
“Invisible Electrostatic Wall” at 3M adhesive tape plant (1996) - sergiotapia
http://amasci.com/weird/unusual/e-wall.html?utm=email
======
superkuh
Bill Beaty's site was and still is amazing. It sparked my interest (and
lifelong hobby) in high voltage back in the late 90s. Some of his essays (and
ascii) art explaining concepts like coherence
([http://amasci.com/miscon/coherenc.html](http://amasci.com/miscon/coherenc.html))
still stick with me today.

As for the electrostatic wall story... it's fun but I don't believe it.

~~~
TaylorAlexander
I ate that site up when I was young. I was 12 in 1996, and by that time had
already decided on a career in robotics. All the little tech projects there
kept me engaged. I built a Tesla Coil after the site inspired me, and today I
work in robotics in Silicon Valley.

I’m struck now with how much power one site has to engage and help so many
people. I hope that I can share enough of my own goofy hobbies [1] to help a
new generation learn what inspires them.

[1] [http://reboot.love](http://reboot.love)

~~~
adrianN
I feel like the pre-monetization Internet had a lot more of these sites. Or at
least they weren't drowned out by the noise of a-b test optimized attention
grabbing time sinks as much.

~~~
kuschku
I've often wondered what'd happen if one were to make a search engine, and
site catalogue (similar to early yahoo) that'd only take sites that do not
match easylist.

You'd have a set of sites without any tracking or ads, and you might have it
much easier to find high-quality sites like these.

~~~
adrianN
Sounds like a brilliant idea. I'd use it.

------
zbjornson
Heh, I read this 20 years ago when I wanted to try to make as much tech from
Star Trek a reality as possible. Being 10 years old the closest thing I could
get my hands on was a megaroll of plastic wrap from Costco that I basically
pulled around some rollers as fast as I could. Suffice it to say it didn't
quite cut it.

I had also tried to make a dermal regenerator after reading an article in
PopSci about infrared radiation speeding up ulcer healing in cancer patients.
Didn't have a good way to test it but I liked to think it worked. :)

~~~
dghughes
Infrared is the new health craze for the super-wealthy. Companies sell beds
with IR lights that shine on you to "heal" you.

The funny thing is the beds glow red I guess the word literally meaning beyond
red (i.e. can't see it) won't sell if there isn't any red to be see.

~~~
wyager
Don’t know anything about IR beds, but near IR (shorter than 800nm) is just
visible as a dull deep red color.

------
mapt
We've called bullshit on this before, and little satisfactory response
resulted. "But he's a professional, with published work!" is not sufficient;
The effect claimed is extraordinarily unlike our understanding of
electrostatics, and no proof has been furnished.

~~~
bpicolo
Without any validity claims there, we don't really seem to have that
tremendous an understanding of these sorts of things. Isn't the exact
mechanics of lightning formation still an unsolved problem? And then there's
all sorts of other mysterious electrical phenomena like ball lightning

> It is well understood that during a thunderstorm there is charge separation
> and aggregation in certain regions of the cloud; however the exact processes
> by which this occurs are not fully understood [0]

[0]
[https://en.wikipedia.org/wiki/Lightning#Necessary_conditions](https://en.wikipedia.org/wiki/Lightning#Necessary_conditions)

~~~
ianai
But there is hope. The Langmuir guys seem to think it’ll get there

[https://www.abqjournal.com/814666/lab-sparks-advances-in-
lig...](https://www.abqjournal.com/814666/lab-sparks-advances-in-lightning-
research.html)

------
ChuckMcM
As pointed out, this has been discussed before. The effect is explainable with
electrostatics. As in "If you assume a net charge on a human of X and a equal
polarity charge of Y being generated by the motion of the tape, a force F
would be felt by a person approaching that went up with the inverse square of
the distance." Simon Field has a great demo where he throws around pie plates
using this effect.

The challenge arises with explaining how the charge is contained such that the
opposing charge that is being attracted does not break down the insulator
between it and this charge. One thought experiment that I heard at the Boston
Science museum was to imagine you are inside the ball of a very large Van De
Graff type generator. If you were charged to the same polarity of the outer
sphere, you would be repelled by the sphere toward the center. The harder you
tried to go to the edge, the more you would be repelled. And, assuming you
were insulated from the sphere. By clothing or some other apparatus, there
would be a point where the electrostatic repulsion would keep you from being
able to touch the sphere and effectively discharge your charge into the
sphere.

This only works as an explanation if the manufacturing facility was acting as
the sphere, and on entering it you found your self inside that sphere _and_
with a net charge of the same polarity.

