[HN Gopher] Invisible Electrostatic Wall at 3M plant (1996)
___________________________________________________________________
Invisible Electrostatic Wall at 3M plant (1996)
Author : Simon_O_Rourke
Score : 251 points
Date : 2025-01-21 17:37 UTC (5 hours ago)
(HTM) web link (amasci.com)
(TXT) w3m dump (amasci.com)
| giantrobot wrote:
| I remember reading about this many years ago but have never been
| able to find the story again. So regardless of its veracity, I'm
| happy to see it come up.
| simpleintheory wrote:
| Previously discussed:
|
| - https://news.ycombinator.com/item?id=16299441 (2018)
|
| - https://news.ycombinator.com/item?id=5387052 (2013)
|
| - https://news.ycombinator.com/item?id=3274335 (2011)
| avidiax wrote:
| Ever notice how UFO and Bigfoot sightings mostly went away once
| everyone had a 4K60 video camera in their pockets?
|
| One thread about this in 1995, and then the phenomenon is never
| seen nor heard about again . . .
| Mistletoe wrote:
| Bigfoot and ghosts yes, but the recent drone mania seems to
| have increased. :) Maybe they would have been called UFOs
| before we had video to look back on.
| colechristensen wrote:
| A lot of the recent drone mania is people taking videos of
| airplanes and helicopters. At this point I don't know how
| many of these videos are making fun or the paranoid people.
| baxtr wrote:
| I was amazed how suddenly it stopped being a thing. It was
| like one day people were talking about it all the time, and
| then the next day it went away completely.
| Mistletoe wrote:
| My Mom was super into this just like all the things her
| TV tells her to be super into. I asked her today what
| happened to them and said she "guessed they fulfilled
| their purpose and went back to China". :D
| mrguyorama wrote:
| It started exactly when the public was getting angry at
| the media about killing healthcare CEOs and expressing
| their joy, and ended as soon as everyone stopped talking
| about that.
|
| Which is just conspiratorial thinking. It also ended as
| soon as people posted pictures of stars and planes as
| "evidence" and insisted that the evidence was still valid
| because "the aliens are just appearing as planes". It
| also ended the moment r/UFO threads showed up on the
| front page of reddit and normal people who thought this
| MIGHT be something got to see the insane mental
| gymnastics of the people insisting we should pay
| attention to it.
| ceejayoz wrote:
| Yeah, my local news had a clip that was _clearly_ an
| American Airlines tail logo.
| giantrobot wrote:
| That's the best way to disguise UFOs! Shape them like
| airliners and carry passengers on regular daily routes!
| No one would ever suspect a thing.
|
| Oh no, I've said too much.
| jacoblambda wrote:
| Not just one thread.
|
| ANTEC '97 Conference Proceedings, CRC Press, pages 1310-1313.
|
| https://www.google.com/books/edition/SPE_ANTEC_1997_Proceedi...
|
| The thread is based on a conference talk and journal
| publication that preceded it.
|
| The reason this particular case hasn't been reproduced is just
| because it has no practical application, requires a lot of
| equipment, requires the equipment to be intentionally
| improperly operated risking damage or injury, and it's
| extremely expensive to test.
|
| Nobody is going to willingly tool up an environment capable of
| running a mile of 20 foot wide PP film at a thousand feet per
| minute, then purposely ungrounding the equipment, and run it at
| 100+ F and 95+ % humidity for hours, days, or weeks. Just
| setting it up would cost millions of dollars and running it may
| cost millions more.
| swayvil wrote:
| We could design the experiment. Then try to reduce the
| experiment to a cheap, convenient form.
|
| Surely somebody has done at least that.
| sunshinesnacks wrote:
| According to https://www.weather.gov/arx/heat_index, 100 deg
| F with 95% RH is a heat index of 185 F. The linked paper says
| "temperature often approached 100 F with relative humidity
| above 95%," and later references specific conditions of 92 F
| and 95% RH (137 F heat index).
|
| Are these sorts of heat index values feasible for a plant
| environment? The line about 100/95 seems almost hyperbolic,
| which doesn't help with credibility in my opinion. Maybe I'm
| missing something.
| dylan604 wrote:
| > 100 deg F with 95% RH is a heat index of 185 F.
|
| So just a typical summer day in Texas
| jacoblambda wrote:
| That's basically normal for unconditioned factory spaces in
| the US south during the summer. Ungodly hot, ungodly humid,
| and generally just shit to exist inside.
|
| This is in large part why historically industrialized
| factories tended to be concentrated in colder, higher
| latitude regions until the 20th century. Without
| refrigeration the work was far harder and more exhausting
| for the workers and that limited efficient use of labor.
