Ken and Physics
August 11, 2011
INTRODUCTION/CHILDHOOD
When I was in high school we were given tests to explore our interests and
suggest suitable careers. It turned out that I was interested in science. This was
considered so weird that I was given more tests, same results. I was also given
tests as to my mathematical abilities and was advised that these abilities were
quite limited. Pretty strange advice for a future physicist! Am I really misplaced
in my career? How could I have such strange interests? Did my life work out OK?
Both of my grandfathers were into engineering.
My mother’s father, Ralph Bennett, was an electrical engineer with a degree from
the University of Illinois. He must have received his degree in the late eighteen
hundreds. Not many such degrees then!
My father’s father, Clyde Cheney, had no degrees but great practical ability.
Typically he designed and built well drilling machines and used them to drill wells
all over the Antelope Valley in California’s Mojave Desert.
My mother’s academic work was in English and sociology but she was interested
in everything and took us to all available places involving science and technology
(not to mention camping virtually everywhere in the west).
My father of course grew up on a farm
but his higher education was in sociology, math, education, and administration.
But he learned auto body work to make money for college and did serious repairs
on cars that broke down on trips, at least once with a hammer and chisel.
I grew up seeing that everything was interesting and with confidence that I could
learn to do whatever needed doing. Strangely I never, as far as I remember, did
experiments at home. I did repair everything on my bike and built model train
sets. When I was employed to actually do experiments I studied hard and found
that physics actually worked, if you worked at it hard enough! More about that
below. 
I do recall that when I was four we lived in an orange grove. For some reason I
wanted to sort oranges – small vs. large. I constructed two v shaped ramps
leading to boxes for small and large oranges. Then I could sit next to the original
box of mixed sized oranges and roll the oranges into the proper boxes.
I enjoyed comics. In fact at five I announced to my mom that I had figured out
how to read one. Perhaps this was even true. I particularly liked Donald Duck and
his nephews. My favorite episodes were when someone built a machine such as
the snowball throwing machine gun wheel the nephews invented once.
I also read everything within reach: the girl's books from my mom’s family, the
boy's books from my dad’s family, Fortune magazine, Scientific American,
anything! I often think I taught myself to read on Fortune magazine, after
mastering comics of course. My favorite articles in Fortune were those on
innovative technology.
Science Fiction and Reality
In the eighth grade I was introduced to science fiction magazines by a friend. I’ve
been reading this ever since. I’ve had all Analog/Astounding magazines published
since 1947, and a few older ones given to me as birthday gifts by my brother or
sister. I’ve read the first publication of many iconic science fiction novels and
series such as the Foundation Series, Ender’s Game, Asimov’s robot stories,
Earthman’s Burden, etc. as stories in Astounding. I have read lots of fantasy also
but I don’t find it new much anymore. I generally prefer “hard” science fiction
where the problems and solutions are technological not social.
Many (most?) scientists of my generation feel in our bones that Heinlein’s “Future
History” really was (or should be) a future history. It seems that we should have
quickly gone from the moon to Mars, to the asteroid belt, to Jupiter’s moons, to
other stars. Progress seems slow (as of 2011) and difficult but in the long run a
few decades or centuries between Sputnik/Apollo and permanent Martin colonies
(or terraforming Mars) will not seem like a long time. But there is the frightening
possibility that humans may decide against expansion and all die when the next
comet or plague strikes. Or, sadly, we may never discover the wonders of other
worlds and species.
HIGH SCHOOL / CAREER CHOICE
Many people spend years or their whole life trying to find out what they want to
do. I never had to give it a thought. I wanted to be a scientist, preferably an
astronomer. I paid no attention to those strange test results. During high school I
took the usual math and science courses plus a honors physics class. When I went
to UCLA I majored in Physics, as I figured that there were not many jobs for
astronomers. Now it has turned out that all the big problems in astronomy (dark
matter, black holes, the Big Bang, dark energy, . . .) are physics problems so
astronomers must be physicists too!
