The Evolution of the Telescope

The Evolution of the Telescope

“My parents gave me a small telescope, then I built my own, and one thing led to another. So that’s how I ended up going from being a hobby astronomer to a professional astronomer.” – Dimitar Sasselov, Bulgarian astronomer based in the United States. He is a Professor of Astronomy at Harvard University and director of the Harvard Origins of Life Initiative.

In the beginning, people’s knowledge about the stars was limited by the power of their own eyes. The inventions of lenses, mirrors, and eventually the telescope made it possible to see more things clearly. The history of astronomy is tied to the development of the telescope, since we need to observe things in order to understand them.

Refracting Telescope

In 1608 Hans Lippershey (or Lipperhey), a Dutch eyeglass maker, was the first man to apply for a patent for the telescope. Others also claimed to be the inventor, but the Dutch government accepted his patent as the first.

Hans Lippershey (or Lipperhey)

Hans Lippershey

While the earliest telescopes only magnified things a few times, Galileo Galilei worked hard and was able to eventually make his telescope magnify things till they were 10 times larger. By 1610, Galileo had a telescope that magnified 30 times. He was able to see craters on the moon and even the moons orbiting the planet Jupiter.

Galileo's ink drawings of the moon. Credit: NASA

Galileo’s ink drawings of the moon. Credit: NASA

A 1754 painting by H.J. Detouche shows Galileo Galilei displaying his telescope to Leonardo Donato and the Venetian Senate.

A 1754 painting by H.J. Detouche shows Galileo Galilei displaying his telescope to Leonardo Donato and the Venetian Senate.

Johannes Kepler also improved upon the early refracting telescopes.  Instead of a concave and a convex lens, he tried two convex lenses.  (Concave lenses curve inward, like a bowl, while convex lenses curve out.) The largest refracting telescope ever built had a lens 40 inches wide.  It opened in 1897 at Yerkes Observatory in Williams Bay, Wisconsin.

A 1610 portrait of Johannes Kepler by an unknown artist

A 1610 portrait of Johannes Kepler by an unknown artist

Yerkes Refractor Telescope, 1897

Yerkes Refractor Telescope, 1897

Yerkes Refractor Telescope, 2006

Yerkes Refractor Telescope, 2006

Reflecting Telescope

Sir Isaac Newton studied Kepler’s work and decided it might be a better idea to build a telescope using mirrors instead of lenses. Mirrors reflect light, while lenses allow light to pass through them and bend (refract) the light.  In 1668 he built the first practical reflecting telescope. For many years scientists used both refracting and reflecting telescopes, but the reflector became the favorite of astronomers.

Diagram of Isaac Newton's reflecting telescope, from the Philosophical Transactions of the Royal Society, 1672.

Diagram of Isaac Newton’s reflecting telescope, 1672. Image courtesy of the Royal Society of London.

Edwin Hubble

Edwin Hubble at the eyepiece of the 100″ Hooker Reflecting Telescope [Photograph by Margaret Bourke-White/Time Life Pictures/Getty Images]

In the 1920’s most STEMists believed the universe was static (unchanging) in size.  But then came along astronomer Edwin Hubble in 1929 who published his findings that the universe is expanding! He did not directly see the universe expand like a balloon but calculated the velocity of light spectra from far away galaxies.  (Light from a galaxy has specific characteristics, spectrum, based on the make-up or composition of the galaxy.) From these calculations, Edwin Hubble determined that nearly all galaxies are moving away from us, and the farther the galaxies are from us, the faster they are moving … the universe is expanding!

Modern Telescopes

Karl Guthe Jansky detected radio waves in outer space in 1931. This discovery inspired engineers to develop radio telescopes and other types of telescopes for measuring and mapping microwaves, gamma rays, and other electromagnetic radiation. These telescopes helped scientists “see” invisible radiation and use it to detect objects such as pulsars.

Hubble Space Telescope Is The GROOVIEST!

The Hubble Space Telescope was launched on April 24, 1990 with the Space Shuttle Discovery. Since then, it has been in a low orbit around the earth. The Hubble Space Telescope is a reflecting telescope that also has digital cameras and satellite communications so it can send us groovy images. These images are clearer than earthbound astronomers can see because the Hubble is outside earth’s atmosphere and gets a clearer view of distant objects. The Hubble is the only telescope designed to be adjusted and repaired in space by astronauts.

Hubble Telescope

Hubble Space Telescope in a low orbit around the earth.

Groovy Images From The Hubble Space Telescope!

“We are like mayflies, fleeting ephemeral creatures who live out their lives in the course of a single day.” – Carl Sagan

A replacement for the Hubble Space Telescope, the James Webb Space Telescope, is planned for launch in 2018. There are always ways to improve the telescope, so we never stop adding to our knowledge of the stars.

Moon Dance” Groovy Lab in a Box

If your STEMist loves telescopes and star stuff, be sure to check out our “Moon Dance” groovy box – explore Earth’s moon, gravity, mass vs. weight, moon phases, tides, light, telescopes and much, much, more.  Join Now! and challenge your STEMists to a monthly Groovy Lab in a Box, full of everything a child needs to learn about and do hands-on science, technology, engineering, and mathematics (STEM) investigations and engineering design challenges. Our monthly box activates thinking, questioning, inquiring and original creation as we guide children through scientific inquiry and the engineering design process.

A groovy thank you to Oh, Star Stuff for providing some of the groovy Hubble Space Telescope images above.