Explore A World Without Friction

Reading Time – 5 Minutes, Difficulty Level 1/5

Have you ever had the soles on your favourite pair of sneakers wear out? Were you annoyed that that happened? What about when you have to change your tires because the treads have become smooth, or when you have to push very, very hard to get things to move?

All of these happen because of friction, which is a force that resists motion between two things. You almost certainly have experienced friction in your life, and probably thought of it as an annoyance, a necessary evil that we have to deal with.

And yes, friction can have many disadvantages, including the ones I listed above. However, without friction, the world as we know it wouldn’t exist!

Let’s imagine that the friction force suddenly disappeared from this world. What would happen?

1. Slowing down would not be possible.

Perhaps one of the most widely known uses for friction is for brakes. Most brakes work by pressing a pad onto the parts that are currently moving, whether it is in a car or in a bicycle. The sliding of that pad with the moving parts create friction, which would then slow down the motion of the vehicle.

However, friction is not just used to slow down vehicles. If you have ever slid an object to your friend across the table, the reason that that object is not sliding around forever is because of the friction between that object and the table. In fact, nearly all forms of slowing down are due to friction.

Without friction, you would not be able to stop moving with control. The motion will stop only if you collide with a stationary thing that would be able to absorb the motion, aka. crashing, or, you could have an elastic collision, and bounce around forever and ever and ever.

• Starting any motion would be very hard.

In fact, not only does slowing down motion would not be possible, starting motion would also be very hard!

To get something moving that was previously still, you have to apply a force onto it. However, Newton’s third law of motion states that every action has an equal and opposite reaction, which means that when you apply a force to an object, that object is also applying the same force to you, in a different direction.

Without friction, this would cause you to remain in place, as the force that you are exerting is also being exerted back to you. You might have experienced this if you tried walking the way you usually would on ice. Without the friction to hold you in place as the ground pushes you, you would slip and thus remain in the same place.

• We wouldn’t be able to hold anything.

Have you ever tried to hold on to an oily jar? It is so hard to hold on to oily things, because the oil causes less friction to be present between your hand and the object.

Likewise, in a world without friction, we wouldn’t be able to hold on to anything. Friction is what allows you to grip on to things, and what allows the object to stay in your hand. Without friction, objects will slip as you’re trying to pick them up, if you can even move towards the objects you want to pick up in the first place!

• Anything not on absolutely flat ground would slide towards the lowest point.

It’s not just that we wouldn’t be able to hold on to anything. In fact, without friction, anything that’s not on absolutely flat ground would start to slide down.

This is because friction is what keeps things from moving. Gravity is always pulling you down, and the reason that you are not sliding whenever you are on an incline is because friction is opposing the gravity that’s trying to cause you to slide.

Without friction, there is nothing that opposes gravity from pulling everything towards the center of the earth! You can’t even nail things down, because nails stay in place because friction!

• Knots wouldn’t be possible (including surgeon’s knots!)

Knots are one of those things that get taken for granted sometimes. Of course, it is there for when you are camping, or hiking, or sailing, but it is also there when you are tying your shoelaces, or hanging something up, and even tying up herbs for cooking.

However, knots are also present in places you might not think of. Without knots, surgery would not be possible, as we would not be able to close any incision made during the surgery. Without knots, clothing would not also be possible, as the threads in your clothing are held together by a series of knots.

Knots maintain their shape through the friction present between the strings. So, if you were to have a world without friction, you wouldn’t be able to tie anything together, you wouldn’t be able to hang anything up using string, any sutures would immediately be undone, and your clothing would unravel!

So, without friction, you would not have any clothes to wear, as all fabric will unravel; no place to live, as everything would be pulled towards the center of the earth by gravity; no way to start or stop moving; and no way to live the same live we’ve been living! Just this once, let’s ignore all the inconveniences that friction causes us, and thank friction for allowing us to do all these wonderful things!