Akron Phy sics Club
Meeting Announcement: MONDAY, January 24, 2000 - TANGIER, 6:00 PM
Our first speaker the new millennium (yes, we all know it really starts next year) will be Dr. Daniel Akerib, Assistant Professor of Physics, Case Western Reserve University. Dr. Akerib’s topic will be:
LOOKING FOR WIMPS IN THE GALACTIC HALO: THE CRYOGENIC DARK MATTER SEARCH
Minutes, January 24, 2000
Present for the first meeting of what some believe was the New Millennium (although that strange-looking date is arresting, technically it isn’t until next year) were Tom & Marie Brooker, Vic Burke, Tom Dudek, Dan Galehouse, Alan Gent, Jack Gieck, Bob Hirst, Bill Jenkin, Robert Mallik, Leon Marker, Peyman Pakdel, Pad Pillai, Lyle Pauer (welcome back, Lyle), Darrell Reneker, Gary Roberts, Ernst von Meerwall, and Charlie Wilson. And we had another new recruit of whom we hope we see more: Welcome John Kirszenberg! Called upon for an opinion regarding the health of the club’s liquidity, Treasurer Dan Galehouse opined that “it looks pretty good,” a view he later quantified at $115.15.
We were also delighted to welcome not only our speaker, Dr. Daniel Akerib, Assistant Professor of Physics, Case Western Reserve University, but also Dan’s wife, Chantal. As the evening progressed, it became obvious how hard Dan and his colleagues are pushing the limits of technology and excogitation in their Cryogenic Dark Matter Search for Weakly Interactive Massive Particles (WIMPS for short) in the Galactic Halo utilizing, to significantly understate the challenge, a SPECIAL kind of particle detector.
Our speaker began by presenting evidence for the very existence of these elusive, extremely small (but by no means insignificant—90% of the mass of the universe?!) particles. There appears to be a variety of astronomical evidence that cannot otherwise be explained, especially dynamical observations that include galactic circumferential motions that are too fast at radii that are much too large for the apparent masses involved. Similar conclusions can be drawn from the motion of galactic clusters. Stuff is spinning much too fast. Worse, analysis of the problem reveals that “dark matter” is not even ordinary matter. It is obviously exotic stuff!
Calculation of how many of these particles (probably produced in the very early universe) are still around yields a value of perhaps a hundred in every coffee cup. But detecting them is not a game for the intellectually timid (especially the timid with limited patience or with a low budget) because, as it turns out, not all cosmic matter particles are equivalent. Their velocities vary by two or three orders of magnitude. And there are all of these other submicrominiature particles (cosmic rays, photons, gamma rays from low-order radioactivity zapping out of just about everything from bricks to fiberglass) that tend to screw up the data.
The (“sophisticated” is too weak a word) equipment used to try to trap these particles, developed by competitors Berkeley and Fermilab (acronymmed “BLIP” and “FLIP” respectively), is basically a very shielded calorimetric detector maintained at a temperature of 20 microKelvins which measure a millionth of a degree temperature rise in a 100 mg speck of germanium when one is lucky enough to have an impact. And then one has to distinguish between and calculate the ratio of energy detected due to ionization and to phonons, respectively. One must reject cosmic ray muons, screen out gallium line internal radiation and rule out (from masses of curves) all causes other than those produced by the impact of WIMPS—pushing sensitivity to smaller and smaller cross sections.
Moreover, even if there are a hundred WIMPS per cup as noted, trapping such tiny particles when there is so much space between particulate bits of matter in such a modest solid sample is chancy indeed. For perspective, Dan explained that most neutrinos go completely through the earth without hitting another particle. (The mean free path for a neutrino turns out to be measured in light years of lead.) Like neutrinos, WIMPS are also weakly interacting particles. In fact, if a WIMP is detected, it will be the first time it has collided with anything since its creation shortly after the big bang! WIMPS are fermions and are massive—on the order of 100 GeV. An electron, another fermion, is 0.5 MeV in mass, so a WIMP is on the order of 200,000 times more massive than an electron! Because of their mass, WIMPs move slowly.
The equipment operated by Dan’s group currently has four detectors 30 feet underground. And speaking of lead, above, like their colleagues elsewhere, these physicists have salvaged century-old lead from ship ballast to minimize (some five half-lives later) the percentage of radioactive Pb210. After completion of their first phase (one quarter of their 1999 data has been analyzed—and we saw a variety of plots showing some meaningful point distribution) they plan to move into an abandoned iron mine two miles deep in northern Minnesota.
Exciting—albeit daunting—isn’t it?
