Get flash to fully experience Pearltrees
Even very young children perform rudimentary experiments in order to learn about the world.
Theoretical physics is a branch of physics which employs mathematical models and abstractions of physics to rationalize, explain and predict natural phenomena .
A unit of measurement is a definite magnitude of a physical quantity , defined and adopted by convention or by law, that is used as a standard for measurement of the same physical quantity. [ 1 ] Any other value of the physical quantity can be expressed as a simple multiple of the unit of measurement. For example, length is a physical quantity. The metre is a unit of length that represents a definite predetermined length.
States of matter in physics are the distinct forms that different phases of matter take on. Four states of matter are observable in everyday life: solid , liquid , gas , and plasma . Further states are possible but do not naturally occur in our environment: Bose–Einstein condensates , neutron stars .
A physical quantity (or "physical magnitude") is a physical property of a phenomenon , body, or substance, that can be quantified by measurement . [ 1 ]
Observation is an activity of a living being, such as a human , which is necessary in order to receive knowledge of the world or about the environment through the senses , which often later involves the recording of data via the use of scientific instruments. The term may also refer to any data collected during this activity. [ edit ] Observation in science
Physical System (example) In physics , the word system has a technical meaning, namely, it is the portion of the physical universe chosen for analysis. Everything outside the system is known as the environment , which in analysis is ignored except for its effects on the system.
The Sun is Earth's primary source of light.
Gravitation , or gravity , is the natural phenomenon by which physical bodies appear to attract each other with a force proportional to their masses .