English
РусскийNobel Prize Recipient Charles Hard Towns at the First Seminar of Light. By Greg Solyar
April 1, 2011 - 20:23
The First Seminar of Light, an event celebrating the 50th anniversary of the laser, took place at Lenox Laser, a company located among the rolling hills of Glen Arm, Maryland, USA.
95-year old Nobel Prize recipient Charles Hard Towns presided as our main speaker as well as the guest of honor at this event. The beginning of the jubilee seminar was scheduled for October 4th, so he flew in a day early and stayed at the Marriott in Timonium for the duration of the seminar. At the Marriott, we had the very rare opportunity to have a discussion with him at dinner.
A few minutes before dinner time, a tall elderly man came down to the registration counter.
The first thing I noticed about Charles H. Towns was his impressively straight posture; it was as if he had found the scientific cure to the common hunch that comes with human aging.
One of my former NASA colleagues had met Dr. Towns five years ago at the observatory on Mauna Kea in Hawaii. This observatory is atop a mountain four kilometers above sea level and its pinnacle is above any clouds. Here, an observation of sky does not depend on the weather conditions. However, the environment is so harsh that simply getting to the observatory and working there require special adaptation as a result of low temperatures and lack of oxygen. But the magic of the stars and the ability to observe them around the clock overcome all hindrances and so astronomers gather and work where even the clouds cannot climb.
After the last orders for dinner were made to the waiters, our conversation began. My seat was next to the Nobel Laureate himself. Charles Towns told me that recently he had delved deeply into astrophysics work. In an effort to understand the nature of stars, Laureate had built an observatory made up of four infrared telescopes. “Some stars change their size by 30%,” he explained quietly, “this is because of gravity which causes the star to shrink, and the nuclear forces of repulsion which commonly lead to the star’s expansion.” He then paused slowly, his eyes lighting up. “But then there are some capricious stars that, despite all of the calculations and predications, do not change their size. It is these stars that are of major interest to me.”
Charles then asked about the work I had done at NASA before coming to Lenox Laser. I very briefly explained to him the essence of the methods of coronagraph, wave front phase diversity, and other technologies that we developed for finding life in outer space. Indeed, near huge and very bright stars, planets themselves almost never can be seen, yet we were looking for the life on these planets.
While much of the conversation was scientific, Dr. Charles Towns also gave us his perspective on the intersection of science with religion: “I am a religious person, but I believe in free will. A person must be creative. In science, much is not disclosed, and will never be understood. But in religion, much is also unclear.”
Nobel Prize recipient Charles Hard Towns. Photo by Gennady Krochik
Charles also told me of his recent meeting with Pope Benedict XVI. He was with a group of scientists flying over to meet with him in Italy. He noted that Pope Benedict’s predecessor, Pope John Paul II, was very wise man. He would gather scientists together and was open to their opinions and advice, showing the mutual respect between leaders of the scientific and religious communities.
The Laureate soon went deep into thought. He seemed uneasy, so in order to distract him, I noted: “Charles, the Bible says that God created light. But you created the laser by saying that light should be monochromatic and coherent.” His eyes twinkled for just a minute, followed by a long and hearty laugh. The comment alluded to the importance of inspiration for discovery, so he answered: “No, no, the inspiration is not material, but it is real. It is definitely very important in creativity process. But what is more important for invention is an idea!”
The evening flew by, illuminated by the presence of unique and fascinating conversation. Three courses later, Charles bid everyone goodnight in order to rest adequately for the seminar the next day. As if being pulled by a magnet, we followed behind him until we passed through the lobby and entered the parking lot. I drove home tired and excited, greatly anticipating what the next day would bring.
Charles Hard Towns and Lenox Laser president Joseph d'Entremont at the Seminar
I arrived at the Marriott before 8:30 am, our scheduled time for breakfast, and found myself waiting in the lobby for the rest of the group. The man behind the front desk greeted me with a smile, “Good morning, care for a newspaper? They are recommending that Americans avoid travel to Italy, saying it is unsafe. But I will go.” The man was good-natured and smiling from ear to ear. It was a good morning for some lighthearted facetiousness, and I jokingly suggested that he ask the Vatican to borrow a few of their guards. “Oh no,” was his hurried reply, “I think the Pope himself needs them.” I grinned.