| sans_souse wrote:
| Tell me about it. I worked for 3M owned Saint Gobain
| running kevlar and fiberglass sheets thru 5-story oven
| feeds. it was often 105degF _on the floor,_ but if you
| were unlucky enough to lose your line you 'd be hiking up
| 5 stories of oven stacks where temps would be soaring.
| Not to mention every Friday PM shift would start with
| running junk lines super hot to "clean" (burn-off) all
| the accumulated Teflon in the oven walls and exhausts
| (which did not work efficiently enough) from the prior
| week. So, at 3PM you would start your shift already
| drenched in sweat watching as a Teflon smoke plume formed
| at the ceiling of the 7-story plant, like a dark storm
| cloud, and slowly make its way down to the floor. By 10PM
| we would all be coughing and exhausted, scratchy throats,
| etc.
|
| A lady on 3rd shift who ran my machine had a near death
| incident and the company swept that under the rug along
| with plenty of other seriously concerning practices.
|
| AMA!
| sunshinesnacks wrote:
| I don't doubt those temperatures at all. But do you know
| what the relative humidity was? It's the combo that
| causes problems fast. 100 F and 60% RH is miserable and
| dangerous, but that's a wet bulb of about 90 F, so
| there's _some_ marginal potential for your body to cool
| itself. 100 F and 95% RH is a WB of 98.6 F. Any heat
| generated in your body has no where to go.
| onlypassingthru wrote:
| A funny thing happens to those who live or train in
| extreme environments, their body adapts over time. You or
| I might pass out if we were suddenly exposed to that sort
| of factory environment, but an experienced worker might
| handle limited exposure just fine. The human body is
| amazingly adaptable.
| sunshinesnacks wrote:
| I've spent a little bit of time in those types of spaces.
| I absolutely believe the temperatures referenced, but
| approaching 100 F with humidity _above_ 95% is likely
| deadly in a short amount of time. And to then seemingly
| make jokes about selling tickets to walk into an area
| where you get physically stuck for mysterious reasons
| adds to my opinion that some of the report seems
| hyperbolic.
|
| Check out the heat index page I linked above, or this
| similar one from OSHA:
| https://www.ohsa.com.au/services/heat-stress-monitoring/.
| pixl97 wrote:
| There are a lot of places in plants that can end up being
| deadly for any extended amount of times in particular
| weather conditions.
|
| There was a grain processing plant up in the midwest were
| my dad worked that had an area enclosed in between building
| they'd close off access to on the hottest summer days.
| Light would be excessively focused in that area from other
| buildings, and moisture from other processes and lack of
| air circulation lead to deadly wet bulb temperatures.
| Workaccount2 wrote:
| There are much easier and cheaper ways of generating
| megavolts of electricity, I think the biggest barrier would
| be getting someone who knows enough about this to build it
| despite their skepticism about the validity of it.
| dotancohen wrote:
| That is what grants are for. And DARPA when something more
| specific, like this, is to be investigated.
| giantg2 wrote:
| "And DARPA"
|
| That was my first thought - the military would be all
| over this if there's even a remote chance you could build
| energy shields or something.
| jacoblambda wrote:
| Sure but for creating fairly uniform/gradual fields of
| static electricity over a large space?
|
| Electrostatic precipitators exist but they aren't large.
| Everything else I'm aware of that works on larger scales
| fails to satisfy the uniform/gradual aspect.
| dist-epoch wrote:
| > The reason this particular case hasn't been reproduced is
| just because it has no practical application
|
| It can be a tourist attraction you sell tickets to.
| dotancohen wrote:
| In the fine article it is mentioned that the plant manager
| debated whether to fix it or sell tickets.
| bluGill wrote:
| Can it? Or are their safety aspects that make it dangerous
| in enough situations that you shouldn't let the public
| there. I wouldn't be surprised if it was mostly safe but
| once in a while there was a deadly spark. For sure I
| wouldn't let someone with a pacemaker or similar device
| near this. I also wouldn't allow phones, wallets, key -
| anything with electronics - near.
| Aurornis wrote:
| > Just setting it up would cost millions of dollars and
| running it may cost millions more.
|
| You're a couple orders of magnitude too high.
|
| Polypropylene film isn't that expensive. A thousand feet per
| minute is only 10 miles per hour, which is not that fast at
| all. Humidity and heat aren't hard to generate in a closed
| space.
|
| This is the kind of thing that's within the budget of some
| ambitious YouTubers, not millions of dollars.
|
| It's a fun urban legend. The red flag for anyone who has
| studied anything related to electromagnetism is the way it's
| described as a wall, not a force that gradually grows
| stronger as you get closer. Forces don't work at distance
| like that.
