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GeneralRe: COVID, there's an app for that Pin
Nelek15-Apr-20 0:11
protectorNelek15-Apr-20 0:11 
GeneralRe: COVID, there's an app for that Pin
Jörgen Andersson15-Apr-20 0:50
professionalJörgen Andersson15-Apr-20 0:50 
GeneralRe: COVID, there's an app for that Pin
Nelek15-Apr-20 1:09
protectorNelek15-Apr-20 1:09 
GeneralRe: COVID, there's an app for that Pin
kalberts14-Apr-20 22:30
kalberts14-Apr-20 22:30 
GeneralRe: COVID, there's an app for that Pin
Nelek15-Apr-20 0:06
protectorNelek15-Apr-20 0:06 
GeneralRe: COVID, there's an app for that Pin
Jörgen Andersson14-Apr-20 22:42
professionalJörgen Andersson14-Apr-20 22:42 
GeneralRe: COVID, there's an app for that Pin
kalberts14-Apr-20 22:57
kalberts14-Apr-20 22:57 
AnswerRe: COVID, there's an app for that Pin
kalberts14-Apr-20 5:29
kalberts14-Apr-20 5:29 
There is at least a dozen (maybe two or three dozen) similar initiatives all over the world. As far as I have been able to find out, the main operation and goal is the same for all of them - the essential difference is how they handle the data.

An app cannot protect you against covid-19. All it gives you is a message a few days after you have been around some other person, that it might be too late: You may be infected yourself.

The real protection comes from here and now not being around people who are infected. The app cannot help you with that; you'll have to take responsibility for that yourself.

The app is like if you receive a phone call from a friend: "Hi, buddy! Bad news - I am sick with covid-19. Since I visited your home a week ago, I thought you should know about it. I can't tell if I was already infected then, but if I was, I may have brought it to you as well. So maybe you should have the entire family tested..."

Sure, you may use an app to send the message, rather than making a phone call. But the end result is the same: The app gives you no protection, only a warning that the protection may have failed.

If the guy getting sick has been in close contact with hundreds of people the last two weeks, he probably won't remember them all, and won't be making hundreds of phone calls. The app could help with that. But if you go to the grocery store six days a week, you probably get within six feet of at least fifty people inside the store, on the walkways and in the parking lot. Six hundred people lining up for being tested, the day you get sick. No, that is not possible to manage. So most apps require the closeness to last for some time, like 15 minutes (the suggested value here in Norway).

None of those six hundred people (50 per day) when I go to the store are closer to me than six feet for as much as two minutes - most of them only for a few seconds. Or we are not close at all, but I empty my cart into the car, and ten minutes later it is picked up by another customer who has never been closer to me than half a mile. Yet I might have left virus on the cart.

Those I spend 15 minutes at a time with at a distance less than six feet, those I know of without any app: Those are family, or if I still went to the office, coworkers in the same 4-cubicle. There might have been others, like hairdressers and dentists, if they were open. They are not, and I would have known about them even without the app.

Then comes this "6 feet distance". GPS is not by far precise enough, especially indoors. Smartphone GPS is very poor at altitudes, and cannot distinguish between floors of a building. Almost all of these initiatives therefore assume that Bluetooth (in addition to GPS) is constantly turned on, and the distance from another smartphone can be determined from the signal strength.

If everybody used exactly the same smartphone, with exactly the same antenna solution. with the BT transmitter set to exactly the same output level, and everybody had fastened their smartphones to their cap, out in open air, at the same altitude above the floor... Then: Maybe. But BT transmit power may vary quite a lot. Antennas differ in how efficient they are. If two guys pass each other in opposite directions, both with their phones in their left pocket, and then repeat, this time with the phone in their right pocket, at the same distance between them, the two signal strength readings is likely to e quite different: The real distance between the phones would be at least 4 ft more or less, and the signal would have to pass through two bodies or none.

It seems like lots of people have come to believe that Bluetooth has some radar-like function. It does not. Signal strength from the other phone is all there is to measure the distance. So it doesn't help much.

In other words: I see this as a result of app-mania. If I get sick, I will make an ordinary phone call to warn those I have spent at least fifteen minutes with the last week or two, urging them to be tested. The will provide nothing beyond that.
AnswerRe: COVID, there's an app for that PinPopular
Sander Rossel14-Apr-20 5:41
professionalSander Rossel14-Apr-20 5:41 
GeneralRe: COVID, there's an app for that Pin
Greg Utas14-Apr-20 5:54
professionalGreg Utas14-Apr-20 5:54 
GeneralRe: COVID, there's an app for that Pin
dandy7215-Apr-20 3:56
dandy7215-Apr-20 3:56 
GeneralRe: COVID, there's an app for that Pin
Greg Utas15-Apr-20 4:39
professionalGreg Utas15-Apr-20 4:39 
GeneralRe: COVID, there's an app for that Pin
Jörgen Andersson14-Apr-20 8:46
professionalJörgen Andersson14-Apr-20 8:46 
GeneralRe: COVID, there's an app for that Pin
kalberts14-Apr-20 9:52
kalberts14-Apr-20 9:52 
GeneralRe: COVID, there's an app for that Pin
Mark_Wallace14-Apr-20 17:49
Mark_Wallace14-Apr-20 17:49 
AnswerRe: COVID, there's an app for that Pin
Mark_Wallace14-Apr-20 17:42
Mark_Wallace14-Apr-20 17:42 
AnswerRe: COVID, there's an app for that Pin
Marc Clifton15-Apr-20 3:10
mvaMarc Clifton15-Apr-20 3:10 
GeneralRe: COVID, there's an app for that Pin
kalberts15-Apr-20 3:37
kalberts15-Apr-20 3:37 
JokeJust a thought... PinPopular
Mike Hankey13-Apr-20 23:56
mveMike Hankey13-Apr-20 23:56 
GeneralRe: Just a thought... PinPopular
Johnny J.13-Apr-20 23:58
professionalJohnny J.13-Apr-20 23:58 
GeneralRe: Just a thought... Pin
Greg Utas14-Apr-20 1:13
professionalGreg Utas14-Apr-20 1:13 
GeneralRe: Just a thought... Pin
W Balboos, GHB14-Apr-20 1:24
W Balboos, GHB14-Apr-20 1:24 
GeneralRe: Just a thought... Pin
Randor 14-Apr-20 1:45
professional Randor 14-Apr-20 1:45 
GeneralRe: Just a thought... Pin
Mark_Wallace14-Apr-20 10:53
Mark_Wallace14-Apr-20 10:53 
GeneralRe: Just a thought... Pin
Mike Hankey14-Apr-20 11:03
mveMike Hankey14-Apr-20 11:03 

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