# Mythbusters test reflective materials



## booradley (Aug 6, 2007)

watching mythbusters, and they are testing reflective material for the most effecient. Now, they were using bronze materials so silver ones might be different. (They were making a bronze age death ray). They tested a mirror, mylar, shiny plastic and polished bronze. (they were all bronze colored) Anyway, they discovered that up close polished bronze was most efficient but at long distance mirrors were the best. 

BTW, they said the sun gives off 100 watts of power per square foot.


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## jamstein (Aug 6, 2007)

ive seen that one, amazing how well it worked.

wouldnt want that happening to my plants though!


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## Mutt (Aug 6, 2007)

Cool man!!! gonna keep an eye out for that re-run.
They get on my nerves so can't watch em on a regular basis.


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## Stoney Bud (Aug 6, 2007)

booradley said:
			
		

> BTW, they said the sun gives off 100 watts of power per square foot.


 
The sun creates 4 × 10 to the 26th watts of energy every second.

The sun's diameter is about 864,000, and its radius is thus 432,000.

Applying the formula for area gives us the following:

3.14 x 4.32 x 4.32 x 10 to the 5th x 10 to the 5th = 58.6 x 10 to the 10th or 5.86 x 10 to the 11th square miles.

Do the math, take two asprin and call me in the morning.


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## Mutt (Aug 6, 2007)

Stoney Bud said:
			
		

> Do the math, take two asprin and call me in the morning.



Remember we are a bunch of stoners man thats why god gave intelligence to a bunch of computers geeks to create a calculator so we don't have to think of this.  :lama:


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## killersmoke (Aug 6, 2007)

omg stoney u expect a site full of stoners and potheads to understand all dat mumbo jumbo??? wow your rly smart lol


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## Stoney Bud (Aug 6, 2007)

Mutt said:
			
		

> Remember we are a bunch of stoners man thats why god gave intelligence to a bunch of computers geeks to create a calculator so we don't have to think of this.  :lama:


 
Ha! Who you callin a geek?


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## Mutt (Aug 6, 2007)

Stoney Bud said:
			
		

> Ha! Who you callin a geek?



OK man I want you to a write a program to tell me the exact lumens per sq. meter of this coordinate 30d-45d N X 75d-90d W.


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## Stoney Bud (Aug 6, 2007)

Mutt said:
			
		

> OK man I want you to a write a program to tell me the exact lumens per sq. meter of this coordinate 30d-45d N X 75d-90d W.


 
At which moment in time?


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## Mutt (Aug 6, 2007)

Sept. 28, 2007 @ 10am EST


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## Stoney Bud (Aug 6, 2007)

Mutt said:
			
		

> Sept. 28, 2007 @ 10am EST


 
Hey, no prob man.

I can have that before you let one breath out.

Ok take a breath....

I'll be right back

hehe, the math is real tho'


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## AlienBait (Aug 6, 2007)

Stoney Bud said:
			
		

> The sun creates 4 × 10 to the 26th watts of energy every second.
> 
> The sun's diameter is about 864,000, and its radius is thus 432,000.
> 
> ...


 
Stoney, Hate to have to correct you, but the sun is a sphere and the surface area of a sphere is 4 x (pi) x r x r.  So if the radius is 432000 miles, the surface area is 4 x 3.14159 x 432000 x 432000 = 2.345 x 10 ^12

So, if it is putting out 4 x 10^26 watts, we have (4x10^26) / 2.345x10^12 = 1.7 x 10^14 Watts/Sq. Mile on the surface of the Sun.

The average distance of the Earth from the sun is 93 Million miles = 9.3 x 10^7.  So, the (average) amount of energy that hits the Earth is:
[4 x 10^26]/[4 x 3.14 x (9.3 x 10^7)^2] = [4 x 10^26]/[1.09 x 10^17] = 4 x 10^9 Watts/sq. mile

There are 5280 feet in a mile, so there are 5280 x 5280 =  2.79 x 10^7 sq.ft/sq.mi

Therefore, there are [4 x 10^9]/[2.79 x 10^7] = 1.43 x 10^2 = *143 Watts/sq.ft* of solar energy hitting the earth at noon. 

So, 100 Watts/sq.foot is about right.  

(Man, I've got too much time on my hands..... )


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## booradley (Aug 6, 2007)

Nah, man, it seems to me you have just the right amount of time on your hands!


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## Mutt (Aug 6, 2007)

HOLY CRAP Alien Bait!!!!!
WOW Man......You get massive kudos for that post. :shocked:
but....it cannot be a steady wattage as each day the distance of the planet to the sun varies...so the formula would have to take that into account. So the 100W rule would only apply for one day. lol but who gives a hoot. the big orange thing in the sky takes care of its own.


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## AlienBait (Aug 6, 2007)

Thanks.  

I have a degree in Physics, but I haven't really used it in 20 years.  