My folks said that I could have qualified for Caltech (then CIT). I have no idea if I
would have been accepted or how I would have done if I had been admitted. It
could have been interesting; the time was just about when Feynman (Nobel Prize,
great teacher, great story teller . . .) was teaching the freshman and sophomore
class with the lectures that led to his great book. Few, if any, of the students
understood a high percentage of what he said but the lectures were, and are to
this day, an inspiring view of physics. I still often refer to his lectures when I don’t
understand some aspects of a subject. Now, if he had just told about String
Theory by some sort of time travel. 
PHYSICS ETC. AT UCLA
My physics career was not brilliant at UCLA (or USC either for that matter).  I
took the courses required for a Physics degree (strangely a B.A. – that is Bachelor
in Arts- rather than a B.S. – Bachelor in Science - since I took extra math classes
rather than extra experimental classes). When I got my Masters much the same
happened, I took a comprehensive exam rather than doing experiments and
received a M.A.! I think my dad and sister received M.S.’s in Political Science!
My judgment in avoiding experimental work was not very good. When I finally
went to work in Physics I was hired to build and run experiments! Here is a
picture of the equipment I was supposed to put together, debug, and do research
with!
We are looking down. L to R Target, LN crio pumps, mass spectrograph, ion
accelerating and focusing electrodes, ion source, Xe supply, HV supplies, on the
floor is a fore pump, hidden is the diffusion pump.
This is a picture after we got it running. Originally it was in a million parts
scattered over the floor and looked as confusing to me as it probably does to you.
This was defiantly not what my school work had been preparing me for! More
when we get to my work in Aerospace.
At college we were not taught anything about becoming Physicists. We had
classes on Physics and Math but there was never any talk about how you got a
higher education, where to go, how to apply, what kinds of things you could do to
earn a living, . . . , nothing! (Medessa –daughter – had a similar complaint about
Stanford law school. She said that they were taught how to be Supreme Court
Justices but not how to chase ambulances and actually make a living as a lawyer.)
(Liz – daughter – on the other hand has had all sorts of exposure to working in the
Library/Data field during her Master’s work at UCLA. Her History professors
earlier at UCLA were also infinitely more interested and interesting than my
Physics professors had been fifty years before)
The lectures at UCLA (huge!) were by full professors who, unfortunately, were
pretty tired of lecturing and, as far as I could tell, Physics. The labs were taught by
student Teaching Assistants, probably very busy with their own research. All in all
not a single inspiring class. I found out later that my upper division Electricity and
Magnetism teacher was involved in the observation of the first antimatter proton
(!) but he never mentioned it.  I simply cannot remember what we did in the
lower division labs, those labs that I am teaching now!
I did have one useful lab, in optics. The lab consisted of making very precise
measurements, always it seemed with yellow sodium light. That was not fun you thought your eyes would fall out. Not only were the measurements tiring but
the data analysis was really miserable. Today the data analysis would be fun, just
dump the numbers into a spreadsheet on your laptop and have instant results. 
As you might expect in 1955 there were no laptops, in fact there may have been
no computer at all at UCLA. IBM did a survey a little before this and determined
that half dozen computers would do for the entire country. For rough
calculations we used slide rules to multiply, divide, take logs, etc. Generally the
results were good to about three significant figures (like 3.14), fine for most
purposes.
For really accurate results more significant figures were needed. All we had were
huge books of log tables. To multiply a times b you used the nice identity that
log(ab) = log(a) + log(b). “Obviously” all you need to do is look up the logs of a
and b, add the logs by hand, and invert the process to find the product of a times
b. This was at least as painful to do as it sounds. I’ve forgotten exactly but I think
this gave an accuracy of five or six significant figures such as 3.14159.
However, I did learn how to estimate errors and how errors combine, a vital skill
that wasn’t taught anywhere else.
