5 Physics Misconceptions You Probably Believe

Often, incorrect statements or 'half-truths' are taught to us in school, and these false notions stick with us for the majority of our lives. Other times, we misunderstand the behaviour and reasons behind certain phenomena in nature. Either way, today, you will learn the truth, and you will become a more informed person because of it.

Planets revolve around the sun due to gravity

This isn't entirely true. Sure, gravity keeps these planets in orbit, but gravity isn't the reason they orbit. In fact, our earth, mercury, venus, mars, and all the other planets, were already in motion and that's what caused them to start orbiting. Gravity simply makes sure they don't go astray.

Mass and weight are the same thing

Weight is dependent on mass, and is directly proportional to it, but they are not the same thing. Mass is the measure of an objects inertia, it's tendency to stay in motion or at rest. Weight refers to how much the object is affected by gravity (the formula for weight is:

weight = mass x gravity )

Weight is actually considered a force, as after all, it is caused by the force of gravity. Because of this, weight is measured in newtons (not in kilograms, as your bathroom scale may suggest). One more integral difference between mass and weight is that mass is constant and does not change upon location. If you put an apple on earth, and then took the same apple up to the moon, it would have the same mass. The weight of the apple, however, would change, since the strength of the gravitational field on the moon is one sixth that of earth (in other words, gravity is weaker on the moon, so the apple weighs less).

There is no gravity in outer space.

This is quite ridiculous, but still very commonly believed.

As I said before, the planets are kept in orbit due to gravity. And planets are in outer space.

So there is gravity in outer space.

The reason people believe this statement is likely due to the weightlessness astronauts feel when in spaceships. The reason they feel this is because spaceships orbiting the earth (like the International Space Station) have both the astronauts in them falling, and the actual ship itself falling at the same rate. So, the astronauts have nothing to break their fall and feel weightless.

Light isn't effected by gravity at all, since it's massless

Granted, gravity affects light barely at all, but it still affects it.

You may be wondering how this works. After all, gravity affects mass, and light is massless. The thing is, however, that mass and energy are treated in a similar manner by gravity, and since light purely energy, it is therefore effected by gravity.

In fact, this is how Einstein began to prove his theory of general relativity (I've done an article on this before. Here's a link).

Atoms look like this

They don't. They actually look like this

But that's a story for another article.

So there you go! Those were 5 physics misconceptions debunked and explained. This is the type of article that could have a sequel, and perhaps that could be done at another point in time. As you may or may not know, NASA's Juno just reached Jupiter this month! I would definately recommend looking into the mission, and following it over the next upcoming months, something promising may come out of it!