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Posted: 1/2/2012 1:42:20 PM EDT
[Last Edit: 1/2/2012 2:33:50 PM EDT by Pauperis]
How does the color of the substrate at the bottom of a shallow body of water affect the amount of heat the water absorbs from sunlight ?

A friend of mine has an inground pool. He claims that if you want the water to be cold you paint the bottom of the pool black. If you want the water to be warm you paint the bottom white. This seems to me to be backwards. A darker bottom would absorb more heat from the sun and thus warm the water more then a lighter one right ? However he has had this pool for 30 years and has painted it many times so he may be right.

What says the hive ?



editted for spelling twice
Link Posted: 1/2/2012 1:45:11 PM EDT
Your friend doesnt understand physics.
Link Posted: 1/2/2012 1:46:11 PM EDT
Just pee in the pool to warm it up.
Link Posted: 1/2/2012 1:46:56 PM EDT
Your friend is stoopid
Link Posted: 1/2/2012 1:47:23 PM EDT
Paint one half black and the other half white and see which end is warmer.
Link Posted: 1/2/2012 1:49:27 PM EDT
Originally Posted By Harvster:
Paint one half black and the other half white and see which end is warmer.


If you do that, you will have two different densities of the water, which won't combine similar to water and oil.
Link Posted: 1/2/2012 1:49:38 PM EDT
Originally Posted By Harvster:
Paint one half black and the other half white and see which end is warmer.


The end chupacabras peed in
Link Posted: 1/2/2012 1:51:29 PM EDT
Originally Posted By The_Reaper:
Your friend doesnt understand physics.


Link Posted: 1/2/2012 1:56:17 PM EDT
[Last Edit: 1/2/2012 1:57:19 PM EDT by Db8sGr8]
Very interesting question. I don't know your answer. I'm curious about the topic as well.

When I was a kid my Dad decided to paint our house black to save money on heating bills. He was... eccentric. Being the enthusiastic-at-the-start-of-a-project kind of a guy, he only painted half. Or maybe he meant to only paint the east and west sides of the house. Of course he never felt the need to explain his idea to us kids.The end result was the same: A half black, half white house. People used our house to give directions to others in the area for years. ("Okay, you go straight, past the segregated house, then...") Did it save him money on heating bills? He never mentioned whether it did or not.
Link Posted: 1/2/2012 1:57:19 PM EDT
Originally Posted By Db8sGr8:
Very interesting question. I don't know your answer. I'm curious about the topic as well.

When I was a kid my Dad decided to paint our house black to save money on heating bills. Being the enthusiastic at the start of a project kind of a guy, he only painted half. Or maybe he meant to only paint the east and west sides of the house. Of course he never felt the need to explain his idea to us kids.The end result was the same: A half black, half white house. People used our house to give directions to others in the area for years. ("Okay, you go straight, past the segregated house, then...") Did it save him money on heating bills? He never mentioned whether it did or not.

Link Posted: 1/2/2012 1:57:48 PM EDT
Originally Posted By Harvster:
Paint one half black and the other half white and see which end is warmer.


Yes, segregate your pool.
Link Posted: 1/2/2012 1:59:19 PM EDT
he's probably thinking about a reflector for a campfire, and applying the concept laterally––radiant energy would heat the water on the way in, and also on the way out after being reflected from the bottom of the pool. but i'm pretty sure this would be dwarfed by effect of the black WRT heating the pool enclosure, and therefore the water. think albedo.
Link Posted: 1/2/2012 1:59:30 PM EDT
Tell your friend to go back to school and take a basic physics class. Tell him to pay attention when the instructor gets to the parts about light and colors, absorption, reflection, and basic thermodynamics.
Link Posted: 1/2/2012 2:00:16 PM EDT
We have a liner pool.

When we had a new liner installed, we went with a darker liner than we had originally.

We no longer have to use a solar blanket as the water heats up nicely on it's own.
Link Posted: 1/2/2012 2:02:38 PM EDT
Originally Posted By The_Reaper:
Your friend doesnt understand physics.

This. Oh, and your friend is an idiot.
Link Posted: 1/2/2012 2:05:08 PM EDT
Originally Posted By Pauperis:
How does the color of the sustrate at the bottom of a shallow body of water affect the amount of heat the water absorbs from sunlight ?

