100 Years of Science

D. Carrigan

"100 year of science" is an outrageous title. My apology is that I have
heard the history of the universe, one hundred million times longer,
painted in one hour before. Over the last years I came to this subject,
the interlocking nature of many sciences, studying potential message
content for SETI. This is not going to be a talk about SETI, but
thinking about SETI does force one to think about what we know now and
what we may know in the future.

I have also been struck by a cosmological diptych from my wife that
wonders about the relation of ants and astronomers.

This talk could equally be entitled "what I learned at Fermilab last
year" or even "what I learned in high school" if I had only gone to high
school last year instead of a half century ago. I apologize for the
superficialities and can only plead that I have had a lot to learn.

What 100 years are we talking about? Perhaps we should start with
Maxwell's unification of electricity and magnetism to give radio about
1870. This is no fun, its' ancient history. The great discoveries of
relativity and the quantum nature of matter occurred in 1905 and 1900.
But that would be the last century. Perhaps starting at the birth of
wave mechanics with heroes like Schrodinger? Interestingly Schrodinger
later turned to an influential investigation of the nature of life
published at the height of World War II in neutral Ireland as "What is
Life?" Shortly after that war there was a fantastic burst of new science
from rocket technology, to the discovery of many mesons heralding the
emergence of particle physics, to untangling DNA in biology, to the
discovery of the Big Bang. Parenthetically I could not find a stamp for
James Watson and had to use a bubblehead. Is it bad form to put living
people on stamps? Based on the fifties explosion I take my hundred years
to be 1944 to 2043.

In what follows I will loosely call the area of particle physics and
accelerator science particles, the broad areas of space, astronomy, and
planetary science "space", all of biology "DNA", and anything covered by
computing, math and electronics just "computing".

The topic closest to most of our hearts is particles. Facilities like
Fermilab along with theorists like Chris Quigg have led us to a picture
of our universe consisting of building blocks of quarks and leptons
bound by force carriers such as Maxwell's photons, gluons, and the
electroweak force carriers born of Fermi's ideas. As Chris Quigg and
others have pointed out the building block picture on the left may
satisfy most high school kids but it disguises all of what we don't
know. In several interesting lectures at Fermilab Chris has built a
picture using teserae that unfolds the questions of the next decades.

The next list highlights some of the history of particle physics. The
list may have been extracted from an LBL site. This particular ensemble
seems to have been generated by an experimentalist interested in Nobel
prizes and showing that all the great accelerators centers had been
important contributors. I did like the reference to Thomson because it
reminds that particle physicists invented TV. The list is really unfair
to the blood, sweat, cleverness, and tears of nearly everyone else,
particularly theorists.

That is the past, what about the future? The next list is an epitome of
some of the outstanding questions on the docket. Chris has pointed out
to me that he actually had more like thirty-three questions in his April
28 talk. This is an earlier set that had the advantage of fitting on one
page. With this list in hand the blood, sweat, cleverness, and tears
will continue on into the distant future.

The next photo is Fermi, one of the better theorists of our 100 years,
at the control panel for the Chicago synchrocyclotron possibly in the
midst of unfolding the first meson-nucleon resonances. This cyclotron
was among a dozen or so instruments built after WWII that established
the foundation for experimental particle physics in Europe and the US.
Fermilab in the middle panel is now the forefront facility in the world.
It seems every week the luminosity at Fermilab leaps up a notch. And, in
Europe, LHC will come on line sometime around 2007. That facility should
throw wide the windows to look out at Quigg's future world.

These facilities are great and LHC should endure as a research facility
to the end of our period. In my own view the future beyond LHC is not so
clear. One interesting possibility, an electron-positron linear
collider, has cost and technology choice problems that leave me with an
uncomfortable feeling. An alternative is to seek a new technology. The
most-talked about possibility is plasma acceleration. The photo
illustrates plasma wake field acceleration. In the photographic metaphor
the surfer is pushed along by the wake field of the powerful motor boat.
A gas plasma driven by a laser or particle beam can produce much higher
gradients than a conventional accelerator cavity as demonstrated by Nick
Barov at Fermilab and at SLAC. Solid-state plasmas can produce gradients
100 times higher but have colossal problems. In any case, the progress
is now too slow to serve the future of particle physics. Something needs
to be done!