|
| You also have to suspend disbelief and imagine this force
| field didn't impact the equipment itself. We're supposed to
| believe that a grown man can't push up against the field at a
| distance away from the source, but the plastic film and
| machinery inside of the field are continuing to operate as
| usual?
|
| It's a fun urban legend. Leave it be, but don't take it
| seriously.
| jacoblambda wrote:
| > it's described as a wall, not a force that gradually
| grows stronger as you get closer. Forces don't work at
| distance like that.
|
| It's described as a wall because it's not just running a
| straight line. The PP line creates an archway where the
| "wall" is located. That's where the field is most intense.
| It's noticeable elsewhere but that's the point where as
| indicated in the paper they can no longer push through it.
|
| > You also have to suspend disbelief and imagine this force
| field didn't impact the equipment itself. We're supposed to
| believe that a grown man can't push up against the field at
| a distance away from the source, but the plastic film and
| machinery inside of the field are continuing to operate as
| usual?
|
| This is also addressed in the paper. The lines can run
| 50-100% faster than it normally does but the faster they
| run it the more problematic the interference is. So during
| normal operation they limited it to 750-1000fpm.
| joemi wrote:
| The article mentions "50K ft. rolls 20ft wide". While you
| might not need the full 50K ft length (if you can even buy
| such a roll with less length), the 20 ft wide spec is
| probably fairly important. I wonder how much that'd cost,
| including transportation? Also, I have no idea how much
| it'd cost to buy or make machinery and supports to
| sufficiently handle such a sized roll. What are you
| estimating these costs would be?
| hinkley wrote:
| I miss MythBusters.
| lxgr wrote:
| On the other hand, we just witnessed a nationwide drone panic,
| and not for a lack of video evidence...
|
| An odd phenomenon being rare and hard to document is neither
| proof nor evidence of absence for it existing.
| EA-3167 wrote:
| I think it's telling that said panic was short-lived, and to
| anyone watching the video, laughably silly. Unless you're a
| psychologist studying the dynamics of digital crowds, it
| probably isn't very interesting at all.
|
| By contrast that same "panic" would probably have been framed
| as UFO's and an alien invasion pre-smartphone era.
| lxgr wrote:
| I personally really wouldn't bet on there being less UFO
| believers these days than before the ubiquitous
| availability of cameras.
| EA-3167 wrote:
| I wouldn't bet on that either, but they're less
| mainstream, less respected, and most of us no longer feel
| a particular urge to humor them. Every passing year makes
| them less relevant, and more like the sort of people who
| believe in any other conspiracy theory or magical belief
| system.
|
| Which is frankly where they always belonged.
| mrandish wrote:
| > magical belief system.
|
| To be fair, if one includes religions this is
| significantly more than half the population. Add in
| astrology, psychics, ghosts, crystals, auras and other
| common 'woo' and it gets higher still. Sadly, HN is not a
| representative population sample. Skeptical non-believers
| are still a minority in the modern world.
| tshaddox wrote:
| I'd say UFO mania is more intense and more mainstream than
| ever. Still no remotely compelling physical evidence, of
| course.
| mrandish wrote:
| > One thread about this in 1995, and then the phenomenon is
| never seen nor heard about again . . .
|
| A default mode of skepticism is best, however the story of this
| incident didn't trigger my "Yeah, probably not" reflex. It is
| based on known physical principles and the extremely unusual
| context seems in the ballpark of sufficient to potentially
| cause something like this. So my assumption was this was an
| extremely unlikely edge case that happened "that one time."
|
| It's also not something which strikes me as being a thing
| people who work in a large 3M factory would lie about.
| dist-epoch wrote:
| > It is based on known physical principles
|
| What exactly does it repel against a human? And why would it
| repel instead of discharge?
| hammock wrote:
| What does this comment have to do with OP?
| tedunangst wrote:
| They even went home and came back the next day. Why not bring a
| camcorder along?
| shepherdjerred wrote:
| https://www.xkcd.com/2572/
| tmjdev wrote:
| I've read this many times over the years, sort of enamored by how
| such a strange phenomenon popped out of a factory setting.
|
| In the most 2016 update the relative says it's common to see
| weird effects from the spools. If it's so common it should be
| reproducible I would think, yet I've never seen it done.
| dekhn wrote:
| I've seen this happen in a wide range of production
| environments (both industrial and computing). Not this effect
| specifically, but "odd emergent behavior that occurs only at
| scale that is non-obvious and state-dependent". For example I
| work at a company that grows a lot of cells is massive
| reactors, and some folks who run the largest reactors commented
| that they saw slow changes in overall production that were not
| explainable by any observed variable (we speculated that slow
| genetic drift occurred in populations, but it may also have
| been seasonal, or due to unobserved variables). And when I
| worked at Google, there were definitely cluster-wide things
| that you'd only notice if you were very knowledgeable and
| attuned to their ongoing processes.
