28 Apr '17
Posted in Articles by Eric Shaw
Like the surreal?
Great big things with mind-numbing complexity?
If you’re saying, “Hot dog!” you’ll dig a trip to New Mexico’s Very Large Array—a huuuge collection of 94-foot tall radio telescopes sitting on superwide flatlands 163 miles southeast of Gallup.
The “VLA” is not like alot of other attractions you see in this state.
But the Very Large Array definitely looks into the past.
It gazes so far back, it might boggle your brain.
Consider a clock rewind of billions of years, dear reader.
If you hang around for just a sliver of that, I’ll tell you what the VLA does—and how it does it.
But first: a wee bit on how you get there.
It’s a Long Wild Ride
You’ll follow a rash of deft turns and twists on the 160-mile trip from Gallup to the VLA.
There’s two routes from town, but the best one spins south on Highway 602 for 30 miles, then bumps 4 miles east on Highway 53 (instead of heading west towards Zuni) to catch Highway 36 and go south once again.
Stay glued to 36 for 80-odd miles till you parade into the charming, teeny-weeny town of Quemado (population 250!).
There, after going past the strangely-made Sacred Heart Church, you’ll crash smack-dab into Highway 60 going east-west.
Twist left, and you’ve got 40 miles to go before bursting through the short mountains around an ancient lakebed where the very large Very Large Array makes its home.
Twenty-seven monstrous radar dishes are “arrayed” there in the vast plain of San Agustin.
They first look like pinpricks as you spy them from the teensier-weensier town of Datil (population 50!) that sits plunked on the overlook to the VLA’s big, flat valley.
From Datil, you descend 500 feet and 20 miles to the desert where a bare-bones visitor-center sits.
Beyond the visitor’s center is the 400-square-miles where the VLA’s dishes point their big “feed horns” (dish noses) skyward.
Welcome to a Godzilla flock of baby sparrows begging food from the stars.
Get to the Big Sky
Like so much of New Mexico, the VLA panorama advertises both absence and presence.
Each dish’s 250 tons makes an even grander impression because of the vast, vast sky that hovers over the wide, wide San Agustin plain.
When I was a kid, I liked to stand next to trains on flat fields as they rocketed by.
I still love dirty construction sites filled with wonkin’ big cranes and earth machines laboring under big city skies.
Two years back, I lived in Australia—and a favorite memory was visiting the eighteen towering turbines of the Albany Wind Farm on the southwest coast.
That group of white colossi born of the engineering mind sits on three winding miles of bushy, ocean-bluff side-paths. I was hypnotized by their breadth that day of my solitary stroll.
The VLA reprises my Australian experience, but it’s got 27 behemoths, not 18, and the wide-spaced forest they create stretches over four times as many miles.
It’s great to saunter through it with a herd of gabby, road-tripping friends or in silent, awed solitude.
Radio Wave “Pictures” from Far Away and Long Ago
After enjoying the eye-candy, you might think, “OK! Why this big steel zoo?”
The blandly-painted guest center tells why America spent 79 million dollars in 1972 to build the thing–and what radio telescopes do.
It also tells you how these dishes—sometimes called “antennae”—sift evidence from electromagnetic waves that started streaming toward Earth a gazillion years ago.
The VLA looks as far back as 14 billion years—towards the moment of the cosmos’ first making.
All Electro-Magnetism—All the Time
The VLA exploits our knowledge of electro-magnetism—the basic universal energy that makes up visible light, microwaves, radiowaves and other phenomena you might know about.
The terrible radiation from an A-bomb—that easily destroys your body—is made of teeny-tiny EM waves—like gamma rays and x-rays.
The radio waves that the VLA catches are much, much bigger (imagine, if you can, electro-magnetic waves 35 miles long).
R-waves are just one sort of weird electro-magnetism that’s thrown off by mysterious things in deep space.
If astronomers want to know the structure of galaxies (which radio-wave patterns reveal), find black holes (which send out R-waves—even though they trap light), or track spinning neutron stars that broadcast a rhythmic pulse of R-waves (giving them their name: “pulsars”)—these telescopes are the technology of choice.
Putting Every Wave-piece in One Place
Think of a galactic radiowave like an acres-wide cloth that flows through space—each ripple as long as a mile.
If this “cloth” spreads over the Earth, the only way to get a clear picture of its whole pattern is to build a single dish miles in diameter (waaaay too costly), or an “array” of receivers that can infer the whole shape by locating it’s parts.
Because the VLA “infers” radio-wave patterns from scattered details, its dishes are also called “inferometers.”
Light is a small EM wave, and we know all the complexity of the visual world is expressed by a slim band of energy in the EM spectrum we call “colors.”
We see “color” when colored light is reflected off of things. When all the colors come together we see “white” light. Without all these EM waves around us, we’d see just black.
Imagine that same complexity in much larger waves, and the “pictures” these, too, might create.
For example, we see the sun as an expression of its light waves, but a radio telescope can see it as an expression of radio waves!
The Very Large Array reads long R-waves from the sun and other space things when they fall over its field of “eyes.” It then digitally re-assembles the info, making a “radio-picture” of these sky-bodies-—some of which are millions of times larger than the sun.
The Big Guy Behind it All
The proper title for the VLA is the “Karl G. Jansky Very Large Array.”
This honors the researcher who first figured out that radio waves come from deep space.
He did it in 1933 when he was just 28.
So, if you’ve got time, take a spankin’ cool roadtrip to the VLA.
Besides learning tons about technology and seeing giddy panoramas, you’ll honor one of science’s greats—the father of deep-space radio whose name graces a very surreal place: Karl Guthe Jansky.
READ THE WHOLE ARTICLE AT GALLUPJOURNEY.COM