|
|
The elevator "cage", steel plates all over, definitely satisfies the first three criteria. It may not have been perfectly grounded, but I would expect it to hang in a steel chain with metallic contact to the walls, and I would expect the chain to have metallic contact to parts of the motor that is grounded. My expectations may be wrong.
The criteria are fine and clearly stated. Yet the realization seems to be more difficult than one might expect from the clearness of the criteria.
|
|
|
|
|
I think you'll find that there is more plastic in those elevator cages than you think. For example, anodized plastic can look very much like stainless steel, but is much cheaper.
Again, just my theory. 
Freedom is the freedom to say that two plus two make four. If that is granted, all else follows.
-- 6079 Smith W.
|
|
|
|
|
Plastic doesn't go clunck! in the same was as steel. Plastic doesn't fee cold the same way that steel does. I know the feeling of steel as opposed to anodized plastic!
OK, I'll accept your belief that if your guidelines are followed, a Faraday cage works as my schoolbooks said they will. You think they will. I'll let you believe so.
So I will have to ask someone else why our elevator cage - and numerous other attempts of shielding a room / cage from electromagnetic radiation - fail in creating an efficient Faraday cage. Your principles are obviously fine - as if quoted from textbooks I read long ago. But they fail do explain why it doesn't work in practice, in lots of specific cases.
If you think it really is as simple as you seem to suggest, then you might make a fortune on offering your services to this French father, to theaters, movie theaters and concert halls.
|
|
|
|
|
trønderen wrote: So I will have to ask someone else why our elevator cage - and numerous other attempts of shielding a room / cage from electromagnetic radiation - fail in creating an efficient Faraday cage. Your principles are obviously fine - as if quoted from textbooks I read long ago. But they fail do explain why it doesn't work in practice, in lots of specific cases.
I give up. Perhaps you can write to the manufacturers of the elevator, and ask them about the design of their elevator cages. All I know is that the physics are correct, and if the Faraday cage is properly designed - it will work.
Freedom is the freedom to say that two plus two make four. If that is granted, all else follows.
-- 6079 Smith W.
|
|
|
|
|
Thing is, you simply repeat what the textbook says, with no indication of where, why, how the straightforward approach fails (beyond repeating the textbook).
If I try building a Faraday cage, and it doesn't work well, I guess you would quote the textbook again. An expert would go searching for well known pitfalls, and probably find some. I'd love to know of those pitfalls in advance.
|
|
|
|
|
That is awesome, give that man a prize!
"the debugger doesn't tell me anything because this code compiles just fine" - random QA comment
"Facebook is where you tell lies to your friends. Twitter is where you tell the truth to strangers." - chriselst
"I don't drink any more... then again, I don't drink any less." - Mike Mullikins uncle
|
|
|
|
|
I've been considering a similar civil disobedience action, more at the "prank" level:
I live at the outer coverage edge of the Frankfurt, Germany, radio clock DCF77 signal. If weather/atmospheric conditions are unfavorable, my 1st floor DCF77 clock may not be able to pick up the signal (once it was a day late before picking up the Daylight Savings Time change), while the 2nd floor clock usually synchronizes without problems. Yet, it shouldn't take much power to drown out the Frankfurt signal.
'77' in 'DCF77' refers to the frequency: 77.5 kHz. For a radio signal, that is very low. It is actually so low that you can generate it with any sound card handling 192 kHz sampling rate, and a lot of them do. A lot of modern stereo amps accept a 192 kHz PCM signal on the digital input, and can generate an analog signal up to 100 kHz on the speaker outputs. The encoding is rather primitive (Wikipedia: DCF77[^]) - I frequently jokingly refer to it as "Morse Mark II".
So if I make a small program for my PC, generating signals for all the DCF77 alarm clocks in the neighborhood that "It is six o'clock, time to get up!" a couple hours early ... My 50 W/channel amp, with an antenna connected to the speaker outlets would easily drown the Frankfurt DCF77 signal.
There is supposed to be a clock signal at 77.5 kHz. I think it would take the authorities a long time to discover that the signal is stronger than it "should be", and carrying an incorrect time value. Probably, the DCF77 alarm clock owners would blame their clocks, not the radio signal. I haven't dared to realize it, an I probably never will. Nevertheless, playing with the idea is sort of fun
(In other parts of the world, there are similar but not identical clock radio services, some at even lower frequencies. The data format may be different. If you pick up this idea to realize it in your district, let us hear about it!)
