Happy Birthday Carl Sagan

Carl Sagan was a towering figure in science. He was born on November 9, 1934, in Brooklyn, New York, and died following a long battle with cancer on December 20, 1996, in Seattle, Washington. In between, in just 62 years, he reshaped public understanding of physics, astronomy, and space exploration. More than this, he was a leader in exploration and discovery, involved in many of the scientific teams behind truly ground-breaking space missions in the 1960s and 1970s, including the Apollo moon landings and the Viking missions to Mars.

I first started to encounter Carl Sagan as a popularizer of science while an undergraduate at University of Guelph, and wrote a couple of columns mentioning him for The Ontarion, the university’s newspaper, in the early 1980s. I briefly thought of pursuing grad work on exobiology but ended up continuing along with evolutionary ecology instead, at Guelph for a few more years. His influences are still all around us.

Visit the Carl Sagan Portal to experience a little of this amazing gentleman’s life and contributions: http://www.carlsagan.com/

One Day, If We Not Destroy Ourselves…

… we will venture to the stars. A still more glorious dawn awaits, not a sunrise, but a galaxy rise. The rising of the Milky Way.

The sky calls to us indeed.

These words are from the musical composition “A More Glorious Dawn” featuring the worlds of Carl Sagan and Stephen Hawking, arranged by melodysheep, AKA John D. Boswell. In his series of compositions entitled “Symphony of Science,” Boswell has certainly struck a chord with me. The tune runs through my head, like many an ear-worm. Over the past couple of weeks, however, it’s been running particularly deep.

At the end of May 2013 I had the privilege of spending a week or so in Arizona. The past six or eight months have been a time of rediscovery for me in several ways. I guess it all started with getting an old, dusty box out of storage in the fall. You see, my father was an engineer, and a very gentle man, and was fascinated with astronomy, and aircraft, and boats, and photography, and so many other things, too.

When I was little Dad bought what was for the time a quite good home telescope – a 4.5″ reflector marketed under the brand name Tasco. It had rather wobbly wooden legs, and the finish on the German equatorial mount wasn’t terribly impressive, and it only had little 0.95″ eyepieces. But it worked. It worked well to show the brighter planets and the moon to whomever wanted to take a look.

Although he never joined an astronomy club, my father loved to introduce people to our neighbours in the solar system with this white 4.5 incher. He was especially fond of taking the telescope up to the family cottage and showing the neighbours around. Today, nearly 20 years after his death, and likely 30 years after he had the ‘scope out of its box, friends at the cottage still talk with me about my Dad and his telescope.

I pulled the old ‘scope out of storage last fall. It had been sitting around its Styrofoam and cardboard carrier for a long time. Something seemed to grab me when I took it out of the box and set it up. I’ve now used the old ‘scope a few times, and have even coaxed it into taking a few photos… something I dreamed of years ago but never accomplished.

It touched off something, putting the telescope together, re-familiarizing myself with the mount and all of its details. It prompted me to start looking up again. And, it fueled the flaring passion for the sky that has resulted in several things. For one thing, this blog was borne out of that renewed passion. For another, I now have quite a fleet of home telescopes, something I fear needs a bit of trimming, actually. Too much of a good thing?

And all of this led me, last week, to a remote inn south of Benson, Arizona. Sitting down in a chair out in the desert, I looked up at the sky, and started taking images of the stars with a camera and tripod. And I listened again to “A More Glorious Dawn” on with my iPhone. I was feeling a bit lonely. I listened to Carl Sagan’s wonderful voice and powerful words. And I wondered once more what it’s all for.

And then I remembered the words in the film Cosmos, based on Sagan’s first-contact novel. In the story an alien that projects itself the image of the protagonist’s father states that in all of their exploration of the galaxy, the only thing that makes it all bearable is each other.

Thanks Carl. Thanks Dad.

Copyright © 2013 David Allan Galbraith

Merry Christmas – a gift for the future

I cannot think of a more powerful message than that offered up by “Symphony of Science” (http://www.symphonyofscience.com/ – AKA John Boswell, AKA melodysheep) in their original music video, composed from the words of Carl Sagan and Stephen Hawking, in A Glorious Dawn. All of the work of this program, and this piece in particular, have captivated me since this past November, when I was introduced to them in a presentation on finding hope in a climate change universe, by Grant Linney.

My very low-cost present to you: enjoy, contemplate, be moved – and take action to help secure a positive, bright, and rational future for our children’s children’s children:

Star Stuff? Try “Big Bang Stuff!”

One of the (deservedly) frequently quoted observations by my hero Carl Sagan is that we are all star-stuff. The chemical elements in our bodies – and everything we see around us on Planet Earth – were forged in exploding stars billions of years ago. This is a profound realization. It seems to me that doesn’t go far enough, however.

I started thinking about the origins of the elements in our bodies, and made a connection I haven’t seen elaborated before. To explain myself, I have to explain the origin of the universe first.

