December 7, 2012 3:32 pm
Humans navigate the world predominantly by sight. And yet there are colors and worlds we cannot see. Infrared light—light whose wavelength is longer than our eyes can detect—exists all around us. But we do not see it. Yet. Scientists have engineered some proteins to “see” infrared. New Scientist writes:
The team created 11 different artificial protein structures and used spectrophotometry – a technology that compares the intensity of light going in and out of a sample – to identify which wavelengths they could absorb. Chromophores within one particular protein were able to absorb red light with a wavelength of around 644 nanometres – tantalisingly close to the wavelength of infrared light, which starts at around 750 nanometres. This was unexpected since natural chromophores have a maximum absorption of around 560 nanometres.
“We were surprised,” says Borhan. “But I still don’t know if we’re at the upper limit of absorption yet. I’ve speculated about 10 times and been proved wrong.”
Just like we can’t see infrared, we can’t see all sorts of other wavelengths. Causes of Color explains:
Visible light is merely a small part of the full electromagnetic spectrum, which extends from cosmic rays at the highest energies down through the middle range (gamma rays, X- rays, the ultraviolet, the visible, the infrared, and radio waves) all the way to induction-heating and electric-power-transmission frequencies at the lowest energies. Note that this is the energy per quantum (photon if in the visible range) but not the total energy; the latter is a function of the intensity in a beam.
If we could see in infrared, we’d be able to detect all sorts of things. Well, there would be some problems. New Scientist writes:
If these proteins were present in the eye you would be able to see red light that is invisible to you now, says co-author James Geiger, also at Michigan State University. But since objects reflect a mixture of light, the world would not necessarily always appear more red. “Something that looked white before would now look green with your new super red vision,” he says.
Artists have been keen on this idea for a little while now. Scientist Patrick Degenaar and design studio Superflux have created a concept video combining the edges of optogenetics and lasers.
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