Has the experiment of growing plants under the light conditions of the
Moon surface ever been done? What would happen if you tried to grow
normal plants with lights on for 14 days and off for 14 days?


--
__Pascal Bourguignon__ http://www.informatimago.com/

Our enemies are innovative and resourceful, and so are we. They never
stop thinking about new ways to harm our country and our people, and
neither do we.

Its probably an experiment that has been done in many high schools around
the world.

How about growing a fungus on Uranus instead?

BTW, what is your idea of a "normal" plant?


"Pascal Bourguignon" wrote in message
...

Has the experiment of growing plants under the light conditions of the
Moon surface ever been done? What would happen if you tried to grow
normal plants with lights on for 14 days and off for 14 days?


--
__Pascal Bourguignon__ http://www.informatimago.com/

Our enemies are innovative and resourceful, and so are we. They never
stop thinking about new ways to harm our country and our people, and
neither do we.

Why doesn't someone moderate this post??



"Cereus-validus" wrote in message
om...
Its probably an experiment that has been done in many high schools around
the world.

How about growing a fungus on Uranus instead?

BTW, what is your idea of a "normal" plant?


"Pascal Bourguignon" wrote in message
...

Has the experiment of growing plants under the light conditions of the
Moon surface ever been done? What would happen if you tried to grow
normal plants with lights on for 14 days and off for 14 days?


--
__Pascal Bourguignon__ http://www.informatimago.com/

Our enemies are innovative and resourceful, and so are we. They never
stop thinking about new ways to harm our country and our people, and
neither do we.

"Cereus-validus" writes:
"Pascal Bourguignon" wrote in message
...

Has the experiment of growing plants under the light conditions of the
Moon surface ever been done? What would happen if you tried to grow
normal plants with lights on for 14 days and off for 14 days?

Its probably an experiment that has been done in many high schools around
the world.

So, what are the results?

How about growing a fungus on Uranus instead?

BTW, what is your idea of a "normal" plant?

Any plant you could find in your garden, like tomatoes, beans, etc.

--
__Pascal Bourguignon__ http://www.informatimago.com/

Our enemies are innovative and resourceful, and so are we. They never
stop thinking about new ways to harm our country and our people, and
neither do we.

On the moon, it is either always sunny or always in the dark, not 14
hours on and 14 hours off.


On 02 Sep 2004 08:58:54 +0200, Pascal Bourguignon
wrote:

"Cereus-validus" writes:
"Pascal Bourguignon" wrote in message
...

Has the experiment of growing plants under the light conditions of the
Moon surface ever been done? What would happen if you tried to grow
normal plants with lights on for 14 days and off for 14 days?

Its probably an experiment that has been done in many high schools around
the world.

So, what are the results?

How about growing a fungus on Uranus instead?

BTW, what is your idea of a "normal" plant?

Any plant you could find in your garden, like tomatoes, beans, etc.

On Thu, 02 Sep 2004 09:04:51 GMT, Elie Gendloff
wrote:

On the moon, it is either always sunny or always in the dark, not 14
hours on and 14 hours off.



\Maybe that's why he said 14 days, not 14 hours. suppose?



On 02 Sep 2004 08:58:54 +0200, Pascal Bourguignon
wrote:

"Cereus-validus" writes:
"Pascal Bourguignon" wrote in message
...

Has the experiment of growing plants under the light conditions of the
Moon surface ever been done? What would happen if you tried to grow
normal plants with lights on for 14 days and off for 14 days?

Its probably an experiment that has been done in many high schools around
the world.

So, what are the results?

How about growing a fungus on Uranus instead?

BTW, what is your idea of a "normal" plant?

Any plant you could find in your garden, like tomatoes, beans, etc.

--

- Charles
-
-does not play well with others

Elie Gendloff wrote in message . ..
On the moon, it is either always sunny or always in the dark, not 14
hours on and 14 hours off.

No, check any adequate reference work for "lunar day". Unless you're
situated on the terminator, it's approximately 14 days 18 hours light,
14 days 18 hours dark.

--
Chris Green

Elie Gendloff wrote:

On the moon, it is either always sunny or always in the dark,

Explain lunar phases.

not 14
hours on and 14 hours off.

Earth days, not hours.

One side of the moon is always sunny and one side is always dark. The
moon turns on its axis once for each rotation of the earth, so only
one side is always facing the sun. When it is appoximately between
the earth and the sun, that is a new moon (not visible) because we are
looking at the unilluminated side of the moon. When the earth is
approximately between the sun and the moon we see a full moon because
we are looking at the entire illuminated side of the moon.


