If you have a piece of matter in front of you, how can you know of which atoms it consists? And starting from nothing, how can I discover all the elements (or just a lot of them) of the periodic ...
Consider the standard unit of length: meter. How was it divided into decimeter, centimeter, millimeter, etc. when there were no shorter lengths than the standard ? What is the physical/experimental ...
How would a physicist measure temperature of molten metals in 1850-1920s? What equipment would be used?
How was Dorsey able to measure speed of light with 3 significant digits in the year of 1907?