This idea is somewhat inspired by a couple of "community FM radio stations" long time ago, when Norway had a state monopoly on radio broadcasts. Usually, there were no broadcasts between midnight and 6 a.m. So some pirate radios picked up the state channel, retransmitting it locally on a different frequency, usually with a much higher signal level. So lots of listeners tuned their receivers to that frequency, giving the pirate radio a lot of listeners for their midnight-to-6am transmissions. At daytime, the authorities never paid any attention to the state radio being available at a frequency where it wasn't supposed to be.
|
|
|
|
|
I know nothing about your countries telecom enforcement agencies; but suspect they'd have as negative a reaction as the French did in the linked story or the US FCC has in various other cases of unauthorized broadcasting I've read about over the years.
Did you ever see history portrayed as an old man with a wise brow and pulseless heart, weighing all things in the balance of reason?
Is not rather the genius of history like an eternal, imploring maiden, full of fire, with a burning heart and flaming soul, humanly warm and humanly beautiful?
--Zachris Topelius
|
|
|
|
|
Well ... They wouldn't exactly embrace me for my inventiveness! There are reasons why I never tried out this in practice.
|
|
|
|
|
Survey of Rust programmers indicates they enjoy using the language but writing production-ready code is sometimes a struggle. Insert almost any other programming language in that headline and it works
OK, maybe not perl
|
|
|
|
|
IDEs are about typing shortcuts, and there are a limited number of things that they can show us and people who aren’t going to see the docs outside of the IDE are unlikely to look through all the options that a cramped dropdown offers them. All right, but apart from providing a common toolset, syntax checking, debugging, auto-completion, and resource management, what have IDEs ever done for us?
This rant brought to you by the 80s
|
|
|
|
|
Kent Sharkey wrote: All right, but apart from providing a common toolset, syntax checking, debugging, auto-completion, and resource management, what have IDEs ever done for us?
Brought peace.
GCS d--(d-) s-/++ a C++++ U+++ P- L+@ E-- W++ N+ o+ K- w+++ O? M-- V? PS+ PE- Y+ PGP t+ 5? X R+++ tv-- b+(+++) DI+++ D++ G e++ h--- r+++ y+++* Weapons extension: ma- k++ F+2 X
|
|
|
|
|
"Hi, I am an idiot. Here's an article explaining why."
|
|
|
|
|
Kent Sharkey wrote: All right, but apart from providing a common toolset, syntax checking, debugging, auto-completion, and resource management, what have IDEs ever done for us?
DRAM Industry Veterans: "They put my kids through college"
Did you ever see history portrayed as an old man with a wise brow and pulseless heart, weighing all things in the balance of reason?
Is not rather the genius of history like an eternal, imploring maiden, full of fire, with a burning heart and flaming soul, humanly warm and humanly beautiful?
--Zachris Topelius
|
|
|
|
|
SQL doesn’t have an open source ecosystem of software libraries to tackle certain common use cases, and that work across popular SQL systems. SELECT new vulnerabilities FROM shared_library
|
|
|
|
|
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has published a list of free cybersecurity services and tools to help organizations increase their security capabilities and better defend against cyberattacks. In case you've heard recently that there are security problems around
|
|
|
|
|
As the article only mentions it and it was not so trivial to find (at least not for me...)
The list can be found in Free Cybersecurity Services and Tools | CISA[^]
Actually interesting. I knew some tools, had heard of others and didn't know about many.
M.D.V. 
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
Rating helpful answers is nice, but saying thanks can be even nicer.
|
|
|
|
|
A new study shows that organizations continued to take an inordinately long time to fix vulnerabilities and fixed fewer known issues in their environments last year than in 2020. On the bright side: job security!
|
|
|
|
|
As a company that has embraced Zero Trust ourselves and supports thousands of organizations around the globe on their Zero Trust journey, Microsoft fully supports the shift to Zero Trust architectures that the Cybersecurity EO urgently calls for. If you think I'm going to make a "US government" and "Zero trust" joke, you're mistaken
I'm only going to allude to it.
|
|
|
|
|
George Carlin: I have certain rules I live by. My first rule: I don't believe anything the government tells me. Nothing. Zero.
|
|
|
|
|
Robert A. Heinlein: “Love your country, but never trust its government.”
|
|
|
|
|
I have negative trust. Consider that trust embeds a somewhat temporal component.
positive trust: I will trust you in the future.
zero trust: I don't trust you now.
negative trust: I will never trust you in the future.
|
|
|
|
|
A behind-the-scenes peek into the machine learning framework powering new code scanning security alerts. It looks like you're trying to write a bug. Would you like help with that?
|
|
|
|
|
Back in 2009 I wrote a distributed system for RFID tracking.
And now in 2022, my Win 10 install flags the binaries as "dangerous programs that execute commands from an attacker." What utter nonsense.
And the bad part is that it doesn't offer the option of allowing the files to exist on the machine. 
The difficult we do right away...
...the impossible takes slightly longer.
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
