Poll Would you like a night Sun?

[Andy44]

If you can do "Sunlight on a small area," as you proposed below for sporting events, you have the potential to weaponize fairly easily (such as by turning multiple mirrors on the same spot). It might not be "blam" style weaponization, but a few days of 120 F (call it 50 C) in a row, without any cooloff during the night, should be pretty damaging.

Indeed. Seems this was thought of a long time ago:

http://en.wikipedia.org/wiki/Archimedes#The_Archimedes_Heat_Ray_.E2.80.93_myth_or_reality.3F

MythBusters pretty much showed it wasn't practicle with the materials of the day, but we know this works in theory, of course.

 

[ex-orbinaut]

Indeed. Seems this was thought of a long time ago:

More than that I think it has already been attempted(?) by the USSR back in the early/mid 1980's, to shed some light on Siberia. I remember Patrick Moore on the "Night Sky" saying something about not being surprised by a bright body never seen before...

Let me see if I can find something...

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Still looking, there's this...

http://articles.baltimoresun.com/1998-11-01/news/1998305052_1_space-mirror-moon-mir-space

...so far...

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Hmm, I am younger than I think. It was not so long ago (1992). It is in here....

http://en.wikipedia.org/wiki/Solar_mirror

I remember Patrick Moore making a humorous quip about "what's next, Coca Cola adverts in orbit?"

 

[Shadow Addict]

There was also an Apollo Applications Program proposal that would've had a modified LM with a mirror attached pointed at the jungles of Vietnam to illuminate them at night.

 

[T.Neo]

If you can do "Sunlight on a small area," as you proposed below for sporting events, you have the potential to weaponize fairly easily (such as by turning multiple mirrors on the same spot). It might not be "blam" style weaponization, but a few days of 120 F (call it 50 C) in a row, without any cooloff during the night, should be pretty damaging.

Well, I'd imagine you could build in a mechanical limit to the "focusing" system of the mirror to prevent dangerous levels of concentration from being reached.

In the end though, the only thing preventing you from waging war in space is international law. We should certainly hope it's effective enough, since we have missles capable of launching warheads into at least a low orbit, and by far in the range of destroying satellites via EMP and ionising radiation.

 

[Sky Captain]

I`m wondering what is the most suitable orbit for this task? Obviously geosynchronous orbit would be the best however beam spreading would be very large because of distance and making parabolic mirrors to concentrate light would work only to certain degree because sunlight is not laser light. I`m guessing the spot size on Earth from several hundred meter mirror in geosync orbit would be dozens of km in diameter.

Putting mirrors in lower orbit would reduce beam spreading but the downside is there must be multiple mirrors to achieve continuous illumination on target area. Also as the mirrors orbit the Earth and change their height above horizon the light spot would continuously change it`s size leading to all sorts of funny effects.

 

[computerex]

Turns out that both continious sunlight and increased concentrations of CO2 cause injury to plants.

Some plants only open their stomata at night because opening them up in the hot sun results in a lost of moisture. There is no such thing as too much CO2 as far as photosynthesis is concerned. In fact rubisco's inability to efficiently distinguish between oxygen and carbon dioxide is attributed to a time period when carbon dioxide was found in a much larger quantity.

 

[lennartsmit]

I already have a nightime sun (a bit weak but still)
The greenhouses west of Rotterdam (the Netherlands) cause the sky in the centre of Rotterdam, 30 km away, to light up with a yellow\orange-ish glow.
If you search ''westland'' on google maps you'll see them.

Also now were on greenhouses,the atmosphere in them is enriched with CO2 from the powerplant here.

 

[Linguofreak]

Well, I'd imagine you could build in a mechanical limit to the "focusing" system of the mirror to prevent dangerous levels of concentration from being reached.

Yeah, and that could prevent "ant frying" style weaponisation, but if you can reach "Sunlight" levels with one mirror, you can reach "it's getting uncomfortably hot" levels with two. Add as many mirrors as you wish.

Also, as the mirror orbits the Earth, its distance from the place it's illuminating will change. So it will need to adjust focus and brightness. "Sunlight" when the mirror is on the horizon might be "weapons grade" when it's overhead.

 

[T.Neo]

if you can reach "Sunlight" levels with one mirror, you can reach "it's getting uncomfortably hot" levels with two. Add as many mirrors as you wish.

Hence the weaponisation-prevention treaties.

Also, as the mirror orbits the Earth, its distance from the place it's illuminating will change.

No, since the mirrors are placed in GEO.

Mirrors would be placed at the same longitude as the target destination to reduce atmospheric losses, so the only way of turning them into "weapons grade" devices would be to point a mirror intended for a high-latitude location at an equatorial (or near equatorial) target.

 

[Sky Captain]

I doubt it would be possible to easily reach weapons grade levels of light intensity, even reaching normal sunlight power might be difficult and require dozens if not hundreds of mirrors pointed at the same place because of beam spreading issues especially if the mirrors are located in geosync orbit.
If it`s possible to somehow manage beam spreading issue and reach several times sunlight intensity then the best application would be large scale reliable 24/7 solar power generation. Build a giant solar panel farm in location that have lowest probability of cloud cover, aim as much mirrors as possible at it and you have a reliable nonpolluting large scale energy source.

