- Technical University of DenmarkPost doc, 2011 - present
- National Institute of Information and Communications Technology, TokyoPost doc, 2008 - 2011
- Niels Bohr Institute, University of CopenhagenPhD student, 2005 - 2008
- University of Copenhagen Faculty of SciencePhysics, 1999 - 2005
- Frederiksværk Gymnasium1996 - 1999
It was always available for download from the University's and my own site, but having one more source can't hurt. And somehow it just looks good to have a DOI attached to it :)
What previously seemed to me like pure, irrational madness now at least makes some kind of sense. It doesn't really make them any less scary, though.
Physicists around the world are gearing up for the International Year of Light and Light-based Technologies (IYL), which kicks off later this month at an official opening ceremony at the headquarters of the United Nations Educational, Scientific and Cultural Organization (UNESCO) in Paris. Some 1500 delegates are set to converge on the French capital for the event, which runs from 19 to 20 January, and will include representatives from the UN and UNESCO as well as the Nobel laureates Zhores Alferov, Steven Chu, Serge Haroche and William Phillips.
Honestly, they couldn't have picked a better year. 2015 marks the anniversary of several important milestones in the study of light, including the 1000th anniversary of the publication of Ibn al-Haytham's seven-volume treatise on optics. Alhazen's work transformed the way in which light and vision was understood, earning him the title the "father of modern optics". 200 years ago Fresnel proposed that light behaved like a wave, 150 years ago James Clerk Maxwell published his Dynamical Theory of the Electromagnetic Field, a 100 years ago Einstein embedded light in cosmology through general relativity and it's been 50 years since Wilson and Penzias discovered the cosmic microwave background.
"One of the most exciting aspects of this International Year is the way in which it brings together such a wide range of different communities, from astronomy to medicine and photonics to arts and culture," says Beth Taylor, chair of the UK National Committee for the IYL. "It creates a unique opportunity to cross traditional cultural divides and engage new and different audiences with the excitement of light and its applications."
The IYL will consist of a series of co-ordinated events around the world to communicate the importance of light and optical technologies in society – ranging from the Story of Light Festival in Goa, India, to Worldwide Pinhole Photography Day. Hundreds of events are planned in countries all around the world.
You can find out about events near you using light2015's event programme; http://www.light2015.org/Home.html
If you haven not yet seen the amazing BBC4 series Light Fantastic, make this the year you do. - http://goo.gl/PyK8YC
“We can easily forgive a child who is afraid of the dark; the real tragedy of life is when men are afraid of the light.” -Plato
Some other interesting links;
A History of Light - http://goo.gl/2Q483w
The electromagnetic radiation spectrum - http://goo.gl/bdq752
The Light of my Life - http://goo.gl/ZbHA4O
I took this photo from the bottom of Canyon de Chelly, in Arizona. These buildings, called the White House Ruin, were built around 1200 AD. A bit later, the civilization that built them disappeared!
They're called the Anasazi, or Ancient Pueblo People. Starting around 800 AD, they started building great houses: multi-storied buildings with high ceilings, rooms much larger than you'd see in houses, and elaborate subterranean rooms called kivas. And around 900 AD, they started building houses with stone roofs. We call this the start of the Pueblo II Era.
For a long time their civilization was centered in Chaco Canyon, in New Mexico, 125 kilometers east of Canyon de Chelly. Their biggest great house was founded in the 800s. Starting in 1020 it grew immensely, and it kept growing until 1120. By this time it had 700 rooms, nearly half devoted to grain storage. It also had 33 kivas.
But this was just one of a dozen great houses built in Chaco Canyon by 1120. About 215 thousand ponderosa pine trees were cut down in this building spree! Building these houses probably took over 2 million man-hours of work. They also built about 650 kilometers of roads! Most of these connect one great house to another… but some mysteriously seem to go to ‘nowhere’.
By 1080, however, the summer rainfall had started to decline. And by 1090 there were serious summer drought lasting for five years. We know this sort of thing from tree rings: there are enough ponderosa logs and the like that archaeologists have built up a detailed year-by-year record.
Starting around 1100 AD, many of the ancient Pueblo people left the Chaco Canyon area. Many moved upland, to places with more rain and snow. Instead of great houses, many returned to building the simpler pit houses of old.
By 1150 AD, some of the ancient Pueblo people began building cliff dwellings at higher elevations—like Mesa Verde in Colorado This marks the start of the Pueblo III Era. The settlements in Canyon de Chelly, shown here, date to 1200. But this era lasted a short time. By 1350, all these cliff dwellings were abandoned!
The people didn't leave... they're still around. But they stopped building large settlements. Why? For some answers, read my article:
Sketch of new experiment. Fig 1 from arXiv:1502.03888 Three months ago, I told you about a paper that suggested a new way to look for certain types of dark matter fields, called “chameleon fields” . Chameleon fields can explain the observed accelerated expa...
The giant Humboldt squid First squid cam
Scientists working with a remote imaging team at National Geographic decided to put camera sweaters - tubes of Lycra-like material - on a few Humboldts to get a squid’s eye view of easily one of their most interesting behavior: Color-flashing communication. Scientists aren’t sure what the squid are trying to say, but they are fairly certain they are communicating with each other. Humboldt squid do this by rapidly squeezing cells in their skin called chromatophores and turning their whole bodies from white to red and back again. This flashing can change speed and direction on the skin in response to all kinds of squid interactions, from mating attempts to displays of aggression. But which patterns the squid show off have yet to be mapped onto some kind of color vocabulary.
Paper: Chromogenic behaviors of the Humboldt squid (Dosidicus gigas) studied in situ with an animal-borne video package
Journal of Experimental Biology: http://jeb.biologists.org/content/218/2/265.abstract
Longer video National Geographic Crittercam:
This is the traditional new year cake in Denmark, kransekage. Eaten with a toast of champagne right after midnight, it is a sweet thing made from marcipan and egg white - and with extra almond and sugar for good measure.
It's supposed to have a decorative icing, but I think the little mischievous fellow here licked it off while I wasn't looking ;-)
I wish everybody a sweet 2015!
Sweet physics in your kitchen! :)
Generation of single photons and Schrödinger kitten states of light
Generation of single photons and Schrödinger kitten states of light
Thomas Müller not to blame for Pepe's headbutt during Germany's 4-0 win ...
World Cup 2014: Germany's hat-trick striker Thomas Müller exaggerated his reaction to a shove by Pepe but defender was then deservedly sent
Magical Photos of Insects Shot Using Ordinary Household Objects
The photographs in Nadav Bagim's project "WonderLand" might look like paintings or computer generated images, but they're actually real phot
Incredible Photograph of the Milky Way Rising Over the Sea
Photographer Yasuaki Segawa captured this incredible photograph of the Milky Way rising above the ocean, as seen from Taketomi Island, Japan
Waterfall, Moonbow, and Aurora Captured in a Single Shot
Photographer Stephane Vetter managed to capture a moonbow, an aurora, and an Icelandic waterfall, all in the same photograph. The longer