All posts tagged light

Please do not make Daylight Saving Time permanent. Not just because I don’t want to have noon coming at 1PM permanently, but for many other good reasons. If you’d like a good synopsis of the reasons, read this Scientific American article. Here’s a sample:

Less sunlight in the morning makes it harder for us humans to get started in the day, and more sunlight in the evening makes it harder to get to sleep. Darkness is a signal to the pineal gland in our brains that it’s time to start producing more melatonin, which is our body’s cue to lower internal temperature and start feeling sleepy. Early morning light is detected by the suprachiasmatic gland, which sits above the optic nerves, and its instructions cause our bodies to stop melatonin production so we can feel wakeful throughout the day.

Maybe the saddest reason to reject this mistake is the fact that in 1973-74, when the US tried permanent DST, more children walking to school in the dark were killed by cars.

Please, don’t be swayed by the false notion that we’d be ‘saving’ daylight. We’d only be shifting it later in the day, and making things worse.


Painting by Edvard Munch – Public Domain

Did Edvard Munch paint nacreous clouds? The hypothesis was put forward by Norwegian scientists at the European Geosciences Union General Assembly in Vienna this spring (2017.) The long-held assumption is that the vividly colored sky in The Scream (1893) is a reflection of the artist’s troubled mind. A facile analysis and attractive mostly for the reason that we like to attribute romantic madness to our artists. More careful research is showing that some paintings that have been thought to contain fanciful imagery are really representing unusual meteorological phenomena, such as the lurid sunsets that happened after the volcano Krakatoa (1883) put huge quantities of aerosols into the atmosphere.

Munch himself said in his diary about the incident that inspired The Scream:

I went along the road with two friends — the sun set

I felt like a breath of sadness —

— The sky suddenly became bloodish red

I stopped, leant against the fence, tired to death — watched over the

Flaming clouds as blood and sword

The city — the blue-black fjord and the city

— My friends went away — I stood there shivering from dread — and

I felt this big, infinite scream through nature

Photo credit – Deven Stross

Check out the links and get the rest of the story. Go have a look at the Green Comet Cloud of the Day post on nacreous clouds and see if they look anything like the sky in Munch’s The Scream. This could be speculation, somewhat like my suggestion that Vincent van Gogh might have been inspired by asperatus clouds to paint some of his skies. It is also quite possible that this hypothesis is accurate and that Edvard Munch really did see nacreaous clouds. Personally, I prefer it to the analyses of pop psychologists.

Photo credit – NASA – PD


Cloud of the Day – International Cloud Atlas

The International Cloud Atlas has recently published a new edition, the first in thirty years. The 2017 edition is only the fifth one, with the first coming out in 1939, so it’s pretty special. The International Cloud Atlas is a product of the World Meteorological Organization, an agency of the United Nations. The Atlas takes much the same approach as I do in their definition of what is a “cloud.” In my Cloud of the Day series I have included many things that aren’t strictly clouds, such as rainbows, haloes and sprites. The Atlas collects them all under the umbrella of meteors. So we have hydrometeors — meteors composed of water — that include things other than clouds, such as fog and rain. And there are photometeors, that are made by light, such as rainbows, etc . Electrometeors include auroras and Saint Elmo’s fire. There are even lithometeors, made of dry particles, like dust and haze. I don’t feel quite so bad now. If the UN can do it, who am I to cavil?

The existing classifications have been reviewed and all have been retained. Several new, formal cloud classifications have been introduced. These include one new species (volutus), five new supplementary features (asperitas, cauda, cavum, fluctus and murus), and one new accessory cloud (flumen). The species floccus has been formally recognized as being able to occur in association with stratocumulus. The separate section on Special Clouds has been removed, and the cloud and meteor types previously discussed within this section have been integrated into the cloud classification scheme as cataractagenitus, flammagenitus, homogenitus, silvagenitus, and homomutatus.

This edition of the International Cloud Atlas includes new additions, including one you might remember seeing here when it hadn’t yet been accepted as a unique type. I wrote about it as asperatus, but they’ve changed the spelling to asperitas. This cloud was championed by the Cloud Appreciation Society, a collection of enthusiastic amateurs, and great photographers.

Photo credit – NASA – PD

Enjoy this fresh edition of the International Cloud Atlas. It has a searchable image gallery.



Levon Biss is a successful commercial photographer. His work has been used in advertising, on magazines and in a book about soccer. Now he has an exhibition of his images of insects, showing the Oxford University Museum of Natural History’s insect collection in stunning detail. The exhibition runs from May 27 to October 30, 2016, and it’s called Microsculpture. The prints range in size up to three meters, each an image of a tiny insect captured down to the finest detail.

These are not just snapshots of pretty bugs. Each image takes about three weeks to complete. He shoots each insect in sections — about thirty on average — and then compiles the shots into a single, complete image. In all, he shoots 8,000 to 10,000 photographs of each bug, then combines the best parts of them into the final product. He needs to get the lighting and the focus just right for each tiny part, so the whole image can be perfectly lighted and focused. Since the depth of field is so small with a microscopic lens, he can only move the camera ten microns between shots. That’s not much more than a tenth of the width of a human hair.

If you want to see the detailed originals of these small samples, follow the links to Levon Biss’s Microsculpture website. There you can see the light reflecting off the individual cells of compound eyes, and count the hairs on little buggy legs. There’s also a video that shows how he did it.

All photos copyright Levon Biss.