Fifteen minutes later, I was enjoying breakfast, again in Charles’s company. Joseph D’Etremont, the president of Lenox Laser, shared his recent issues regarding copyrights with the group and asked a few questions. Charles was sympathetic, having gone through numerous copyright issues himself. “Dealing with dishonesty is difficult,” he explained, “it’s not worth it—better to just be more selective when choosing employees and partners.” His wise words were well received and with that, we concluded breakfast and headed to Lenox Laser, where the seminar was scheduled to begin. The extensive guest list included graduate students, university professors, heads of scientific and military laboratories, and editors of leading scientific journals and newspapers.
Upon our arrival at Lenox Laser, I presented a lecture on laser processing materials until we were notified that the seminar was to commence. We all gathered into the spacious conference hall, taking our reserving seats and preparing ourselves mentally for the presentations and discussions about to ensue. The seminar began with an introduction from the Patent Examiner of the Federal Patent Office, the same man who had once stamped Charles’s laser patent application with approval.
Dr. Charles Towns then took the stage.
The speech of Dr. Charles Towns
I’m going to be talking about “How New Things Happen.”
Most discoveries involve an interaction between different fields, and an interaction between different people, who exchange ideas. Well, many discoveries occur by accident. But the accidents are generally a result of very careful investigation, thought, exploration, and a lot of hard work. And the laser is an example.
A first example of an accidental discovery is Columbus. He wanted to go west and get to India and China. But he got to a completely new part of the world that nobody knew about. Of course that’s why the people here were called Indians. A little different from the ones he was looking for, but he discovered something new. He took a big chance- he made great plans and a great effort- and look what he discovered.
As a second example, I want mention the discovery of the transistor by a friend of mine at Bell Telephone Laboratories, Walter Brattain. He was just examining semiconductors, copper oxides, and so on, when he found something peculiar and unusual. Searching for an explanation, he went to John Bardeen, who was also at Bell Labs. “You’ve got amplification!” – was the answer. That was the semiconductor amplifier. Their boss, Bill Shockley, had actually tried to make such a semiconductor amplifier a year or two before, joined them. And later all three got the Nobel Prize together.
The third accidental discovery was the discovery of the Big Bang. One of my former students, Arno Penzia, had worked with me trying to pick up a particular spectrum out in space using microwaves. Later he continued this effort at Bell Labs with Bob Wilson, and didn’t find that spectrum. But they found a very weak continuum radiation as a result of having a maser amplifier. That radiation was a remnant of the beginnings of the universe, the origin of the Big Bang.
Thinking of the maser and the laser, those came about not by accident, but by a hard effort on my part. I went to Bell Labs to do physics, but World War II came along. Oh dear, I was becoming an engineer assigned to do radar! But I learned a lot about microwaves and amplifiers. After the war, I worked on the radar with the shortest wavelength of the time- one and a quarter centimeters- and that was getting us more directivity. But, it turned out that the water vapor in the atmosphere absorbed that wave length, and because of it the radar didn’t work. One mistake frequently leads to success, because I said, “I’ll just study this water vapor absorption in a laboratory with microwave oscillators.”
It was really exciting, you could measure the shapes of nuclei- their spins, their shapes, and so on, by doing spectroscopy on molecules with microwaves. It became so important that I was offered a job at Columbia University, which is where I always wanted to be.
My goal was to get on down to shorter wavelengths- down in the infrared, below a millimeter. Microwave oscillators at that time could be made to wavelengths of a little bit shorter than a centimeter. But all of our efforts so far were fruitless.
Then I was appointed as chairman of a national committee by the Navy, to find out how we can get to shorter wavelengths. I formed a group of very famous engineers, and for a year we traveled all over the country trying to find anybody that had any ideas.
At the last meeting we were going to write a report saying that we couldn’t find out anything. Early in the morning worrying about it, I went out and sat out on a park bench. Suddenly I understood that, of course, molecules and atoms produce short waves, but you can’t get more than a certain amount of energy without heating them up. By heating, it looked possible to get more molecules in an upper state than in a lower state. From the upper state, they can fall down and amplify and I can get radiation from them. I wrote down some equations. But since it was quite doubtful, I didn’t bring it up with the committee, and we wrote our report saying we didn’t have any ideas.