On Fri, 03 Sep 2004 17:17:32 -0700, Father Haskell
wrote:

Elie Gendloff wrote:

On the moon, it is either always sunny or always in the dark,

Explain lunar phases.

not 14
hours on and 14 hours off.

Earth days, not hours.

So, what are the results? BRBR

Why don't you try it yourself? I think you would find it very enlightening.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)

Pascal Bourguignon schreef
Has the experiment of growing plants under the light conditions of the
Moon surface ever been done? What would happen if you tried to grow
normal plants with lights on for 14 days and off for 14 days?

* * *
This will depend on exact circumstances, but put like that plants will grow
as much in a day no matter how long it lasts (24 hours or a month)

In article ,
P van Rijckevorsel wrote:
Pascal Bourguignon schreef
Has the experiment of growing plants under the light conditions of the
Moon surface ever been done? What would happen if you tried to grow
normal plants with lights on for 14 days and off for 14 days?

* * *
This will depend on exact circumstances, but put like that plants will grow
as much in a day no matter how long it lasts (24 hours or a month)

Surely they'll grow more in 14 days of constant light than in 12-24
hours of same, but the 14 days of darkness will be very harmful for
most plants at growing temperatures. Prolonged darkness causes
etiolation and yellowing in all growing plants. If I leave
something on the lawn, the grass underneath takes only a few days to
look unhealthy, and two weeks would kill most of it, except, of course,
in winter when the plants are dormant. You can kill most weeds, or set
them way back, by use of light blocking mulches.

Constant light can be helpful when plants are in a vegetative state,
but if you do or don't want flowering, you have to control night
length. For example, short nights (long days) will make lettuce and
most brassicas (cabbage family vegetables) go to seed instead of
producing leaves, which is undesirable. Many ornamentals (and
fall-flowering weeds) need long nights (short days) to stimulate
flowering. I don't know which vegetables are in this group because
most of my experience is with a cold temperate climate. I do know that
beans (Phaseolus) had their short-day-flowering requirement bred out of
them as agriculture moved north from Mexico to southern Canada in
pre-Columbian times. Day length requirements could probably be bred
out of a crop, possibly very quickly by genetic engineering techniques
once the relevant genes are idenitified, but you aren't going to have
as easy a time getting around the fact that most plants will use up
their reserves and begin to die well before they've survived 14 days of
darkness.

Considering the difficulties of building a transparent structure that
is strong enough to resist vacuum and meteorites on the moon, I think
it would be much more practical to have surface solar collectors to
generate electricity to power lights to grow plants. Obviously, you'd
need some method of energy storage for the lunar nights, but growing
crops under artificial lighting is a solved problem. For example,
vegetables have been grown in deep mines in northern Ontario, taking
advantage of the natural heat at depth and the cost of supplying
vegetables in reasonable condition to remote areas with too short a
season and too little heat to grow them on the surface profitably.
IIRC, these projects mostly produce tomatoes and cucumbers, but there's
a lot of developed technology for growing lettuce in surface
greenhouses with supplemental lighting in winter at higher latitudes in
Europe where less supplemental heating is needed in such structures
than in Canada.

Note that your lunar garden provides the valuable function of removing
CO2 from the air as well. Many plants grow better in elevated levels
of CO2, and it's sometimes used commercially to increase growth in
greenhouse lettuce crops, usually by burning propane.

Btw, you might consider how else this lunar colony is getting its
energy. Is it all solar, or is some derived from e.g. a nuclear
reactor? In the latter case, there may well be plenty of energy
available to power lighting for plants.

writes:

In article ,
P van Rijckevorsel wrote:
Pascal Bourguignon schreef
Has the experiment of growing plants under the light conditions of the
Moon surface ever been done? What would happen if you tried to grow
normal plants with lights on for 14 days and off for 14 days?

* * *
This will depend on exact circumstances, but put like that plants will grow
as much in a day no matter how long it lasts (24 hours or a month)

Surely they'll grow more in 14 days of constant light than in 12-24
hours of same, but the 14 days of darkness will be very harmful for
most plants at growing temperatures. Prolonged darkness causes
etiolation and yellowing in all growing plants. If I leave
something on the lawn, the grass underneath takes only a few days to
look unhealthy, and two weeks would kill most of it, except, of course,
in winter when the plants are dormant. You can kill most weeds, or set
them way back, by use of light blocking mulches.