And now, to sing the familiar refrain, to assure your place at the dinner table for Dr. Patterson’s talk, please call in or otherwise zap your reservations (or regrets) by Thursday afternoon, February 24th, to Reservations Secretary Charlie Wilson: 836-4167
With an assist by Vic Burke
Meeting Announcement: MONDAY, February 28, 2000 - TANGIER, 6:00 PM
Our February speaker will be Dr. Michael J. Patterson of NASA’s Glenn (formerly Lewis) Research Center, whose specialty is
ION PROPULSION SYSTEMS (& OTHER EXOTIC THRUSTERS)
Minutes, February 28, 2000
Gathered for the warmest February on record were the usual regulars as well as our welcome recent acquisitions: Tom & Marie Brooker, Vic Burke, Tom Dudek, Dan Galehouse, Jack Gieck, Bob Hirst, Bill Jenkin, John Kirszenberg (welcome back, John!) Robert Mallik, Leon Marker, Peyman Pakdel, Lyle Pauer, Darrell Reneker, Gary Roberts, Ernst von Meerwall, and Charlie Wilson. Invited by Chairman Ernst, Treasurer Dan Galehouse announced that our burgeoning treasury has reached the astonishing value of $148.99.
After piquing our interest in presentations scheduled for the rest of the year (our own Darrell Reneker in April, NASA/Allied Signal alumnus Bob Chapman in May), Program Chairman Vic Burke introduced our speaker for the evening , Dr. Michael Patterson, of NASA’s Glenn Research Center, where he is Leader of Research & Development Programs for electrostatic ion propulsion and cathode technology for electric propulsion and spacecraft charging. Although that title probably does not fit readily on a business card, from the volume and amazing variety of material that Mike presented on Ion Activities at NASA, it became apparent that every one of those definitive words was appropriate.
Electric propulsion is state-of-the-art technology, low thrust systems which, because of their prodigious propellant velocities, provide enormous savings in fuel over familiar chemical rockets. Our speaker gave us a progressive list, beginning in 1994 with the introduction of arc jets, which are electrothermal thrusters — followed by ion thrusters and Hall thrusters, which produce greater thruster efficiencies, and could be designed to operate at some 75 kilowatts of power. In the wings are magnetoplasmadynamic thrusters, PIT, microwave, and other advanced high power concepts escalating to a megawatt or more. Mike first reviewed some of these.
As many as a hundred Hall thrusters, it turns out, may have been built by the Soviet Union for military purposes. Using an axial electrical field, Hall accelerators shoot out electrostatically accelerated xenon ions. Current models operate at about 300 volts, consuming 1 kilowatt to generate 2-300 miliNewtons of thrust. Although that’s only a little over an ounce, Hall thrusters are ideal for controlling satellites in geosynchronous orbit. Twenty years downstream, NASA expects to have units operating in the 10 kW range.
Ion thrusters, first developed by in the 1950s, squirt out a beam of electro-statically generated xenon plasma at velocities in the 30,000 meters per second range. They have the potential of lasting four times as long as their internal combustion engine counterparts in our passenger cars, without the luxury of returning to the dealership for periodic (e.g. 5000 mile) maintenance checks — making them appropriate candidates for deep space missions. Current NASA ion thrusters in real-world operation, e.g. the one employed on Deep Space 1, carrying 83 kilograms of xenon propellant, have a 30 cm beam diameter, operate at 1300 volts, consuming 2.3 kW of power generated by solar panels, and generating 92 miliNewtons. (Solar panels are capable of generating about 100 watts per square meter).
With some beautiful overhead graphics and a three-minute video, our speaker showed us what makes these devices work. Permitting us to peek “under the hood,” he demonstrated how they ionize the propellant, heating it to 200-400° C, ejecting the electrostatically focused plasma through some 15,000 precision-aligned circular apertures out their business end.
For future programs employing much bigger stuff (e.g. a Mars cargo vehicle, Venus surface sample gatherer, or Neptune orbiter), we saw test beds currently being evaluated — huge ionization chambers 15 feet in diameter by 60 feet long, equipped with diagnostics for efficiency, life, beam shape and strength, erosion and other things a pilot would like to know about his engine during his very long flight.
Current NASA projects that are generating a profit are mostly concerned with commercial communications satellites. Client/participants include government, industry, and academia. One recent project generated $2 billion in contracts on $20 million in investment. By 2005 the agency expects to launch an ion engine probe to a nearby comet, landing, scooping material, and returning with a sample!
And a bit of inside table talk. Likely cause for the recent failure of the Mars Lander: When the legs deployed at altitude, microswitches in the feet may have been inertially triggered, causing the vehicle to believe it had landed.