The 98 elements that occur in nature are divided up by astronomers into two groups: hydrogen and helium, and “metals:” all the other stuff. Hydrogen and helium were the products of the evolution of matter following the big bang. The “metals” were subsequently produced in a process dubbed nucleosynthesis: nuclear fusion taking place within stars (the process was worked out over half a century ago; the landmark paper is E. M. Burbidge, G. R. Burbidge, W. A. Fowler, F. Hoyle. 1957. Synthesis of the Elements in Stars, Rev. Mod. Phys. 29: 547). The proportions of these things are considered very important. The ration of hydrogen to helium in the observable universe is one of the hallmark tests for cosmology and models of the origins of the universe. Different models predict different ratios, and only the natural ration of about 76% hydrogen to 24% helium gets to decide which models fly.

The other stuff is used to characterize stars, with a measure called metallicity – the proportion of the stuff of the star that is not hydrogen or helium. For example, the metallicity of the sun is approximately 1.8% by weight. Put the other way, the sun is 98.2% hydrogen+helium by weight. This quantity is very helpful to astronomers as it’s a measure of the age of stars, among other things. The older the star, the higher the expected metallicity, as the metals are added by the very process of fusion. Looked at one way, it’s stellar pollution.

This started me thinking about human metallicity. There’s a nice summary on Wikipedia on the elemental composition of the human body (http://en.wikipedia.org/wiki/Composition_of_the_human_body). Here are the top ten elements and the percentage of the body, by weight and atomic proportion, that they represent:

  • Oxygen – 65% by weight but 24% by atomic proportion
  • Carbon – 18% by weight but 12% by atomic proportion
  • Hydrogen – 10% by weight but 63% by atomic proportion (!!)
  • Nitrogen – 3% by weight but 0.58% by atomic proportion
  • Calcium – 1.4% by weight but 0.24% by atomic proportion
  • Phosphorus – 0.78% by weight but 0.14% by atomic proportion
  • Potassium – 0.25% by weight but 0.033% by atomic proportion
  • Sulfur – 0.25% by weight but 0.038% by atomic proportion
  • Sodium – 0.15% by weight but 0.037% by atomic proportion
  • Chlorine – 0.15% by weight but 0.024% by atomic proportion

Ok, so what, I hear you say. Well, look at #3 in this list – hydrogen. Ten percent of our body mass is hydrogen, in chemical compounds like water, sugars, and all sorts of other things. However, two facts about hydrogen are important. First, it’s the lightest element there is, so 10% by weight is a big number by atoms. Second, hydrogen was not made by nucleosynthesis. It was made by the Big Bang itself – and sixty-three percent of the atoms in our bodies are hydrogen.

If we shift our attention away from overall proportions by mass and re-list things by number of atoms, we see a different picture of our own composition. Yes, we are star-stuff – but 63% of the atoms in our bodies have their origins in the Big Bang itself. These humble hydrogen atoms that are the majority population in our bodies – and are the most abundant stuff in the visible universe –  went through stars that exploded, but they came from the Big Bang. In a real sense, so did we.

© 2012, David Allan Galbraith

Enjoy Winter Solstice 2012!

It’s the moment of the Winter Solstice, an event that has both cultural relevance around the world and is an element of a real science (Astronomy). Read something meaningful today, like Ann Druyan and Carl Sagan’s “The Demon-Haunted World: Science as a Candle in the Dark.” (http://books.google.ca/books/about/Demon_Haunted_World.html?id=5QpLlsPPM_YC&redir_esc=y)

Today (21 December 2012) was hyped onto a cottage industry of world-wide catastrophe by a few self-interested charlatans who prayed on the gullible. It’s a very, very old story. Carl Sagan has been quoted as saying that extraordinary claims require extraordinary evidence. The whole proposition that an ancient Mayan calendar foretold that today would be the end of the world was based on less than evidence – just a misinterpretation of an ancient document. This was not the first time, or the last time, that whole industries will be built on taking ancient texts and cooling up some baloney about their inferred meaning for the future.

There is only one knowledge system that can make evidence-based predictions about the future, and that’s science. Furthermore, the method of science is dependent on putting out predictions and then testing them against nature. In science, a failed prediction just means that the hypothesis upon which it was based was falsified – it didn’t work, and we try again. In chicanery a failed prediction has no consequences, except that it’s further evidence that, as is attributed (without evidence that he said it) to P. T. Barnum, “There’s a sucker born every minute.” It’s sad. The universe is beautiful, mysterious, and rich beyond the imaginings of any of us, modern or ancient. Get to know it for itself. Look for yourself, ask questions for yourself. Get to understand. Reject what doesn’t work. And – surprise – you will be applying the scientific method yourself. It’s not about believing in anything except that the evidence you can trust is evidence that has passed the test of being put up against the touchstone of nature.

© 2012, David Allan Galbraith