Have you ever wondered how history will compare the scientists and engine ers of today with those who worked in the last few centuries? I overhear d a discussion where everyone was in agreement that the explosion in tech nology experienced during this century is positive proof that the scienti sts and engineers of today are the impressive winners in this comparison.
Now I personally like discussions and debates. I have my opinions, and I generally stick to them unless someone can convince me that I have not l ooked at the complete issue. However, I dislike discussions where everyo ne picks the same side of an issue. When that happens I often find mysel f picking the opposite side just to see where it leads. As a result, I j oined in on the conversation and played devil92s advocate even though I really had no opinion at the time.
My thesis went as follows. The giants of science such as Sir Isaac Newto n (1642-1727), Georg Simon Ohm (1787-1854), Michael Faraday (1791-1867), James Clark Maxwell (1831-1879), Lord Rayleigh (1842-1919), Boltzmann (18 44-1906) appeared every 50 to 100 years and influenced forever the direct ion of science.
These giants were multi disciplinary people. For example, besides calcul us, Newton gave us the theory of gravity and discovered the secrets of li ght and color. Ohm gave us the relationship between voltage and current o n which electronic circuits are based and Faraday gave us the principle o f magnetic induction on which the electric motor and generator are based. However, Faraday also worked in electrochemistry and gave us the mathem atical relationship between electricity and the valence of a chemical ele ment. Maxwell is most famous for bringing together the concepts of elect ricity and magnetism, but he is also well known for developing the kineti c theory of gases. Lord Rayleigh gave us the theory of sound, but he als o taught us about the growth of instabilities in liquids and how light is scattered. Ludwig Boltzmann (1844-1906) advanced Maxwell92s kinetic th eory of gases, but he also gave us the relationship between radiation and temperature of a body. Interestingly, many (but not all) were relatively wealthy so that they could enjoy science as a hobby rather than be requi red to engage in it as a job.
If we look at the present century, we can invoke the names of giants in t he first half of the century like Albert Einstein (1879-1955) or in the p resent half like Hannes Olof Gosta Alfven (1908-1995).
Einstein gave us relativity; but, by treating matter and energy as exchan geable, he also gave us the basis for controlling the release of energy f rom the atom. Alfven developed MHD (magnetohydrodynamics) and showed that as a plasma passes through a magnetic field it produces electromagnetic waves and these Aafven waves are today used in studying astrophysics and space science. Interestingly, in this last century most (but not all) of these giants were not relatively wealthy so that they were required to co nsider science and engineering as their job.
The names I have listed here are only a small number of the names that ha ve contributed significantly to science and engineering. However, becaus e there are so many more people in science and engineering today, I argue d the number of giants to the total number of people engaged in the scien tific activity has decreased.
Did I win the discussion? No, someone pointed out that it usually takes
50 to 100 years before a giant is truly recognized. I must admit that I
buy that statement. As a result, the verdict is not yet in. Perhaps the
many giants of this century will receive their note in the next 100 year
s. In the meantime I will enjoy the computer, printer, photocopier, airp
lane, automobile, air conditioner, cell phone, etc. that have been develo
ped in this century and take my hat off to all the scientists and enginee
rs who made these conveniences possible.
For the Friendly Society
Albert E. Seaver
The summer, in England at least, is now a distant memory, and I sit on a dismal November evening writing this, and trying to recall the warmth and brightness of California in June. It is high time that I wrote a genera l 91thank-you92 to the ESA, for all the kindness shown to a Limey philo sopher, and for the honour which you did me in presenting me with the 91 Teacher of the Year92 award at Palo Alto. It92s quite a sobering exper ience to have something like that happen to you, and after all the fun of the ESA-IEJ conference had subsided a bit, I sat down to try to think it all out. Of Course there always have been, are, and will be many far be tter teachers than I, at whose feet I can only sit, but to have one92s e fforts recognised, and by a group who not only represent the forefront of research and development of a subject, but who are also based outside on e92s own country, is a humbling experience. The openness, kindness and hospitality of the ESA, both corporately and individually, never ceases t o amaze and uplift me. Thank you, all of you, for these things - would t hat all dealings with one92s fellow man were so delightful.
Being honoured like this concentrates the mind wonderfully, and above all else it gives one something to live up to. Of course, being a teacher n ot just of electrostatics (where I should make a very precarious living), but of general science, means that there is a limited time available for the things that I really like most. Acid/base reactions and photosynthe sis claim their share too. However, apart from my own private fascinatio n in the electrostatics of water boules which I had the opportunity of ta lking about a little back in June, I have been having a few 91new92 ide as for school92s (and my!) edification.
I should like to share one of these with you now. There is nothing reall
y original about it, but it came to me over the summer as a simple soluti
on to a traditionally tricky problem, namely that of demonstrating not on
ly the presence of electrostatic charges, but also their polarity and the
ir field dynamics (well, sort of
)
Simple electroscopes are fine, and there is nothing like a the good old g old leaf electroscope for showing the presence of charge, but they have t heir limitations, especially at the very elementary level. What I felt I needed was a device which was not only sensitive to reasonably small cha rges, but which would also discriminate between positive and negative one s. Now there are many simple circuits, mostly making use of field-effect transistors, which will detect either small positive or small negative c harges, but circuits sensitive to both usually result in dual-rail op-amp s., with all the added paraphernalia of dual power supplies and careful o ffset adjustment. What I wanted was a cheap, simple robust and reliable 91field indicator92. A bit of lateral thinking (one of the things whic h Mave, my far better half, tells me I do all too much) brought me to con sider the problem from the other end. C-MOS devices are notoriously stat ic-sensitive. Why not exploit the fact? A little thought suggested that a c-mos NAND device might well do the trick. After a few runs, which mo stly resulted in chips being destroyed by voltages greater than they coul d handle, I came up with the following, which is good-tempered, and does just what was wanted.
