Physics is a fascinating subject for students, for it seems to offer answers to all the mysteries of the universe. There is plenty to discover in this field of study, from understanding the science behind how specific objects function to testing out relevant laws and theories.
But as aspiring scientists, it is vital to question the concepts you are presented with and gather evidence in proving the hypotheses. That way, constant experimentation and findings can hone your mastery of physics. In fact, throughout the history of science, many physicists have uncovered several shocking truths about our universe through such a method. However, there have also been several physics misconceptions that have arisen. Let us share and debunk four common physics myths you may have come across.
Misconception #1: Dark matter and dark energy are the same entity
Most people assume that dark matter and dark energy are the same entity due to their similar names. Contrary to popular belief, no evidence supports the correlation between both parties. In fact, it is proven that dark matter and dark energy are two different types of matter in the cosmos producing contrasting effects. Dark matter attracts gravity, whereas dark energy causes the expansion of the universe to speed up.
Dark matter constitutes approximately 25 per cent of the universe. It cannot be seen by light and does not interact electromagnetically. However, it exerts gravitational force and draws other forms of matter towards it. Its gravitational pull is even strong enough to hold entire galaxies, such as the Milky Way, together!
On the other hand, dark energy is a mysterious force generated by quantum fluctuations in the universe. It pushes matter apart, causing our universe to expand at an accelerated rate. Like dark matter, scientists have no accurate observation of dark energy because it cannot be seen – it is an enigma and cannot be explained by standard particle theories.
Misconception #2: There is no gravity in space
Movies and television shows have tricked us into believing that there is no gravity in space. That is factually inaccurate, for gravity is everywhere, just less evident in space. This is because gravity holds planets in orbit, and gravitational force is found throughout the universe.
The science behind it is that the magnitude of the gravitational force depends on the distance between objects with mass. For instance, the further apart objects are, the weaker the gravitational force.
Furthermore, gravity is constantly tethering us down to the ground on Earth, and we are unable to experience the free fall that astronauts experience in space. However, because spaceships are far from Earth and are constantly orbiting and falling towards the ground at a consistent speed, astronauts enter a state of weightlessness without ever touching the floor – as if there were no gravity.
Misconception #3: There are only three natural states of matter – solid, liquid, and gas
For decades, students have been ingrained with the notion that there are only three natural states of matter – solid, liquid, and gas – present in our universe. But did you know that plasma is also a natural state of matter? In the opinion of many astrophysicists, it is the very ‘first’ state to form after the Big Bang.
Nearly all visible matter in the cosmos exists in the plasma state, with 99 per cent of it occurring predominantly in the form of the sun and stars in interstellar space. While plasma is often thought of as a subset of gases, the two states behave very differently.
Firstly, plasmas have no fixed shape. They are also less dense than solids or liquids. Secondly, they are composed of atoms in which the majority, or even all, of their electrons are stripped away, and their positive ions roam freely. Unlike gas, plasmas are also excellent electrical conductors that can be confined and shaped by a magnetic field.
Misconception #4: Heavier objects fall faster than those of lower mass
Even though Italian scientist Galileo Galilei’s experiment previously debunked this myth, many people are still unaware that heavier objects do not fall faster than those of lower mass. Instead, all objects fall freely at the same rate irrespective of their mass, subject to the effects of wind resistance. Therefore, in a vacuum, every object will hit the ground at the same time.
However, you might still wonder why feathers float gently in the breeze instead of plummeting to the ground quickly as a brick does. Let us explain – in Galileo’s test, using a feather and brick, he discovered that denser objects with higher mass fall at a faster rate than less dense objects due to air resistance.
This is because the force of air resistance is proportional to the area of the object in the direction of motion. For example, air offers greater resistance to the falling movement of the feather than it does the brick, thanks to its lighter mass. Contrarily, the brick has a higher density and lesser air resistance. Therefore, it hits the ground faster than a feather does.
Aside from the four myths outlined above, there are still a plethora of physics concepts yet to be scientifically proven. The mentioned examples are only a tiny fraction of the many astounding discoveries we will uncover in the future.
If you are interested in exploring the inner workings of the scientific realm or delving deeper into specific physics topics, it is advised that you seek proper guidance from a reputable physics tutor. At Best Physics TuitionTM Centre, we provide O level and JC physics tuition classes to equip you with comprehensive knowledge about the subject. So why not sign up for our lessons and get started today!