Monday, April 13, 2009

Vesto Melvin Slipher - the man who saw Red

The Clark telescope dome on Mars Hill, Flagstaff Arizona
From wikipedia

The Lowell Observatory located on Mars Hill in Flagstaff, Arizona cannot boast a huge super-duper telescope like the Hooker on Mount Wilson. In fact, the 24-inch Clark Refracting Telescope is a rather modest affair according to modern concepts. The famed telescope maker Alvan Clark (1804-1887) constructed it using glass blanks made by Chance Brothers of Birmingham and Feil-Mantois of Paris.

But at the time it was taken into use in 1896 the instrument was definitely a great achievement. And also in this case, as in the case of the massive 100-inch Hooker in Mt. Wilson Observatory, the decisive matter was not the power of the telescope itself but the power of the mind that was looking through it.

The founding of the Lowell observatory was made possible by the dedication and skill of Percival Lawrence Lowell (1855 -1916). He is best known for his burning vision to identify that distant dwarf planet that has detectable gravitational effects but is so hard to see. In 1930 his interest finally carried fruit fourteen years after his death when a real nerd, Clyde Tombaugh (1906-1997), discovered it using the 13 inch astrograph in this observatory. In honor of the observatory founder Percival Lowell this "almost planet" was given a name that has his initials PL.

Lowell Observatory astrograph
Discovery of Pluto in 1930

Today the original 24-inch Clark Telescope is still in working condition and is used for educational purposes. The observatory has a place of honor in the history of Astronomy because of the discovery of Pluto. So for good reason it is protected as cultural heritage and as a National Park by the US government.

But on Mars Hill something much more significant was noticed than yet another rock orbiting our sun.

Slipher crater on the moon

The director of Lowell Observatory Earl C. Slipher (1883-1964) had a brother with the unlikely name Vesto Melvin (1875-1969). The boys must have made their mom and dad very proud since their name is now engraved on the moon - the Slipher crater is called after them.

In the time of the First World War things were in quite a flux among the most advanced students of cosmology. A strange fellow who rarely combed his hair had published some of his mathematical thinking on 30th of June, 1905 in a paper titled "On the Electrodynamics of Moving Bodies". This introduces the special theory of relativity which, simply put, is the physical theory of measurement in inertial frames of reference. Easy peacy. Some respected professors of Physics deep in Newtonian world were not all that impressed.

It is one of the three revolutionary papers published in Einstein's Annus Mirabilis that is still causing waves among humanity. Or rather tsunamis, nuclear powerstations and bombs and black holes and so.

The point is that the mathematics this fellow was thinking were indicating that the space is not such a static place after all as the mainstream cosmology based on Newtonian physics had suggested.

But where is the proof? How to verify such cosmic theories that go far and beyon the conditions on planet Earth?

Well - let us see how was my introduction to the subject - does the following sentence ring any bells my dear fellow citizen on planet Earth:

1912, three years after the publication of Einstein's Special Theory of Relativity, an astronomerwith the unlikely name of Vesto Melvin Slipher used the 24-inch Clark Refracting Telescope in Lowell Observatory, Mars Hill, Flagstaff, Arizona, to demonstrate that light coming from the spiral nebulae, those hazy clouds in the sky, has a spectral shift towards red.


  1. Nyt en oikein löydä tuota johtolankaa - punainen? Näki punaista? Missä kerrot siitä enemmän?

  2. tekstin viimeinen lause kertoo, että vuonna 1912 Slipher havaitsi nebuloiden spektreissä siirtymää kohti punaista. käytän tässä tekstissä paljon aikaa kuvatakseni niitä puitteita, joissa tämä äärimmäisen tärkeä havainto tehtiin. kirjoitan pian tästä suuresta aiheesta lisää Edwin Hubblen yhteydessä.