I went back to Columbia University to try to figure out some more. With the student who worked with me on his thesis, Jim Gordon, we decided to try experiments. We started first with microwaves because I had some microwave equipment. Now I figured the way to do it would be to use molecular beams. At Columbia University, researchers were working on atomic and molecular beams, trying to study molecular properties. For the next couple of years we worked on ammonia.
One day the chairman of the department, Professor Rabi, a Nobel Prize winner, and a professor in the department, Professor Kusch, who got a Nobel Prize soon after, came into my laboratory. They said: “Look, that’s not going to work. You’d better stop. You’re wasting the department’s money.” I was an associate professor by then. Well, fortunately, you can’t fire an associate professor just because he’s stupid, only if he does something morally wrong. So I said that I was going to continue the work. Well, they marched out of my lab very angry.
About three months later, Jim Gordon came into my classroom saying: “Hey, its working, its working!” Yes, it was a new kind of oscillator, using molecules to amplify in the microwave region. As the molecules were stimulated by radiation, they gave up their energy and amplified some more. We decided to choose the name MASER, for microwave amplification by stimulated emission of radiation.
Once it got working, oh, everybody was excited. Industries were interested in these amplifiers and began to hire all the students in the field. We made one of the most sensitive amplifiers we’d ever had the country- a new kind of oscillator with very pure frequencies.
Pretty soon I took a sabbatical leave, and went to Paris. One of my former students, Autler, had found that in a magnetic field, electron spins could be made to go up, and they would stay there for a while (normally electron spins fall back down quickly). He also found material in which they stay there for some time. I thought about tuning spins by changing the magnetic field so we could pick frequencies and have amplification. Later, Nicolaas Bloembergen in Harvard read our published paper. He had been working on electron spins. But with two electrons joined together, instead of having two states, an upper state and a lower state, you have a total of three states. Nic recognized that you could excite them by pumping to the upper state, and they could fall back down, emit, and amplify. That was a great discovery of the so-called three level maser.
Also while in Europe, I went to visit Ole Bohr up in Denmark. He was walking down the street with his father Niels Bohr, who I was just delighted to meet and get acquainted with. I told Niels Bohr we’ve made a very pure frequency oscillator by using molecules. He looked at me, and said: “No, that’s not possible, you must be misunderstanding something.” I’m sure he was thinking of Heisenberg’s uncertainly principle. He knew that you can’t define the frequency better than one over the length of time required for molecules go through the cavity. But what he didn’t recognize was that we were using a collection of molecules, not a single one. So the uncertainty principle didn’t apply. So I said: “No, it’s working, it’s working.” He wouldn’t talk with me about it anymore. I don’t think he ever caught on…
After about two or three years since the invention of the maser, I started thinking how to get to amplifiers and oscillators at shorter wavelengths. I thought that maybe I could induce spectroscopy down in the infrared. My equations showed a possibility of going down to light waves. But if I mentioned it, a lot of people would jump into the field and then I’d have a lot of competition. So I didn’t mention it to anybody, I just kept thinking about it.
I was consulting for Bell Telephone Laboratories when my brother-in-law, Art Schalow,was working there on the Faby-Perot systems for very precise spectro-measurements. He had done his post doc with me. When I went to see him, I told him about my new idea. He suggested adding two parallel plain mirrors to the cavity so the light would bounce straight back and forth from these mirrors. This would make a very pure, directional amplifier.
We decided that we’d better publish a theoretical paper before starting to work on it experimentally. First, though, we took it over Bell Laboratory’s lawyers to obtain a patent. But the lawyers refused to patent it because light has never been used for communication, but we finally convinced the lawyers to do it. I already had the basic patent for all masers, which included all wavelengths, even though I hadn’t been able to see just how to build light waves. In 1958, we were given a patent for “optical masers in communications systems.”
And then everybody jumped into the field. The industry had a lot of skillful people by that time. They could work very fast and very quickly. And the very first laser was built in the Hughes Research Laboratory by Theodor Maiman in 1960. He used a ruby crystal. Art Schalow and I had thought about ruby, but since ruby decayed fast, we had thought we wouldn’t be able to get enough light to excite enough of the molecules. But Maiman recognized that with pulsed light he could get much higher intensity.
Pretty soon it was called the laser. Gordon Gould even patented the word LASER (Light Amplification by Stimulated Emission of Radiation).
