5 ms·

I don't have a horse in the race either way but > it is good intuition that we survived for thousands of years stark naked without sunscreen and vitamin suplem

I don't have a horse in the race either way but > it is good intuition that we survived for thousands of years stark naked without sunscreen and vitamin suplements That, as an argument, is completely worthless. You don't know how those people lived, how they died, what diseases they had, all you can deduce is that some of them managed to reproduce before keeling over.

slothtrop 4y ago
> You don't know how those people lived ... without sunscreen.
- clint 4y ago
  How do you know they went out during the day and weren't completely or mostly nocturnal?
  - comicjk 4y ago
    Within living memory, Americans wore hats pretty much whenever they were outside. If we decide to give up sunblock, we might want to reconsider the change in fashions that got rid of them.
    - slothtrop 4y ago
      That's a relatively recent phenomenon in human history as well. What about the middle ages? What about the bronze age?
      - xeyownt 4y ago
        Yeah... let's live like we did in the middle age. Lifetime expectancy was HUGE.
        aksss 4y ago
        “There is a basic distinction between life expectancy and life span,” says Stanford University historian Walter Scheidel, a leading scholar of ancient Roman demography. “The life span of humans – opposed to life expectancy, which is a statistical construct – hasn’t really changed much at all, as far as I can tell. Life expectancy is an average. If you have two children, and one dies before their first birthday but the other lives to the age of 70, their average life expectancy is 35. That’s mathematically correct – and it certainly tells us something about the circumstances in which the children were raised. But it doesn’t give us the full picture. It also becomes especially problematic when looking at eras, or in regions, where there are high levels of infant mortality. Most of human history has been blighted by poor survival rates among children, and that continues in various countries today.” https://www.bbc.com/future/article/20181002-how-long-did-ancient-people-live-life-span-versus-longevity https://www.bbc.com/future/article/20181002-how-long-did-anc... Adjust for infant mortality, war, etc., humans are still humans.
        deleted 4y ago
        [deleted]
  - throwaway202022 4y ago
    Our human ancestors were not nocturnal. Sleep patterns were probably different, sure, but they went out during the day to gather and hunt for food.
  - bgandrew 4y ago
    Because it's obvious to anybody. It's also obvious that modern humans are far less exposed to UV than our ancestors, who pretty much lived like current days hobos spending most of their time on fresh air.
  - guerrilla 4y ago
    You realize hunter-gatherers exist today, right? They go out during the day and are not mostly nocturnal. They're found all over the world.
    - deleted 4y ago
      [deleted]
nostromo 4y ago
And white people that live in California or Florida should note that our complexion evolved in latitudes similar to Canada.
- robocat 4y ago
  And if you are in the equivalent Southern latitude to Canada (e.g. New Zealand), you still sometimes need sunscreen to avoid the extra UV due to the ozone hole. Perhaps not as bad as it was, but cannot be ignored, although it is variable: https://www.rnz.co.nz/national/programmes/ourchangingworld/audio/2018774144/ozone-holes-and-uv-radiation https://www.rnz.co.nz/national/programmes/ourchangingworld/a...
  - flog 4y ago
    The NZ sun is terrible. You feel the sun burning you as soon as you get outside. Burn time can be about 10 minutes on a sunny day, and maybe 20 on a cloudy day in summer. In NZ we get about 4000 in-situ melanoma diagnosis a year. I was one of them a couple of years ago (at 37). Wear sunscreen!
  - incompatible 4y ago
    Perhaps if we are talking about the South Island of New Zealand and the southern tip of Canada (Toronto). Most of Canada would be closer to the pole.
    - robocat 4y ago
      Yeah, good point. NZ has similar latitudes down here as the USA has up there. Weather is very different since we don’t get continental effects. Also NZ wasn’t really affected by ozone depletion, but the effects are definitely in our neighbourhood and we were worried. “While the ozone hole does not directly affect ozone concentrations over New Zealand, when it breaks up in spring it can send ‘plumes’ of ozone-depleted air towards us. This briefly decreases column ozone levels by around 5 percent, about the same amount as normal daily variation.”. Also see graph at https://niwa.co.nz/our-services/online-services/uv-ozone https://niwa.co.nz/our-services/online-services/uv-ozone and notice ozone is lowest in NZ summer. Also measuring a column of ozone is most relevant in the tropics when the sun can be directly above one at noon, and less relevant when the sun doesn’t get so high above the horizon (location further towards poles, and winter versus summer). https://pubmed.ncbi.nlm.nih.gov/9671831/ https://pubmed.ncbi.nlm.nih.gov/9671831/
cfn 4y ago
Sunscreen, as we know it, is barely 100 years old (see https://pubmed.ncbi.nlm.nih.gov/33583116/ https://pubmed.ncbi.nlm.nih.gov/33583116/) and we have a lot of information up to that point. We can also deduce from many sources that humanity did not just "managed to reproduce before keeling over".

