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uhoh
uhoh
01:19
12
Q: Are two colors (red + blue) necessary for LED grow lights, or would either color be sufficient?

uhohBelow are some chlorophyll absorption spectra from other answers here. There is strong absorption at both the blue/violet end, and the red end of the spectrum, and presumably both of these contribute to steps in water splitting used in photosynthesis. Do the two broad but widely-separated peaks ...

botany plant-physiology photosynthesis light
Considering the lower gravity cues on Mars, tweaking red/blue ratio may be helpful.
7
Q: Have there been at least continuous periods of plants growing on the ISS?

uhohI know there have been some experiments in hydroponics that are addressing issues related to growing significant quantities of food and even fresh vegetables in space in the future. I was wondering; Have there been at least continuous periods of plants growing on the ISS? For example, the title...

food plants
"Grow lights" on the ISS.
@kimholder if you think having ones internet activity is tracked is alien to you, then you are already on the Moon; Big brother has been watching us on earth for a long time now.
user image
My concern in that case was for others, not myself. It's a big planet, there are about 200 countries and 200 governments and most of them have access to Stack Exchange. I was concerned that linking to a site about Marijuanas without putting something that let people know where the link went might cause trouble to someone.
People frequently add messages like "huge PDF" as warnings. Some countries have the death penalty for drugs, so my concern was the unexpected destination.
kim holder
kim holder
01:42
@uhoh sure, but for me there are no consequences.
the point was well taken, though
actually, i wonder if anyone tracks what i do, here in mexico.
you know - besides google. :]
(i'm almost never on facebook)
 
10 hours later…
uhoh
uhoh
11:48
I see what happened. When you talked about "natural lighting" in the "Chalets" I assumed these were vacation spots for people, and so "natural lighting" would need to be full spectrum.
But now I'm wondering if the "Chalets" are primarily for plants, in which case I would understand why @MolbOrg reacted strangely to my factor of 2 or more LED heat over sunlight.
I was only talking about full spectrum lighting for happy people.
If you read this comment you'll see I understand that if you convert Sunlight to electricity then back to red/blue with LEDs, things are much better.
Actual light-piped Sunlight is great for people, but for plans, give 'em LEDs.
uhoh
uhoh
12:05
"LEDs allow you to shift and concentrate wavelengths. Photosynthesis does not use the wavelengths where sunlight is the strongest. i.stack.imgur.com/oi8Yk.png It pretty much only uses red and blue."
"PV/LED allows you to collect the intensity in the broad range in the middle of the visible spectrum and shift it into narrow peaks where chlorophyl can actually use it. See this question. It also allows you to shift in time to optimize use patterns, and shift in space by concentrating light dynamically on the plants vs the space between. "
 
1 hour later…
Feeds
Feeds
13:16
0
Q: Were the Apollo lunar transmitter signals ever analyzed or used after the experiments were shut down?

uhoh This answer to the question Why were the “perfectly functioning” seismometers placed by Apollo 12, 14, 15 and 16 astronauts all shut off in 1977? links to a NASA News Release No: 77-47 dated September 12, 1977. It says: Lunar Science Stations to Cease Functioning September 30 On Septem...

orbital-mechanics the-moon apollo-program history

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