Now then, at the risk of sounding redundant, please call in or otherwise zap your reservations (or regrets) by Thursday afternoon, March 23rd, to Reservations Secretary Charlie Wilson: 836-4167
Meeting Announcement: MONDAY, March 27, 2000 - TANGIER, 6:00 PM
For our March meeting we will be honored to hear Prof. R. Earle Luck, Director of the Case Western Reserve Observatory and Chairman of the University’s Department of Astronomy. Prof. Luck’s topic will be:
CURRENT TRENDS IN ASTRONOMICAL RESEARCH: WHAT’S HOT AND WHAT’S NOT
Minutes, March 27, 2000
Record attendance at our first spring meeting included Tom & Marie Brooker, Vic Burke, Dan Galehouse, Jack Gieck, Bob Hirst, Bill Jenkin, John Kirszenberg, Dan Livingston, Robert Mallik, Leon Marker, Peyman Pakdel, Lyle Pauer, Pad Pillai (welcome home, Pad), Jack Strang (who’s been under the weather; welcome back, Jack!), Darrell Reneker, Ernst von Meerwall, and Charlie Wilson; and we were pleased to welcome Dr. Tony Pan, guest of Peyman Pakdel, who recently joined Firestone Research. And those of us privileged to have dinner with our speaker had the added pleasure of getting acquainted with Christa Luck.
Responding to the growing crisis created by the club’s increasing popularity, after consulting with Chairman Ernst von Meerwall, Treasurer Dan Galehouse reduced the dinner tab by one dollar to avert an embarrassment of riches — leaving a treasury balance by evening’s end of $105.46. Chairman Ernst reminded members that nominees for next year’s club officers should be given to Charlie Wilson by (or at) our April meeting. (We’ll be going through that again in May.) At which point Program Chairman Vic Burke, after giving us an impressive bio and a printout of his several URLs (of which more later) introduced our speaker for the evening:
Prof. R. Earle Luck, Director of the Case Western Reserve Observatory and Chairman of the University’s Department of Astronomy, thoroughly entertained us while bringing us up to date on Current Trends in Astronomical Research: What’s Hot and What’s Not — aided and abetted by a marvelous little liquid crystal projec-tor (new to this AV aficionado), fed by a 10-gig laptop that not only summarized and illustrated our speaker’s points on cue, but blew our minds with two spectacular, 25-meg animations of galaxies in collision — courtesy of his colleague, Chris Manhos.
Partly, it turns out, what’s hot and what isn’t is a function of funding, and Dr. Luck first addressed whether funding drives research or vice versa [the answer seems to be both]. Partly, it depends on who is giving out the money. NSF and NASA have different goals — as do different countries. The U.S. and Japan are both big on planets; not so Russia. Europe is high on the evolution of stars — more, it seems, than the evolution of the Milky Way. But everybody is into cosmology.
In this country for the last part of the 20th century, our speaker explained, the focus was on stars. But self-confessed optical astronomer Earle Luck was forced to admit that, no matter what the power of the telescope (anything over six inches gathers additional light but offers no improvement in resolution), a star is a point is a point — from which we can measure brightness and temperature and composition, however. Since he can’t interact with the objects of his affection, an astronomer has been limited for centuries to his brain, a pencil and his telescope. What caused a revolution in the field was the advent of the computer. First applied to stellar evolution, it led to a change of focus from stars to extragalactic topics.
But that wasn’t the only push. In 1950, Vera Rubin showed that the rotation curves of galaxies did not behave according to Kepler’s law — which ultimately led to an admission that there is lots more invisible matter out there than what we’ve been staring at. When stellar masses were simply luminous matter controlled by Newtonian gravitation and stellar physics, life was easier. But when it was (slowly) realized that most of the mass was unseen, the new quests became: What was the nature of dark matter? Was it baryons — exotic particles — WIMPS [probably not]? How was it distributed? How did galaxies form? Was dark matter involved?
The concepts our speaker laid on us accelerated after that. Unlike stars, galaxies are separated by only tens of diameters. So they are constantly running into each other. Gas clouds collide and form new clouds of stuff. Interactive galaxies are common. Our Milky Way and Andromeda are closing on each other. It was then that we saw animated simulations of colliding galaxies: how a small one plunging into a big one results in a cartwheel pattern just like [cut to] a real galaxy we had seen earlier from the Hubble. Impacting galaxies of equal size metamorphized into a pair of spindly antennae [cut to real telescope image]. And we saw striking views of gravitational lensing, possible accreting of low-metallicity gas, and so it went. These and other glorious images may be had by dialing up CWRU’s Physics Department home page at http://burro.astr.cwru.edu/dept/ People > Chris Mihos > etc.].