A friend of mine has an inground pool. He claims that if you want the water to be cold you paint the bottom of the pool black. If you want the water to be warm you paint the bottom white. This seems to me to be backwards. A darker bottom would absorb more heat from the sun and thus warm the water more then a lighter one right ? However he has had this pool for 30 years and has painted it many times so he may be right.

What says the hive ?



editted for spelling

You actually think more than 1% of GD will know what this word means?


Link Posted: 1/2/2012 2:13:49 PM EDT
Originally Posted By sirensong:
he's probably thinking about a reflector for a campfire, and applying the concept laterally––radiant energy would heat the water on the way in, and also on the way out after being reflected from the bottom of the pool. but i'm pretty sure this would be dwarfed by effect of the black WRT heating the pool enclosure, and therefore the water. think albedo.


I was also thinking maybe this made sense.

Also if a darker bottom makes a pool warmer, then why are 99% of pools painted a light color on the bottom ?

Link Posted: 1/2/2012 2:23:35 PM EDT
Look up blackbody heat absorbtion and radiation in a Thermodynamics book and you will find your answer. I will dig mine up and see if I can find you a good answer. A perfectly black body will absorb heat in air, but I am not sure about water.
Link Posted: 1/2/2012 2:30:43 PM EDT
Originally Posted By Pauperis:
Originally Posted By sirensong:
he's probably thinking about a reflector for a campfire, and applying the concept laterally––radiant energy would heat the water on the way in, and also on the way out after being reflected from the bottom of the pool. but i'm pretty sure this would be dwarfed by effect of the black WRT heating the pool enclosure, and therefore the water. think albedo.


I was also thinking maybe this made sense.

Also if a darker bottom makes a pool warmer, then why are 99% of pools painted a light color on the bottom ?



Because most people find it more attractive.
Link Posted: 1/2/2012 2:32:14 PM EDT
Originally Posted By Pond_Scum:
Originally Posted By Pauperis:
How does the color of the sustrate at the bottom of a shallow body of water affect the amount of heat the water absorbs from sunlight ?

A friend of mine has an inground pool. He claims that if you want the water to be cold you paint the bottom of the pool black. If you want the water to be warm you paint the bottom white. This seems to me to be backwards. A darker bottom would absorb more heat from the sun and thus warm the water more then a lighter one right ? However he has had this pool for 30 years and has painted it many times so he may be right.

What says the hive ?



editted for spelling

You actually think more than 1% of GD will know what this word means?




Given that it is not an actual word . . .
Link Posted: 1/2/2012 2:37:54 PM EDT
Originally Posted By Pond_Scum:
Originally Posted By Pauperis:
How does the color of the sustrate at the bottom of a shallow body of water affect the amount of heat the water absorbs from sunlight ?

A friend of mine has an inground pool. He claims that if you want the water to be cold you paint the bottom of the pool black. If you want the water to be warm you paint the bottom white. This seems to me to be backwards. A darker bottom would absorb more heat from the sun and thus warm the water more then a lighter one right ? However he has had this pool for 30 years and has painted it many times so he may be right.

What says the hive ?



editted for spelling

You actually think more than 1% of GD will know what this word means?



Good question.

I know I sure don't know what "sustrate" means.

__________________________________________________________________
Cross-platform gun database/electronic bound book (v1.2) (and the original thread).
«nolite confidere in principibus, in filiis hominum quibus non est salus»
Link Posted: 1/2/2012 2:38:45 PM EDT
[Last Edit: 1/2/2012 2:39:48 PM EDT by AR4U]
Water absorbs poorly in the visible part of the spectrum (which is why it's transparent...) and this accounts for about half of the available solar energy. A black pool bottom will absorb nearly all the energy in the spectrum.

Link Posted: 1/2/2012 2:39:59 PM EDT
Regardless of the heating or cooling, what kind of retard would paint a fucking pool bottom black anyway?
Link Posted: 1/2/2012 2:40:49 PM EDT
Originally Posted By Pauperis:
Originally Posted By sirensong:
he's probably thinking about a reflector for a campfire, and applying the concept laterally––radiant energy would heat the water on the way in, and also on the way out after being reflected from the bottom of the pool. but i'm pretty sure this would be dwarfed by effect of the black WRT heating the pool enclosure, and therefore the water. think albedo.


