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Meaningness's profile
David Chapman
David Chapman
David Chapman
@Meaningness

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David Chapman

@Meaningness

Better ways of thinking, feeling, and acting—around problems of meaning and meaninglessness; self and society; ethics, purpose, and value.

meaningness.com/about-my-sites
Joined September 2010

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    1. Sarah Constantin‏ @s_r_constantin 23 Aug 2019
      • Report Tweet

      https://journals.sagepub.com/doi/abs/10.1177/074873049701200205 … very weird: nonhuman primate lives 9-10 seasonal photoperiod cycles (days getting short and then long again) and if you speed up those cycles its lifespan drops 30%. If you slowed down the photoperiod cycle could you *increase* lifespan?!

      4 replies 4 retweets 23 likes
      Show this thread
    2. David Chapman‏ @Meaningness 23 Aug 2019
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      Replying to @s_r_constantin

      As a person with SAD, my theory is that old age is caused by winter :)

      2 replies 0 retweets 6 likes
    3. Michael Chapiro  ☣️‏ @mchapiro 23 Aug 2019
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      Replying to @Meaningness @s_r_constantin

      Re-creating the solar environment with higher fidelity than existing products in a way that is compatible with modern lifestyles/environment is a trillion dollar opportunity if that's correct. Otherwise, it might only be a $10-100b opportunity.

      1 reply 0 retweets 0 likes
    4. David Chapman‏ @Meaningness 23 Aug 2019
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      Replying to @mchapiro @s_r_constantin

      There’s certainly an opening for something better than what I did here:https://meaningness.com/metablog/sad-light-led-lux …

      1 reply 0 retweets 3 likes
    5. Michael Chapiro  ☣️‏ @mchapiro 23 Aug 2019
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      Replying to @Meaningness @s_r_constantin

      Michael Chapiro  ☣️ Retweeted Michael Chapiro  ☣️

      Nice! Much brighter than what I've done. You can probably get an app on your phone to estimate lux. This is only about 2000 lux at eye level, but people in the vicinity still found it unpleasant. Maybe a gradually brightening environment helps adjust.https://mobile.twitter.com/mchapiro/status/1082023050504155137 …

      Michael Chapiro  ☣️ added,

      Michael Chapiro  ☣️ @mchapiro
      Replying to @mchapiro @andy_matuschak
      Here is my current setup with 4k lumens of Soraa 5000k bulbs, which have a good amount of cyan, and high CRI (CRI is a good proxy for spectrum uniformity). They use a violet LED rather than blue (one of my startup advisors invented it), and going further left spans better. pic.twitter.com/zLpbyU0Ddp
      2 replies 0 retweets 0 likes
    6. Michael Chapiro  ☣️‏ @mchapiro 23 Aug 2019
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      Replying to @mchapiro @Meaningness @s_r_constantin

      Michael Chapiro  ☣️ Retweeted Michael Chapiro  ☣️

      I'm also interested in getting the right spectrum, maybe with a peak to match melanopic sensitivity. Almost all white LEDs and SAD lights have a peak around 440 nm and a big dip around 480 nm where sensitivity peaks.https://mobile.twitter.com/mchapiro/status/1139944338773778432 …

      Michael Chapiro  ☣️ added,

      Michael Chapiro  ☣️ @mchapiro
      Trying out my new 6000 lumen cyan LEDs. 490nm is close to the peak sensitivity region of the melanopic spectrum so perfect for telling my brain it's daytime. You won't find this wavelength in consumer products due to slightly lower efficiency. pic.twitter.com/ygPBh55t06
      1 reply 0 retweets 1 like
      David Chapman‏ @Meaningness 23 Aug 2019
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      Replying to @mchapiro @s_r_constantin

      Yes ... there’s some people saying this is a big risk for macular degeneration. They don’t seem to have any meaningful evidence for that, but it’s not impossible

      7:49 PM - 23 Aug 2019
      • 1 Like
      • Michael Chapiro ☣️
      1 reply 0 retweets 1 like
        1. Michael Chapiro  ☣️‏ @mchapiro 13 Sep 2019
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          Replying to @Meaningness @s_r_constantin

          Would you DM me? I'd be interested in chatting more about what you would value in a product like this since I think I might go forward with it.

          0 replies 0 retweets 0 likes
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