slothtrop 4y ago

> You don't know how those people lived ... without sunscreen.

clint 4y ago
How do you know they went out during the day and weren't completely or mostly nocturnal?
- comicjk 4y ago
  Within living memory, Americans wore hats pretty much whenever they were outside. If we decide to give up sunblock, we might want to reconsider the change in fashions that got rid of them.
  - slothtrop 4y ago
    That's a relatively recent phenomenon in human history as well. What about the middle ages? What about the bronze age?
    - xeyownt 4y ago
      Yeah... let's live like we did in the middle age. Lifetime expectancy was HUGE.
      - aksss 4y ago
        “There is a basic distinction between life expectancy and life span,” says Stanford University historian Walter Scheidel, a leading scholar of ancient Roman demography. “The life span of humans – opposed to life expectancy, which is a statistical construct – hasn’t really changed much at all, as far as I can tell. Life expectancy is an average. If you have two children, and one dies before their first birthday but the other lives to the age of 70, their average life expectancy is 35. That’s mathematically correct – and it certainly tells us something about the circumstances in which the children were raised. But it doesn’t give us the full picture. It also becomes especially problematic when looking at eras, or in regions, where there are high levels of infant mortality. Most of human history has been blighted by poor survival rates among children, and that continues in various countries today.” https://www.bbc.com/future/article/20181002-how-long-did-ancient-people-live-life-span-versus-longevity https://www.bbc.com/future/article/20181002-how-long-did-anc... Adjust for infant mortality, war, etc., humans are still humans.
      - deleted 4y ago
        [deleted]
- throwaway202022 4y ago
  Our human ancestors were not nocturnal. Sleep patterns were probably different, sure, but they went out during the day to gather and hunt for food.
- bgandrew 4y ago
  Because it's obvious to anybody. It's also obvious that modern humans are far less exposed to UV than our ancestors, who pretty much lived like current days hobos spending most of their time on fresh air.
- guerrilla 4y ago
  You realize hunter-gatherers exist today, right? They go out during the day and are not mostly nocturnal. They're found all over the world.
  - deleted 4y ago
    [deleted]

nostromo 4y ago

And white people that live in California or Florida should note that our complexion evolved in latitudes similar to Canada.

robocat 4y ago
And if you are in the equivalent Southern latitude to Canada (e.g. New Zealand), you still sometimes need sunscreen to avoid the extra UV due to the ozone hole. Perhaps not as bad as it was, but cannot be ignored, although it is variable: https://www.rnz.co.nz/national/programmes/ourchangingworld/audio/2018774144/ozone-holes-and-uv-radiation https://www.rnz.co.nz/national/programmes/ourchangingworld/a...
- flog 4y ago
  The NZ sun is terrible. You feel the sun burning you as soon as you get outside. Burn time can be about 10 minutes on a sunny day, and maybe 20 on a cloudy day in summer. In NZ we get about 4000 in-situ melanoma diagnosis a year. I was one of them a couple of years ago (at 37). Wear sunscreen!
- incompatible 4y ago
  Perhaps if we are talking about the South Island of New Zealand and the southern tip of Canada (Toronto). Most of Canada would be closer to the pole.
  - robocat 4y ago
    Yeah, good point. NZ has similar latitudes down here as the USA has up there. Weather is very different since we don’t get continental effects. Also NZ wasn’t really affected by ozone depletion, but the effects are definitely in our neighbourhood and we were worried. “While the ozone hole does not directly affect ozone concentrations over New Zealand, when it breaks up in spring it can send ‘plumes’ of ozone-depleted air towards us. This briefly decreases column ozone levels by around 5 percent, about the same amount as normal daily variation.”. Also see graph at https://niwa.co.nz/our-services/online-services/uv-ozone https://niwa.co.nz/our-services/online-services/uv-ozone and notice ozone is lowest in NZ summer. Also measuring a column of ozone is most relevant in the tropics when the sun can be directly above one at noon, and less relevant when the sun doesn’t get so high above the horizon (location further towards poles, and winter versus summer). https://pubmed.ncbi.nlm.nih.gov/9671831/ https://pubmed.ncbi.nlm.nih.gov/9671831/

cfn 4y ago

Sunscreen, as we know it, is barely 100 years old (see https://pubmed.ncbi.nlm.nih.gov/33583116/ https://pubmed.ncbi.nlm.nih.gov/33583116/) and we have a lot of information up to that point. We can also deduce from many sources that humanity did not just "managed to reproduce before keeling over".