The coronavirus has caused a massive pandemic across the world, and yet, the virus itself, like any, is absolutely tiny, with a diameter of about 120 nanometers (or about .000004724 inches). It is so small, in fact, that traditional imaging techniques cannot resolve it. So, how do scientists create crucial images of the virus to better understand it and lead the fight against it? This excellent video will show you the science behind creating those images.
Coming to you from Vox, this great video will show you the techniques scientists use to create images of the coronavirus. The problem is that the smallest wavelength of light human eyes can see is about 400 nm, but since the virus is about 120 nm, a traditional light microscope cannot resolve it. Light microscopes also become limited by diffraction around 200 nm (and a magnification of about 2,000x). This is where electron microscopes save the day. An electron's wavelength is about 100,000 times shorter than the wavelength of visible light photons, allowing magnifications on the order of 10,000,000x. They are incredible machines that have enabled many scientific advances in the past century; check out the video above to see how the process works, and stay safe and healthy!
Does this count as macro photography?
Maybe. Macrophotography is difficult enough. The first images of a coronvirus taken several decades ago were dissmissed as being fuzzy images of a flu virus. They weren't. However, my macro snaps are unfortuately usually pretty blured.
Schoolboy question: If the virus is smaller than the smallest wavelength of the visible spectrum of light, does that mean they actually do not have any color at all? Wait, black and white are also visible colors as well? This video is fascinating, but my small my brain hurts, I'm going back to bed.
The human eye can detect electromagnetic radation within a certain band of frequencies. It is also differentiate beteen different frequencies in this band. We perceive these different frequencies as different colours.
The sensitivity of different animals eyes, photographic 'films' and imaging sensors of different frequencies varies. For example the first photographic emulsion were only sensitive to blue light (and UV I think). Later this was extended to green and finally, with panochromatic film, red.
These early panochromatic film were the basis of early colour films. These were made in many different ways. A pair of famous French brothers used dyed pototo-starch grains to produce an early 'organic-Bayer filter' for example.
I know nothing about electromicroscopes but would asume that the source has a relatively norrow bandwidth and the detector only records intensity. Therefore, the images can be considered analogous to being monochromatic.
Are black and white colours? What depends upon how you define colour. There is not a single frequency of light that can be considered white. It has be produced from two (at a pinch) or more frequencies of light.
So, using a rather narrow definition, the answer is no, they are not.
It looks nice and sunny, so I think I will got out on the balcony and take some photos of the birds if they get close enough.