Reflection

We draw your attention to the fact that this Mc Cree absorption curve is only an indicator. In reality, light absorption varies according to the species and stage of development of the plant. In some cases, light intensity can even saturate certain photoreceptors and change this absorption spectrum.

• Red light between 570 and 700 nm is the most absorbed, with a major absorption peak at 660 nm for chlorophyll A and 645 nm for chlorophyll B.

Specularreflection

Reflection of light (and other forms of electromagnetic radiation) occurs when the waves encounter a surface or other boundary that does not absorb the energy of the radiation and bounces the waves away from the surface. This tutorial explores the incident and reflected angles of a single light wave impacting on a smooth surface.

In reality, not all wavelengths in the PAR spectrum are absorbed in the same way. This has been highlighted by Mc Cree’s work that characterizes photosynthetic activity as a function of each wavelength.

Refraction oflight

When light reflects from a smooth surface, the incoming light wave is referred to as an incident wave, and the wave that is bounced away from the surface is termed the reflected wave. Visible white light that is directed onto the surface of a mirror at an angle (incident) is reflected back into space by the mirror surface at another angle (reflected) that is equal to the incident angle, as presented in the tutorial for the action of a sinusoidal light wave on a smooth, flat mirror. Thus, the angle of incidence is equal to the angle of reflection for visible light as well as for all other wavelengths of the electromagnetic radiation spectrum. This concept is often termed the Law of Reflection. It is important to note that the light is not separated into its component colors because it is not being "bent" or refracted, and all wavelengths are being reflected at equal angles. The best surfaces for reflecting light are very smooth, such as a glass mirror or polished metal, although almost all surfaces will reflect light to some degree.

Reflection, refraction diffraction

All plants absorb light radiation nearby to grow, with no differentiation between a natural source such as the sun or artificial sources such as LED lighting. Plants have evolved millions of years under sunlight and are able to absorb most of the wavelengths present. They derive most of their energy between 400 and 700 nm. This is called the PAR (Photosynthetically Active Radiation) spectrum, which has become the standard measurement for horticulture. (Link to article 1)

Notes forreflectionoflight

The tutorial initializes with a red sinusoidal wave incident on a smooth, mirrored surface at an angle of 40 degrees. The incident light is reflected from the surface according to the Law of Refraction and leaves with the same angle at which it arrives. The Wavelength and Incident Angle sliders can be utilized to adjust these parameters of the wave, which will be immediately executed in the tutorial. Beneath the sliders, the mathematics involved in calculating the angle of the reflected wave is reviewed for each incident and reflected angle as the Incident Angle slider is adjusted.

If we take a closer look at this phenomenon, we notice that plants absorb light in two distinct forms: photosynthetic light and photosignaltic light.

The quality of the spectrum received by the plant affects its growth rate, appearance and hormonal reactions. A spectrum adapted to your crops will always allow you to optimize energy consumption as well as the yields and quality of your productions.