What is most remarkable about the story, and causes many (myself included) to
doubt it, is that 3M is/was a company that was famous for its core competency
of taking unexpected effects and turning them into products (the post-it note
story is a great example of that). Because of that competence, it is
challenging to imagine that they had accidentally created something, which if
understood better could potentially be the foundation of a multi-billion
dollar product industry (force fields are widely sought out by people wishing
to exclude access). And yet they left it as a "wow, that's funny" sort of
moment? A more expected outcome would be for 3M to build an identical plant to
see if they could replicate the effect and if they did, begin to instrument
and remove components until they understood (and probably patented) all of the
ways the field could be generated. And then decided if it was possible to make
as a product or not.

~~~
Retric
When you are in a sphere you feel zero net forces from the sphere.

Here is an example using gravity but electrostatic forces should operate the
same way.
[https://www.grc.nasa.gov/www/k-12/Numbers/Math/Mathematical_...](https://www.grc.nasa.gov/www/k-12/Numbers/Math/Mathematical_Thinking/grvtysp.htm)

You can only feel forces if it's some other shape.

~~~
ChuckMcM
Charge doesn't work the same way. All of the charge is on the surface of the
sphere (that is how a Van deGraff generator works). Unlike gravity, like
charged things inside the sphere are repulsed by the surface just as things
outside the sphere are.

~~~
jcranmer
The shell theorem holds true for spherically symmetric distributions and
inverse-square laws. The electrostatic force within a spherically-symmetric
charged object is exactly 0.

(cf.
[https://en.wikipedia.org/wiki/Shell_theorem](https://en.wikipedia.org/wiki/Shell_theorem)
for some proofs)

~~~
tzs
As you mention, this assumes a spherically symmetric distribution.

In the case of a charged conductive sphere, the charges are free to move. With
no charge present other than that on the sphere they will arrange themselves
spherically symmetrically.

But if there is other charge near the sphere (outside or in), shouldn't that
cause some rearrangement of the charges on the sphere, breaking in most cases
the spherical symmetry?

~~~
ScottBurson
That's an interesting question! I think the effect would be the opposite of
what ChuckMcM imagines: as a (say) positively charged particle inside a
positively charged conductive sphere moves from the center toward one side of
the sphere, it repels the charges on that side more than it does on the
opposite side. It does seem like that would cause those charges to spread out
slightly, making that part of the sphere negative relative to the other side,
accelerating the particle in the direction it was already going, until it hits
the sphere. The minimum energy is thus where all charges within the sphere are
on its surface; none are inside. I believe this is consistent with
observation.

~~~
ChuckMcM
It has been an interesting conversation so far. Since I have been going
through Jackson's text it makes a useful problem to work. I'm working up the
field equations for inside the sphere, inside a charged concave surface, and
inside a concave depression in a sphere. I suspect that this thread will be
dead before I'm done but the next time around I'll be able to post a link to a
paper :-).

~~~
ScottBurson
Coming up with a closed-form solution would be beyond my mathematical
abilities at this point, having not done any calculus to speak of in 40 years,
but I'll be interested to see if you can.

------
agjacobson
Optical physicists and chemists need a laser with a knob on it to tune the
laser to an exact desired color. In the 70s and 80s, the preferred method was
the use of liquid dyes as the laser medium, typically dissolved in alcohol.
The dye was pumped at high speed through quartz cells, and was gotten to lase
by striking it with a fixed wavelength green or ultraviolet laser. Now the
best practice was to use Teflon tubing. It cleans up better, and that’s
important because when changing colors, the new dye’s wavelength might be
absorbed by the previous dye residue, if any. Man, the triboelectric shock you
can get from high speed flow of alcohol through Teflon! The Livermore Lab was
worried about this during the laser isotope separation program, as a fire
hazard. The problem is solved by installing stainless steel ground wires in
the Teflon tubes.

------
Animats
They built a Van de Graaff generator[1] by accident.

[1]
[https://en.wikipedia.org/wiki/Van_de_Graaff_generator](https://en.wikipedia.org/wiki/Van_de_Graaff_generator)

~~~
ateesdalejr
A very big one at that.

------
greggarious
Interesting to see this on HN.

I've seen this link being passed around in the paranormal/conspiracy circles
as a possible Earthly explanation for those UFOs the NYT reported a while
back:

[https://www.nytimes.com/2017/12/16/us/politics/pentagon-
prog...](https://www.nytimes.com/2017/12/16/us/politics/pentagon-program-ufo-
harry-reid.html)

One theory is these "tic tacs" are yet another example of test aircraft being
mistaken for extraterrestrial aircraft and this paper's findings were noted
and expanded on, in secret, to create some novel form of propulsion by either
the US or China.

There's precedent for human test craft being mistaken for "alien" technology.
The best example being a rash of "triangle shaped UFOs" in the early/mid 80s
was eventually revealed in 1988 to have been the F117.

------
dghughes
Electrostatic force is incredibly powerful. I read a great bit of info that
said just two Coulombs concentrated in the equivalent area of two electrons
repel with the force of one million tons.

