The fact that when we look up at the sky we are also simultaneously looking back into time is one of the most mind-bending points to ponder in science. We can literally see distant galaxies as they looked billions of years before Earth even existed.
Indeed, the images compiled from these very large arrays of radio wave antennas are astounding. However, the VLA and other radio astronomy observatories' use of radio waves is more accurately described in analogous human biological terms as "seeing" as opposed to "listening." It's more akin to our eyes, sensitive to electromagnetic (EM) radiation, not our ears, which pick up tiny pressure waves in the atmosphere.
I know that "listening" has been commonly used for the VLA, but reenvisioning it as "watching" opens up a world of insight into modern devices which rely on detecting, imaging, and emitting photons. The complete spectrum includes a very narrow band of frequencies (wavelengths) that make up the familiar rainbow of visible light. But other bands of shorter and longer wavelengths, discovered in the late 1800s, over the past century have been exploited in hundreds, perhaps thousands, of useful (some would say essential) applications.
- radio waves (as detected by the VLA) with radio stations appearing in America in the 1920s
- microwaves (as in your oven, cellular phone networks, WiFi, GPS and radar) developed during and after WWII
- visible light (LEDs, incandescent and fluorescent bulbs, lasers)
- infrared radiation (used in night vision goggles and military applications)
- X-Rays and gamma rays (used in medical imaging)
The most mind-boggling recent discovery in astronomy has not been in the imaging of EM waves, but in the detection of gravitational waves, tremors in the very fabric of space itself. The first event was detected in 2015 by the LIGO (Laser Interferometer Gravitational-wave Observatory) arrays in Louisiana and Washington (state), a century after the use of the observational technologies based on EM radiation. These incredible sensors also passively "listen" and "watch," but more precisely in human terms, they "feel" these infinitesimally small vibes. The events they detect are also way back in time. One possible objective is to go back in time so far as to sense the very origin of the universe itself, impossible with traditional technologies.
From the LIGO web site: (https://www.ligo.caltech.edu/page/why-detect-gw) "Detecting and analyzing the information carried by gravitational waves is allowing us to observe the Universe in a way never before possible, providing astronomers and other scientists with their first glimpses of un-seeable wonders. "
The fact that when we look up at the sky we are also simultaneously looking back into time is one of the most mind-bending points to ponder in science. We can literally see distant galaxies as they looked billions of years before Earth even existed.
I keep a folder on my desktop of places to visit, this is going in that folder! thanks Rainey :)
Indeed, the images compiled from these very large arrays of radio wave antennas are astounding. However, the VLA and other radio astronomy observatories' use of radio waves is more accurately described in analogous human biological terms as "seeing" as opposed to "listening." It's more akin to our eyes, sensitive to electromagnetic (EM) radiation, not our ears, which pick up tiny pressure waves in the atmosphere.
I know that "listening" has been commonly used for the VLA, but reenvisioning it as "watching" opens up a world of insight into modern devices which rely on detecting, imaging, and emitting photons. The complete spectrum includes a very narrow band of frequencies (wavelengths) that make up the familiar rainbow of visible light. But other bands of shorter and longer wavelengths, discovered in the late 1800s, over the past century have been exploited in hundreds, perhaps thousands, of useful (some would say essential) applications.
(https://en.wikipedia.org/wiki/Electromagnetic_spectrum)
- radio waves (as detected by the VLA) with radio stations appearing in America in the 1920s
- microwaves (as in your oven, cellular phone networks, WiFi, GPS and radar) developed during and after WWII
- visible light (LEDs, incandescent and fluorescent bulbs, lasers)
- infrared radiation (used in night vision goggles and military applications)
- X-Rays and gamma rays (used in medical imaging)
The most mind-boggling recent discovery in astronomy has not been in the imaging of EM waves, but in the detection of gravitational waves, tremors in the very fabric of space itself. The first event was detected in 2015 by the LIGO (Laser Interferometer Gravitational-wave Observatory) arrays in Louisiana and Washington (state), a century after the use of the observational technologies based on EM radiation. These incredible sensors also passively "listen" and "watch," but more precisely in human terms, they "feel" these infinitesimally small vibes. The events they detect are also way back in time. One possible objective is to go back in time so far as to sense the very origin of the universe itself, impossible with traditional technologies.
From the LIGO web site: (https://www.ligo.caltech.edu/page/why-detect-gw) "Detecting and analyzing the information carried by gravitational waves is allowing us to observe the Universe in a way never before possible, providing astronomers and other scientists with their first glimpses of un-seeable wonders. "
Excellent choice! Truly AMAZING..."in service of our wonder." Thank you!