Constant light can be helpful when plants are in a vegetative state,
but if you do or don't want flowering, you have to control night
length. For example, short nights (long days) will make lettuce and
most brassicas (cabbage family vegetables) go to seed instead of
producing leaves, which is undesirable. Many ornamentals (and
fall-flowering weeds) need long nights (short days) to stimulate
flowering. I don't know which vegetables are in this group because
most of my experience is with a cold temperate climate. I do know that
beans (Phaseolus) had their short-day-flowering requirement bred out of
them as agriculture moved north from Mexico to southern Canada in
pre-Columbian times. Day length requirements could probably be bred
out of a crop, possibly very quickly by genetic engineering techniques
once the relevant genes are idenitified, but you aren't going to have
as easy a time getting around the fact that most plants will use up
their reserves and begin to die well before they've survived 14 days of
darkness.

Considering the difficulties of building a transparent structure that
is strong enough to resist vacuum and meteorites on the moon, I think
it would be much more practical to have surface solar collectors to
generate electricity to power lights to grow plants. Obviously, you'd
need some method of energy storage for the lunar nights, but growing
crops under artificial lighting is a solved problem. For example,
vegetables have been grown in deep mines in northern Ontario, taking
advantage of the natural heat at depth and the cost of supplying
vegetables in reasonable condition to remote areas with too short a
season and too little heat to grow them on the surface profitably.
IIRC, these projects mostly produce tomatoes and cucumbers, but there's
a lot of developed technology for growing lettuce in surface
greenhouses with supplemental lighting in winter at higher latitudes in
Europe where less supplemental heating is needed in such structures
than in Canada.

Note that your lunar garden provides the valuable function of removing
CO2 from the air as well. Many plants grow better in elevated levels
of CO2, and it's sometimes used commercially to increase growth in
greenhouse lettuce crops, usually by burning propane.

Btw, you might consider how else this lunar colony is getting its
energy. Is it all solar, or is some derived from e.g. a nuclear
reactor? In the latter case, there may well be plenty of energy
available to power lighting for plants.

Thank you for your comprehensive answer.

Indeed, if there's nuclear energy available, it would be simplier to
use artificial light. But storing solar energy is hard and not too
efficient (you need a lot of heavy batteries, or complex
electro-chemical processing), so if natural light can be used at least
half of the time, the better.

--
__Pascal Bourguignon__ http://www.informatimago.com/

Our enemies are innovative and resourceful, and so are we. They never
stop thinking about new ways to harm our country and our people, and
neither do we.

In article ,
Pascal Bourguignon wrote:
Thank you for your comprehensive answer.

You're welcome. I had fun thinking about it.

Indeed, if there's nuclear energy available, it would be simplier to
use artificial light. But storing solar energy is hard and not too
efficient (you need a lot of heavy batteries, or complex
electro-chemical processing), so if natural light can be used at least
half of the time, the better.

If you want to think about this like an engineer, you have to consider
all factors. You may find that building vacuum and meteorite proof
transparent surface structures that require supplemental lighting for
half the month is much more difficult, expensive and unreliable than
having sturdier structures that are artificially lit the whole month
through. After all, if you have to have the spare generating capacity
to provide lighting for half the month (at least - the sun isn't always
high enough in the sky to provide adequate light) you've got it for the
other half as well.

In my example of hydroponic vegetable production in deep mines in
northern Ontario, you have an example of a situation where it's much
cheaper to light a naturally heated (cost-free) area than to heat a
naturally illuminated area on the surface. What's more, it costs to
build a greenhouse, but worked out areas of the mine are already
there. Transportation to the area is time-consuming and expensive
enough that fresh vegetables arrive in poor condition especially in
winter, so it's competitive to raise them locally with free heat even
though electricity for lighting is not very cheap. It's much easier
and cheaper to control environmental factors in the mine than on the
surface, e.g. temperature, day length, light intensity, etc., because
the background environment is constant. (IIRC, the crops are grown at
a depth corresponding to 30C - about 1km underground - while surface
temperatures often go below -40C.)

Conditions on the lunar surface vary drastically from intense heat to
bitter cold over the lunar day/night cycle of 29+ days. You can't
readily dissipate heat by better ventilation as you can in a
terrestrial greenhouse, and shading kind of defeats the purpose. You
don't get conductive or convective cooling of the structure either, and
you'll either have to have movable insulation or expend a lot of energy
to keep your plants from freezing in the lunar night, when your
structure is radiating to unobstructed sky at 3K. At any rate, you'll
need a lot more technology to keep your plants alive in such a
structure than you would in one that has a more constant background.
You'll need heating, cooling, variable amounts of light, protection
from small meteorite strikes, as well as vacuum resistance, not so easy
in a transparent material. When spare parts are fantastically
expensive and may take weeks to obtain even in an emergency, you want
the simplest technology feasible, because it's likely to be the most
robust and easiest to repair. When your air supply depends on your
greenhouse, you don't want to worry about it catastrophically failing
when it gets hit by a pebble, or a bit of caulking cracks.