 

[T.Neo]

If it`s possible to somehow manage beam spreading issue and reach several times sunlight intensity then the best application would be large scale reliable 24/7 solar power generation. Build a giant solar panel farm in location that have lowest probability of cloud cover, aim as much mirrors as possible at it and you have a reliable nonpolluting large scale energy source.

Better yet, collect the energy in-situ and beam it to Earth more efficiently (via microwaves).

 

[Donamy]

How about a nuclear candle in space ?

 

[T.Neo]

How about a nuclear candle in space ?

Because we already have one.

 

[Dig Gil]

One problem of having morning all the time is that hunting become difficult... umm maybe easier, since animals will not sleep. Not sure: it will depend on what you are hunting down.
Being dark helps the use of camouflage.

By the way, there was a story of an alien civilization that lived in a binary star system. Can't remember, what, where neither who wrote that book, but the matter is that in the story, only after a million years, the citizens experienced night time and that was a very terrifing event!

 

[Urwumpe]

What would you say?

It is already impossible to see the real beauty of the night sky in Berlin, and even more impossible in Wolfsburg (which has a Megacandela Volkswagen ad there).

Also you can't sleep as good when it is bright as you do when it is really dark.

Also I doubt that a brighter city from an artificial sun will have less crime during the night hours. Darkness is not required for crimes, what you rather need is a preferable ratio between criminals, victims and cops. Which you have during the night hours...or in dormitory cities during the working hours.

And the street lights should be disabled in the dark night (like it often already is because of energy costs), and the high beam banned and replaced by a constant 80 km/h speed limit during night... Then night-vision people like me wouldn't be blinded by night-blind people who need to high beam all the time for seeing the road at all...yes, that is egoist, but I think night-blindness should be a reason to be prevented from getting the drivers license, just like you can't get it if you are color-blind.

 

[T.Neo]

but I think night-blindness should be a reason to be prevented from getting the drivers license, just like you can't get it if you are color-blind.

Yeah, and far fewer people will be allowed to drive, and they will dislike it and vote you out of power.

If idiots blind you with their high-beam, suck it up and get used to it.

Anyway, in South Africa and the US you can still drive if you are colour blind, AFAIK.

 

[Cerebus]

Maybe a nice highschool assumption, but incorrect. So is the assumption that increased CO2 levels lead to better growth of plants.

Turns out that both continious sunlight and increased concentrations of CO2 cause injury to plants.

Photoperiodism is the effect of the relative length of the daily light/dark
period mainly on flowering. Some plants flower only when the daily light period
is above a certain length (long day plants), some when the daily light period is
below a certain length (short day plants), and some flower regardless of the
length of the daily light period (day neutral plants). (David Hershey, Faculty, Botany, NA ).

Therefore a change to the natural diurnal cycle of an area of the earth may result in changes to the indigenous plant population, certain species dying out due to them not receiving their normal 'cues' to flower. This in turn may lead to similar changes to the animal and insect population of that area, we've seen plenty of examples of how Mankind has changed ecosystems, not always for the better, extinctions, explosive population growths, and more subtle effects may follow even the most seemingly trivial changes to the environment.

As far as CO2 enrichment is concerned, mostly it benefits the plant population, I didn't find any studies which showed that a rise in CO2 would be detrimental to plant growth.

Since the use of such a system would likely be in more northern latitudes, the effects on plant growth would be likely to be greater, as there is a larger variation in day length than in equatorial regions.

Anyway I voted No (I wish to sleep in the dark) option, since there was no ( I wish to avert a potential ecological catastrophe )...

 

[T.Neo]

Yeah, we need to be uber-careful, since big cities have such delicate indiginous ecosystems...

 

[Cerebus]

Yeah, we need to be uber-careful, since big cities have such delicate indiginous ecosystems...

Do I sense a smidgeon of sarcasm there?

There are delicate ecosystems even in the largest cities, plant life colonises niches wherever an opportunity presents itself, and where there are plants, there are animals and insects to benefit from them, furthermore healthy competition between plant species for the available resources promotes diversity in the entire ecosystem, removing the long day and short day plants could unbalance this urban ecosystem, and once unbalanced, can anyone predict which animals and insects would benefit, and which suffer? Or what effects this might have on us, perhaps an sudden population growth in the cockroach population might be good for the urban rodent population?

I'm sure that the introduction of rabbits to australia in the 18th century seemed a good idea, and generally benefited the small human population, however, in hindsight perhaps it wasn't such a great idea?

 

[RisingFury]

And the street lights should be disabled in the dark night (like it often already is because of energy costs)

I'd like to see that happen as well, but they're kept on for a good reason...

Power plants can't just be shut off at night and the energy has to go somewhere. Where ever they're shutting off the lights, it's because they probably have a saving mechanism in place - pumping water uphill so it can be released in the morning, or something similar like that.

A good idea would be to have a giant superconducting coil being charged at night for 6 hours and then releasing energy during day. The losses due to cooling would be ~5%, instead of ~80% now.