I was also thinking maybe this made sense.

Also if a darker bottom makes a pool warmer, then why are 99% of pools painted a light color on the bottom ?


To make them look clearer and more inviting.

At least that's what I've always thought.

Who wants to jump into a murky black pool, anyhow?

Also, drowndeded kids are easier to spot in pools that are painted a light color. I think.

__________________________________________________________________
Cross-platform gun database/electronic bound book (v1.2) (and the original thread).
«nolite confidere in principibus, in filiis hominum quibus non est salus»
Link Posted: 1/2/2012 2:41:31 PM EDT
Originally Posted By RDP:
Originally Posted By Harvster:
Paint one half black and the other half white and see which end is warmer.


If you do that, you will have two different densities of the water, which won't combine similar to water and oil.


Might forma thunder storm over his pool.
Link Posted: 1/2/2012 2:41:35 PM EDT
Originally Posted By RDP:
Originally Posted By Harvster:
Paint one half black and the other half white and see which end is warmer.


If you do that, you will have two different densities of the water, which won't combine similar to water and oil.


This is combined excellence.
Link Posted: 1/2/2012 2:42:32 PM EDT
Originally Posted By IchWarrior:
Originally Posted By Db8sGr8:
Very interesting question. I don't know your answer. I'm curious about the topic as well.

When I was a kid my Dad decided to paint our house black to save money on heating bills. Being the enthusiastic at the start of a project kind of a guy, he only painted half. Or maybe he meant to only paint the east and west sides of the house. Of course he never felt the need to explain his idea to us kids.The end result was the same: A half black, half white house. People used our house to give directions to others in the area for years. ("Okay, you go straight, past the segregated house, then...") Did it save him money on heating bills? He never mentioned whether it did or not.



[loll]
Link Posted: 1/2/2012 2:45:20 PM EDT
Originally Posted By Pond_Scum:
Originally Posted By Pauperis:
How does the color of the sustrate at the bottom of a shallow body of water affect the amount of heat the water absorbs from sunlight ?

A friend of mine has an inground pool. He claims that if you want the water to be cold you paint the bottom of the pool black. If you want the water to be warm you paint the bottom white. This seems to me to be backwards. A darker bottom would absorb more heat from the sun and thus warm the water more then a lighter one right ? However he has had this pool for 30 years and has painted it many times so he may be right.

What says the hive ?



editted for spelling

You actually think more than 1% of GD will know what this word means?




Well I think he meant substrate which doesn't make sense either, but hey this is a thread full of fail anyway. Try this OP, the bottom of the pool is painted black. Is English a second language?

Link Posted: 1/2/2012 2:47:09 PM EDT
Originally Posted By MotorMouth:
Originally Posted By Pond_Scum:
Originally Posted By Pauperis:
How does the color of the sustrate at the bottom of a shallow body of water affect the amount of heat the water absorbs from sunlight ?

A friend of mine has an inground pool. He claims that if you want the water to be cold you paint the bottom of the pool black. If you want the water to be warm you paint the bottom white. This seems to me to be backwards. A darker bottom would absorb more heat from the sun and thus warm the water more then a lighter one right ? However he has had this pool for 30 years and has painted it many times so he may be right.

What says the hive ?



editted for spelling

You actually think more than 1% of GD will know what this word means?




Given that it is not an actual word . . .


If you live in Brazil and have a heart problem it's a word...

Propatyl nitrate. May be a little expensive to line the bottom of a pool with....

And being a vasodilator funny things may happen to your guests.
Link Posted: 1/2/2012 2:49:10 PM EDT
While the sun is shining, the pool will heat up with a black bottom.

However, at night a black bottom will radiate back out into space thus cooling the water more than a white bottom.

The ideal situation would be to have a black bottom during the day and an aluminum surface at night.
Link Posted: 1/2/2012 2:50:12 PM EDT
Heat is long wave radiation which is emitted at a higher rate from a dark colored surface than a light relective surface see albedo.

However since water will absorb most of its heat from direct sunlight at the surface the color of the bottom is of little importance.
Link Posted: 1/2/2012 2:51:43 PM EDT
Originally Posted By Db8sGr8:
Very interesting question. I don't know your answer. I'm curious about the topic as well.

