How big is HIV?
145 nanometers!
HIV infects 0.6% of the world's population and causes AIDS. Although a single HIV virus is very small, in fact, so small that not a single human being on the face of this planet can see it with their naked eye, it can still kill.
Ultraviolet Wavelength
Ultraviolet light can give you a tan. I used to think the sunlight and heat burnt your skin to make it darker, like how a barbecue grill turns all of the food black. Now I know that's not true.
Hepatitis B Virus
Hepatitis B infects a lot of humans. In fact, almost one third of the world population has been infected at some point. This virus can cause vomiting, liver inflammation, and possibly death, but you most likely won't even notice if you have it at all!
Transistor Gate
Transistors in computers are continuing to get smaller. In 1971, they were 10 micrometers, more than 500 times the 18 nanometers of today's gates. In the future, they might be even smaller. How small will they get? Moore's Law predicted that the number of transistors on a chip would double about every 2 years.
Smallest Thing Visible to an Optical Microscope
Optical microscopes cannot see objects smaller than 200 nanometers because the wavelengths of visible light will pass right through them.
Bacteriophage
The bacteriophage, or just "phage" for short, is a type of bacteria-infecting virus. I think they look like robots, not life forms. But it also could be argued that viruses are not alive at all.
Violet Light Wavelength
Also known as mauve, purple, or even regalia, violet, which can be called lavender, periwinkle or iris, and sometimes even amethyst or eggplant, is also referred to as fuchsia, indigo or lilac, and on rare occasions, byzantium, thistle, wisteria, fandango and heliotrope.