The next transparencies illustrate the revolution in cosmology
schematically. At the beginning of our 100 years there were conflicting
pictures of the universe. A particularly intriguing but also frustrating
one was the idea of continuous creation advanced by Fred Hoyle. With the
discovery of black body radiation the idea of the Big Bang took hold.
This paradigm explained the formation of the elements and the atomic
constituents. When the revolution started these charts of the Big Bang
were more fun. One of the bests, possibly due to Jim Walker and BJ
Bjorken, graced the wall of the Fermilab Curia for many years. Later
Mike Turner and Rocky Kolb created ever more colorful charts. Now
professional illustrators have wrung the fun and some of the physics out
of them. Searching the Web I could not find one that came close to doing
what Turner used to do. Beyond that, one is confronted at every
keystroke with creation science, often quite nicely done. On this chart
from Berkeley much of the role of particle physics is embedded in the
quark soup slice. There were parts that were missing from the initial
picture like inflation to the left. There was missing matter and more
recently missing energy. The paradigm was able to accommodate and in
some cases predict the need for new factors.

The next chart from Cambridge unfolds the region around the quark soup
section and shows some of the detail and illustrates our reach back to
the Planck epoch.

With the tremendous success of the WMAP satellite we have put many parts
of the Big Bang paradigm in very solid focus. On the other hand this
very power is now leading to a host of new questions. Investigations of
dark matter and dark energy will continue trying to understand the
natures of the dark questions. Tools for investing gravitational
radiation are only now emerging. Most of us do not understand the fabric
of space and time.

As an observer of this revolution I can say that the linking of
cosmology and particle physics has been the most powerful lesson of my
scientific life. I can remember the exact moment when I realized it was
here to stay. I picked up PRL one day in 1979 and saw John Preskill's
article discussing the absence of magnetic monopoles in terms of
inflation. I stopped searching for monopoles after that. The
particle-cosmology linkage was explaining the origin of the universe!

Much of our recent progress in cosmology has come with our increasing
power for investigations in space with missions like WMAP. This V2 at
the White Sands Missile Range goes back to a time before our 100 years
when much of modern rocket science was born at Penemunde in the
thirties. I have a fondness for this particular V2 because it was
sitting on a dolly outside my barracks when I began life as a rocket
scientist. The next panel is a glimpse of a shuttle service mission to
the Hubble Space Telescope. People love to kick around man in space
these days but in the context of the times some of the Hubble service
work could not have happened without astronauts. The next panel shows
Harrison Schmitt on the moon in 1972 inspecting a boulder. Schmitt was
the last person and only scientist to visit the moon. The fourth panel
shows a photo of the surface of Mars taken by the Mars Rover a few
months ago. The difference here is in part that robotic intelligence has
become much greater and more compact in the intervening decades so that
the robot can work much like a person.

Access to space has opened tremendous windows for science. This panel
illustrates some of the recent fruits from this access. In the last
years WMAP has provided a beautiful picture of minute variations in the
black body temperature over the universe. This map has done much to
refine the understanding of cosmology. On a different front satellite
pictures of Jupiter's Galilean satellites have shown four entirely
different planet-like moons. The pictures from Europa are particularly
intriguing since they show icy surfaces with tectonic-like ridges that
may be floating on an ocean. The lower picture is roughly ten miles on a
side. This has opened the possibility of another abode for life outside
of the planetary habitability zone imagined only a few years ago. The
third panel is a recent spectrograph from Hubble showing the presence of
Oxygen and Carbon, some of the ingredients of life, in the atmosphere of
the famous extrasolar planet HD209458. Interestingly, none of these
results depend directly on humans in space although people in space have
been important in refurbishing Hubble.

