One of the founders of American Country Music was Jimmy Rogers (1897 – 1933), who sadly died young of TB. In 1930 Jimmy first recorded his song “Muleskinner Blues”, a yodelling lament of a muleskinner looking for work. Over nearly a century this song has been covered by all the greats of country music. One of my favourite versions is by the “Sweethearts of the Rodeo” singing at “Larry’s Country Diner”. You can find that on YouTube.
How can Americans have a job for someone skinning mules? That sounds barbaric! But it is not what you think. In early 20th-century American slang, to “skin” a mule meant to outwit it. Mules are stubborn, and the muleskinner was a mule driver who could coax the animal into doing work. Incredibly, a teenage muleskinner became a famous astronomer, one of the discoverers of the expansion of the Universe.
Milton Humason (1891 – 1972) was born in Dodge Center, Minnesota, a small town that still has only 3000 people. In 1903, aged 12, he was sent to a summer camp in California where he fell in love with the environment of Mount Wilson, a 1740-m peak in the San Gabriel Mountains above Los Angeles. Two years later at age 14 he had dropped out of school and got a job as a muleskinner, leading mules laden with building materials up Mt Wilson to build the then-largest telescope in the world, the 100-inch (2.5-m) Hooker Telescope. The 2.5-m refers to the diameter of the mirror that collects the light from stars and galaxies. The biggest telescopes can see the faintest, therefore furthest, objects.
In 1910 Milton the muleskinner met Helen Dowd, the daughter of the new observatory’s chief engineer. Milton and Helen married in 1911 and moved off to begin farming. But a new opportunity came up. Helen’s father was able to offer Milton a job at the Mt Wilson Observatory – as janitor! There were objections, as this was clearly nepotism, but Milton got the job.
It was quickly recognised that he had skills well beyond tidying up, and the foremost astronomer, Edwin Hubble, eventually promoted Milton to observer. This was a tough job, working all night in the dark in often freezing conditions. (I know. I did this myself for many decades at Sutherland in the Karoo, and then eventually with the world’s biggest telescopes – up to 8-m – in Hawaii and Chile.)
Galaxies are systems of about 100 billion stars. Our Milky Way is one. By the 1920s astronomers could measure the velocities of galaxies using spectroscopy and had noticed that that the fainter (therefore further) galaxies were often moving away from the Milky Way at high speed.
Hubble needed spectra of faint galaxies to study this in more depth. He offered Milton the job of doing the observing. To get the spectrum of a galaxy could take up to three nights and the observer had to sit looking through the eyepiece making sure that the telescope tracked the galaxy very precisely. From the end of twilight in the evening until dawn the next day Milton sat with eye glued to the eyepiece in the freezing cold darkness. He then had to go to the darkroom and develop the photographic plates, and then measure them to determine the velocity of the galaxy. This was hard, hard work, but he was patient, meticulous and very good at it.
From Milton’s observations Hubble discovered the law of the expansion of the Universe, now known as Hubble’s Law. That was published in 1931 with Milton Humason as the co-author. Hubble’s Law contains the “Hubble constant” which is the number that tells us that the universe had a beginning 13.8 billion years ago.
Over a career lasting decades Milton measured the velocities of 650 galaxies, each one taking from 1—3 nights of observations. Today a giant telescope operating electronically and automatically can do all this in one or two nights with instant results. Times do change.
Milton Humason, a teenage muleskinner who dropped out of school at 14, had an illustrious career as an astronomer, as the co-discoverer of the expansion of the universe. In 1950 he was awarded an honorary Doctor of Science degree by Lund University in Sweden. When he retired in 1957, he and Helen moved to Mendocino, California (current population 1000). Their son offered to buy him a small telescope for his retirement, to which he said an emphatic “No!”. He said he had spent a life looking through the eyepiece of a telescope and that in retirement he was going fishing. Which is what he did.
Students now must study maths, physics, astronomy, engineering, and computer science to become astronomers. Being a muleskinner is no longer a pathway to this career.
- Donald Kurtz is Extraordinary Professor at North-West University in Mahikeng. He has an A-1 rating from the South African National Research Foundation, its highest rating. He also holds appointments in the UK of Emeritus Professor at the University of Central Lancashire and Visiting Professor of Astrophysics at the University of Lincoln.
- This article was first published in Talk of the Town, June 27, 2024. The newspaper serving the communities of Ndlambe and the Sunshine Coast, with a weekly wrap of Makhanda news, is available at stores from early on Thursdays.