|
| My guess is that this happens in nearly all large-scale
| production systems but goes mostly unobserved.
| swayvil wrote:
| It reminds me of that experiment where they had an audience
| of 1000 focus their attention upon a chair on a stage.
| krackers wrote:
| What happened?
| swayvil wrote:
| The chair got chairier.
|
| I don't recall what that means.
| egypturnash wrote:
| Do you recall anything that would make it possible to
| find any descriptions of this experiment? When I try to
| search for "a thousand people focus attention on a chair"
| I just get stuff about meditation and an "ADHD chair".
| Which is apparently a thing.
| toast0 wrote:
| From experience with large scale clusters, yeah. Weird stuff
| happens. But it's very hard to setup a test cluster that is
| actually representative, and you can only do so much on a
| live cluster. Occasionally, I have been able to find
| explanations for some of the weird behavior, but usually it's
| like here's a bug in Linux packet forwarding that was fixed
| in Linus's tree 15 years ago, but apparently has never been
| deployed to some router, so it's just going to keep
| aggregating input packets because large receive offload, and
| then drop them with needs frag because the aggregated packet
| is too big to forward. _sigh_ (that 's not exactly a cluster
| scale issue, but it's the most relatable example of an
| investigation that comes to mind)
|
| You're pretty unlikely to get academic papers when the
| required setup involves having 100M+ clients geographically
| dispersed. And it's going to be very hard for peers to
| reproduce your findings.
| empathy_m wrote:
| I think the disappearing polymorph stories are also pretty
| spooky. These have real-life impacts, like with ritonavir.
| MarkusQ wrote:
| Every time I look into those I come away thinking that
| Occam's Razor would suggest a different explanation: the
| original characterization was, knowingly or not, incorrect.
| Patents so frequently fail to contain sufficient
| information to allow a practitioner skilled to in the
| appropriate arts to reproduce the claims that it seems more
| plausible that the disappearing polymorph stories should be
| reclassified as "someone was caught fibbing" stories. In
| the replication crisis, we don't assume that the problem is
| that something about the world has changed, we assume that
| the original was flawed, and we should do the same here.
|
| It would be much more convincing if there were more cases
| that weren't economically significant. A strange property
| of chemistry that only comes up when money and lawyers are
| involved seems inherently suspicious.
| gopher_space wrote:
| > My guess is that this happens in nearly all large-scale
| production systems but goes mostly unobserved.
|
| Not unobserved. Unremarked maybe? It's expected behavior that
| leads us into personification of systems e.g. calling ships
| 'she' or talking about temperament between similar machines
| on a line.
| TeMPOraL wrote:
| In case of this "invisible electrostatic wall", there were
| likely significant amount of people in that company who were
| at least somewhat into Star Trek[0], so I'd expect more than
| mere "meh, this happens" from people who had just seem to
| have accidentally invented _a force field_. It 's not merely
| a weird emergent behavior, it's a behavior closely resembling
| a sci-fi technology, and therefore likely to have similar
| applications - so quite obviously a potential money and fame
| printer.
|
| -- [0] - Which was well-known around the time of that event,
| and at its peak of popularity when the report in the article
| was filed!
| dekhn wrote:
| When you work in production and have quotas to meet, you
| often ignore interesting side-effects. When I worked at
| google I worked at global cluster scale and frequently saw
| any number of events that in themselves would have been
| graduate-student-for-two-years projects that I had to force
| myself to ignore so I could get my main work (large scale
| protein design using 1-3 million cores in prod) to finish.
|
| As a side note, always test any global-scale torrent system
| for package distribution carefully, as sometimes the code
| can have "accidentally n**2" network usage that only shows
| up when you have a worldwide grid of clusters.
| boxed wrote:
| I wish Mythbusters still existed to test stuff like this.
| sonofhans wrote:
| Can you imagine the expense? "We need 1 mile of poly film,
| 20-feet wide ..."
| SequoiaHope wrote:
| A 5000 foot long roll of plastic is common. Here is a 50 inch
| wide roll that is over a mile long which costs $400:
|
| https://www.mcmaster.com/19575T43
|
| Or here is a 20 foot wide roll 1/10th of a mile long:
| https://www.uline.com/Product/Detail/S-20063/Plastic-
| Sheetin...
|
| Based on the cost of the roll from McMaster, a wider roll
| with the same cost basis would be $2000.
| observationist wrote:
| An experimental setup, including the land and a new used
| steel construction could cost less than $500k. Someone
| could throw a couple million at it to control for humidity,
| temperature, airflow, etc, with all sorts of variety, and
| it could be a lot of fun.
