zlacker

It is perfectly within our reach to simulate a bright daylight sky with the sun behind clouds - around 5k-10k lux - it just requires a fairly large wattage of lighting in a number of indirect fixtures. White metal halide, LEDs, and fluorescents all have efficiencies in the 50-100lumen/watt range, that just means you need to apply around 100 watts per square meter of matte white ceiling you're trying to illuminate. I like the idea of supplementing the white lighting with colored (eg: red, red-orange, green) LEDs, which can be throttled to achieve a particular color temperature.

Ideally your ceiling would be very high for this setup to give space for the light to diffuse from hanging ceiling reflectors, which is unfortunately not the case for most homes. For realistic homes, there is a style of floor lamp termed 'torchiere' that may work, though for best results you're going to want to find one with a large, fully reflective shroud - lights this bright are pretty harsh if they're not diffused well.

Set up something like this on an automatic timer to simulate the sky, and I suspect a lot of our sleep issues would go away fairly quickly.

>>mapt+(OP)
I don't believe you need high ceilings; you can diffuse light just as well over short distances with metamaterials. Look at http://coelux.com/, for example. Ideally, you'd want one of those, brighter, covering your whole ceiling.

>>mapt+(OP)
> Set up something like this on an automatic timer to simulate the sky, and I suspect a lot of our sleep issues would go away fairly quickly.

I had a similar hypothesis, so I built something like what you describe:

https://github.com/wpietri/sunrise

Currently I'm at only 4000 lumens or so in my main space, and I'd like it brighter. But my sleep is definitely better. I attribute it not so much to the daytime light, but to the way my apartment gradually gets dimmer and redder in the evenings.

I had set out to make something like a SAD lamp for my whole apartment. But as a side effect, I also basically made f.lux for my apartment, and I really like it. When evening comes, I generally have to fight to stay awake rather than fighting to go to sleep.