We all have looked upon a clear sky night and saw 100s of stars in the sky, It's beautiful and it can really make you wonder about space. Space is just one of the many topics students can learn in their high school physics class. It can be a fascinating class with so many awesome things to learn. Any student with an interest in space can benefit.
Most students are unaware of the great things they can learn in physics. We have created a series of articles that look at the many topics in physics class. This article focuses on space. After going through all our physics articles students can then make the informed decision if High School Physics in Canada is right for them.
The Solar System
Our solar system is a unique and awe-inspiring place. The milky way galaxy is filled with billions of stars and the sun is one of them. Our solar system consists of important elements that make it one of a kind:
- The Sun: the largest object in the solar system. Due to its large gravitational field, planets, asteroids and comets all orbit around it.
- Planets: there are eight planets that orbit around the sun at different times. The third rock from the sun, also known as Earth, is our home due to its perfect position that makes life possible. All planets are distinct and have different properties. For example, Mercury is the closest to the sun and has a temperature of 430 Celsius and Neptune is the farthest and has a temperature of -200 Celsius. In order for a planet to form, its gravity needs to be strong enough to make it a sphere or round in shape.
- Moons: natural satellites that orbit a planet. Many of the planets in our solar system have more than one moon with Saturn having more than 50.
- Dwarf planets: Pluto has been considered a dwarf or "minor" planet since 2006 when it was considered not strong enough to "clear the neighbourhood" so there may be other objects in its orbit around the Sun. There have been hundreds of dwarf planets discovered in The Solar System.
- Asteroids: these oval-shaped objects that are made of rocky materials orbit the Sun and may take millions of years to complete their obit.
- Comets: very similar to asteroids, however, they are made up of rocky material, dust and ice. When a comet approaches the sun it begins to vaporize and turns into a gas.
The sun is a big topic when looking at space. One of the facts students will learn is about the sun's core. It became hot and dense through nuclear fusions which caused hydrogen nuclei to join together and form helium nuclei. The sun's energy was transferred by radiation.
Orbital Speed and Orbits
Gravity is an important force that maintains the stable orbit of planets around a star, moons and artificial satellites around a planet. For an object to remain at a stable, steady orbit it must be moving at the right speed. The orbital speed of a planet can change with its distance from the Sun.
The Life Cycle of a Star
The life cycle of a star completely depends on its size. In this section of the Solar System topic, students study a diagram to show how long the life cycle of stars would be for those who are about the same size as the sun and far greater than the size of the sun. All-stars begin life in the same exact way: a cloud of dust and gas, also known as a nebula, becomes a protostar which goes on to become a main-sequence star.
Stars that are about the same size as the sun take the left path on the diagram and those who are larger in size than the sun take the right path on the diagram. Here are some further details about each type of star and how they are formed:
- A nebula: stars are formed from massive clouds of dust and gas, known as nebulas. Gravity does its job and pulls the gas and dust together to make the new star.
- Protostar: a new star is formed when it is hot enough for the hydrogen nuclei to form together and make helium.
- Main Sequence Star: also known as the stable phase of the star due to the fact that the force of gravity that is holding the star together is balanced by high pressure due to the high temperatures. The Sun as we know it is in its stable phase in its life.
- Red Giant Star: after all the hydrogen has been used in the fusion process of the star, larger nuclei begin to form and the star may expand to become a red giant.
- White Dwarf: after all the nuclear reactions are over, a small star may begin to contract under the pull of gravity. If this is the case, the star becomes a white dwarf which changes colour as it cools down.
- Supernova: a very large star with more mass will continue to get hotter and hotter until it explodes as a supernova. This massive star throws hot gas into space when it explodes.
- Neutron Star (aka Black Hole): becoming a neutron star or black hole all depends on the size of the supernova when it was first formed.
The Expanding Universe
For years theories about the development of the universe have been analyzed by scientists. These theories are based on astronomical observations and ideas.
Using the colours from the electromagnetic spectrum, scientists notice that elements in the star absorb some of the emitted wavelengths and dark lines become present in the spectrum when it is analyzed. Students acquire important information in this section such as how distinct elements produce different patterns of dark lines. Astronomers use the spectrum to observe light from distant galaxies, the dark lines in the spectra show an increase in wavelength. When the lines are moved towards the red part of the spectrum, the effect is known as red-shift.
The Big Bang Theory
The concept of the Big Bang Theory is it happened over 13.8 billion years ago. The whole universe was a very small and dense region and from this small point expanded to become what it is today. The Red-shift has proven this theory because it shows the universe is always expanding. Students also analyze supported evidence from the Cosmic Microwave Radiation Background (CMRB) that was discovered in 1964 and shows the remains of the thermal energy from the Big Bang.
Another concept that still needs time to be thoroughly understood is dark matter. Dark energy is not well understood but it is believed to be the reason why the Universe is expanding all the time. This mass is invisible to the instruments used by scientists and is credited with being responsible for the fact that the galaxies move too quickly for the mass of their stars.
What is the Future of the Universe?
The future of the universe is a difficult question to provide answers to. Scientists are unsure what we can expect to see. It is said scientists and astronomers still know so little about the universe. There is still a lot to be discovered. By studying space in physics you could make the next space discovery. We'll need scientists to continually study space so we can have a better understanding.
Sample Exam Questions
Examination periods are very stressful for students in their last years of secondary school. They want the best test results in order to be considered for admission to the most prestigious universities in Canada
Knowing what type of questions to expect on the examinations for the high school Physics Syllabus relieves the stress of students and boosts their overall results. Here are the different kinds of questions that can be anticipated on the exams:
- Multiple choice questions: the easiest to complete because all students have to do is put across in a box to choose the correct answer,
- One and two mark questions: these ones usually start with the words "describe" or "explain" and require students to write down a few logical sentences explaining their response,
- Three and four mark questions: these are the same as the previously mentioned questions, however, they require slightly longer answers,
- Maths questions: these ones might include graphs, tables and calculations. Students need to show their workings on how they arrived at their answer,
- Six mark questions: these are considered the most difficult for students due to the fact that long and logical answers are needed to get good results,
- Equations: these questions require pupils to recall the equations and information they learnt in previously taught classes.
Space is fascinating but can ultimately be called a giant mystery. The few things we know and can learn about captive the attention and the mystery of the things we have yet to learn have kept individuals intrigued for centuries. Learning more about the topic of space physics in the high school Physics Syllabus provides students with a great base for a future of studying the stars.