|
| If something like this could be made safe, I imagine there
| are applications in security and process safety in places
| like nuclear power, water treatment, any facility where you
| want to restrict access in an extreme way. I'd imagine that
| it would never be safe, any discharge is going to fry
| whatever completes the circuit.
| littlestymaar wrote:
| > Someone could throw a couple million at it to control
| for humidity, temperature, airflow, etc, with all sorts
| of variety, and it could be a lot of fun.
|
| That's the kind of projects I'd fund if I were a
| billionaire, not trying to buy the biggest yacht ...
| harrall wrote:
| Rolls like those were common in the warehouse at the place I
| worked.
| baggy_trough wrote:
| Wouldn't a field strong enough to somehow produce this effect be
| more likely to short out on anything, taking you out like a bug
| zapper?
| rUsHeYaFuBu wrote:
| Yeah I'm not sure this story makes sense either. Shoes may act
| as an insulator but wedding rings and belt buckles would
| presumably conduct.
|
| Additionally potential differences tend to attract rather than
| repel unless these individuals were also charged with the same
| polarity as the field as far as I know.
| gridspy wrote:
| When someone is talking about insulating shoes their point is
| that the body is electrically isolated from the floor.
| Without that isolation charge can travel between the two.
| Concrete and skin are fairly good conductors by comparison
| with air or insulators.
|
| Wearing a conducting ring might make it easier for charge
| from the air to move into your body through your skin - but
| it will not make it easier for that charge to get to the
| floor (and then to ground) from your body.
| rUsHeYaFuBu wrote:
| > Wearing a conducting ring might make it easier for charge
| from the air to move into your body through your skin.
|
| Which would likely make you a pretty nice load or resistor!
| bluGill wrote:
| Generally when people talk about shoes (or tires) they are
| talking about voltages that can jump the distance from
| their foot to the ground through air - around the shoe.
|
| Most shoes are not great insulators - they insulate but how
| knows who much. electricians sometimes buy special shows
| that do insulate. Those shoes come with care instructions
| and dust on the outside compromises their insulation.
| bongodongobob wrote:
| Conduct... to where?
| baggy_trough wrote:
| Good point, a repulsive effect would have to be the same
| charge sign so no bug zapper.
| VikingCoder wrote:
| https://skeptics.stackexchange.com/questions/53985/was-an-in...
|
| "The article says that because of the insulating nature of the
| floor and and footwear, no discharges occurred."
| Noumenon72 wrote:
| From my experience rolling up 1500-pound rolls of plastic, it
| will start arcing out a few feet to the metal of the winder
| when it gets strong enough.
|
| Charge builds up over time, so there ought to be some
| discussion of how the field changed between 0 charge and the
| invisible wall state.
| dyauspitr wrote:
| If this was reproducible I could think of so many real world
| uses. Invisible force fields that can move hundreds of pounds is
| a holy grail in several fields.
| rUsHeYaFuBu wrote:
| Ever see an electromagnet crane at a junk yard?
|
| https://youtube.com/watch?v=XBWy9gzGGd4&pp=ygUVZWxlY3Ryb21hZ...
|
| You can make one yourself with a nail, some copper wire, and a
| battery.
| swayvil wrote:
| That's pretty darn far from what we're talking about here.
| The comparison is absurd.
| rUsHeYaFuBu wrote:
| How so? It's literally an invisible (to the eye) field that
| can lift hundreds of pounds.
|
| And magnetic fields are directly related to electric
| fields. It's called electromagnetism for a reason.
| function_seven wrote:
| Of metal, yes. That's not what we're talking about here.
| We're talking about force fields in the sci-fi sense. An
| invisible wall that a person can't pass through.
| rUsHeYaFuBu wrote:
| The article is about an electrostatic field. That's far
| from sci-fi.
|
| https://en.wikipedia.org/wiki/Electric_field
| function_seven wrote:
| I was clarifying the sense I was using the term "force
| field". Not a generic field of electromagnetic forces,
| but the fantastical one that can contain arbitrary
| matter.
|
| Like the one described in the article, that a person was
| leaning against and could not pass through. If this were
| something that we could reproduce, it would have awesome
| real-world uses. Like a real hover board! Or the best
| anti-theft protection for my parked car.
| rUsHeYaFuBu wrote:
| You could though. Given a sufficiently strong enough
| positively (or negatively) charged electric field and
| yourself equally positively (or negatively) charged
| sufficiently you could have an 'invisible' wall that you
| couldn't walk through. Assuming that neither yourself or
| the field you're walking into has anywhere to discharge
| to.