I just think it's fun to do little calculations like this every now and then.

Of course, anyone, feel free to check my math.  It's been a while and I'm a bit rusty.:holysheep:


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## Mutt (Aug 6, 2007)

Yo bait...ever get bored. You can actually win $$ for solving math ?.
Just search unsolved math problems.
http://mathworld.wolfram.com/UnsolvedProblems.html


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## AlienBait (Aug 6, 2007)

Mutt said:
			
		

> but....it cannot be a steady wattage as each day the distance of the planet to the sun varies...so the formula would have to take that into account. So the 100W rule would only apply for one day. lol but who gives a hoot. the big orange thing in the sky takes care of its own.


 
That is why I say it is the "average" distance.  Also, I specify at noon (when the sun is directly overhead).  

Here is a little trivia:  The Earth is actually closer to the Sun during the Northern Hemisphere's Winter and further away during the it's Summer.



			
				Mutt said:
			
		

> Yo bait...ever get bored. You can actually win $$ for solving math ?.
> 
> Just search unsolved math problems.
> 
> http://mathworld.wolfram.com/UnsolvedProblems.html



That's a little out of my league...LOL!


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## Mutt (Aug 6, 2007)

Thats a mind bender...farther away more light???!!!!???? might search that one up.


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## AlienBait (Aug 6, 2007)

Mutt said:
			
		

> Thats a mind bender...farther away more light???!!!!???? might search that one up.


 
It has to do with the tilt of the Earth.


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## Mutt (Aug 6, 2007)

some of those problems "look" simple until you really get into em. They'll send you into a loop man.


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## Stoney Bud (Aug 6, 2007)

hehe



MyBad


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## Kupunakane (Aug 6, 2007)

Did the math, I came up with 4.20  LOL

smoke in peace
KingKahuuna


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## gottagrow_420 (Aug 6, 2007)

I'll take his word for it.


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## ktownlegend (Aug 7, 2007)

I'm curious though has ne one on this forum ever used the polish brass as a lining for a grow room/box? I think i might try it for the next indoor grow.


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## gottagrow_420 (Aug 7, 2007)

ktownlegend i really like the quote you have from the devils advocate, words to live by.


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## jamstein (Aug 7, 2007)

Stoney Bud said:
			
		

> The sun creates 4 × 10 to the 26th watts of energy every second.
> 
> The sun's diameter is about 864,000, and its radius is thus 432,000.
> 
> ...



wait a minute i lost track, area of a sphere is pi radius cubed?  i cant see for looking but did you just square it?

im going to find my calculator


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## Hick (Aug 7, 2007)

"PIE" are round..."cake" are square..


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## jamstein (Aug 7, 2007)

i got all excited before, me and my friends often derive pleasure from calculating insanely large numbers, a few days ago we worked out how many hydrogen atoms you could line up end to end from london to paris


i have way too much spare time


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## Firepower (Aug 7, 2007)

Thats it, Stoney and Alien , ill be sending you guys the bill FOR KILLING MY HIGH!!!!....:shocked: :shocked: :shocked: :shocked: 

it was some Good Hydro i found Expensive too, so i was so happy and came into the forums!! BAD move  saw the math problem and actually tried to figure it out!!.. bad idea...  LOL>>:hubba:


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## Mutt (Aug 7, 2007)

Hick said:
			
		

> "PIE" are round..."cake" are square..



Now THATS stoner math.


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## jamstein (Aug 7, 2007)

yay physics!

only A level here.

praise alienbait!


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## Stoney Bud (Aug 7, 2007)

AlienBait said:
			
		

> Therefore, there are [4 x 10^9]/[2.79 x 10^7] = 1.43 x 10^2 = *143 Watts/sq.ft* of solar energy hitting the earth at noon.
> 
> So, 100 Watts/sq.foot is about right.


 
No, it isn't. It's 30% off. hehe, I wish you had been one of my teachers.


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## AlienBait (Aug 7, 2007)

Stoney Bud said:
			
		

> No, it isn't. It's 30% off. hehe, I wish you had been one of my teachers.


 
LOL!  

Well......when you factor in that the Earth is rotating and it is not noon most of the time and the tilt of the planet and the different seasons and lattitude adjustments, etc., you really can't get an exact number.  Having an order-of-magnitude value is acceptable. :smoke1:


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## Cannabis (Aug 14, 2007)

When researching home made projectors, to project t.v. or a first person shooter computer game onto a wall, i found out that you can buy reflective faced mirror tiles, for not much more than the price of regular ones: the light never has to travel through the glass, eliminating the double image haze a regular mirror creates.

That also removes the 5 or 6% loss of light, and the heat build up that occurs when the light has to travel through the glass twice.

 They're made using the same formulation as a standard mirror, except that the process is reversed: the glass is coated with the silver/aluminum whatever it is they use in standard mirrors,  and that surface is used to reflect the light.


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