On 20 December 2013, The
United Nations General Assembly 68th Session proclaimed 2015 as the
International Year of Light and Light-based Technologies. "An
International Year of Light is a tremendous opportunity to ensure
that international policymakers and stakeholders are made aware of
the problem-solving potential of light technology. We now have a
unique opportunity to raise global awareness of this." John Dudley,
Chairman of the IYL 2015 Steering Committee
2015 is also the Einstein Centenary. In 1915, the theory of General
Relativity developed by Einstein showed how light was at the center
of the structure of space and time.
Thought I would toss in a few facts about light.
Lighting represents almost 20% of global electricity consumption.
The first commercially viable incandescent light bulb, patented by
Thomas Edison in 1880, used a filament made from burned bamboo.
Other animals can see parts of the spectrum that humans can not, for
example, a large number of insects can see ultraviolet light.
The giant squid, Taningia danae, has the largest light-producing
organs of any living creature. The lemon-yellow light organs are
called photophores and are found at the tip of the two of the
squid’s feeding arms and they flash blinding light.
The speed of light in a vacuum is about 186,000 miles per second
(300,000 kilometers per second).
Light takes 1.255 seconds to get from the Earth to the Moon.
More than half of the visible sunlight spectrum is absorbed within
three feet of the ocean's surface; at a depth of 10 meters, less
than 20% of the light that entered at the surface is still visible;
by 100 meters, this percentage drops to 0.5%.
Refraction can make things look closer than they really are. The
difference in speed between light traveling through water and
through air means that, from the surface, a 13ft (4m) pool appears
to be just 10ft (3m) deep.
Between 18% and 35% of the human population is estimated to be
affected by a so-called "photic sneeze reflex," a heritable
condition that results in sneezing when the person is exposed to
bright light.
Here is a link to "Light my
Fire" by the Doors, just because.