The future of observational astronomy, Earle explained, will lie in new (binocular!) earthbound telescopes — 8-10 meters are rampant — and in the next generation of (infrared) space telescopes, one of which (8M) may be ready by 2007. It was an exhilarating look. Space permits only a few highlights. Thanks, Earle!
So, now that most of us have got the hang of it, please call in or otherwise zap your reservations (or regrets) by Thursday afternoon, April 20, to Reservations Secretary Charlie Wilson: 836-4167
Meeting Announcement: MONDAY, April 24, 2000 - TANGIER, 6:00 PM
For our April meeting we are pleased to announce a return engagement of our own Dr. Darrell H. Reneker, Professor of Polymer Science, University of Akron. Giving us an update on a subject for which he is famous, the title of Darrell’s April presentation is:
POLYMER NANOFIBERS, FLUID JETS, AND ELECTRICAL FORCES — HOW LONG AND HOW THIN CAN NANOFIBERS BE?
Minutes, April 24, 2000
Present for our April meeting were Tom & Marie Brooker, Vic Burke, Tom Dudek, Dan Galehouse, Jack Gieck, Bob Hirst, Bill Jenkin, John Kirszenberg, Dan Livingston, Robert Mallik, Darrell Reneker (and his assistant presenter, Tony Kataphinan), Ernst von Meerwall, and Charlie Wilson. Called upon for a pecuniary report by Chairman Ernst, Treasurer Dan Galehouse advised that, despite recent lowering of our dinner price, our treasury balance remains in five impressive significant figures at $104.98. In other news, Charlie Wilson advised that Leon Marker would be undergoing multiple bypass surgery on Tuesday. [Charlie and I have both been to see Leon since, and he seems to be making an outstanding recovery.]
Assistant Secretary/Bylaws Author Charlie Wilson, having declared that the only nominations he had received for next year’s officers was a creative motion by Alan Gent that “the incumbents be retained — by force if necessary,” Chairman Ernst presided over the cursory reelection of:
|Chair||Ernst von Meerwall|
|Assistant Secretary||Charlie Wilson|
|Program Chair||Vic Burke|
|Program Vice-Chair||Leon Marker|
Following an impressive bio by our chairman for our speaker, our own Darrell Reneker gave us a sneak preview of his paper and his May seminar on Frontiers of Polymer Science, focusing on Polymer Nanotechnology.
Our speaker began by reminding us that some of the nanofibers he has been generating in the laboratory with his magical “electrospinning” process have a diameter smaller than the wavelength of light. But his nanofamily tree actually plunges four orders of magnitude from small textile fibers to single molecule strands. E.g., we saw electron microscope images of deposits of long, twisted nanofibers lying across a textile fiber that looked like human hair lying on a log.
For a 3D example, Darrell first exhibited a polymer molecule model about a foot in length — then projected a map that illustrated what the cross section of a fiber from his necktie would look like at the same scale: It covered downtown Akron! His tiniest nanobundles of about 40 parallel molecules, we learned, have enormous surface area per unit mass (equal to that of activated charcoal) — making them ideal for surface adsorption fabrics in protective clothing, filtration systems, advanced composites, biotechnology uses, e.g. collagen for artificial joints, maybe even skin for artificial organs; and their incredible lightness of being has fired the imagination of those contemplating mirrors in space, or, better, sails propelled by light — riding sunlight to the outer planets or a laser beam to outer space.
Like the masked magician on TV, Darrell showed us how he does it. A simple glass pipette nozzle containing a liquid polymer solution is aimed at a grounded metal plate. The liquid is charged to about 20,000 volts (a potential that would to draw a one cm spark). The charge coaxes the liquid out while surface tension tends to hold it in.
Oozing from the tip of the pipette, the droplet forms into a cone before suddenly bursting from the tip, looking like a single stream of milk from a nipple — before almost instantly branching into scores of substrands that further subdivide, some of them into beaded strings no more than six molecules in diameter. (The solvent evaporates in the air.) These wispy subdivided streams can be incorporated into textile yarn; or the expanding coils of fuzz can be deposited as a random-oriented fabric. We could see why it is sometimes called gossamer technology.
