Kelvin and Watts

[Skewed]

Hi,

 

I have a question regarding light, specifically artificial light. Please forgive me I am not a physics guru by any means and my terminology may be completely wrong, but hopefully someone will be able understand what I am trying to ask.

 

First, the only way I know how to ask is in basic terms, I know that there is much more to it than that. So, I am asking in terms that I feel that I understand.

 

Ok here it goes.

 

Lets assume you have two lights, one light is 5000k and the other is 2700k. Considering that both lights are 23 watts each. Which light has the energy to penetrate...lets say a plant canopy better? The blue or red?

 

Or another another way to ask could be..

A 23watt 5000k bulb could produce light that would travel 2 miles. A 23watt 2700k bulb produces a light that would travel 1 mile. In order to to get the red light to reach 2 miles I would have to increase the 2700k bulb to 40 watts????

 

Here is what I think. I feel that the blue light will penetrate deeper than the red given that they are the same wattage. Now, if I am correct in my thinking would it be fair to say that if I should want the red light to penetrate to the level of the blue light at 23watts I would need to increase the wattage of the red bulb to lets say 40 watts? I know the numbers may not be correct, this is all generally speaking of course. I am just trying to keep it on a basic understanding level at this moment. TIA.

[swansont]

It's going to depend on what is absorbing and scattering the light. If you have an isotropic point source, the baseline behavior is that the intensity will drop off as r^2.

 

In air, blue light scatters a little more readily than red light (which is why sunrises and sunsets are often reddish in color).