The next several decades of science in space look very promising as
shown by the NASA mission profile that stretches to the end of our 100
years. Certainly humans have a role in space but for the very distant
future. Robotics beyond the surface of the earth is increasingly
important. We can be in space through our surrogates. Space telescopes
are important for every phase of astronomy from the infrared to
ultraviolet, to supernova searches, and for gravity wave observatories.

When I was in high school biology was a science entirely separate from
physics. Darwin's "The Origin of the Species" includes no mention of
DNA. For that matter there is no citation to Mendel in the index. Around
1953 the picture changed. Watson and Crick unfolded the fantastic
structure of DNA with information from Franklin and Wilkins . The
structure they found was like a computer tape made up of combinations of
four bases. The information content per base pair is 1.44 bits. A
typical base pair with the associated backbone and bonds weighs 600
Daltons. This is a fantastically efficient energy storage medium
compared to some sort of silicon device. The human genome contains about
3 billion base pairs but the actual information content is more like
0.05 Gbytes because of junk DNA. This is something on the order of a
Microsoft program. DNA plus Darwin's "survival of the fittest" plus the
changing environment explains a great deal about biology on the earth.

Like particle cosmology, biology has a big bang with associated parts
like quarks and leptons. Life on the earth may have originated from a
soup of natural organic molecules including amino acids. In one picture
something happened and RNA formed. DNA evolved out of the RNA world.
Complex life arose out of DNA. This process is the Big Bang part. The
linked action of DNA and RNA both propagates the genetic code quite well
and also generates the proteins needed for life. It is as though one had
a computer code capable of producing central processors as needed.

As far as I know the origin of life is not understood. An interesting
and useful place to read about all of this is de Duve's 2002 book "Life
Evolving." De Duve argues that getting RNA by chance is implausible. A
complex chemical environment is needed. Catalysts may or may not be
required. Clays might help. Perhaps there is a natural selection for
molecules. One interesting clue may be chirality, handedness in
molecules. The history of the first billion years on earth also should
offer clues. For the first 0.1 Gyr there was a hot atmosphere of water,
carbon dioxide, carbon monoxide, nitrogen and oxygen. Then the rain came
and a rocky crust appeared in the 0.2 to 0.4 Gyr period. Biologically
processed carbon appeared at 1 Gyr generated from self-replicating,
carbon-based microbial life. This was anaerobic life without much free
oxygen around. Then photosynthesis began to produce oxygen. One point is
that life started relatively early!

A word of caution is in order here. The biology we are talking about is
not your daddy's biology. The tree of life I met in high school is in
the small box. Particularly note the archaea with the halophiles and
thermophiles.

These so-called extremophiles have been popping up in a number of
unusual places such as hot deep-sea vents and very salty environments.
Indeed nearly all the earth's surface layer, wet, dry, land, sea, and
even ice is permeated with life. Life fits many environments! This is
one of the aspects that helped to speed life along. A second, almost
crazy factor is the idea of symbiosis, the concept that some early
creatures evolved as aggregations of one cell or relatively simple
structures. Most of us would have no trouble with this concept in the
context of electronic systems but are surprised that it could have
worked with life. Lynn Margulies is one of the main proponents of this
idea.

Determining the origin of life in different astronomical environments
has become known as astrobiology. What was fringe not too long ago is
becoming more mainstream by the month. In the next several decades we
can look to a number of places to find signatures of life beyond earth
including meteors, planets and satellites like Mars and Europa, and
atmospheres of extrasolar planets.

On the more theoretical side one can assay the planetary, galactic, and
even cosmological habitable zones. This subject has been covered
recently in the book "Rare Earth". Rare Earth is useful but I take issue
with the word "rare" and find their conclusions sometimes pushed aside
by new developments. I suspect a book "Not So Rare Earth" might be just
as interesting and perhaps closer to the ultimate truth.

