[6:99] The Green Material

EXTRAORDINARY RELATIONSHIP BETWEEN
SUN LIGHT AND PHOTOSYNTHESIS

Plants have been doing something for hundreds of millions of years that no high-tech lab, run by scientific specialists, has yet been able to do: They produce their own nutrition by a process called photosynthesis, using sunlight. A precondition of this process, however, is that suitable light reach the plants in the first place.

As a result of photosynthesis, the cells in plant leaves store solar energy as food. All life obtains its energy from sunlight, either directly or indirectly. But only within a very specific range of light can any plant make photosynthesis. This range corresponds exactly to the spectrum emitted by the Sun.

Photosynthesis is made possible by the light-sensitive chlorophyll molecules in the plants' cells. But chlorophyll however can make use of light at a certain wavelengths only, and the ones emitted by the Sun are just right. (Interestingly, the one required for photosynthesis is one in the 10 25 different wavelengths.)

That sunlight identical to the light necessary for photosynthesis shows its perfect design. In The Symbiotic Universe, American astronomer George Greenstein writes as follows:
Chlorophyll is the molecule that accomplishes photosynthesis... The mechanism of photosynthesis is initiated by the absorption of sunlight by a chlorophyll molecule. But in order for this to occur, the light must be of the right color. Light of the wrong color won't do the trick.



A good analogy is that of a television set. In order for the set to receive a given channel it must be tuned to that channel; tune it differently and the reception will not occur. It is the same with photosynthesis, the Sun functioning as the transmitter in the analogy and the chlorophyll molecule as the receiving TV set. If the molecule and the Sun are not tuned to each other-tuned in the sense of color-photosynthesis will not occur. As it turns out, the sun's color is just right. (Ian M. Campbell, Energy and the Atmosphere, London: Wiley, 1977, pp. 1-2, emphasis added.)

Those who examine this subject of plants and photosynthesis superficially could argue that if sunlight had different properties, plants would have adapted accordingly. But this is most certainly impossible. George Greenstein admits that this is, even though he is an evolutionist:

With regard to visible light, another interesting point is that its different colors can travel varying distances through water. Red light, for example, comes to an end below 18 meters (59 feet). Yellow light can travel up to 100 meters (328 feet). Green and blue light descend to 240 meters (787 feet). This design is most important, because the light necessary for photosynthesis is primarily blue and green. Since water can transmit light of these colors further than other wavelengths, plants that make photosynthesis can live at depths of up to 240 meters (787 feet).

One might think that a certain adaptation has been at work here: the adaptation of plant life to the properties of sunlight. After all, if the Sun were a different temperature could not some other molecule, tuned to absorb light of a different color, take the place of chlorophyll? Remarkably enough the answer is no, for within broad limits all molecules absorb light of similar colors. The absorption of light is accomplished by the excitation of electrons in molecules to higher energy states, and the same no matter what molecule you are discussing. Furthermore, light is composed of photons, packets of

When sunlight fallson a leaf, it is transmitted along the layers in the leaf. In the leaf cells, chlorophylls in the chloroplast organelles turn this light intochemical energy. The plant securing this chemical energy immediately uses it to create sugaras food. It took scientists until the mid-20th century to discover this process, which we have summarized in a few words. Pages of chemical reactions have been written in order to understand the process of photosynthesis, yet still there are missing links in the chain. Plants have been carrying out this process for hundreds of millions of years, thus providing the Earth with oxygen and food. Out of the 1025 different rays in the universe, only solar rays are suitable for photosynthesis in plant chlorophylls.





















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