Unfortunately no one in the physics department mentioned that math was
REALLY useful in Physics so I was not inspired to pay much attention to my math
classes. Einstein said that he could have received a really good education in
college (one of his math teachers was one of the outstanding mathematicians of
the century) but that he spent his time playing with experiments. Somehow
shortchanging math did not lead to quite the same results for me as it did for him!
GRADUATE SCHOOL AT USC
I rather blindly (I had no idea how Physics Departments ranked, or if any would
admit me) applied at the last second to USC’s Physics Department and was
admitted. My father had also gone to UCLA for his bachelor’s degree and USC for
his masters, I don’t know why in his case.
The application was at the last second because I was not at all sure that I wanted
to do graduate work. Late in the summer I went to Yosemite by myself (almost
empty campgrounds!!!!). After a bit of peace in my favorite spot in the world I
was inspired to get on with my education.
At USC time there was not even any advice about obtaining degrees in the Physics
Department, just what was in the Catalog. I should have, of course, found out
about all the professors and consulted them for advice. I was far too shy.
More about USC and looking for a job later, now on to aerospace.
WORKING IN AEROSPACE AT MARQUARDT
Marquardt Corporation made ram jet engines. The founder, Roy Marquardt,
wanted to do some more scientific work in addition so the branch that hired me
had contracts to do a number of experiments relating to space travel. 
When I refer to “Marquardt” below I will mean the Corporation not the founder.
Ion rockets
I was hired in particular to direct an experiment in support of ion rockets. Almost
all rockets work by burning some high energy fuel. This got us to the Moon and is
very spectacular but it does take a LOT of fuel, take the Saturn Moon rocket or the
Space Shuttle for example. The limiting factor is that chemical fuels can only burn
so hot, hence the velocity of the exhaust and the acceleration you get from a
given amount of fuel is limited. If the exhaust can be made faster than the same
amount of exhaust will give your rocket a bigger acceleration. The nice result is
that you don’t need as much exhaust and can arrive with more payload.
An alternative way to get a high velocity exhaust is to charge the exhaust
electrically (make it into ions) and use electric charges to accelerate the “exhaust”
to almost any velocity you want. Since there is no high temperature the exhaust
is called “reaction mass”. Reaction in homage to Newton’s third law that assures
us that if we push on the “reaction mass” we will feel a reaction force in the
opposite direction. There are, of course, complications! The rate you can
produce these ions is pretty small so the acceleration you can produce is also very
small. You can’t get off the ground at all (you must use chemical rockets for that),
it will take a long time to reach your destination, but you will arrive with lots more
payload than if you used chemical rockets all the way.
Aerospace people were working on this when I was hired in 1960. It turns out
that ion rockets do just what they were expected to do and a number of them
have “flown”. As I write this in August 2011 a spacecraft propelled by ion rockets
(Dawn) has just put itself in orbit around a the asteroid Vesta. After it has
investigated Vesta for a year there will be enough reaction mass to move to the
largest asteroid Ceres and repeat the process.
Also, here is where I came in, some of the accelerated ions will hit the charged
electrodes that are accelerating the ions and gradually wear away the electrodes.
This wearing away is called “sputtering” and limits the life of an ion rocket. My
job was to direct the investigation as to how this sputtering depended on
materials, angles, temperature, and anything else we could investigate.
When I was offered the job () it was quite clear to me that I was completely
unqualified.  I told a friend who was experienced in aerospace about this
ridiculous offer and he told me “Take the job; otherwise they will have to hire
someone even more incompetent.” After some time in aerospace I found he was
right!
Notice the safety cage, warning light and interlock for the door at upper left, target at the left,
neat high voltage gauges above, neat counsel with control knobs and low voltage gauges at the
lower right.