To illustrate the next part of his narrative, Dr. Towns told a story about a rabbit and a beaver. The animals visited the Hoover Dam on the Colorado River, and the rabbit was amazed with the magnificent construction of the concrete structure. The beaver, however, noted that although he did not build it himself, the dam was definitely built from one of his ideas.
Of course we just called it optical maser. But optical maser was too long a name, and it became laser. With a smile we thought, well, after that, it’d need to be alternated to gamma ray, it then would be a GASER! Now lasers include everything even on down to the x-ray region. The longer waves lengths are masers, the shorter wavelengths are lasers, but it’s basically the same thing, of course.
There are more and more lasers in all varieties of wavelengths, sizes and for many applications. It never occurred to me that it would be useful in medicine. I thought, well, it can burn people, why would you want to do that? But now even I’ve had a little eye operation with a laser.
The field grew. An enormous amount of science has been produced, and I am delighted. I was primarily interested in getting a new scientific tool that would allow for measuring distances more precisely and frequencies more accurately than we had before in order to make all kinds of new discoveries. Just think about the energy intensity when you can focus an enormously high-powered laser of five hundred- thousand- billion watts to a point that is just a couple of microns in size. You can get the highest temperature with the highest intensity. But it also may produce the lowest possible temperatures if the intensity is enough to grasp atoms and hold them still. When atoms are made stiller, and stiller, they essentially reach zero motion and therefore the lowest temperatures. All kinds of industrial uses have come out. Now you can put enormous information on one light beam in little fibers for communications, do very little pointing, or use lasers as the most powerful sources of energy. About twenty billion dollars is invested in the industrial production per year.
There have been thirteen Nobel Prizes given as a result of using lasers as tools after we shared the Nobel Prize in 1964 with the Russian scientists Basov and Prokhorov. New discoveries are very important. By carefully looking at things you may recognize something new that people hadn’t seen before. The laser is perhaps a particular example of systematic experimentation in which, after trying to do something and after many years of effort, we finally hit on the right thing eventually.
You have to be willing to explore, and be at odds with other people, especially outstanding people. See, Rabi and Kusch both wanted me to stop, they said they knew it wouldn’t work. Bohr though, that it was not possible. When new ideas are new, people can find something negative about them, especially the ones who don’t have those ideas.
I hope all of you will think about new things- things that would be helpful to people, and you will be willing to take some chances.
Dr. Towns finished his speech. He received a standing ovation. Suddenly I understood why Laureate liked when he was called by his full name Charles Hard Towns, it has to do with the meaning of the word “hard’ – strong, hardworking, not bending. He proved it one more time by not making any attempt to sit down at his five- of one- hundred years.
As Charles began to walk away from the podium and to his seat, Joseph D’Etremont and I announced that we had a surprise gift for Laureate. We approached the stage, and with extreme pleasure, I handed one of the finest men I have met Picture of Time, stating “Dr. Townes, you once said to me that you love fine art.”
I crafted “Picture Time,” a piece of artwork in which one line weaves itself into an hourglass and old camera on a tripod, representing the continuum of life. Picture of Time was accompanied by a poem I wrote, which extended the drawing’s meaning into the realm of the written word.
The Time is frozen in old snapshots,
No beat has bid the heart farewell.
The prize to get in madcap Ascot
Is but a moment’s breathing spell.
The silver smile that curls unbidden
Keeps mysteries of years seen,
The way a master’s craft is hidden
In curves of perfect violin.
The shades, the light, all sepia-toned,
The wash of sadness on soft ice.
The tears with faith are interwoven:
Source of the Nile in tired eyes.
But then a flash, and grief is thrown,
Into eternal speeding swirl,
As if our way its light has shone
A careless and merry soul.
Translated by Rachel Fogl.
Dr. Townes arose from his seat and took the artwork out of my hands. He smiled with an understanding of the drawing and appreciation for it. Then he held it up for all of the guests to view and thanked Lenox Laser and myself profusely. It was a wonderful moment
Greg Solyar presents his work "The Picture of Time" to Dr. Charles Towns
Dr. Charles Towns demonstrates "The Picture of Time"
The seminar continued, replete with experiments, demonstrations, and interesting lectures. It was highly enjoyable for all who attended. Nevertheless, I doubt that anyone will forget the wisdom imparted by Dr. Townes, truly illuminating the creation of light in the world of laser research.
Photos © 2010 by Gennady Krochik
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