T.R | Title | User | Personal Name | Date | Lines |
---|
784.1 | capacitance was involved, I presume | INK::KALLIS | Don't confuse `want' and `need.' | Thu Jun 30 1988 16:48 | 7 |
| Re .0 (Carla):
Insufficient data. Could've been that she had more conductive shoes
on than others (or was moister, or both), this making something
like a closer ground connection.
Steve Kallis, Jr.
|
784.2 | Either C or R, or both. | MIDEVL::YERAZUNIS | Caution: Contains subliminal suggestions | Thu Jun 30 1988 18:04 | 6 |
| Moister, sweatier, cleaner skin, more conductive (or more capacitive
because thinner) footwear, etc.
No great mystery here... yet.
-Bill
|
784.3 | thanks | DANUBE::C_JALBERT | | Thu Jun 30 1988 20:31 | 17 |
| Thanks for the info/input... I don't think she was any sweatier,
or moister than anyone else there?? don't know, I can say her hands
were ice cold (it was a cool day, and the museum was cool) BUT,
it had been raining when we entered, however we were at the RAMSES
exhibit about an hour or so before we went to look at other exhibits.
Her shoes, she had on a pair of "suede-type" flats with "plastic-
type" heels and "alleged leather look" soles.
Mystery or not, it was most interesting to watch ... it was almost
beautiful (the designs the electricity made) in a rather bizarre
fashion.
Thanks again...
Carla
|
784.4 | The Eye of the Storm | HPSCAD::DDOUCETTE | The WP is mighter than the Gun | Fri Jul 01 1988 10:10 | 13 |
|
In case anyone is interested, they sell a smaller version of the glass ball
under the name "eye of the storm" for around $150-$200. It's usually
available in electronic novelty stores and catalogs, as well as the Museum
of Science gift shop! They're great, and it doesn't seem to matter what type
of shoe you wear to have those effects.
As to how it works. . . Don't forget we're bioelectric, I've touched
the sphere with a coin at the tip of my finger for a "strong reaction,"
but I HAVEN'T tried to touch one of those with a battery, loop of wire,
superconductor, etc.
They can be a lot of fun to experiment with, for childern and adults alike.
|
784.5 | Doesn't mean much. | PBSVAX::COOPER | Topher Cooper | Fri Jul 01 1988 11:46 | 22 |
| I've seen them for as low as $110, and suspect if you wait for an
sale you might get them for a lot less.
They work by a form of high-frequency electric discharge into a
mixture of low pressure gases. The result is very complex interation
of forces which is likely to be rather sensitive to very small
external influences. I dobut if the bodies intrinsic electric
field has much of an influence though. It is so much smaller
than induced fields from static charges picked up by friction
and your body acting as an "antenna" picking up ambiant radio
frequencies and 60Hz signals. The amount of sweat in the
skin needed to modify these effect is very small, and it is not
clear whether more or less is "better" (it probably varies up
and down and depends on the other factors in addition). A person's
exact size, the shape of their fingers, when the last cut their
fingernails, and much else are all likely to have an unpredictable
effect on these plasma-discharge spheres.
So, no significance can be attached to differences for different
people, but they *are* fun.
Topher
|
784.6 | Look and look some more. | WRO8A::GUEST_TMP | Going HOME--as an Adventurer | Fri Jul 01 1988 23:55 | 9 |
| re: last couple
I just paid a visit to the Price Club today and they happened
to have one of these eye-of-the-storm type balls...I didn't look
very closely at it to see more but I did notice the price at, I
believe, $79.
Frederick
|
784.7 | Who was standing where? | CIMNET::PIERSON | on vacation 23/7-6/9 | Fri Jul 08 1988 20:00 | 13 |
| A conventional possibility. If the display is the one I am thinking
of, it is noticably elongated, perhaps 3 ft by 1ft? IF Kristina
was standing nearest one end, she would tend to draw the discharge
preferentially from that end. Also, if she was the shortest present
her impedance (used in its technical sense) to ground could well
have been less than for an adult/older child.
If memory serves, the discharge appears to "orignate" from one end,
leaving the other end dark if the discharge is "detoured" to a side
wall. It is a fascinating, and beautiful display.
thanks
dave pierson
|
784.8 | Strange lightning | USAT05::KASPER | Life is like a beanstalk, isn't it... | Thu Jul 28 1988 22:41 | 11 |
| I have a question and I guess this is an okay place to put it.
I heard something interesting on the radio today and would like to solicit an
explanation from some of you electric types.
Somewhere in California some children in an open area were struck by
lightning, none fatally but serious enough. The strange part is that it
was (according to witnesses and the ABC radio story) a bolt of lightning -
but there was no rain and *no* clouds. How can that be???
Terry
|
784.9 | possible | MARKER::KALLIS | Anger's no replacement for reason | Fri Jul 29 1988 08:56 | 12 |
| Re .8 (Terry):
That's unusual, but not impossible. If somehow a static electric
difference built up sufficient so that a lightning bolt [which is
a great big spark] could bridge the gap, that would explain it.
It might also be that if the air was sufficiently hazy, a
lighter-colored cloud might not have been visible.
In short, data too scanty to form a definite opinion, but it's not
out of the question.
Steve Kallis, Jr.
|
784.10 | More possabilities | PBSVAX::COOPER | Topher Cooper | Fri Jul 29 1988 11:52 | 17 |
| RE: .8 (Terry) supplementing .9 (Steve)
Although it is *very* rare and not well understood occasionally
lighting move horizontally for dozens of miles (from a storm over
the horizon) before striking the Earth. I'm not sure how well
established this phenomena is, but I do know that it is taken seriously
by at least some people who study lightning.
There are also theories -- and these are definitely *not* well
accepted, but are not outright rejected either -- which claim that
quite large electric charges can build up occasionally in earth
faults by piezoelectric action. Conceivably this could have been
such a discharge. I doubt if anyone close to where a lightning
bolt struck would be able to see much more than a flash of light,
i.e., they wouldn't have any idea of the direction it came from.
Topher
|
784.11 | as I said, too many variables | MARKER::KALLIS | Anger's no replacement for reason | Fri Jul 29 1988 12:01 | 14 |
| Re .10 (Topher):
>......................I doubt if anyone close to where a lightning
>bolt struck would be able to see much more than a flash of light,
>i.e., they wouldn't have any idea of the direction it came from.
Actually, it's worse than _that_. Most people are unaware that
the initial current surge in a lightning bolt is up, not down.
And that further, once the ionized path is established, there's
an oscillating current as the initial flow of electrons overshoots
straight balance (a quickly damped oscillation to be sure, but an
oscillation nonetheless).
Steve Kallis, Jr.
|
784.12 | Who you gonna call??? | USAT05::KASPER | Life is like a beanstalk, isn't it... | Fri Jul 29 1988 12:14 | 6 |
| Thanks! I knew I could count on the 'Kallis-Cooper' ghostbuster squad to
help me out. No stone is left unturned...
Much appreciated.
Terry
|
784.13 | Lightning strikes twice | USAT05::KASPER | You'll see it when you believe it. | Fri Aug 19 1988 16:26 | 11 |
| re: .8 (me)
In .8 I mentioned some kids struck by lightning without any
clouds around. Well, while on vacation in Florida last week
I heard about two guys walking down the beach - the same thing
happened to them. The bolt struck one then passed along to the
other. No clouds in sight??? For a rare event, that's twice
in the course of a couple weeks. (One was left in critical
condition, the other experienced minor injuries).
Terry
|