All matter has a charge too so I could see with the right conditions a large
electrostatic force being formidable.

------
i_am_nomad
There are all kinds of crazy energies released by adhesive tape:
[https://www.technologyreview.com/s/411085/x-rays-made-
with-s...](https://www.technologyreview.com/s/411085/x-rays-made-with-scotch-
tape/)

------
Topgamer7
"didn't know whether to fix it or sell tickets." Pretty sure that any fan of
Star Trek would pay a pretty penny to touch a real force field ;)

~~~
lucb1e
Only Star trek fans? I'd say anyone interested in science and then some.

~~~
komali2
Or like, a Navy contracted weapons developer...

------
tsomctl
Does anyone know how dangerous this actually is? Could an esd be big enough
(basically lightning) to hurt or kill you?

~~~
viraptor
> An Australian man built up a 40,000-volt charge of static electricity in his
> clothes as he walked, leaving a trail of scorched carpet and molten plastic
> and forcing firefighters to evacuate a building.

[https://forums.firehouse.com/forum/firefighting/firefighters...](https://forums.firehouse.com/forum/firefighting/firefighters-
forum/59086-man-sets-fire-to-carpet-with-40-000-volt-static-charge-that-built-
up-in-his-clothes)

~~~
8bitsrule
1\. In winter, take any decent house anywhere with a severe winter climate.

2\. Wait until it's -30F outside, open the doors to let that dry air in. Close
the doors.

3\. Heat the interior to +70F to make --extremely-- dry air.

4\. Shuffle across the plastic carpet in leather-soled shoes.

5\. Do NOT touch the metal door knobs.

~~~
IntronExon
Without meaning to, and without any of that I still managed to destroy a set
of dimmer switches with a static shock from my finger, in winter. Boy did I
feel stupid.

------
matte_black
I would not play with this until I knew exactly why it was happening. You
could easily be killed by an electrostatic phenomenon that is poorly
understood. Remember in the old days when ball lightning would just straight
up kill people by passing into them? Still does, but I think most people know
better now than to touch such a ball.

~~~
Avshalom
When were these old days?

~~~
matte_black
1800s.

------
baxtr
This has been discussed a while ago:
[https://news.ycombinator.com/item?id=5387052](https://news.ycombinator.com/item?id=5387052)

~~~
okket
Even further ago:
[https://news.ycombinator.com/item?id=3274335](https://news.ycombinator.com/item?id=3274335)

------
fermienrico
Did people try to go through an imaginary plane and felt a force? Or did
people try to go through an actual cling film?

>> When he attempted to walk through the corridor formed by the moving film,
he was stopped about half way through by an "invisible wall."

A corridor formed by the moving film?

I have a hard time understanding the situation.

~~~
IncRnd
According to the next few sentences in the article:

> _The film was taken off the main roll at high speed, flowed upwards 20ft to
> overhead rollers, passed horizontally 20ft and then downwards to the
> slitting device, where it was spooled onto shorter rolls. The whole
> operation formed a cubical shaped tent, with two walls and a ceiling
> approximately 20ft square._

------
ioquatix
Any videos of it?

~~~
wbeaty
August 1980, they coulda used a Betamax camera! Of course megavolt-scale
voltages would tend to fry any device not protected by a screen cage.

"Why didn't they take pictures" is a minor question, compared to "WHY DIDN'T
THEY THROW STUFF AT IT?!!" Did the invisible wall block flying objects? Or was
it really just caused by shocks, by tazed human muscles locking up?

------
exabrial
Giving the amount x-rays released, surprised they don't have cancer!

------
mrfusion
There’s a lot we don’t understand about electro statics.

~~~
tzahola
So you’re saying that Maxwell’s equations are not enough?

~~~
xelxebar
Not really, especially for nonlinear systems. It's like how just knowing the
rules of chess doesn't mean you're a good player.

------
ohiovr
Could this be used to trap a net neutral plasma?

------
jlebrech
could this have application for VR?

~~~
ateesdalejr
Invisible walls? Yes, if it were controllable. The only problem I see would be
the prohibitive costs.

~~~
bastawhiz
And size, and noise, and power consumption

~~~
tinus_hn
And some minor irradiation

~~~
logicallee
And sudden electrocution. Seriously we've all been zapped after walking across
the wrong type of carpet and touching something/someone, why does no one in
these stories think "Oh I hope this doesn't have the potential (hehe) to
suddenly discharge through me." They're all like - COOL!!

------
sklivvz1971
Dupe of
[https://news.ycombinator.com/item?id=5387052](https://news.ycombinator.com/item?id=5387052)

~~~
Sharlin
It's not a dupe if the last submission was five years ago.

------
ada1981
Could we put this on the blockchain?

~~~
arcaster
The real question is... Will there be an ICO??

~~~
ada1981
WAL Coin is a token that represents fractional ownership of a static generated
wall.

