Sun light.

[Monsieur Catt.]

First of all I would just like to say thank you to those reading this and those who help me understand more, please bear with me whilst I tell you about my day

 

My Wife and I was lying on the lawn enjoying the days sunshine, during that time I got up, placed the news paper on top of the wall (4ft) then returned to where we were lying and said to my wife that the newspaper was getting more sunshine than us as it was nearer to the sun, she laughed, I laughed, then it got me thinking more in depth as I looked at the different height of the surrounding trees and shrubs and started thinking some more:D

 

I have googled LOL and the popular answer is that on a sunny day there is 10,000 lumens, would that be at ground level? and if so would my newspaper on the wall be receiving more lumens? or would it be the same? think i can put my hand on my heart and say it would not be less LOL.

 

Once again thanks again for staying with this

[StringJunky]

The fractional difference in the distance between the two positions relative to the Sun would so negligible as to render the difference in light intensity as unmeasurable I would think. If you are talking about a light source some meters away the difference would be measurable between the two positions but when looking on the scale of 10's of millions of miles and the two positions are only meters away from each other it's out of the question.

 

 

 

http://imagine.gsfc.nasa.gov/YBA/M31-velocity/1overR2-more.html

[Monsieur Catt.]

Thank you stringjunky

 

I don't as yet understand the diagram, but thatss why I am here, to learn.

 

I think I have gone from newspapers to trees now:D some trees are taller than others and think that without light non of them would grow, so each tree has different needs for life to survive, from a daisy to a mighty oak, if we take the "popular" google answer of a bright sunny day being 10,000 lumens (which is probably very debateable) as a base.. then a daisy on the ground is pretty happy with the 10,000 lumens it recieves, so would a tree, say 15ft tall survive on the same intensity of light or has it increased, if so how do we calculate that increase, is there some law that can explain this?

 

Also if for instance aeroplanes had some sort of greenhouse on them.. would the daisy survive the light intensity at 35,000 ft? or would it be considerable more than what it is genetically programmed to do, (in my garden the biggest daisy is just under 2 inches (have not switched to metric yet, its an age thing )

 

The more and more I think of the sun as a giver of life, the more and more I am getting curious about it.

 

Although science fiction, there was a star trek film where they had this amazing forest onboard another star ship, the "genesis" project it was called in the film, maybe one day all this will be possible and already thinking about a place in cornwall the eden project? who i think use artificial light to mimmick the sun.

 

thank you once again for the reply, it is very much appreciated.

[D H]

The Sun is about 93 million miles away from Earth. If the atmosphere was perfectly transparent, the intensity of sunlight after traveling an extra 62 miles (the altitude at which ones earns their astronaut wings) is reduced by a paltry 0.0002%.

 

One problem with that analysis: That is a mighty big if. The atmosphere is not perfectly transparent. The sky is blue, after all. The atmosphere, excluding clouds, reflects about 6% of the incoming radiation right back into space and absorbs another 16%. Sunlight on a sunny day at sea level is 22% less intense than it is up on the Space Station.

[swansont]

The difference between ground level and tens of feet is negligible. A couple parts in 100 million per meter of height, ignoring scattering and absorption. By comparison, blocking a square millimeter of light out of a 1 meter area — like a small insect flying by (ignoring diffraction effects) — is a part in a million reduction.

[Mchurd]

You must also keep in mind the rays level of incidence and solar footprint on the specific area based on the areas latitude.