Tiny worlds: it’s the small things in life

Look around you. There is stuff you can’t see but it exists, like magic. In this side of our world,  the human notions of ‘seeing is believing’ fail to exist. This, my friend, is the microscopic world, the one naked to the human eye. Except for humans who have technology at their disposal that help them see this world, such as by using a microscope. We do however manage to see shadows of the Muscae volitantes (Latin: “flying flies”), or mouches volantes (from the French), commonly known as floaters. These are deposits within the eye’s vitreous humour.

It’s amazing how technology helps us see things we can’t normally see. For instance, we know why the wings of a Morpho butterfly are blue even if they contain no blue pigment. The physics of light at the nanoscale tells us that the structures/ridges on their wings have a peculiar structure that refracts light giving out blue and cancelling out other colors of light, a phenomenon called constructive interference. A similar thing happens to gold when we see it on a nanoscale. Colors of monodispersed gold nanoparticles are not golden at all!

The microscopic world also puts a spell on the environment we live in. The spores that mushrooms give out as a part of their reproduction cycle are nature’s very own cloud seeders. Aerosols too do the same, 90 % of which have natural origins such as the sea salt, dust, and volcanic ash, the first two being the most abundant aerosols on the planet. The clouds that these cloud seeders create reflect about a quarter of the Sun’s energy back to space. Aerosols however have a love and hate relationship with global warming. Depending on their physical structure, they either aid or prevent warming/cooling. For more information, see my article ‘Polluted atmospheric layer in the making‘.

It also works the other way round. Warming of oceans could kill phytoplankton, and eventually all life on the planet. This is because these microscopic marine plants are the base of several aquatic food webs, they provide two-thirds of the planet’s total atmospheric oxygen and absorb as much carbon dioxide as tropical rainforests. If the water temperature of the world’s oceans increases by six degrees Celsius, it could stop oxygen production by phytoplankton by disrupting the process of photosynthesis. The macro is deeply connected to the micro, whether you see it or not.

We have slowly entered into the depths of Microbial ecology (or environmental microbiology). It is the ecology of microorganisms: their relationship with one another and with their environment. Phytoplanktons provide oxygen and absorb carbon dioxide, chemosynthetic microbes living in the dark corners of our world provide energy and carbon to the other organisms. There are decomposers that keep the nutrient cycle (one of the biogeochemical cycles) running.

Microbial processes have a central role in the global fluxes of the key biogenic greenhouse gases (carbon dioxide, methane and nitrous oxide) and are likely to respond rapidly to climate change. – Nature Reviews Microbiology

An estimated 5 trillion trillion bacteria reside on this planet. They are in the oceans and the soils. A handful of soil contains about 10 billion bacteria! These keep our soils healthy and ultimately keep us healthy. Overuse of certain chemical fertilizers, fungicides, herbicides, pesticides are rendering soils infertile as they kill these microbes. Technology has a solution for this too. Scientists are now able to map genetic sequences of soil microorganisms, understand what they actually do and how to grow them, and reintroduce them back to the soil.

Last but not the least are the tiny worlds inside our own houses. Molds, mildews, bacteria, and dust mites are potential human health hazards. These are called bioaerosols and are found in homes. These can be controlled just like the indoor non-bio aerosols that are harmful to our environment. Consumer products such as Fingernail polish, perfumes, mouthwashes, pump hair sprays, and roll-on and stick deodorants emit Volatile Organic Compounds (VOCs), which not only affect indoor air quality which may cause short- and long-term adverse health effects, but can also act as greenhouse gases, and cause smog.

Further reading:

Microorganisms and the natural environment. P. A. Trudinger, B. Bubela. Mineralium Deposita November 1967, Volume 2, Issue 3, pp 147-157. This paper looks good to read, however I had no access to the entire text.