Telescopes have been around since the very early 17th century when Hans Lippershey, Dutch lens maker, applied for a patent in 1608.  They haven’t been around quite long enough for us to take them completely for granted, especially when we have Hubble, et al, rocking our world on a daily basis; but we do tend to look back at those first telescopes and cough politely.  What I think is almost as amazing as the fact of the telescope itself is how bright, how scary-brilliant, men like Galileo, Herschel and Newton were to see so much with so little.

1843 Refracting Telescope, Cincinnati Observatory

What I toss off as “so little” was, in fact, unadulterated genius.  The first telescopes were “refracting”, where basically a lens and eyepiece are used to gather more light than the human eye alone is capable of doing, bending the light (refracting it) so that it comes to a focal point, then giving you a brighter, cleaner magnified image.  The foundation of this science was in the manufacture of eyeglasses.  Can you imagine how boggling the concept of bending light was to the general public?

Although refracting telescopes revolutionized our understanding of astronomy, there are many flaws inherent to the design.  There is distortion of the image that can’t be corrected, for one thing.  Also, although you can place multiple refracting lenses in a line to increase magnification, you’ll quickly have a telescope so unwieldy it’s impossible to use.  Working to correct these (and other) problems, the next major advancement was the reflecting telescope.  A reflecting telescope uses a system of parabolic mirrors instead of refracting lenses.  Isaac Newton had developed a good, working reflector by 1668, but the idea was being kicked about since at least 1616.

Replica of Newton's second telescope, ca. 1672

A “catadioptric” system is one that combines refraction and reflection.  This combination has the advantage of very good error correction coupled with a wide view field.  This is what you’ll often find in telephoto lenses.

Other than optic telescopes (of which these three are examples), there are radio telescopes; infrared telescopes; ultraviolet, x-ray, solar, and space telescopes; gamma-ray, cosmic-ray, gravitational wave, and high-energy particle telescopes, just to name a few.  Seems like for everything at which you would wish to look, there’s a telescope designed for the job.

Very Large Array Radio Telescopes, USA, New Mexico, by Hajor 080804

The science of “seeing far” is really still in its infancy, and every time there’s an advancement in telescopes, there’s a shock wave through the astronomical community.  Imagine what Galileo could have accomplished with a decent, mid-priced modern telescope.  Imagine what he could have accomplished with the Hubble, Webb, or Spitzer space telescopes.

Maybe our next “Galileo” is reading this blog right now, imagining what he (or she) will see when it’s his turn to see far.

Future Astronomers - Image found published to PD on PhotoBucket