Everytime I go to the movies, they tell me to turn off my cell phone. If they are so concerned with cell phones, why don’t they just put up metal mesh wall paper, and create a faraday cage, which according to my grade 12 physics will stop radio waves.
How much could it cost to put up a faraday cage around a movie theater? Wouldn’t it be worth it to stop those idgets from spoiling the movie with their cell phones?
Obviously too much. No one is stupid enough to blame the theatre when a guest’s cellphone rings therefore it’s not their problem therefore they aren’t going to spend money on it.
I personally haven’t heard a phone ring in a theatre in years and I go to the movies quite often. Even when cell phones were first getting really popular in the late 90s and they did ring in theatres a lot it didn’t exactly spoil the movie.
Maybe new theatres will be built with something like this but I can’t see a single theatre owner justifying the cost of retrofitting his entire structure to stop the occasional ringtone.
It’s expensive.
It may not be legal - the wireless company has a license under federal law (FCC) to provide service in that area, and has generally paid handsomely for the opportunity, counting on being able to make money from customers. I’m not sure regular business establishments can just not allow the wireles companies to operate “within their borders”. Obviously there are exceptions for situations like hospitals, etc. (Maybe someone else can elucidate this further - I’ve always kind of wondered about the definitive answer to this myself).
It would stop all calls - even for phones on vibrate - which certain people may want/need during the movie/performance. If a person gets a call and it doesn’t bother anyone else, whats the problem?
On re-read, this sounds like it could come across a bit snarky, which I’m not intending at all. Just listing some facts (I hope!) as I understand them.
As Cisco said, it would cost too much. I don’t know much about them, but I imagine that they would be a pain and expense to maintain, too. Movie theater technology might also come up with some gizmo which CAN NOT be activated in a Faraday cage. It’s not all that likely, but it’s possible.
I’d also rather that parents have the option to have their cell phones on “vibrate”, so that sitters can reach them in an emergency. Other people also have emergencies, as well. As long as the phones are on “vibrate”, and the person receiving the call steps out of the theater itself to take the call, I don’t begrudge other people their electronic leashes.
This’d probably present a problem for people who really need to have a cellphone or a pager handy. Like someone on an organ-transplant list, or someone who works on a bomb squad. One weird, freak occurance where blocking a pager or cellphone call causes a really serious problem, and boom…lawsuit city.
Usually if you try and retrofit something like this into a public place a bunch of people complain usually for the reason that Ranchoth states, it interferes with emergency communications. There’s no way you can retrofit it into an existing theatre without ticking someone off.
However, if you build the building out of materials that naturally form a faraday cage (like that wire mesh stuff that they spray stuff over to make a wall) then nobody complains.
Go figure.
They have a license, but not a requirement to provide service in particular areas; if it was a requirement, my cell phone company would be in big trouble for the big holes in their coverage areas.
That said - I don’t think it’s generally written into law that private businesses have to accomodate other private businesses, particularly when doing so might infringe on their own.
I thought they were already doing this. I never get signal any more when I go into a theater, even when I sit way up in the nosebleed section of the “stadium seating”. Right outside the theater door, I get full signal (5 bars).
While a Faraday Cage is a more elegant solution with no moving parts or power requirements, it looks like the quick fix is to use jammers. Apparently from the article’s text,
The article also discusses the passive jamming approach you highlighted. If a theater used active jammers, any of the personnel you mentioned above (organ transplant candidates, EMTs, etc.) could probably see the manager before the show and request that either (a) their phone be watched by the projectionist, or (b) the jammer in their theater be deactivated.
I imagine in the big “ego” cities (LA, DC, NYC) that you’d have all sorts of characters demanding this special treatment, but that in most other markets, the silence would be a blissful boon.
I figure they’re doing something similar at my local hospital - outside the emergency room doors, full signal. Two steps towards the door, (and all throughout the hospital) no signal whatsoever.
Me,neither. I would actually like to credit cell phones with convincing people with pagers to set the things to vibrate; I rarely hear pagers go off anymore, either.
Now, people talking on cell phones in theatres, that’s a different story…
Was I the only Doper to hope that this thread was all about the electrical equipment used in the old Univeral Frankenstein films? 
All of the laboratories in old movies contain:
A faraday cage is just a fancy name for a metal box. Keep on the lookout for threads mentioning Jacob’s Ladders if you want the really cool sci-fi stuff.
Jacob’s Ladder link: http://www.kronjaeger.com/hv/hv/exp/jacob/
And, just to keep this post on topic, here’s some info about faraday cages as well:
http://www.boltlightningprotection.com/Elemental_Faraday_Cage.htm
These are almost always lissajous patterns, which are formed by feeding different waveforms to the horizontal and vertical axes. We used static ones (formed by two signals of the same frequency, in or out of phase) to test turns ratio in certain types of toroidal transformers where I used to work. When the two signals are in phase, it forms a diagonal line.
I don’t know why it would be illegal to construct any building that would block phone transmissions. My office building has no Faraday cage, but its construction is such that cell phones may only be used near a window. Building constructors have no obligation to make their structures transparent to cell phones, do they?
In a town were I lived there was a cinema (built in the late nineties) that was advertised as cell phone proof - and it was. However the outer shell of the building was mostly metal anyway, so it might have been unintentional.
A laboratory is certainly the place for a “Jacob’s Ladder”; they produce poisonous nitrogen oxides, and a variant process was used at one time to manufacture nitric acid.
Thank you.
Laboratories may be the *ideal * place for a Jacob’s ladder, but I can assure you they’ll live in a basement just fine 
Recently, a school in Europe installed a jammer, for the purpose of preventing students from cheating on exams. Students were text messaging questions to friends, who would look up the answers and send them back.
Apparently enough of a problem that the school went to the effort of obtaining a government variance to allow them to operate this jammer.
Any shielding that would block cell phone signals would also block police and fire radio signals, might be some public safety issues here.