4 ms·

The article is saying "cool it and dim it" but I think they mean to say "warm it and dim it". They suggest the temperature should not be above 3000 kelvin.

jwuphysics 10y ago
That is because redder colors correspond to a cooler or lower color temperature. Colloquially, we think of blues as cool and reds as warm, but blue light is actually more energetic (or "hot") than red light.
- deleted 10y ago
  [deleted]
- p1mrx 10y ago
  Probably because fire is red-orange, and snow is most often seen reflecting sunlight.
ridgeguy 10y ago
Yes. It's the blue component (large with high color temperature lights) that is thought to most strongly affect human melatonin secretion and sleep. Here's one of many studies that indicate this: http://www.ncbi.nlm.nih.gov/pubmed/8979406 http://www.ncbi.nlm.nih.gov/pubmed/8979406
- stephengillie 10y ago
  Studies involving 5 subjects are not capable of being rigorous. Considering this with equal weight as LHC discoveries is harmful. Please stop.
  - ridgeguy 10y ago
    At posting, I didn't have time to provide more references. You'll see I've given three more references below. Sources include Acta Physiologica, SPIE, and Neuroscience Letters. They discuss different effects of illumination color temperature in human systems. I posted the initial reference as an entry point to follow literature on potential effects of illumination color temperature on human sleep, or perhaps circadian rhythms, through action on a hormone known to be critically involved in sleep. I didn't suggest it was the end of the story. My post was on topic and it contributed to the discussion. Would be glad to review data you think interesting. http://onlinelibrary.wiley.com/doi/10.1111/apha.12552/abstract;jsessionid=989DF70382D816B5118B4D8BE9921614.f03t03?userIsAuthenticated=false&deniedAccessCustomisedMessage= http://onlinelibrary.wiley.com/doi/10.1111/apha.12552/abstra... http://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=1660969 http://proceedings.spiedigitallibrary.org/proceeding.aspx?ar... http://www.sciencedirect.com/science/article/pii/S0304394008006757 http://www.sciencedirect.com/science/article/pii/S0304394008...
    - stephengillie 10y ago
      The first article isn't valid as it's paywalled and the abstract doesn't mention any studies; it could be someone's well-educated opinion. The second article covers how bright light can be without being painful, and doesn't mention sleep or melatonin. Or at least the abstract does, again the article is paywalled, but at least it involves 500 participants. The third study only covers 12 participants. I'll grant there may be thousands of these studies, each with a handful of subjects. Is there some statistical way to stitch the results together in any meaningful fashion - or would that just result in a low p-value?

jwuphysics 10y ago

That is because redder colors correspond to a cooler or lower color temperature. Colloquially, we think of blues as cool and reds as warm, but blue light is actually more energetic (or "hot") than red light.

deleted 10y ago
[deleted]
p1mrx 10y ago
Probably because fire is red-orange, and snow is most often seen reflecting sunlight.

ridgeguy 10y ago

Yes. It's the blue component (large with high color temperature lights) that is thought to most strongly affect human melatonin secretion and sleep. Here's one of many studies that indicate this: http://www.ncbi.nlm.nih.gov/pubmed/8979406 http://www.ncbi.nlm.nih.gov/pubmed/8979406

stephengillie 10y ago
Studies involving 5 subjects are not capable of being rigorous. Considering this with equal weight as LHC discoveries is harmful. Please stop.
- ridgeguy 10y ago
  At posting, I didn't have time to provide more references. You'll see I've given three more references below. Sources include Acta Physiologica, SPIE, and Neuroscience Letters. They discuss different effects of illumination color temperature in human systems. I posted the initial reference as an entry point to follow literature on potential effects of illumination color temperature on human sleep, or perhaps circadian rhythms, through action on a hormone known to be critically involved in sleep. I didn't suggest it was the end of the story. My post was on topic and it contributed to the discussion. Would be glad to review data you think interesting. http://onlinelibrary.wiley.com/doi/10.1111/apha.12552/abstract;jsessionid=989DF70382D816B5118B4D8BE9921614.f03t03?userIsAuthenticated=false&deniedAccessCustomisedMessage= http://onlinelibrary.wiley.com/doi/10.1111/apha.12552/abstra... http://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=1660969 http://proceedings.spiedigitallibrary.org/proceeding.aspx?ar... http://www.sciencedirect.com/science/article/pii/S0304394008006757 http://www.sciencedirect.com/science/article/pii/S0304394008...
  - stephengillie 10y ago
    The first article isn't valid as it's paywalled and the abstract doesn't mention any studies; it could be someone's well-educated opinion. The second article covers how bright light can be without being painful, and doesn't mention sleep or melatonin. Or at least the abstract does, again the article is paywalled, but at least it involves 500 participants. The third study only covers 12 participants. I'll grant there may be thousands of these studies, each with a handful of subjects. Is there some statistical way to stitch the results together in any meaningful fashion - or would that just result in a low p-value?