What's your idea of a "Light lunch? Mine is soup and salad which fills me up and leaves me feeling well-nourished and ready to get going on what I want to do next.
But what if the energy we get from our food could be got from light itself? Could light really be our lunch?
Sounds wacky I agree but stay with me here in our mood of "What if?"
Energy is at the Root of all Science.
In Physics we learn about the different forms of energy and how we can turn these types of energy into each other. We can turn the energy in sunlight into electricity in a solar panel which can then be stored in a battery which we could then use to heat our homes or to power an electric car.
In Biology we find energy from the sun can be stored in a plant as it builds oils and carbohydrates and stores them in its leaves and roots. And in Chemistry we learn about the energy in materials and how they can combine and transform
Sunlight has energy and we can measure how much it has and what it can do.
Which is especially interesting in this year of 2015 which is the Official Year of Light.
We all know about calories and many of us know the calories values of all or many of our favourite foods. But what is a calorie really?
Turns out to be one of the ways we can write down how much energy there is in a food or how much energy we get from an electric heater.
So counting calories is counting energy!
And to me that suggest the intriguing possibility of getting our calories from light, from sunlight.
Plants can make their carbs from sunshine and we can make vitamin D from sunshine for sure but can we do better than this? Aren't we as clever as a plant?
Sadly it seems that although plants can make a lot of food from sunshine all we can manage is tiny amounts of vitamin D.
In spite of this there are persistent groups claiming otherwise.
One group claims that they get their energy not from food or breath but directly from the sun and for that reason have been called Sungazers
Another, called Breatharians have claimed for centuries that they can exist from the energy they get by breathing.
One such was Therese Neumann about whom the Wiki tells us that " Therese Neumann professed to have consumed no food other than The Holy Eucharist, and claimed to have drunk no water from 1926 until her death", in 1962.
Here is the method that he uses according to a modern sungazer and I have to say that as a Physicist I am very sceptical of the procedure – but see for yourself
One of the most documented Sungazers is Hira Manek who says that from, "18 June 1995 he has lived on water and occasionally tea, coffee, and buttermilk " and here is an interesting video where he is interviewed.
How About That Light Lunch?
Although in history there are persistent claims of people living without food for extended periods such people are few in number and none of them to my knowledge have been verified scientifically.
Sunlight carries energy and as mentioned triggers the manufacture of vitamin D in the skin by transforming cholesterol in the top layer of the skin into the essential vitamin for our health – vitamin D.
Beyond that we humans cannot go and so we have to say that plants are much cleverer than us because by the "magic" of photosynthesis sunlight is turned into food for us and for herbivores.
There is scientific support for a calorie restricted diet but we do need to eat. For our best health what we do eat should be what the research scientists call a Plant Based diet and not a sun based diet.
Huge amounts on the Science and technology of Light on the official UN website.