What is physics?
Physics is the study of matter, energy, and the relationship between matter and energy. The key term in physics is energy. We follow the energy. Everything which is happening in the universe involves the conversion of energy from one form of energy to another. The principle of conservation of energy states that energy is neither created nor destroyed, but merely changed from one form to another. This smartphone converts electrical energy into light, sound, and heat energies.
Machines
We use machine tools to convert energy from one form to another. By definition, a smartphone is a machine. Tools allow us to do work through energy conversions. We rate devices by their Power or the speed at which they do work or by their efficiency. Efficiency is a percentage to show how much of the supplies energy has been useful. We are always trying to build more efficient machines such as car engines. Most of the fuel that we buy due to inefficient car engines which are about 20%. That means for every 100 litres, only 20 litres is what you use, the rest is wasted energy in the form of heat and sound. We use water coolants to try to cool the engine.
Efficiency
Car engine manufacturers are always trying to build a more efficient engine. Not only are we wasting the energy from the fuel, but we are also releasing greenhouse gases which cause global warming. Global warming is responsible for the adverse weather conditions which we are experiencing. Hurricanes Harvey and Irma are a reminder that climate change is real. It is a wake-up call to Donald Trump and Climate change deniers. The universe does not care what we think; it just obeys the laws of physics.
Trump is Wrong on Climate Change
It’s a pity that Trump is using his political influence and possible business or economic interests to deny climate change and encourage the continued use of fossil fuels such as coal and crude oil. Politicians are driven by personal interest first and foremost. The advantage that America has is that it has been a web of institutions which makes it difficult for dictatorial tendencies to find the light of day. American presidents are not as powerful as people believe.
Trump has dismantled most of the policies put in place by Obama to fight the causes of global warming. He has also promised to pull out of the Paris treaty on climate Change to which China is also committed. Although the resolutions are nonbinding, meaning countries can invest in them but not necessarily implement them; they show real intent that the world is tackling global issues together. After all, we share this planet and what happens in each corner of the globe has implications everywhere. There is a famous statement to the effect that if a butterfly flaps its wings in the Amazon, it may cause a storm on the other side of the globe. The climate decisions that America makes may cause extreme weather conditions in sub-Saharan Africa.
Global Warming
Hurricanes get their energy from the warmer air due to rising global temperatures, and the increased rainfall comes from a greater amount of water which is evaporating. But what is global warming? It means that the globe is getting warmer. And why is that? It is because less heat is now able to escape into the atmosphere because greenhouse gas emissions are accumulating in the air. Smoke is made up of unburnt carbon particles. They physically trap heat from escaping into and warm up the earth. It means that sea levels are rising due to the water in the oceans expanding and the ice from the polar caps melting. When water is heated, it expands because the space between the water molecules increases. It also means that more water is evaporating into the air and causing more rain. The rain caused by Hurricane Harvey is the heaviest that has fallen due to a hurricane in the history of extreme weather conditions. Africa has experienced regular droughts due to climate change.
One of the devastating effects of greenhouse gas emissions is acid rain. Exhaust and industrial emissions include sulphur dioxide gas. When sulphur dioxide chemically reacts with water, it produces sulphuric acid. The sulphuric acid affects plants and contaminates drinking water. It also
Science Does Not Care
Science is evidence based. It does not care what we say or think. It is what it is. The problem with politics across the world is that some of the leaders choose to ignore science for personal biases. They are ignorant of the benefits of scientific research and findings. The world has improved due to science, and anyone who disagrees is using the inventions of science to do so. Life expectancy has trebled in the past 200 years. It is due to improvements in personal health and sanitation. We have eliminated or reduced some of the conditions which were causing premature death.
Science is not a body of unchangeable facts but a way of thinking. We use the scientific method of enquiry to ask questions about our observations of natural phenomena. When we observe a phenomenon, we try to understand it by asking questions. We make a proposal based on what we already know then we test the hypothesis by using variables. We control some of the variables and change some of them. The variable that we control is called the control variable. We refer to the variable we change as the independent variable, and the one that we measure is known as the dependent variable. If we can not measure something about a physical phenomenon, then we need to look for new questions. The questions help us to identify variables. The scientific method of enquiry has served science well for a very long time. Anyone who doubts its relevance only has to look around and see all of the applications of science and the improvements it has made to our daily lives. We take a lot of things for granted now until we experience a power cut or water not coming out of the tap.