Take a quick scan around you, and what do you see?
Everything we see is, in fact, composed of elementary particles of light called photons that reflect off of the objects in our visual path. Our eyes collect these reflected particles and, with the help of our brain, generate images for us to see. Although the human eye consists of remarkable machinery that enables us to interact with the world, it has some limitations.
First, our eyes have evolved to capture only a fraction of the light emitted by the sun, which we refer to as “visible” light.
Second, within this spectrum of light, the smallest distance at which the human eye can resolve objects is approximately 0.1 mm.
Third, a minimum number of reflecting photons is needed to sufficiently activate our visual system for us to recognize it as an object.
Hence, objects smaller than 0.1 mm cannot be seen using our naked eye. To give you some perspective, this means that, while we still see the pillows on our bed, we cannot see the tiny dust mites crawling all over them! Such objects, which are too small to be seen by the naked eye, are called microscopic objects. In order to see such objects, we will need to use specialized equipment known as microscopes.
The discovery of microscopes played a very important role in biology. By as early as the 17th century, scientists had already used early forms of the modern microscope to identify the existence of small living structures, advancing the field of biology by leaps and bounds. Pioneering work by Anton Van Leeuwenhoek and Robert Hooke laid the foundation for the field of cell and molecular biology – work that could not have been done without the help of microscopes.
Fast forward four centuries later and today there are many different types of microscopes available depending on what we wish to see and investigate. In our laboratory, we have various microscopes that can resolve biological structures at the cellular and subcellular level as small as 200 nanometers. That’s approximately 500 times as small as we can see with our naked eyes!
Here’s an informative link that provides more detailed information into the different types of microscopes used in the field of biology: https://www.microscopyu.com
Abinaya Ravisankar & Gaia Skibinski