Physics is often called our most fundamental science because it describes the way natural things work, such as gravity, weight, speed, mass, electromagnetics, heat radiation, cold, and anything else found in nature.
After physicists describe, measure, quantify and explain the dynamics of these basic qualities of the universe, it sets the stage for building technologies that can take advantage of that knowledge.
A simple example is the use of a lever. People have understood for thousands of years that using a lever can move a much heavier weight than what could be accomplished by hand.
Physics informs us that the longer the lever, the more weight it can lift.
A lever is one of our earliest forms of technology. Ancient structures, such as the Egyptian pyramids, could not have been built with levers and other technologies.
Fast forward to the future, and we see that physics underpins every technology we use. For example, that smartphone you check dozens of times per day would not work unless we understood a variety of different natural forces described by physics.
Smartphones use satellite signals. Before we could send satellites into low earth orbit, we had to understand the physics of gravity, planetary motion, velocity, mass, and more.
The average rocket that carries satellites into space range from around 4,400 pounds to 45,000 pounds. These are called medium-lift launch vehicles.
How much force (power/thrust) is needed to counter the downward force of Earth’s gravity to boost medium-lift rockets into space to an orbit that is from 100 to 1,200 miles above our planet’s surface?
It’s the calculations derived from physics equations that give us the answer to these kinds of questions.
Furthermore, satellite technology relies on another type of physics called orbital mechanics. That informs scientists about the motions of objects in space in relationship to each other. For example, a satellite must obtain a specific speed – 7,000 MPH – if they are to remain stable in an orbit that is 22,223 miles from Earth.
The physics that help us accomplish these amazing space technology feats can be traced back to Isaac Newton. Sitting under a tree one day, as the story goes, an apple famously fell on his head. It got him thinking about gravity. Using mathematics, Newton worked out the Inverse Square Law.
It states that a known physical quantity will be inversely proportional to the square of the distance from the source of that known quantity. Without understanding this law of physics, the technology of space travel would be impossible.