WHATS IN THIS BLOG:
• Space science started with Sputnik.
• Discovery of Van Allen belts of radiation.
• Cosmic rays.
• My supervisor was famous.
• Life-learnings for me.
I worked in space science for over ten years. This blog article is about my initial study of cosmic radiation. It was a critical step in my R&D career.
But first, a brief laugh. In my early days in the USA an airline stewardess leaned across the empty seats and said, “I just love your accent.”
After I explained it was an Australian accent, she asked what my work was.
“I’m a space scientist,” I said.
She looked blank for a minute, then said with a big smile, “Oh, I’ve always loved spices.”
The following is a mix of history and technology in the dramatic discoveries of space science in the early days. My involvement was minor, but I did reach out and touch some famous personalities who influenced my career. The story includes some valuable life-learnings. If its heavy going, jump over the DIVERSION parts. If its still heavy going, jump to the LIFE-LEARNINGS at the end.
SPACE SCIENCE STARTED WITH SPUTNIK, the Russian satellite that was launched in 1957. I remember lying on the lawn in Jamestown, South Australia looking up at Sputnik, no larger than any other star, moving slowly across the night sky. The USA was beaten out in getting the first satellite up there and was awfully embarrassed. However just one year later in 1958 the USA discovered the Van Allen belts of charged protons and electrons that were trapped in the earth’s magnetosphere. A major scientific accomplishment!
Just last week, I drove past the University of Iowa, Iowa City, in a state that in summer is covered in cornfields. This is where a scientist called James Van Allen became a famous space scientist. His tiny little Geiger counter was sent aloft on a small satellite, Explorer 1, that looked like a torpedo. The satellite was carried up into orbit by a Redstone rocket designed by Wernher von Braun, a famous rocket scientist.
DIVERSION: FOR FOLKS WHO LOVE HISTORY. Von Braun worked for the Nazis in World War II designing their new V-2 rocket. Beginning in September 1944, over 3,000 V-2s were launched by the Germans against Allied targets, London being the first. Wernher von Braun and over 100 key V-2 personnel finally surrendered to the Americans. The Redstone rocket was the American version of von Braun’s V-2 rocket.
DISCOVERY OF THE VAN ALLEN BELTS. It was an unexpected discovery. Van Allen’s detector failed for a period, then seemed to work fine before failing again. The scientists were worried that it would fail permanently. But the regular failings provided a clue. It turned out the detector was overloaded with so many counts that it seized up when it passed through belts of intense radiation – which came to be known as the Van Allen belts. The USA recovered much of its lost pride.
It was ten years later in 1968 when I entered graduate school. Space science was still hot. Just one year later in 1969, Neil Armstrong stepped onto the moon’s surface and announced it was “One small step for a man, one giant leap for mankind.”
Many years later in 1977, during a presentation at a national conference, Van Allen unexpectedly praised some of my own space science work (diffusion of solar cosmic rays from sun to earth, see below). He had dabbled in this kind of modeling himself, and said he was impressed with my work. I breathed in the accolade and felt very proud. I ran into him that evening strolling down main street and shook his hand warmly. I can’t recall anything he said, just that the snow crabs at the restaurant down the street were outstanding.
COSMIC RAYS. My Ph. D. project was to analyze data collected by a satellite called IMP. The data was collected by a sophisticated Geiger counter, and I was looking for solar cosmic rays – energetic protons and electrons that were released by a solar flare and travelled 93 million miles to earth. The detector on IMP was built in Dallas by my Ph. D. supervisor, Dr Ken McCracken, originally from Tasmania, the smallest state in Australia. McCracken had returned from the USA to Adelaide University a bit over a year before, in 1966.
In between crossings of the Van Allen belts I found the solar cosmic rays, plotted them, and built a model for how they traveled through interplanetary space. The movement is similar to perfume particles after pulling the cap off a perfume bottle in one corner of a room. You have to wait a while until the first whiff of perfume percolates to the other corner of the room. It’s called diffusion. I spent four years in the prime of life studying the diffusion of cosmic rays from sun to earth.
DIVERSION: DETAILS OF COMPUTER MODELING (next three paragraphs).
The diffusion was due to cosmic ray particles, protons or electrons, bouncing around on their way from sun to earth. The Russians were tossing coins to represent this, and McCracken heard about it and passed the idea onto me. If “heads” dominated then a cosmic ray particle would travel swiftly to earth.