For a repeat of the stunning 2000 fps ultra-slow-motion movie of the process that we saw (twice thanks to Tony), here are some hints — albeit less than a detailed spec:
Name of file: bending-movie.avi
So then, for the last time before the summer solstice/hiatus, please call in or otherwise zap your reservations (or regrets) by Thursday afternoon, April 18, to Reservations Secretary Charlie Wilson: 836-4167
Meeting Announcement: MONDAY, May 22, 2000 - TANGIER, 6:00 PM
Speaker for our May meeting will be Dr. Robert D. Chapman, of Columbia, MD, who taught astronomy at UCLA before embarking on subsequent careers at NASA’s Goddard Space Flight Center, Johnson Space Center (Houston), and Allied Signal. Dr. Chapman spent last Christmas Eve in the Hubble control room, with which instrument (as well as others) he has been a major player. His topic will be:
ARE COMETS AND ASTEROIDS DANGEROUS?
Minutes, May 22, 2000
Present for our last meeting before our summer hiatus were regulars Tom & Marie Brooker, Vic Burke, Tom Dudek, Dan Galehouse, Alan Gent, Jack Gieck, Bob Hirst, Bill Jenkin, John Kirszenberg, Robert Mallik, Darrell Reneker, Jack Strang, Ernst von Meerwall, and Charlie Wilson. Some of us were privileged to have dinner with our speaker’s wife, Susan, and daughter Jennie Vasarhelyi, CVNRA’s Director of Interpretation and Visitor Services. And we were pleased to welcome visitors Jim Bunyan and Stu Clary. We hope we’ll see you both in our new season, which is leaving the launching pad with this mailing.
Charlie Wilson, having been to see Leon Marker earlier in the day, reported that Leon is doing remarkably well after his quintuple bypass surgery, but he wasn’t yet up to joining us for the evening. Treasurer Dan Galehouse, having gone a whole year without asking for an assessment(!), announced that we had squeaked by with a treasury balance of $87.28—so we will open the new season untaxed. Obviously stellar financial management, Dan.
Well known for his work on orbiting imaging satellites at both NASA and Allied Signal, especially the Hubble, our speaker, astronomer Robert D. Chapman allayed some (but by no means all) of our fears as he offered detailed answers to the question, “Are Comets and Asteroids Dangerous? Opening with a photo revealing a felled forest of bare, leveled trees, Dr. Chapman explained that something—most likely a comet nucleus tens of meters in diameter—had exploded 5-10 kilometers above this spot in Siberia’s Tunguska Basin on June 10, 1908. Instead of a round crater, however, the shock wave produced by the rapidly moving explosion had plowed an oval furrow about 10 km wide and a 100 km long—not unlike the string of craters seen on one of the moons of Jupiter; or the recent spectacular “string of pearls” impact into Jupiter’s gassy surface.
Comets, our speaker confirmed, are giant icebergs—but a special kind of ice: a crystal lattice hydrate that entraps methane, ammonia, organic molecules and other cosmic garbage that is released when the ice sublimates in the sun’s radiation. Dr. Chapman showed us several craters resulting from incoming material, including the famous Arizona crater produced by about 100 lb of metallic debris that dates back only about 50 million years. And we saw a magnificent close-up of the cratered asteroid Eros.
Superimposing transparency plots of semi-major axis vs. orbit eccentricity for hundreds of comets and comparing them to the same for asteroids, it was apparent that for a significant number of these objects, it is difficult to tell which is which. Some that have been regarded as asteroids are very likely crusts of comets that no longer have tails, having sublimated all their water. And the composition of asteroids has been rethought: With reference to the April Scientific American piece, most asteroids are probably not monolithic bodies, but are stuck-together gravel piles, as evidenced by the fact that only small asteroids revolve more than once in 72 hours (slower big ones turn once in 5-6 days)—for if they revolved faster they would tear apart—as indeed something did as it became the famous “string of pearls” Jupiter impact.
And yes, there is a danger of (probably predictable) collisions with these objects, if we get in each other’s way. In 1996, although it missed us by almost the distance to the moon, an object 100 meters in diameter crossed the earth’s orbit only half an hour after we had passed. While watching a Leonid meteor shower, we are free to ponder the liklihood that its nucleus is probably an object about one km in diameter. And in the recent geologic past (65 million years ago), leaving a tell-tale iridium stratum behind, an object less than 10 km in diameter slammed into the Gulf of Mexico at 200,000 kph with the energy of 100 trillion tons of TNT (10 billion Hiroshima bombs) producing a “nuclear winter”-type blackout that wiped out 50-70% of all living species (annihilating the dinosaurs), and making a 180 km crater centered at Cicxulub, in the Yucatan Peninsula. The impact created an earthquake of 12-13 on the Richter Scale (1000 times greater than any experienced by human creatures), producing a wave in the Caribbean about one km high.