| dyauspitr wrote:
| Can an electromagnetic move organic material?
| rUsHeYaFuBu wrote:
| If it's strong enough, probably. I mean, MRIs kind of work
| that way.
| SigmundA wrote:
| Yes the 45 Tesla magnet in Tallahassee can levitate small
| non ferrous things like a strawberry in a little tube and
| draws 56 megawatts about 7% of the cities power grid.
| kragen wrote:
| Probably not in a useful way; the induced currents would
| produce far too much heat.
| jhgorrell wrote:
| Extremely powerful fields can levitate a frog - so yes.
|
| https://news.harvard.edu/gazette/story/2024/04/how-did-
| you-g...
| 1970-01-01 wrote:
| Selling tickets on those non-humid days would have been more
| profitable than fixing anything.
| lxgr wrote:
| Static discharge from machines like that has killed people in
| the past, so I'm not sure if that's the best idea.
| IAmGraydon wrote:
| The phenomenon in question has been discussed before, and its
| underlying mechanism can be attributed to electrostatics. A
| simple thought experiment illustrates this concept: imagine a
| person with a net electric charge approaching a similarly charged
| object. As they draw closer, a force of repulsion builds up,
| increasing exponentially with the inverse square of the distance.
|
| However, a crucial aspect of this phenomenon remains unclear: how
| does the charge maintain its containment? What prevents the
| opposing charge from breaking through the insulating barrier and
| neutralizing the charge? A fascinating analogy from the Boston
| Science museum offers some insight. Picture yourself inside a
| gigantic, electrified sphere - akin to a Van De Graff generator.
| If your charge polarity matches that of the sphere, you'll
| experience a repulsive force, pushing you toward the center. The
| harder you try to reach the sphere's edge, the stronger the
| repulsion becomes.
|
| This phenomenon becomes even more intriguing when considering the
| context in which it allegedly occurred. A company renowned for
| its innovative prowess, 3M has consistently demonstrated its
| ability to harness unexpected effects and transform them into
| groundbreaking products. The Post-it note's origin story is a
| testament to this innovative spirit. Given this track record,
| it's puzzling that 3M seemingly failed to capitalize on this
| electrostatic phenomenon. One would expect the company to
| rigorously investigate and replicate the effect, with the
| potential for a multi-billion dollar industry hanging in the
| balance. Instead, the story suggests that 3M dismissed the
| phenomenon as a mere curiosity.
| kragen wrote:
| > _Picture yourself inside a gigantic, electrified sphere -
| akin to a Van De Graff generator. If your charge polarity
| matches that of the sphere, you 'll experience a repulsive
| force._
|
| This is not correct. The field inside a charged conductor is
| zero. You will experience no force. If there is a hole in the
| sphere you will experience a repulsive force if you are close
| to the hole (compared to its size).
| Arnavion wrote:
| Yes, just like with Newtonian gravity. Any inverse-square law
| force will be zero inside a spherical shell. The higher force
| from parts of the shell closer to you is exactly canceled out
| by the farther parts exerting less force but there being more
| of those farther parts.
|
| https://en.m.wikipedia.org/wiki/Shell_theorem
| schmidtleonard wrote:
| Why do you think that? Negative results are boring. A failure
| to publish them does not indicate a lack of investigative
| rigor. Speaking of which, if you're going to complain about
| rigor, this is a bad look:
|
| > increasing exponentially with the inverse square
| jcarrano wrote:
| We are talking about a sci-fi style force-field here! I'd be
| surprised if the military didn't secretly experiment with this.
| swayvil wrote:
| You can count on that.
| bluGill wrote:
| Unless engineers looked at it and said not reliable (only works
| with low humidly), prone to breakdowns, and might randomly kill
| people. And then some general stood up and said what is wrong
| with your standard reinforced door?
| TeMPOraL wrote:
| > _not reliable (only works with low humidly)_
|
| That's merely an engineering issue. Keep spraying it with
| water or something. You do it right, and you might even get
| the familiar buzzing and shimmering of Star Trek force
| fields!
|
| > _prone to breakdowns_
|
| Ah yes, that's very much _like_ Star Trek force fields.
|
| > _and might randomly kill people_
|
| That might be an issue _for Starfleet_. A real-world military
| today will definitely see this as a _feature_.
|
| Ultimately, you're not wrong, but I would hope some military
| or other entity with deep budget would try building it
| anyway, simply because science isn't about "why?", it's about
| " _why not?_ ". I would also imagine, should this design work
| and became widely-known, some hacker would build and operate
| it _just because_.
| bluGill wrote:
| water would be high humidity not low.
