What I Learnt Today

“All right… all right… but apart from better sanitation and medicine and education and irrigation and public health and roads and a freshwater system and baths and public order… what have the Romans done for us?”

How Stuff Works has a feature on “10 Cool Engineering Tricks the Romans Taught Us“

If you wanted someone to explain geometry, you asked a Greek. If you wanted someone to build you a floating bridge, a sewer network or a weapon that could fire flaming balls of gravel and tar 300 hundred yards (274 meters), you called a Roman. As much as the Greeks gave us, Rome’s brilliant architectural, organizational and engineering feats that make them stand out among the ancient peoples.

You can read about the ten top engineering tricks of the Romans here.

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“Sometimes I wonder whether the world is being run by smart people who are putting us on or by imbeciles who really mean it.” Mark Twain

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(There is an updated version of this post available here.)

Do you know why Summer is hotter than Winter?

Most people are confident that they know the answer to this. Because the earth is closer to the sun in summer than it is in winter. Right?

No, not right. This is one instance when most people are wrong. The earth is not closer to the sun in summer.

The earth does not spin in a direct up and down axis, but is tilted at an angle of 23 degrees. Because of this tillt, for six months of the year the north pole is on the side tilted away from the sun, and for six months it is on the side tilted towards the sun.

 

These cool photos from a NASA satellite show the amount of sunlight hitting different parts of the earth on different days.

 

NASA also has a time lapse video of the process

It is warmer in summer than winter because

– the days are longer, with more hours of sunlight heating the earth.

-the sun is higher in the sky, meaning more sunlight shines on the earth more directly.

 

At 9am today, September 23, it is the vernal equinox. The sun will be directly above the equator, and it is the first real day of Spring. There will be 12 hours of daylight, and the same amount of night. The days will get longer until the longest day of this year, December 22nd.

The days will be longer than the night till the next equinox, on March 19th

For this six months of the year – from today till March 19th – we in the Southern Hemisphere are on the side leaning towards the sun.

Sometimes our ‘mental models’ of how things work are wrong.

Jonathon Drori discusses these incorrect mental models in this TED talk.

Happy Equinox.

 

 

 

 

 

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You might find out more than you expected.

The fellow who found this message (no, Alex, it wasn’t me), said “But I only wanted to play Angry Birds”.

from Imgur via Gizmodo Australia

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There is nothing in this world that does not have a decisive moment – Cardinal de Retz

French photographers Robert Doisneau and Henri Cartier-Bresson are known as the fathers of photojournalism.

The Decisive Moment is the title of Henri Cartier-Bresson’s 1957 book, which showcased the portfolio of ‘street photography’ he had produced in France, India and China over the preceding 20 years. 

He photographed exclusively in black and white, using a Leica 35mm rangefinder camera.

The Queensland Art Gallery is hosting an exhibition of his works until 27th November.

You can download the QAG / GoMA iPhone app to get an interactive guide to the exhibition.

Robert Doisneau is known for his ‘candid’ shots of amusing and eccentric life in Paris. His most famous work is ‘Kiss by the Hôtel de Ville’, which in fact was not candid at all. Doisneau asked a couple he had seen kissing in Paris to recreate the moment at a number of locations. Being Parisian, they were only too happy to oblige.

There are 60 minutes in an hour, and 1440 minutes in a day.

The Sydney Morning Herald today announced the winners of its photography competition ‘1440: A day, a minute, a moment. Your moment’. Amateur photographers were challenged to capture an image of one moment on a particular day in Sydney. Entires were judged in three themes – Red, Public Transport, and City Living.

The winning entry by Jaroslaw L. Gasiorek was entitled Just Curious.

A gallery of finalists is available at smh.com.au

 

 

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