But, the experiment I was to direct (see the pictures above) involved an ion
source, accelerating and focusing electrodes, high voltage power supplies, a mass
spectrograph, many aspects of high vacuum systems (fore pump, cryogenic
pumps, oil diffusion pump, O rings, vacuum seals, vacuum valves, vacuum gauges,
materials, welding, implosion safety, etc.), precision mass measurements, high
voltage safety, and (of course) sputtering. I did not even know of the existence of
much of this much less how it worked. 
The experiment and me
Why was I to be in charge? Two reasons: First evidently no one at Marquardt
realized that there were two very different types of Physicists. There were pencil
and blackboard type theoretical physicists (that was what I was trained to be),
and hands on experimental physics (which I defiantly was not trained to be).
Second although Marquardt had the Air Force contract another company had
constructed the equipment and (perhaps) done the first year’s work. I can’t recall
actually seeing that there were any sputtering results reported for the first year.
Marquardt decided to do the second year’s contract work in house. Evidently
they figured that since the work involved atoms and electricity a Physicist would
know all about it.
Odds and ends of work aside from sputtering
The equipment didn’t show up at once so I got to work on a number of projects
for other groups. This really worked out well. I was the only Physicist around so
whenever anyone had a wild idea they would fly it by me to see if it violated too
many laws of physics. This was a blissful case of having some “authority” with
little responsibility. I might be able to show that the proposal did violate some
important laws and therefore should be dropped. On the other hand if I didn’t
see anything obvesely wrong it wasn’t my responsibility if the engineering was so
difficult or costly that the idea wasn’t practical. This was the sort of thing I was
trained to do, sort of. Occasionally I could contribute suggestions about
implementation or other possibilities. I was happy and my bosses were happy.
The ideas could be pretty far out. One of my favorites was using the ionosphere,
a planet’s magnetic field, and the motion of electrons along a “spacecraft” to
provide forces on the spacecraft or to generate power! We came close to getting
a scientific paper published on this, some else published first 
A second plan (not original at Marquardt, it has a popular name that I can’t recall
at the moment) was to propel an interstellar spacecraft using atoms swept up
from space and accelerated by the spacecraft. Evidently I suggested a new shape
inspired by “focusing” the atoms with the shape of the scoop that made up the
front of the spacecraft. I have not heard of sending out any such interstellar craft
yet.
Back to “my” sputtering experiment. A million small pieces
When the equipment for the experiment arrived it was in small pieces, with no
labels, wiring diagrams, or instructions. The people who built the equipment
were evidently a bit annoyed at losing the sub-contract and “disassembled” the
machine with wire cutters! What we (actually “I”) had were some nice pictures of
what it had looked like assembled and parts all over the floor. Since this was a
new experiment for Marquardt naturally there was no support equipment, no lab
benches for example.
“All over the floor” is quite literal. We started with an empty room and boxes of
disassembled equipment. I and my technician unpacked the equipment and
spread it out on the floor. Unfortunately we just left the packing material all over
the floor too. I was informed the next day that the janitors were not happy about
the mess we left. My VERY ignorant reply was “’ weren’t janitors supposed to
pick up messes?”. On more mature consideration I realized that it was time well
spent to keep EVERYONE happy, this mature consideration took a while though!
There was never any hesitancy in getting us what we needed once I asked for it.
I did have a fine technician (well, my second technician was fine) who was
experienced in conventional electricity. He kept us from being electrocuted and
made very professional displays and control panels (see the picture above!).
However he knew even less than I did about the list of vital knowledge I
mentioned before. When our attempts failed (this is the norm, even with people
who know what they are doing) he would cheerfully point out the Physics didn’t
really work. I maintained that Physics always worked, we just didn’t understand
it. I still try to convince my students of this!
At any rate this was Marquardt’s total store of knowledge about my list above,
except for welding. They did have a REALLY fine shop that, along with many other
wonders, could even clean up the crude welds in the aluminum box that held all
the other parts of the experiment together. This is hard aluminum doesn’t glow
to tell you how hot it is, it just melts 
There were many fine engineers. Much to my surprise I found that engineers
knew many things that Physicists did not. For example I might know how to
calculate some properties of a transformer from theory but some engineer would
know what could actually be built and where to buy it! Marquardt was a
company that was expert in the aero part of aerospace. These engineers knew
more than I ever would about fluid dynamics but did not have the background to
do other things. But if you wanted something done with their areas of
competence these, like all good engineers, would know how to do it quickly and
economically.
