Physics is the study of matter.
Matter is anything that has mass and can occupy space.
All objects contain mass, both in the universe and outside the universe, but weight is expirienced where acceleration due to gravity acts. Outside the universe where satellite are lunched, its beyond the acceleration due to gravity otherwise known as Escape velocity.
1. Medical physicist/Radiation Bio physicists
works in hospitals and administer doses of radiation in the blood stream of cancer patients instead of amputation, effective but expensive.
2. Nano Physics
works in industries to produce semi conductor electronics, here we hear of conduction band and valence band.
3. Material science /material selection engineering
works in industries to ascertain deformation in produced goods in form of plastic and steel, as well as the tensile strenght of the materials, here we talk of frenkel defects and plastic deformation, as a result of improper bonding during production.
3. Instrumentation and control physicists
help in calibration of hospital equipments.
4. Astro physicists/space science
assist in lunching of satelite in communication industry, assist in lunching of missiles and anti ballistic missiles for armed forces.
5.Nuclear physicists.
Assembling of Nuclear reactors for electricity production and otherwise.
6.Geo physicists.
Help in oil exploration, breaking of rocks using ultra sound with high frequency for construction of roads.
7. Envioronmental physicists.
Uses dust sampling machine to detect the amount of air pollution around a living area.
You can add yours great physicists in the house am and Industrial physicst with interest in medical, physics. Physics is the father of all. A physicist is automatically a mathematician but a mathematician can never be a physicts.