isn't What It Used To Be

Underwater farms...protected by robot shepherds
...that guard their flocks autonomously

The twenty-first century is here and it's awesome!


Cavendish


In 1797, Henry Cavendish performed one of the ten most clever science experiments in history by "weighing the earth".

Last month, John Walker recreated it in his basement.

A Winter Jacket

...in winter, a spring jacket in spring.

Sunday, February 5, 2017

Visiting Other Stars

The Breakthrough Starshot project has a realistic plan for humans to have a spacecraft inside another solar system in 20-30 years. Their idea is to make a swarm of tiny vehicles. They would be thrown into space somehow and propelled onward using a lightsail. Power for the lightsail doesn't need to be stored on the ship. These ones would get little power from the sun. The light would come from a massive laser on earth. The physicists figure they can  achieve speeds of 1/5 the speed of light or 6000 km/s.

Each ship would have a mass of a gram or two. It would be a couple of cm in size but have a light sail that folds out to an area of 4m x 4m.

There are a lot of challenges: powering a computer for 30 years; recording, storing and transmitting photographs and video; cosmic rays; dissipating waste heat and impacts with space debris.

Ultimately, after all that journey, the craft would spend about two days travelling the distance of the earth's orbit.

If you want a ship that can take up orbit around the next star, that will take 100-150 years.

Wednesday, January 25, 2017

Bellyaching about Autism


Now there's a claim that gut bacteria is related to autism.
Apparently gastrointestinal  problems are common among those with autism. This study claims that a transplant of fecal microbes reduces gastrointestinal problems 80%, not too surprising. More remarkable is that it improves social and sleep habits by 20%.

Sunday, January 8, 2017

Dinosaurs Had Feathers

We have long imagined dinosaurs as mighty lizards: scales and all. Every once in a while it is good to be reminded just how little of what we know is fact and how much is speculation.

Our beliefs about dinosaurs are based on reconstructions of skeletons or parts of skeletons. No one has ever seen dinosaur skin. (Whoops, we have, or at least impressions of dinosaur skin.)

Only now, it seems we may have seen the tail of a dinosaur, down to the smallest detail of texture, possibly even some hints of coloring.

(Jun'17 - ...or maybe not.)

Thursday, December 1, 2016

Cuban Life


There is a lot of romance about Cuba. At Castro's death, there has been an attempt to restart the flame. This article from travel journalist Michael Totten puts life for the average Cuban into perspective.

And it doesn't mention Concentration camps, executions, firing squads, the exodus, families fleeing by sea.

Friday, August 5, 2016

Kipling Readings

The Washington Post defends Rudyard Kipling from the fashionable haters. From my point of view it's a Reading list of Kipling, “the greatest short-story writer in English“.

Though I notice three major omissions: If, The Gods of the Copybook Headings * and Tommy.

Sometime in my twenties I noticed a trend.
The time has come to confess that I am an admirer.

(Feb'16) A real fan's guide

* And in song!
**not actually in twenties

Wednesday, May 25, 2016

Living in a Time of Wonders

https://ourworldindata.org/grapher/world-population-in-extreme-poverty-absolute?tab=chart

Note that 1970 is just about exactly when your average North American decided that world poverty was a hopeless problem. 1990 was when international socialism collapsed.
Sept'16-Dierdre McCloskey hazards a guess as to why.

Monday, April 18, 2016

Slow Progress Expected for Zika

http://www.sciencealert.com/this-is-why-it-s-going-to-be-so-hard-to-create
Above is an excerpt from an infographic for a Zika virus vaccine. It politely hints at the problem.
  1. Zika most strongly affects pregnant women and their newborns.
  2. Any tragedies, whether caused by the vaccine, unrelated to the vaccine or even mitigated by the vaccine will be blamed on the vaccine. There will be lawsuits and the damages will be astronomical.
  3. Revenue will not be astronomical. 
 (July'16) I'm not sure I like where this is going.

Sunday, April 17, 2016

Perceiving the Flow of Reality

It seems natural to say that we see the world as it is presented to us, a continuous flow of new situations and new information. On the other hand, if you've ever seen an optical illusion, you know that perception is imperfect. How do we interact with the world?
This study says that our perceptions come to us in the form of "'time slices' lasting only milliseconds." Our mind perceives the world as a moment: all at once for about a quarter of a second, then it goes on to perceive the next moment.
The description reminds me of Ridley Scott's filming technique in the most intense battle scenes of Gladiator. (starting at about 4 minutes)

Saturday, March 26, 2016

Professionalism and Professional Success

http://legacy.ksdk.com/story/news/crime/2016/01/15/madison-county-coroner-record-number-heroin-deaths-2015/78833446/We like to think they go together. Here is an example of a doctor for whom they conflict.
“Why wouldn’t I give patients a Percocet prescription? It makes their life easier and my life easier.”

Wednesday, March 9, 2016

Do You See the Volcano Tornadoes?


http://www.aapt.org/Programs/contests/winnersfull.cfm?id=6571&theyear=2015

The American Association of Physics Teachers has posted the results of its 2015 photo contest. Sure the pictures are great; even better are some of the explanations that go with the winners.