So what are our odds? Switching units (Ref TIME, 4-10): 1000-foot objects hit us once every 50,000 years; 200-footers (e.g. Tunguska, 1908) every 200 years; 35-ft chunks arrive every 10 years; smaller ones much more frequently. But most small objects tend to explode harmlessly in the atmosphere or they land in the ocean. However, if one dares to calculate such things, a 10-100 km body plunking into the Atlantic Ocean, would produce a wave that would break against the Rocky Mountains. Whoosh!
So what if? What do we do about them? Comets, it seems, are easier. A little heat on one side would cause sublimated outflow to provide enough rocket effect to change the orbit (as seems to happen naturally to Halley). Asteroids would require a much more sophisticated engine. What we don’t want to do is blow them to smithereens, producing multiple impacts—each een with its own new time table!
So: after taking a deep breath, please call in or otherwise zap your reservations (or regrets) by Thursday afternoon, September 21, to Reservations Secretary Charlie Wilson: 836-4167
Meeting Announcement: MONDAY, September 26, 2000 - TANGIER, 6:00 PM
Minutes, September 26, 2000
Present for the first meeting of our new season were regulars Tom & Marie Brooker, Vic Burke, Tom Dudek, Dan Galehouse, Jack Gieck, Bob Hirst, Bill Jenkin, John Kirszenberg, Dan Livingston, Robert Mallik, Leon Marker, Lyle Pauer, Pad Pillai, Gary Roberts, Jack Strang, Ernst von Meerwall, and Charlie Wilson. And we were pleased to welcome H. A. Morton Visiting Professor Gregory Rutledge of MIT; we hope to see more of him during his Akron visit.
After Treasurer Dan Galehouse reassured us that we still don’t need a dues assessment (our treasury balance being the grand sum of $70.90), Program Chairman Vic Burke first introduced Dr. Mary Turzillo (http://www.dm.net/~turzillo/), who retired as a KSU professor of English to be a full-time writer. Mary is the author of scores of academic and popular works that include fiction, non-fiction, and poetry, including, significantly, dozens of science fiction short stories, one of which won a Nebula award last year . . . significantly because her husband has had more than fifty science fiction stories published, one of which won a Hugo. And in December his first novel, Mars Crossing, will be published by Tor.
He is, of course Dr. Geoffrey Landis (http://www.oai.org/landis.html + cascade of links that include http://www.sff.net/people/Geoffrey.Landis), currently of the Ohio Aerospace Institute and a consultant to NASA on most of the neat Mars stuff we have all seen on television (broadcast from there). Dr. Landis spoke on the general subject of Interstellar Probe Techniques — quickly focusing on Lightsails, which turn out to be the only current technology that offers real possibilities for interstellar exploration — outdistancing (no pun intended) such no-hope competitors as rocket propulsion, fission, fusion, anti-matter, Bussard ram, and ram-augmented rockets.
Lightsails avoid the monstrous drag imposed by having to accelerate the fuel one must otherwise carry along by literally leaving it behind, relying instead on beamed energy propulsion. Forces generated by lasers don’t sound like much (6.7 Newtons [1.5 lb] per gigawatt), but that’s sufficient to accelerate a 10 kg probe riding the beam to 10% of the velocity of light in two years — if you make a sail one kilometer square out of very flimsy plastic, covered by a really thin layer of aluminum to provide the needed “wind.” (Aimed [by lens or mirror] sunlight proposals turn out to be impractical because incoherent light can’t be focused reliably over great distances.)
Such a sail would have to be assembled in space. And as long as we’re going to that much trouble, using a king-size laser for propulsion will permit us to discard the plastic substrate — our sail becoming only the reflective layer, maybe 20 nanometers (200 atoms) thick. (We are going to need a really big Fresnel lens, however.)
Lightsails are thermally limited by their operating temperatures, so aluminum is less than great as a candidate metal. Materials studies (we saw plots of reflectivity vs. thickness for various materials) have included platinum, iridium, titanium, beryllium, scandium, and niobium — the last being the best. But dielectric films can be 200 times better than aluminum, yielding 44% reflectivity for a thickness of 44 nanometers. And diamond could be as much as 50% for a 20 nanometer thickness. (Geoffey admits to a bit of an engineering problem there.) Realistically, our speaker estimates that it will be decades before near-term laser-pushed sails are launched; and centuries before farther-term launchings are attempted.
Alternatives, technologies here today, include micro-wave pushed sails, promis-ing much higher efficiencies through phased arrays of large-aperture transmitters, in combination with even lighter meshed sails. Here, graphite beats all other materials for acceleration, promising Pluto in three weeks (with 20 hours of acceleration) — and the nearest star in 400 years. It would require 56 gigawatts of power, however, measured at the sail. That accomplished, with a little tweaking we might expect to push on to the nearest star in a human lifetime. There are collateral problems, of course, such as space dust, each particle of which, at 0.1c, would hit the sail like a nuclear bomb — but at that velocity the blast would be mostly behind the sail.