When I was a kid my Dad decided to paint our house black to save money on heating bills. He was... eccentric. Being the enthusiastic-at-the-start-of-a-project kind of a guy, he only painted half. Or maybe he meant to only paint the east and west sides of the house. Of course he never felt the need to explain his idea to us kids.The end result was the same: A half black, half white house. People used our house to give directions to others in the area for years. ("Okay, you go straight, past the segregated house, then...") Did it save him money on heating bills? He never mentioned whether it did or not.


I've never met your dad, and yet I feel a deep and abiding respect for the man.
Link Posted: 1/2/2012 3:00:28 PM EDT
Originally Posted By WinstonSmith:
Originally Posted By Db8sGr8:
Very interesting question. I don't know your answer. I'm curious about the topic as well.

When I was a kid my Dad decided to paint our house black to save money on heating bills. He was... eccentric. Being the enthusiastic-at-the-start-of-a-project kind of a guy, he only painted half. Or maybe he meant to only paint the east and west sides of the house. Of course he never felt the need to explain his idea to us kids.The end result was the same: A half black, half white house. People used our house to give directions to others in the area for years. ("Okay, you go straight, past the segregated house, then...") Did it save him money on heating bills? He never mentioned whether it did or not.


I've never met your dad, and yet I feel a deep and abiding respect for the man.


I'm going to repeat this experiment with a black and white cookie in the sun tomorrow.

Link Posted: 1/2/2012 3:15:05 PM EDT
Originally Posted By ArimoDave:
While the sun is shining, the pool will heat up with a black bottom.

However, at night a black bottom will radiate back out into space thus cooling the water more than a white bottom.

The ideal situation would be to have a black bottom during the day and an aluminum surface at night.


There will be a greenhouse effect.
Link Posted: 1/4/2012 7:50:14 PM EDT
Originally Posted By hammet:
Originally Posted By WinstonSmith:
Originally Posted By Db8sGr8:
Very interesting question. I don't know your answer. I'm curious about the topic as well.

When I was a kid my Dad decided to paint our house black to save money on heating bills. He was... eccentric. Being the enthusiastic-at-the-start-of-a-project kind of a guy, he only painted half. Or maybe he meant to only paint the east and west sides of the house. Of course he never felt the need to explain his idea to us kids.The end result was the same: A half black, half white house. People used our house to give directions to others in the area for years. ("Okay, you go straight, past the segregated house, then...") Did it save him money on heating bills? He never mentioned whether it did or not.


I've never met your dad, and yet I feel a deep and abiding respect for the man.


I'm going to repeat this experiment with a black and white cookie in the sun tomorrow.



Well? How'd the cookies experiment go? or did you eated them?
Link Posted: 1/5/2012 5:29:38 PM EDT
Originally Posted By NwG:
Originally Posted By MotorMouth:
Originally Posted By Pond_Scum:
Originally Posted By Pauperis:
How does the color of the sustrate at the bottom of a shallow body of water affect the amount of heat the water absorbs from sunlight ?

A friend of mine has an inground pool. He claims that if you want the water to be cold you paint the bottom of the pool black. If you want the water to be warm you paint the bottom white. This seems to me to be backwards. A darker bottom would absorb more heat from the sun and thus warm the water more then a lighter one right ? However he has had this pool for 30 years and has painted it many times so he may be right.

What says the hive ?



editted for spelling

You actually think more than 1% of GD will know what this word means?




Given that it is not an actual word . . .


If you live in Brazil and have a heart problem it's a word...

Propatyl nitrate. May be a little expensive to line the bottom of a pool with....

And being a vasodilator funny things may happen to your guests.


"Come over and swim in my pool - it'll improve your circulation, I guarantee it!"

Link Posted: 1/5/2012 5:32:31 PM EDT

Originally Posted By RDP:
Originally Posted By Harvster:
Paint one half black and the other half white and see which end is warmer.


If you do that, you will have two different densities of the water, which won't combine similar to water and oil.


This makes the most sense to Deepak Chopra.
Link Posted: 1/5/2012 5:34:35 PM EDT
Originally Posted By sirensong:
he's probably thinking about a reflector for a campfire, and applying the concept laterally––radiant energy would heat the water on the way in, and also on the way out after being reflected from the bottom of the pool. but i'm pretty sure this would be dwarfed by effect of the black WRT heating the pool enclosure, and therefore the water. think albedo.


Bingo.
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