| TeMPOraL wrote:
| Second paragraph of the article starts with:
|
| > _This occurred in late summer in South Carolina, August
| 1980, in extremely high humidity._
|
| But I may have misunderstood this as high humidity being
| key to it happening, rather than an impediment.
| ibizaman wrote:
| This reads like a good SCP.
| swayvil wrote:
| A sheet of plastic. With a heavy static charge. Moving at 10mph.
| Assumedly in the vicinity of a big ground.
|
| Is that the whole experiment?
| airstrike wrote:
| The Board <denies/demands> comprehensive analysis of this
| <occurrence/breach>.
| silisili wrote:
| > He said it was actually known to the technicians for awhile
| before he experienced it and they just were kinda like "meh".
|
| I think this was my favorite part of the article. These workers
| apparently hit this force field prior and just figured that was a
| normal part of the job, who cares.
| Workaccount2 wrote:
| I actually work with high voltage for a living, and I have high
| skepticism about this story. While it is technically possible if
| you work out the math and somehow get an extremely dense e-field
| flux, from a practical standpoint it might well be impossible. HV
| like they describe, especially in high humidity, really likes to
| equalize itself in a big flash.
|
| I strongly suspect instead is that there was a spot where you
| could really feel the e-field, and people just through rumor and
| story telling morphed it into "the wall".
| 1propionyl wrote:
| I tend to agree with you. But on the other hand, if true, this
| is the kind of crazy situation that could also lead to new
| mathematics where regimes considered unstable are revealed to
| have surprising stable nodes.
|
| The big problem here is that it's described as a wall and not a
| progressively (quadratically) increasing field.
|
| But what if there actually are network effects propagated by
| charge carrying particles in a suitably humid environment that
| turn the power of 2 into something else? Even a power of 3
| could be perceived reasonably as a wall at human scale.
|
| It's not "I want to believe" so much as "it feels like the
| maths might allow this under odd but reproducible
| circumstances" (my relevant background here is in math-physics
| and specifically analytic solutions to the relevant PDEs, which
| do have some very odd solutions). Would be nice to see people
| try.
|
| There are differences between effects we can observe between
| ideal point charges and ones that only emerge as network
| effects when propagated across a network of less than ideal
| point charges that at least merit some investigation.
| PicassoCTs wrote:
| But if its a wall and you touch it - you should become part
| of it and thus be unable to leave it ?
| maushu wrote:
| I believe the description as a "wall" is not completely
| correct. Yes, it's a wall as a unpassable obstacle, but the
| description they gave when walking into it seems more like a
| field "can't turn around just walk backwards". The field was
| just dense enough to stop people from continuing moving
| forward similar to molasses.
| TeMPOraL wrote:
| This is the same impression I got, precisely because of
| this description. If it's the effect of a field, it would
| seem that by the point you notice it blocking your forward
| progress, you're already rather deep in it.
|
| Perhaps humans feel resistance/repulsive forces non-
| linearly?
|
| Makes me think of magnets, too - when you have two strong
| magnets oriented so they repel each other, and try to get
| them closer, the effect is very strongly non-linear and,
| unless you're intentionally pushing the magnets together
| with significant force, can feel like it turns on almost
| instantly.
| TimTheTinker wrote:
| > Perhaps humans feel resistance/repulsive forces non-
| linearly?
|
| That's got to be the key here. Human perception is known
| to be logarithmic in so many other ways.
| RajT88 wrote:
| Scotch tape produces X-Rays, so something like this feels
| similarly plausible:
|
| https://www.technologyreview.com/2008/10/23/217918/x-rays-
| ma...
|
| (Even if that feeling is misplaced and uninformed)
| EncomLab wrote:
| This pops up at least once a month and has been thoroughly
| debunked.
| mmcgaha wrote:
| I used to work for a company that bought off cuts from this
| plant and the static that comes off of these rolls is scary.
| I heard this story years ago and no one in our plant had a
| doubt about it being true because 3M ran enormous rolls.
| devnullbrain wrote:
| See, I can believe that there are enormous EM fields in
| play. But I can't believe that the employees working there
| would react to them without code brown-ing.
| margalabargala wrote:
| Considering that it's possible to levitate a live frog
| with a (very strong) magnet without killing it, I'm able
| to believe that a sufficiently strong magnetic field can
| be detectable by a human without killing or immediately,
| obviously harming them.
| AlotOfReading wrote:
| This is an electrostatic field, which has no magnetic
| component in the classical model.
| hinkley wrote:
| I accept that a reel to reel could generate a high static
| charge field but I would expect anything creating this level of
| physical phenomenon would be dangerous to humans.
|
| Wouldn't it be much more likely for someone walking into such a
| space to become a lightning rod rather than a fly in a spider
| web?
