Physicists recognize four forces of nature. These are identified as interactions that include all known phenomena in nature. Some of the four are easy to recognize because they are seen every day. Others are happening all around, but not necessarily seen.
Gravity
While gravity is the weakest of the four forces, the range of gravity is unlimited. Every single object in the universe exerts a gravitational force on everything else. However that force can be broken quite easily because there is very little strength.
This experiment shows how weak gravity really is. A piece of paper sitting on a desk stays on the desk because of the force of gravity. The gravity of the entire planet is engaged in holding that piece of paper. Take a dry comb and run it across your shirt a couple times to create static electricity. Hold it over the piece of paper and see how quickly it pulls up. This is an example of another one of the four forces of nature. It is electromagnetic force in action.
Electromagnetic force
Electromagnetic force is another force that is very familiar. This is the force that balances all of the chemical reactions. It controls the photons. Examples of electromagnetic forces go from cosmic rays, visible light and radio waves.
Electromagnetism comes in to charges, positive and negative. Two positive charges or two negative charges will always repel each other. One positive charge and one negative charge will attract to one another.
This is the principle that holds atoms together. The electrons are negatively charged. The nucleus has a positive charge.
Electromagnetic force is also infinite in range.
Weak nuclear force
Weak nuclear force is responsible for radioactive decay. It centers on the extremely short distance scales that are found in the atomic nucleus. radioactive decay is when a neutron breaks down into a proton and an electron or positron.
Strong nuclear force
The strong is another example of forces at subatomic distances. The main job of the strong nuclear force is to manage the gluons between quarks that make up protons and neutrons. When nuclei are smashed in nuclear reactions, energy from the strong force is released.
One of the most interesting theories about the four forces of nature is how they existed in our Universe in earlier times. There are many theorist who believe that the weak nuclear force, the strong nuclear force and elcectromagnetic force were unified into one force. At that time the temperature of the Universe was much higher. This theory has yet to be proved in experimentation.
