These wavelengths have the rather ungainly "millimeter and submillimeter" label. There's "far-infrared" at about 100 microns, and this regime runs from there out to, well, about a millimeter.:-)
I am an astronomer who works with submillimeter wavelengths at the James Clerk Maxwell Telescope (JCMT). In this regime, we're really at the boundary between optics and radio. You can almost think of it as the boundary between whether you treat light as a wave or as a particle.
Some of our astronomical instruments are radio-style "heterodyne" receivers which treat the light as a wave and produce spectral line information (telling you what molecules are out there and what they're doing). It's a bit like sweeping a radio dial through a range of frequencies and marking the signal strength of all the stations.
Other detectors treat the light much more as a particle, just measuring the total amount of radiation falling onto a pixel. On the JCMT we have such an instrument called SCUBA (the Submillimeter Common User Bolometer Array). They're analogous to the CCDs used at optical and infrared wavelengths. I'm guessing that the work mentioned in the article refers to detectors of this type, but I could of course be wrong.:-)
Telescopes like the James Clerk Maxwell Telescope (JCMT) and the Caltech Submillimeter Observatory (CSO) have been using these THz waves to do astronomical research for about 15 years.
THz waves are in the millimeter/submillimeter regime of the electromagnetic spectrum, placing them between the far-infrared and the radio.
Just like we use infrared light to look at things which are at roughly room temperature, we use submillimeter light - with wavelengths about 10 times longer - to look at things which are about ten times cooler, down to a few tens of Kelvin above absolute zero.
This includes solar system bodies, comets, and clouds of interstellar gas and dust - the birthplaces of new stars. Just like in the articles, we can use submillimeter waves to see through things that entirely block visible (optical) light.
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Erm, but 540 nm = 540e-9 m = 5.4e-7 m, not 5.4e-10m. So, the frequency of 540 nm wavelength light is about 3e8/5.4e-7 = 5.6e14 Hz = 560 THz.
This is roughly in the middle of visible light (400 to 700 nanometers) so light is indeed about 550 THz.
The article's talking about stuff with a frequency down about 1 THz, though, rather than hundreds of THz (which puts you up near a petahertz).
These wavelengths have the rather ungainly "millimeter and submillimeter" label. There's "far-infrared" at about 100 microns, and this regime runs from there out to, well, about a millimeter. :-)
I am an astronomer who works with submillimeter wavelengths at the James Clerk Maxwell Telescope (JCMT). In this regime, we're really at the boundary between optics and radio. You can almost think of it as the boundary between whether you treat light as a wave or as a particle.
Some of our astronomical instruments are radio-style "heterodyne" receivers which treat the light as a wave and produce spectral line information (telling you what molecules are out there and what they're doing). It's a bit like sweeping a radio dial through a range of frequencies and marking the signal strength of all the stations.
Other detectors treat the light much more as a particle, just measuring the total amount of radiation falling onto a pixel. On the JCMT we have such an instrument called SCUBA (the Submillimeter Common User Bolometer Array). They're analogous to the CCDs used at optical and infrared wavelengths. I'm guessing that the work mentioned in the article refers to detectors of this type, but I could of course be wrong. :-)
Telescopes like the James Clerk Maxwell Telescope (JCMT) and the Caltech Submillimeter Observatory (CSO) have been using these THz waves to do astronomical research for about 15 years.
THz waves are in the millimeter/submillimeter regime of the electromagnetic spectrum, placing them between the far-infrared and the radio.
Just like we use infrared light to look at things which are at roughly room temperature, we use submillimeter light - with wavelengths about 10 times longer - to look at things which are about ten times cooler, down to a few tens of Kelvin above absolute zero.
This includes solar system bodies, comets, and clouds of interstellar gas and dust - the birthplaces of new stars. Just like in the articles, we can use submillimeter waves to see through things that entirely block visible (optical) light.