SETI is a subject closer to the fringe. There is nothing wrong with
searching for intelligence out there. The problem may be that the best
searches have the "drunk searching for his keys under the light post
problem." I don't want to go into this here but I do want to mention the
so-called Fermi question or paradox. In the early fifties Fermi may have
observed that it is not so hard to get around the galaxy on the time
scale of evolution on the earth. If that is so we might expect spacemen
to be everywhere. This New Yorker cartoon from 1950 has been used to try
to tie down when Fermi made this observation. One source suggested he
liked the hypothesis in the context of the cartoon because it explained
both the missing New York garbage cans (you had to be there) and the
space aliens.

A rather direct link between particle physics--cosmology and biology is
posited by the anthropic principle first suggested by Brandon Carter. A
recent article that speaks to this is one by BJ Bjorken. In brief, we
have our universe because it is the only universe that works for us. The
actual theses for this principle can be considerably more complicated. A
particularly telling argument is the reaction pushed by Fred Hoyle. For
myself I wonder if this point of view does not suffer from some of the
problem with "Rare Earth." "Life" out there may be considerably more
diverse than we credit it with. We need to ask the question posed by
Schrodinger, namely "What is Life."

So we now have biology linked to particles and cosmology and needing
more information from outer space. There is one more booming science to
add to the chart namely computing. Remember, read mathematics,
computing, electronics, ...

For years at Fermilab I rode heard on technology transfer. I cataloged
about 800 technological developments that were touched by Fermilab work.
I totally missed the important one, the World Wide Web. Granted the
development occurred at CERN but some diligent heroes at Fermilab like
Ruth Pordes worked to establish one of the first transoceanic links. One
can safely say that Berners-Lee utterly changed the world. At this point
we think of it mostly in terms of business and information and annoying
viruses. The ultimate impact will be much larger than that. A second
"computing" wave is the advance of Moore's law, the shrinking of the
feature size of a transistor on a silicon chip with time. Electronics
technology is sweeping over us at a rate so that it may outdistance us
intellectually before the hundred years is over. The next Fermi may be
an Apple computer!

Here is a table of some databases. We have discussed the human genome
already. The Fermilab tape robot handling colliding beam data and Monte
Carlo calculations is 10 to 100 million times larger. The Sloan database
is a fly on the robot. The robot could handle several years of printed
material from the world. A typical graduate education might be 1 to 10
Gbytes while a lifetime of images is roughly 1000 times larger. The
knowledge base in a human brain is in the 0.25 to 2.5 Gbyte range
(stuffed in 1011 neurons). 6\*109 people gives 1.5 to 15\*109 Gbytes to
profile everyone on earth. The lesson here is that the capacity for
these databases is within range in the next decades.

Kurzweil estimates the speed of the human brain is 200\*103 Giga
computations/s or 105 times this computer. Kurzweil calls the crossover
point when computing speed exceeds our brain computing speed a
"singularity". "Phase change" might be a better term. At the present
rate the crossover point is 2020 to 2030. Actually the computing rate
for QCD processors, 1000 Giga Flops, is getting in range. Over the
horizon is another powerful possibility, quantum computing. So ... there
are many computing factors in our future. Some of the problems and
challenges include the virus mess, the approach of the Kurzweil
"singularity", qualifying Internet and World Wide Web information, and
indeed qualifying programs. Finally we need working theories of
computing, knowledge, and mind

. Computing needs to be made into a science!

Computing then, is deeply linked to DNA. It has already been applied to
untangling the human genome. Even more important we have seen biology go
from being wet, icky stuff to irritating computer code. Life is
mathematical. The future possibilities are vast. Computing is also tied
to particle physics and cosmology as a faithful servant and is
absolutely necessary for space exploration as we now know it.

Before closing I want to note that many of these threads are embodied in
the NASA "Origins" program. This is an important agenda for us as
particle physicists, astronomers, and cosmologists.

In summary, particle physics and cosmology link and explain much of the
universe. Biology has become a mathematical science

. Scientific experiments have moved into space. Computers and computer
science are reaching human capabilities. We may find extraterrestrial
life

. This future ahead promises a very interesting 100 years.

Thank you.