Our speaker has a documented history of this sort of thinking — a kind of dreaming with quantitative precision — and when I suggested to him that it had earned his presentation the highest Wi coefficient (for innovative wildness) we have experienced to date, this writer of hard-nosed, scientifically-correct science fiction countered that we had heard only the conservative stuff.
And so: It is time to get back into the habit of calling in or otherwise zapping your reservations (or regrets) by Thursday afternoon, October 19, to Reservations Secretary Charlie Wilson: (330) 836-4167
Meeting Announcement: MONDAY, October 23, 2000 - TANGIER, 6:00 PM
You are not having a deja vu experience! Speaker for our October meeting really will be author/physicist Prof. Jay Dratler, recently appointed to the Goodyear Chair in Intellectual Property, University of Akron Law School. Prof. Dratler has graciously readjusted his schedule to solve our club’s recent scheduling enigma. His topic will be:
HAS INTELLECTUAL PROPERTY GONE TOO FAR?
Minutes, October 23, 2000
Present for our October meeting, were Tom & Marie Brooker, Dan Galehouse, Bill Jenkin, John Kirszenberg, Dan Livingston, Robert Mallik, Leon Marker, Bob Marx, Lyle Pauer, Pad Pillai, Darrell Reneker, Gary Roberts, Jack Strang, Ernst von Meerwall, Jerry Potts, Joe Walter, and Charlie Wilson. And Jack Strang brought two guests: Thomas & Marriane Legeza. We hope we’ll see more of them.
And since, as is apparent, your secretary couldn’t make it, the following minutes have been graciously provided by our own Chairman Ernst, master of many languages — with profuse thanks from this quarter:
“Our speaker was Dr. Jay Dratler, the Goodyear Chair in Intellectual Property at the University of Akron's law school. He posed the provocative question: "Has intellectual property gone too far?" — and proceeded to set the issue firmly in Anglo-Saxon historical context. In an effort to avoid the unpopular choice between direct taxation and bankruptcy, a British monarch 400 years ago conceived of selling exclusive rights to favored manufacturers, allowing the latter to recover costs by increasing their products' price, thus still taxing the people, albeit indirectly. Common law courts soon struck down the monopolies, and Parliament adopted a statute expressly prohibiting them, but did provide for patents and rudimentary copyright.
“The US constitution contains these provisions as well, but without an explicit prohibition of monopolies. Intellectual property law in general attempts to seek a balance between a prohibition of exclusive ownership and exceptions honoring some social purpose; this usually involves limitations in time, and notions of the good of science and the useful arts. Patentability under American law requires that an invention be novel, non-obvious, and useful, but there are no explicit exceptions as to subject other than matters of grave public danger such as atomic weapons. But as a common-law country, we have "judgment exceptions": abstract ideas, phenomena, and laws of nature are deemed to be unprotectable. As for items that are protectable, in the extended question period following the formal presentation we were treated to a succinct explication of patents, copyright, and trade secrets, the nature of their protection, and the differing requirements for their applicability.
“Much difficulty has lately arisen as a result of universal computerization. To what extent is computer software an expression of abstract ideas rather than a practical implementation of a method? To what extent is the "look and feel" of commercial software a superficial, inevitable artifact of the user interface rather than arising from a substantive textual expression deserving of copyright protection? Dr. Dratler cited voluminous case law illustrating the difficulty courts have drawing consistent distinctions; this legal amateur could find little comfort in the apparently haphazard ways such problems are resolved even if courts rule on substance rather than technicalities. A current example involves the State Street hub-and-spoke investment scheme, whose accounting procedure is an implementation of a simple algorithm (abstract) to a business practice (applied). There are between one and two thousand U.S. patents protecting business practices involving algorithms, but whereas there are now some grandfather defenses against patents of this sort, the very existence of legal limitations on these patents by implication somehow legitimizes the patents.
“Thus, Dr. Dratler finally answered his rhetorical question in the affirmative. He feels that intellectual property protection has, indeed, gone too far. The legal profession may, as seems customary, be engaging in a somewhat cynical effort to favor a maximum in legal protection, hence legal complexity, and consequent full employment for legal specialists. He is in a position to do something about this, by writing articles showing that current levels of protection may be excessive by reasonable standards and precedent.
