Timeline for How to prevent invisible people from committing crimes?
Current License: CC BY-SA 4.0
19 events
| when toggle format | what | by | license | comment | |
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| S Dec 18, 2020 at 21:03 | history | suggested | user11111111111 | CC BY-SA 4.0 |
Fixed spelling, punctuation, etc
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| Dec 18, 2020 at 19:38 | review | Suggested edits | |||
| S Dec 18, 2020 at 21:03 | |||||
| Aug 17, 2017 at 12:03 | comment | added | Amadeus | The pressure plate idea does not have to be expensive: I have heard of many materials that are cheap and change color under pressure, these could be painted on a floor (or rolled out like plastic and glued to it, like vinyl tiles or carpet). A camera monitoring such a floor will see nearly nothing if a visible person is standing; their body blocks the color change; and if walking the color change would fade quickly. But if invisible, the footprints would be unblocked, larger and brighter; easy to distinguish with a regular camera and sound an alarm. Plus the recording gives an exact position. | |
| Aug 17, 2017 at 11:56 | comment | added | Amadeus | I like this answer because several answers work even if the person is invisible throughout the photonic spectrum we can detect, from infrared to ultraviolet and X rays, and it seems to me complete invisibility (of a person, not a simple atomic structure like diamond or glass) would have to be some magical thing. So why limit invisibility to our visible spectrum? If we do, pressure plates, oxygen consumption, air disturbances, etc should all still work. | |
| Aug 16, 2017 at 17:39 | comment | added | Liquid | @IllusiveBrian That's exactly the thing, thanks for pointing that out. Added to the answer. | |
| Aug 16, 2017 at 17:38 | history | edited | Liquid | CC BY-SA 3.0 |
Added the correct definition for the mantrap kind of door, with the link provided by @IllusiveBrian
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| Aug 16, 2017 at 17:14 | comment | added | IllusiveBrian | As an aside, the door you are thinking of to let one person in at a time is a mantrap. Entry control would still have other issues though, since often they are designed with the assumption that security guards will prevent anyone from entering through the wrong entrance - consider the exit-only part of an airline terminal. | |
| S Aug 16, 2017 at 13:49 | history | suggested | Null | CC BY-SA 3.0 |
fixed spelling
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| Aug 16, 2017 at 13:44 | review | Suggested edits | |||
| S Aug 16, 2017 at 13:49 | |||||
| Aug 16, 2017 at 10:44 | comment | added | Liquid | @Jules it's the same as today. At least in my country, we are not allowed to wear masks, helmets, scarfs or other things that completely cover the head in public buildings and banks for security reasons. | |
| Aug 16, 2017 at 8:52 | comment | added | Angew is no longer proud of SO | @Jules They are not invisible all the time, they can become invisible at will. So just ask them not to do that when facing the camera. | |
| Aug 16, 2017 at 7:48 | comment | added | Jules | "only allowed people, based on facial recognition" -- you're going to have the Invisibility Rights Campaign furious about that. You're discriminating against invisible people just because some of them are criminals. | |
| Aug 15, 2017 at 23:22 | comment | added | WGroleau | Afloor full of pressure sensors and several cameras connected to a computer. Image processing determines the locations of all the visible peoples' feet and triggers an action if it doesn't match the pressure readings. | |
| Aug 15, 2017 at 18:39 | comment | added | John | simple bead curtains can make it easier to see people entering restricted areas. | |
| Aug 15, 2017 at 18:33 | comment | added | Shawn V. Wilson | Then add a visible-light sensor to the others. If the pressure plate senses something but the laser doesn't, it alerts the guard instead of opening the door. | |
| Aug 15, 2017 at 18:21 | vote | accept | Gustavo Gabriel | ||
| Aug 15, 2017 at 18:20 | comment | added | Sebastian Lenartowicz | @ShawnV.Wilson It varies, but in many cases yes. Automatic doors will often use a pressure plate, an interrupted beam ("electric eye"), or microwave/ultrasonic/passive IR detector (more common these days - it's the thing mounted above the door). And, if the invisible person is only invisible in the visible spectrum, they'll foil absolutely none of those. | |
| Aug 15, 2017 at 18:03 | comment | added | Shawn V. Wilson | Pressure plates shouldn't be that expensive; don't ordinary supermarkets still use those? | |
| Aug 15, 2017 at 15:39 | history | answered | Liquid | CC BY-SA 3.0 |