The Physical Universe

 

Time and Space

The physical Universe exists in time and space.

We live and exist in time and space. We know that we exist because we occupy space. Everything we are physically aware of occupies space. This is the physical universe. We detect and interact with things in the physical universe via our physical senses. The Physical Universe consists of everything we can see, hear, smell, taste or touch.

We are also aware of time. It’s something that keeps moving. We exist in time. Everything that we do – or everything that happens in and around us – takes time. But what is time? The simplest definition is that it is something that can be measured with a clock.

 

The Physical Universe exists only in time and space. It consists of everything we can see, hear, smell, taste or touch. It is what we detect or interact with through our physical senses. If we can’t detect it with our physical senses, it’s not physical. It’s super-natural. It’s not what we are interested in if we are studying physics.

We sometimes need instruments like microscopes or telescopes to see things that are very small or very far away. We also need instruments to detect forms of energy like radio waves.

The physical universe is incredibly large. We don’t know how big it is. The known universe is that part that we are able to detect using the latest telescopes. There are more than 100 billion galaxies in the known universe. Each galaxy has more than 100 billion stars – each with its own set of planets, moons and asteroids.

The latest estimate of the distance of the farthest galaxy from ours is that it could be in the region of 13 billion light years away. (One light year being about 6 trillion miles – where 1 trillion is one million million – or 10¹²)

 

What does it consist of?

The Physical Universe consists entirely of Matter, Energy and Forces. Although most of what we are aware of in the universe is material, matter is actually a condensed form of energy.   

Forces push, pull and hold things together – or keep them apart. Forces can make things move, make them move faster or slow them down. Everything in the universe is moving relative to something else and there are countless forces at play.

Energy is what makes things happen. Everything that happens in the universe involves releasing, transferring or transporting some form of potential energy. Energy is regarded as the capacity to do work. When forces move things, accelerate things or heat things, work is done - and energy is involved.

When we study physics, we study the behavior of forces and energy in time and space.

 

Why Physics?

             The Physical universe we live in consists of everything we can see, hear, smell, taste or touch. It is what we detect or interact with through our physical senses. We sometimes need instruments like microscopes or telescopes to see things that are very small or very far away. We also need instruments to detect forms of energy like radio waves.

             The scientific study of the physical universe is called physics.

             Every day you wake up and go to school, your life is impacted by the scientific study of physics. From the bed you sleep on to the cereal you eat; from the bus or car you take to school to the laptop, tablet or smart phone you use to check your Facebook, Instagram or twitter (or do your homework)  – all of these things are possible because of physics.

             Physics has spanned thousands of years and developed incredibly advanced technology. Studying the physical universe has made it possible for us to communicate through books, phones and the internet, to cross continents in trains, cars and airplanes and to launch rockets into outer space. If you are reading this in a book, on a computer or any other sort of smart device – physics has made that possible.

             Physics is interesting and fun, but it can also be a challenge. If you apply yourself to studying physics, however, it can open up a world of possibilities for creating new things. Physics helps us survive and thrive, gain knowledge and avoid disaster. It can even empower us to create things that would be otherwise impossible, like rockets.

Physics is a study of the physical universe. It is a collection of language, images and models of things and systems in the universe. Physics helps us to remember how things work – and to predict how other things might work.

Knowledge of the physical world helps us to stay alive and avoid painful situations. We all start at a very early age to understand the value of sound – such as screaming. No too long thereafter, we start to understand the dangers of gravity.

We constantly interact with the physical world. We constantly study physics during the course of our lives in order to live, thrive and survive.

If we want to make things or use things (for fun and profit), we usually adopt a more formal, systematic or scientific approach to studying physics. This helps us to gather the maximum amount of accurate and reliable knowledge. Otherwise we tend to gather knowledge by experience only and may end up having a lot of unreliable or even superstitious ideas on how things work.

The study of physics can be regarded as taking a scientific approach to collecting knowledge about the physical world around us – the Physical Universe.