| petee wrote:
| What do you make of the statement that it pulled in a fly,
| potentially a bird, yet repels humans?
| umvi wrote:
| Maybe someone here knows a science youtuber (Veritasium/Smarter
| Every Day etc) with enough clout to try to get an in with 3M or
| similar and try to reproduce
| hammock wrote:
| Can this be used in a bank vault?
| rich_sasha wrote:
| Why would an electrostatic force repel humans? We are neutrally
| charged.
|
| And if anything, in metals I think (???) you can get _attraction_
| as free electrons in the neutral body are attracted /repelled
| towards the charge and the neutral body becomes a dipol (so eg.
| if the charged body is positively charged then the negatively
| charged electrons are attracted towards it, and vice versa). But
| that's weak and acts the wrong way.
| dcminter wrote:
| I suppose you could take advantage of diamagnetism if a
| _moving_ charge was involved... it works for frogs :)
| more_corn wrote:
| Reminder to everyone to divest of your 3M stock. They lied about
| the dangers of PFAs for decades. Suppressing science to create
| the biggest mass poisoning in human history needs some pushback
| from reasonable people.
| flerchin wrote:
| Van de graaff generators discharge with painful shocks. I would
| expect something like described in the article to kill someone.
| VikingCoder wrote:
| https://skeptics.stackexchange.com/questions/53985/was-an-in...
|
| "The article says that because of the insulating nature of the
| floor and and footwear, no discharges occurred."
| BenjiWiebe wrote:
| In that case, the person would've been very quickly equalized
| to the same charge, and the wall would be gone (for you at
| least) more quickly than you could even feel it.
| cmpalmer52 wrote:
| Reminds me of the time I turned myself into a Van de Graff
| generator at work.
|
| I was a theater projectionist, back when you had 20 minute reels
| you had to constantly change, while babysitting two high-voltage,
| water-cooled, carbon arc projectors. Sometimes the film would
| break and you'd have to splice it. So when the theater got a
| print in, you had to count and log the number of splices for each
| reel, then the next theater would do the same and retire the
| print when it got too spliced up (plus, sometimes if it was the
| last night of a run, some lazy projectionists would splice it in
| place with masking tape and then you'd have to fix it). Sometimes
| you had to splice in new trailers or remove inappropriate ones as
| well.
|
| Anyway, you counted splices by rapidly winding through the reel
| with a benchtop motor with a speed control belted to a takeup
| reel while the source spun freely. Then, while letting the film
| slide between your fingers, counting each "bump" you felt as it
| wound through. I was told to ground myself by touching the metal
| switch plate of the speed control knob with my other hand. One
| night I forgot and let go until my hair started rising. I'd gone
| through most of the reel at a very high speed and acquired its
| charge.
|
| I reached for the switch plate and shot an 8-10" arcing discharge
| between the plate and my fingers.
|
| Lesson learned, I held the switch plate from then on.
| wumms wrote:
| Did you finish your shift that night? (Some 2cm arc from an
| electric fence brought me to my knees one time.)
| anotherevan wrote:
| "So that's what an invisible barrier looks like."
| swayvil wrote:
| We can turn beans into peas.
| hinkley wrote:
| All that static discharge is coming at the expense of the
| mechanical energy in the system is it not? I'm surprised they let
| it zap like that video and don't try to recuperate it somewhere.
|
| One of the weirdest power scavenging solutions I ever saw used a
| spark gap and a bespoke transformer to make a reverse Tesla coil
| - taking the very high, very brief voltage spike of a static
| discharge and stepping it down to create low voltage over a a
| longer interval. They attached it to their shoe.
| littlestymaar wrote:
| > All that static discharge is coming at the expense of the
| mechanical energy in the system is it not? I'm surprised they
| let it zap like that video and don't try to recuperate it
| somewhere.
|
| Yes, but while the voltage is very high, the _energy_ stored is
| very low so I don 't think it makes any sense to try recover it
| (there's probably much more energy being wasted by poor
| insulation of the heated offices or stuff like this).
| hinkley wrote:
| I was thinking less of energy efficiency and more of
| containment. Possibly damage reduction.
| ericye16 wrote:
| It's been a while since I took electrostatics, but I don't
| understand the theory behind this. If the rolls become charged
| and you are presumably neutral, wouldn't they attract you rather
| than repel you? That's what makes me think this story is
| apocryphal.
| st-keller wrote:
| Wow - nice to know that this old story has survived for so long!
| I remember reading it a long time ago. Has this phemomenon been
| repicated by someone or has someone invented something because of
| that?
| sans_souse wrote:
| There's a lot of interesting ideas in the experiments section,
| here: http://amasci.com/freenrg/iontest.html
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