Editing Talk:2286: 6-Foot Zone
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: Love it. Given the extra 1.7 feet for the person, a radius of 20.53 hands. If it were just 6 feet, 18 hands -- brad --[[Special:Contributions/108.162.216.122|108.162.216.122]] 00:55, 28 March 2020 (UTC) | : Love it. Given the extra 1.7 feet for the person, a radius of 20.53 hands. If it were just 6 feet, 18 hands -- brad --[[Special:Contributions/108.162.216.122|108.162.216.122]] 00:55, 28 March 2020 (UTC) | ||
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So Randall is figuring about 1.7 feet diameter for the person. --[[Special:Contributions/172.68.174.70|172.68.174.70]] 00:40, 28 March 2020 (UTC) | So Randall is figuring about 1.7 feet diameter for the person. --[[Special:Contributions/172.68.174.70|172.68.174.70]] 00:40, 28 March 2020 (UTC) | ||
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Interesting that the population density he gives ignores circle packing. Population should be 174,000. -- coyne -- [[Special:Contributions/162.158.122.156|162.158.122.156]] 04:06, 28 March 2020 (UTC) | Interesting that the population density he gives ignores circle packing. Population should be 174,000. -- coyne -- [[Special:Contributions/162.158.122.156|162.158.122.156]] 04:06, 28 March 2020 (UTC) | ||
: Circle packing is unimportant since he's just giving the population of this one circle. He's taking a radius of 6 foot ''around'' that person without specifying what he considers to be the radius of the person, but it can be inferred from the numbers: <br>from area: <math>\sqrt{145/\pi} \approx 6.8</math>, <br>from circumference: <math>43/(2\pi) \approx 6.8</math>, <br>from population density: <math>\sqrt{1/190000/\pi} \cdot 5280 \approx 6.8</math>,<br>so apparently he considers a person to have a radius of 0.8 ft, or about 0.5 m diameter, which seems reasonable. [[User:Zmatt|Zmatt]] ([[User talk:Zmatt|talk]]) 05:11, 28 March 2020 (UTC) | : Circle packing is unimportant since he's just giving the population of this one circle. He's taking a radius of 6 foot ''around'' that person without specifying what he considers to be the radius of the person, but it can be inferred from the numbers: <br>from area: <math>\sqrt{145/\pi} \approx 6.8</math>, <br>from circumference: <math>43/(2\pi) \approx 6.8</math>, <br>from population density: <math>\sqrt{1/190000/\pi} \cdot 5280 \approx 6.8</math>,<br>so apparently he considers a person to have a radius of 0.8 ft, or about 0.5 m diameter, which seems reasonable. [[User:Zmatt|Zmatt]] ([[User talk:Zmatt|talk]]) 05:11, 28 March 2020 (UTC) | ||
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: Note that even if you want to know the population of optimally packed people, your number is still wrong since the circles overlap: your circle is supposed to exclude other people, it doesn't exclude other people's circles. Optimally you'd have a triangular lattice of people with a lattice distance of 7.6 ft (assuming we want 6 ft between people and we consider people to be circles of radius 0.8 ft). This yields a population density of 1 person per <math>\tfrac{1}{4}\sqrt{3} \cdot 7.6^2 \text{ ft}^2</math>, which is about 1.1 million people per square mile. [[User:Zmatt|Zmatt]] ([[User talk:Zmatt|talk]]) 05:24, 28 March 2020 (UTC) | : Note that even if you want to know the population of optimally packed people, your number is still wrong since the circles overlap: your circle is supposed to exclude other people, it doesn't exclude other people's circles. Optimally you'd have a triangular lattice of people with a lattice distance of 7.6 ft (assuming we want 6 ft between people and we consider people to be circles of radius 0.8 ft). This yields a population density of 1 person per <math>\tfrac{1}{4}\sqrt{3} \cdot 7.6^2 \text{ ft}^2</math>, which is about 1.1 million people per square mile. [[User:Zmatt|Zmatt]] ([[User talk:Zmatt|talk]]) 05:24, 28 March 2020 (UTC) | ||
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Much as I love thinking about circle packing density in the plane, I think the above explanation is slightly overthinking the issue. The population density figure appears to be using the idea that one person's zone contains one person; 1 person / (145 ft^2) does indeed equal 192,000 people/square mile. So, he's not saying that 'given these constraints, we can pack people at this maximum density'. He's saying 'given this area, and counting it as a tiny sovereignty, we can calculate its population density to be this'. For this reason, I don't think you should say that the 'population density' figure has an error, only that it is calculated in a different sense than you were thinking about. [[User:Dextrous Fred|Dextrous Fred]] ([[User talk:Dextrous Fred|talk]]) 18:58, 28 March 2020 (UTC) | Much as I love thinking about circle packing density in the plane, I think the above explanation is slightly overthinking the issue. The population density figure appears to be using the idea that one person's zone contains one person; 1 person / (145 ft^2) does indeed equal 192,000 people/square mile. So, he's not saying that 'given these constraints, we can pack people at this maximum density'. He's saying 'given this area, and counting it as a tiny sovereignty, we can calculate its population density to be this'. For this reason, I don't think you should say that the 'population density' figure has an error, only that it is calculated in a different sense than you were thinking about. [[User:Dextrous Fred|Dextrous Fred]] ([[User talk:Dextrous Fred|talk]]) 18:58, 28 March 2020 (UTC) | ||
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Thanks for that explanation! When I saw the title text, I was worried that WHO had increased the recommendation and I'd missed it. [[User:TobyBartels|TobyBartels]] ([[User talk:TobyBartels|talk]]) 00:47, 29 March 2020 (UTC) | Thanks for that explanation! When I saw the title text, I was worried that WHO had increased the recommendation and I'd missed it. [[User:TobyBartels|TobyBartels]] ([[User talk:TobyBartels|talk]]) 00:47, 29 March 2020 (UTC) | ||
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