But, as I tell my students, I did not know how to do much of anything but I did
have the tools to learn. Originally I didn’t even know the theory of our diffusion
pump; but I read every recent issue of the journal on vacuum and figured out how
to improve the vacuum in our system by an order of magnitude. This was the way
it went, but slowly.
Learning slowly
Notice the copper tubing above and at the rear of the apparatus. These are
carrying the high voltages needed for accelerating and focusing the ions.
We are now looking sideways and a
little down. At the left and rear are high voltage DC power supplies.
We didn’t understand why these tubes were used. If there had been high
currents having massive “wires” would make sense but the currents here were
measured in millionths of amps – really tiny. We did the natural thing and used
everyday wires to carry the high voltages. Much to our surprise the first time we
actually turned on the high voltage the wires glowed blue and arced into the air!
Just like a prototypical mad scientist’s lab.  After a bit, probably quite a bit, of
thought I realized that this was a natural consequence of a couple of those
strange bits of knowledge I was supposed to have learned (no one told me why)
about electric fields and the radius of conductors. In brief the electric field near a
sharply curved conductor can become so big that electrons are actually pulled
right out of the conductor and sent out into the air or vacuum. So, we went back
to the “silly” copper tubing with its big smooth curves. Evidently we learned
slowly, nature had to demonstrate the same effect with the screws we used to
fasten down our equipment to a plywood sheet. The huge electric fields made
arcs right through the plywood!
Electrocute suits?
Eventually we had a very professional cage built around the equipment to protect
everyone from the high voltages. The door had an interlock so there could be no
high voltages anywhere when the door was open. To be doubly safe there was a
red light that came on when the high voltage was on.
The downside of all this safety was that we couldn’t work on debugging the
equipment from outside the cage. Naturally we disabled the light and door
interlock and proceeded with our work, very carefully!
But Murphy’s Law cannot be flouted! One day a group of managers unexpectedly
came by to see our strange, exotic machine. The door was open, the warning
light was off, and the high voltage was definitely on. My technician and I watched
and hoped that none of the managers would decide to go inside the cage and
inspect the equipment close up. We did not relish having to tell the managers
that they could be electrocuted due to our disabling the safety equipment.
Happily no one was that curious, or they may not have had much confidence in
any kind of electricity.
Notice the glass tubes holding together much of the equipment:
Target assembly. The center part is a big glass “drain pipe”. There are clamps at
the ends and the vacuum seal is by “O” rings. The ion beam enters from the right
and strikes the target at the center. We can’t see the target, it is partially
surrounded by LN cold traps. The target could be rotated from the top. Sticking
out the bottom is a glass tube with a vacuum gauge. There was a BIG sliding
vacuum valve on the right to isolate the target assembly from the rest of the
apparatus. This allowed us to open the target assembly to the outside air without
losing the vacuum in the rest of the apparatus..
You might ask what happens when the glass breaks and implodes from the
outside air pressure. Happily I can’t speak from experience because the glass was
thick and strong and we were very careful. But I understand an implosion sends
glass fragments everywhere. The proper design is to surround the glass with a
wire mesh to break the glass up into little pieces and then surround that with
Plexiglas to stop the little remaining fragments. Unfortunately I only learned this
many years later 
A series of miracles occurred (or I was much more cleaver than I deserved to be)
and we actually got the data that we were being paid to get. Not only that but we
got a paper published in the Journal of Applied Physics, the prestige journal in
which to publish such results  Actually, this was my only paper published in the
scientific literature.
To be continued  Keep reading, there is a happy ending 