Another particle with equal numbers of “heads” and “tails” would take a longer time to get to earth because it was bouncing back and forth on its journey. A particle dominated by “tails” would bounce around so much that it would take a long time to reach earth. If a thousand cosmic ray particles were injected during a solar flare, the result at earth was an intensity of cosmic rays which rose rapidly with time but then decayed slowly in a long tail. And this is what we saw in the satellite detector recordings.
MONTE CARLO MODEL
I built a computer model which tracked one particle at a time, using a random number generator to choose “heads” or “tails” for a particle, until it had gone way beyond earth. Then another particle would be started at the sun, and so on, until a thousand particles had been injected. This approach was called a Monte Carlo model, for obvious reasons. I loved this modeling work and became addicted to it. Its fair to say that because of this experience, I was able to find things to model like this for the rest of my R&D career. I owe a great deal to Ken McCracken for introducing me to computer modeling.
MY SUPERVISOR WAS FAMOUS.
In his book, Dr Ken McCracken admitted as a younger man he had an inferiority complex. Yet he was a remarkable physicist gifted at theory and experiment. It’s a strange condition — I know because I had it for years — and it can immobilize a person from taking on a goal. Accomplishments, bit-by-bit, can cure this.
In 1959, Ken McCracken moved to Massachusetts Institute of Technology (MIT) in Boston after his Ph. D. In 1960 he was studying solar cosmic rays from a large solar flare in May of that year. Using earth-based detectors called neutron monitors, he was able to show that the solar cosmic rays initially came from a direction 50 degrees away from the direction of the sun. He concluded there was a magnetic expressway connecting the sun to earth (see image). He published this result in 1962, and he became famous.
FAMOUS FOR TWO THINGS.
First, this result confirmed Eugene Parker’s theory of the solar wind, which was published in 1958. I’ll talk more about this in Part 2.
Second, McCracken’s analysis had serious implications for NASA’s manned spacecraft program, which began with John Glenn in 1962 and culminated in Neil Armstrong’s moon-walk in 1969. If a big solar flare exploded on the right side of the sun, the solar cosmic rays would stream along the interplanetary spirals to earth and the moon. The fastest ones would arrive within ten minutes and could result in a lethal dose to a man in a space-suit if he was outside the main spacecraft. This meant the solar weather forecasters needed to look for solar flares on the right side of the sun, especially if astronauts were planning to leave their spacecraft.
IN THE RIGHT PLACE AT THE RIGHT TIME. I entered space science in 1968 only ten years after it began. It was the golden age of space science and my supervisor, Dr Ken McCracken, gave me access to a ton of novel cosmic ray data. I was able to get papers published, because few referees in this new field knew enough to reject them. Ken McCracken was an amazing mentor. He never criticized me. He always believed in me. And he taught me to be proactive, which is at the top of Stephen Covey’s list of seven habits for success.
LIFE-LEARNINGS. The life-learnings I took away from these ten years included:
1. Beware an inferiority complex. Understand it. Then work to overcome it by always trying new things, which will be uncomfortable at first. But as we accomplish things, discomfort will dissipate, and so will the feeling of inferiority.
2. Believe in yourself. Don’t criticize yourself too much. Instead, believe you can achieve and push on to the next step.
3. Believe in someone else. This is a rare gift but it can be learned. It means less criticism, more trust, and expressing confidence in the other person. They will feel it, they will stand up straighter, and they will do better.
4. Be proactive. Animals are reactive — if they are hungry they bark. As humans we can think ahead and imagine what might happen. We can take steps to avoid bad things (like driving too fast), or we can make good things happen (by eating more fruit and vegs).
Ken McCracken has written a delightful book called Blast Off, detailing scientific adventures at the dawn of the space age. Click HERE to see the book on Amazon.
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The Gray Nomad ….. Think and grow wise
Basically I regard myself as a scientific pioneer. I relish the completely unknown or the un-conventional view (or worse). I have no fears of ridicule. I like to go back to first principles, and see what the present generation has forgotten, or where new technologies allow the impossible of a previous decade to be done. I like doing this both in ‘pure science’ and in applied science. I have a 7 to nil success ratio. This doesn’t mean I am smart – it may mean that other people are too conservative. My work has created careers for a lot of people who tread the new paths I have opened up. [Ken McCracken, 2010].