One micron is equal to one-millionth of a meter, or 1/26,000 of an inch. On average, the human eye cannot see particles that are smaller than 50 to 60 microns. To give you a better idea of just how small a micron is, consider this: the diameter of a human hair is 80 to 100 microns in size.

In physical sciences, subatomic particles are smaller than atoms. They can be composite particles, such as the neutron and proton; or elementary particles, which according to the standard model are not made of other particles. Particle physics and nuclear physics study these particles and how they interact.

about 0.1 millimeters

The naked eye can see objects as small as 40 microns. As a point of reference, the diameter of a human hair is 70 microns, and a red blood cell is 8 microns.

For inspection purposes laboratories use a viewing distance of 200–250 mm, which gives the smallest size of the object recognizable to the naked eye of ~0.058- 0.072 mm (~55-75 micrometers). The accuracy of a measurement ranges from 0.1 to 0.3 mm and depends on the experience of the observer.

576 megapixels

If you’re viewing 4K content on a 4K TV and you sit at the optimal distance for a 1080p TV, a 4K picture will be on your screen, but your eyes will see 1080p. A 4K screen is 3840 pixels wide and a 2160 high; 1080p screens are 1920 pixels wide and 1080 pixels high.)

8K is a higher resolution than 4K—and that’s it. 4K screens double those numbers to 3,840 by 2,160 and quadruple the number of pixels. 8K doubles the numbers again, to a resolution of 7,680 by 4,320. That’s four times the number of pixels as 4K, which means it’s 16 times that of a 1080p TV.

Streamed 4K HDR movies can look and sound very good, but discs are even better. An Ultra HD Blu-ray movie typically has at least five times as much data as a streamed version of a film, which means sharper fine details, fewer distracting artifacts, and a better overall image.