Overall, you're much further ahead in an underground structure or one
protected from drastic thermal variation and mechanical damage from
small meteorites by a thick layer of regosol, even if you have to light
it. You'll probably be living in exactly the same kind of structure
already, so you'll know how to build and maintain one.

You can generate some of the energy needed for lighting with solar
panels on the surface, but they are only useful for part of the month,
and you'll need another source of energy for the rest of the month.
Your colony is going to need energy for other purposes than growing
plants, so you've got to deal with the problem of intermittent
availability of solar energy anyway.

At any rate, I had fun speculating about all this. Are you planning to
write some science fiction against this background, Pascal? If so,
remember that good writing can carry the reader blindly past a lot of
leaps of faith in science and technology. If you want to correspond
with me by email, take the no-uce and yyz out of my address.

Excuse me, but only one side of the moon always faces the sun. See:
http://www.astro.umd.edu/education/a...on/phases.html
But that would be good for growing plants because they could
photosynthesize constantly. Solar collectors would also be very
efficient on the moon - no clouds, constant radiation.




On 3 Sep 2004 17:22:49 GMT, wrote:

In article ,
Pascal Bourguignon wrote:
Thank you for your comprehensive answer.

You're welcome. I had fun thinking about it.

Indeed, if there's nuclear energy available, it would be simplier to
use artificial light. But storing solar energy is hard and not too
efficient (you need a lot of heavy batteries, or complex
electro-chemical processing), so if natural light can be used at least
half of the time, the better.

If you want to think about this like an engineer, you have to consider
all factors. You may find that building vacuum and meteorite proof
transparent surface structures that require supplemental lighting for
half the month is much more difficult, expensive and unreliable than
having sturdier structures that are artificially lit the whole month
through. After all, if you have to have the spare generating capacity
to provide lighting for half the month (at least - the sun isn't always
high enough in the sky to provide adequate light) you've got it for the
other half as well.

In my example of hydroponic vegetable production in deep mines in
northern Ontario, you have an example of a situation where it's much
cheaper to light a naturally heated (cost-free) area than to heat a
naturally illuminated area on the surface. What's more, it costs to
build a greenhouse, but worked out areas of the mine are already
there. Transportation to the area is time-consuming and expensive
enough that fresh vegetables arrive in poor condition especially in
winter, so it's competitive to raise them locally with free heat even
though electricity for lighting is not very cheap. It's much easier
and cheaper to control environmental factors in the mine than on the
surface, e.g. temperature, day length, light intensity, etc., because
the background environment is constant. (IIRC, the crops are grown at
a depth corresponding to 30C - about 1km underground - while surface
temperatures often go below -40C.)

Conditions on the lunar surface vary drastically from intense heat to
bitter cold over the lunar day/night cycle of 29+ days. You can't
readily dissipate heat by better ventilation as you can in a
terrestrial greenhouse, and shading kind of defeats the purpose. You
don't get conductive or convective cooling of the structure either, and
you'll either have to have movable insulation or expend a lot of energy
to keep your plants from freezing in the lunar night, when your
structure is radiating to unobstructed sky at 3K. At any rate, you'll
need a lot more technology to keep your plants alive in such a
structure than you would in one that has a more constant background.
You'll need heating, cooling, variable amounts of light, protection
from small meteorite strikes, as well as vacuum resistance, not so easy
in a transparent material. When spare parts are fantastically
expensive and may take weeks to obtain even in an emergency, you want
the simplest technology feasible, because it's likely to be the most
robust and easiest to repair. When your air supply depends on your
greenhouse, you don't want to worry about it catastrophically failing
when it gets hit by a pebble, or a bit of caulking cracks.

Overall, you're much further ahead in an underground structure or one
protected from drastic thermal variation and mechanical damage from
small meteorites by a thick layer of regosol, even if you have to light
it. You'll probably be living in exactly the same kind of structure
already, so you'll know how to build and maintain one.

You can generate some of the energy needed for lighting with solar
panels on the surface, but they are only useful for part of the month,
and you'll need another source of energy for the rest of the month.
Your colony is going to need energy for other purposes than growing
plants, so you've got to deal with the problem of intermittent
availability of solar energy anyway.

At any rate, I had fun speculating about all this. Are you planning to
write some science fiction against this background, Pascal? If so,
remember that good writing can carry the reader blindly past a lot of
leaps of faith in science and technology. If you want to correspond
with me by email, take the no-uce and yyz out of my address.