“The satisfyingly large audience was treated to a superb exposition of ideas whose clarity and cogency left us delighted. Many of us are seriously considering an upward revision of our opinions of lawyers. But we would also be glad to claim that Dr. Dratler's PhD and several years of research in physics, prior to his legal studies, may be at the root of his extraordinary competence.”
Our next meeting being the Monday after Thanksgiving, we ask that you zap or phone your reservations (or regrets) a day early: by WEDNESDAY afternoon, November 22, to Reservations Secretary Charlie Wilson: (330) 836-4167
Ernst Von Meerwall and Jack Gieck
Meeting Announcement: MONDAY, November 27, 2000 - TANGIER, 6:00 PM
Speaker for our November meeting will be Dr. David W. Ball of Cleveland State University, Department of Chemistry, author of some 85 publications in both scientific and science education literature. Prof. Ball’s topic will be:
SKEPTICISM IN SCIENCE
Minutes, November 27, 2000
Present for our last Old Millennium meeting were regulars Vic Burke, Tom Dudek, Dan Galehouse, Jack Gieck, Bob Hirst, Bill Jenkin, John Kirszenberg, Leon Marker, Pad Pillai, Jack Strang, Darrell Reneker, Ernst von Meerwall, and Charlie Wilson. Visitors recruited and introduced to the group by pro-tem membership chairman Charlie Wilson included David Brown, Beverly Mugrage, Richard Sharp, and David Wynn. [Welcome aboard, folks! We hope we’ll be seeing more of you in future months.] And some of us were privileged to have dinner with Gail Ball, wife of our speaker and a successful engineer (and certified mother) in her own right — who is but one notch away from her own PhD in material science.
Reassuring the membership once again, Treasurer Dan Galehouse reported that the current net of $49.62 in his (manila envelope) coffer has permitted the club to complete yet another year without one of our rare 5-buck assessments.
For our last meeting of the year, we were privileged to hear a seminar/lecture entitled SKEPTICISM IN SCIENCE — a talk that Dr. David W. Ball (by popular demand) has previously given in four different states. Associate Professor of Chemistry at Cleveland State University, and author of some 85 publications in both scientific and science education literature (about whom more can be discerned at http://www.csuohio.edu/chemistry/dwb.html), Dr. Ball held our attention with a high-energy, spirited lecture, replete with lots of Saganesque quotations, despite its prosaic sounding title.
Our speaker began by defining what science is not, and what skepticism is. Science, he emphasized, is not facts. Rather, it is a way of knowing about the universe — a method by which we determine facts. Skepticism, he explained, is a philosophical doctrine which demands that any process of inquiry must include and deal with elements of doubt. Science, to put it bluntly, is that which is falsifiable. It is not a model of the universe but rather a process of testing models of the universe. Moreover, as Carl Sagan cautioned. “Nature is subtle. Be wary.”
Too often, our speaker suggested, in the process of such inquiry we don’t ask the right questions — especially when a new hypothesis, or worse, a full-blown refined theory (sometimes even with a product thrown in!) is dumped upon us at a news conference instead of in a peer-reviewed technical paper. David offered two major examples of our gullibility. The first of these, “cold fusion” was reviewed and critiqued for us by Rex Ramsier in January, 1997. It has been largely derided in the scientific community ever since — at least after that august body recovered its wits and stopped spending millions of dollars in futile efforts to duplicate its “discoverers”’ claims. “Cold fusion” has turned out to be a classic illustration of the need for compliance with another Carl Sagan dictum: “Extraordinary claims require extraordinary proofs.” Further, “If conditions are not set up properly, results are suspect.”
Currently, it is “hydrinos” (hydrogen hydrides!) and the head-spinning “gyrotrons” of Black Light Power, Inc. (http://www.blacklightpower.com) that leave one with the feeling that he has been sprayed with a fine mist of questionable scientific-sounding jargon designed to attract disciples and/or investors to the “field.” BLP’s seemingly random extraordinary claims of “37 times more efficient [than fuel cells],” and their spouting of values like “45 orders of magnitude [!] . . .” seem to cry out for appropriate skepticism (or an exponential BS coefficient).
That our speaker made a convincing case is evidenced by this audience member’s submittal herewith: That a degree of robust skepticism might be appropriate in evaluating David’s final suggestion: that the skeptistic process he champions could be equally effective in moderating disputes or studying unsub-stantiated claims in such other fields as religion, politics, advertising, and personal relationships — at least some of which, your secretary suggests, just might not be able to stand the gaff.
And so, with best wishes for a Happy New Millennium (or a reasonable portion thereof), please consider yourself reminded to call in or otherwise zap your reservations (or regrets) by Thursday afternoon, January 18, to Charlie Wilson: 836-4167