The circuit is basically simple, but there are a few bits which require e xplanation. First, the connexion of NAND inputs to give inverter mode mi ght well suggest that using ready made inverters would be more elegant, In practice I found that standard CMOS 4000-series inverters functioned poorly, possibly due to lower output sensitivity and different switching thresholds. Second, the question of the capacitors. I found that to ach ieve initial stability I needed to bias the gates to their 91quiescent92 state. A resistor of about 10 G-ohm did the trick, but these are hard t o find - in my spares boxes at least. Small ceramic capacitors in the 30 - 50 pf range seem to have about the right resistance, and the added eff ect of the capacitance gives a little hysteresis to the input circuit, an d prevents the LEDs from going into Las Vegas Saturday-Night mode! The i nput diodes are not strictly necessary, I suspect, but they do help to gi ve a better isolation between the two inputs, which have a common source, and again help cut instability. The 3 megohm input resistor makes all t he difference between a live and a dead 4011 if you bring too hefty a cha rge close to the device!
In practice, I use a short antenna as a probe - mine is a 1094 telescopi c one, which closes to about 394, from some sort of pager - a piece of w ire does just as well. Finally, if, like me, you make the thing in a pla stic case, then it needs a grounding plane (piece of tinfoil) on the unde rside of the case, connected to the circuit ground within.
If you make one of these, try it with the two traditional 91electrics92
beloved of the old electricians, viz. glass and sealing wax. Charge a p
iece of glass (+ve) and as you approach the antenna the red LED will ligh
t. Withdraw it, and the LEDs flip over. Excess -ve charges are flooding
in. These will die away. With sealing wax the results are reversed. Y
ou can discharge the device, if necessary, by briefly touching the antenn
a or grounding it. The electroscope will indicate the following:
1) Positive charge approaching (red)
2) Positive charge receding (red switching to green)
3) Negative charge approaching (green)
4) Negative charge receding (green switching to red)
5) No measurable charge (both lamps off)
6) Positive and negative charges present (both lamps on)
The electroscopes can be made for cents rather than dollars, and I feel h
alf inclined to go into small-scale production! (If anyone is interested
in the idea, let me know!!) Any constructional or other queries I will
try to help with. E-mail me on jahern@ndirect.co.uk
HAVE
FUN!!
Jeremy Ahern
Every two years the Membership of ESA has the opportunity to nominate a s late of candidates (President, Vice-President, and three Council Members) for positions in the Executive Council. Any ESA member may nominate a s late, but the nominating person must insure that all those on the slate h ave been contacted and have agreed to serve if elected. Any person nomin ating a slate should send the names and positions of all five candidates to the ESA Secretary/Treasurer (Dr. Tim Erin, 723 Woodshire Way, Dayton, OH 45430) by March 31, 1999. If there are two or more slates of candidate s a mail ballot will be sent out to the membership. If only one slate of candidates has been received, then following ESA tradition, that slate o f names will be brought before the Membership attending the Annual Meetin g for a show-of-hands vote. The term of office for the elected officers will be from July 1, 1999 to June 30, 2001.
The following is the pertinent information from Article 4 of the ESA Cons
titution regarding the election. (Note: the full ESA Constitution can be
found on the ESA Home Page at www.electrostatics.org)
4c) The Council shall be nominated as a full slate, naming the officers a
nd members.
4d) Slates may be self-nominated, each being presented by a member of the
slate. Also, the Council may nominate a slate.
4e) The several slates shall be presented to the Secretary three months b
efore the end of the Council's term. After validation of the nominated s
lates the Council shall cause the Secretary to present the slates to the
membership two months before term end, with the mail vote deadline to be
one month before term end. The slate receiving the largest number of vot
es shall be declared elected. If two slates are tied in receiving more v
otes than any other slate, the Council shall act to break the tie.
Details of the 2000 ESA Annual Meeting has been firmed up. We92ll meet at Brock University which is located in St. Catherines, Ontario, Canada w hich is about 15 miles from Niagara Falls. The dates - June 18-21 (Sunda y - Wednesday). Campus rooms are air conditioned, small single rooms wit h an attached, shared bathroom between each pair of rooms. An Embassy Su ites is also available just off campus. There are many attractions in th e Niagara Falls area which we will describe in greater detail in subseque nt Newsletters. Our thanks go to Bill Vosteen who has made all the arran gements for this location.
One result of this research will be an exhibition titled 93Franklin and his Friends: Portraying the Man of Science in 18th Century America94, wh ich will be on view April 16 through Sept. 6, 1999, at the National Portr ait Gallery. Another result is a book of the same name by Fortune and Wa rner which is scheduled to be released next year.
Franklin turned out to be the linchpin of this exhibition and book becaus e he knew or was known to almost all of the subjects of the portraits stu died, and many were his friends. He also proves a point the researchers were seeking to make: Franklin92s work with electricity, dramatically de picted in his portraits, gave him a universal scientific reputation and w as largely responsible for the access and influence he enjoyed in France.
(Abstracted from Smithsonian Institution Research Reports No. 94, Autumn 1998)
People will accept your idea much more readily if you tell them Benjamin Franklin had it first.