# How does the brain instinctively know the math behind Newtonian Physics?

A 10 year old child does not have the intellectual power to accurately calculate the energy required to throw a ball an arbitrary distance. Yet they are able to accurately throw a ball at a distinctive target.

Similarily, we often "instinctively" know an approximation of the amount of energy and force required to accomplish certain tasks, even considering that many of us have minimal knowledge of the mathematical complexity behind the tasks.

How does the human brain know the values of force, energy etc. required when accomplishing certain tasks, while being ignorant of the mathematics behind the Newtonian Physics of the task? Is it just a game of "guess and check"?

• @nico It would unreasonable to expect a 10 year old of average intelligence to be able to create a mathematical model of a a ball thrown - a concept taught in highschool. I do not understand your second comment. Could you clarify it?
– user1199
Aug 1, 2012 at 16:41
• You don't need to generate a complex mathemathical model in order to throw a ball. A toodler can do it. You just try and try and you learn. A 10 year old may not be able to tell you that a 45° angle is the optimum to have a long throw, but he can easily realise that when he throws balls at that angle (even if he does not quantify it exactly) they go further away. Think of walking: most of us do it with no issue. Almost noone, however, is able to do a correct mathematical/physical model for standing and walking.
– nico
Aug 1, 2012 at 17:15
• The second comment was just a reference to the old myth that -according to the laws of physics- bumblebees could not fly. However, as they don't know these laws they continue to fly with no problem. Of course this is false: you don't need to know the laws of physics in order for them to work (and for you to make use of their effects).
– nico
Aug 1, 2012 at 17:17
• Forget 10-year-old children. Pigeons literally have a pigeon brain, yet they can integrate complex ODE systems in real-time. Aug 1, 2012 at 21:30
• I think this question makes much more sense, and will receive a better answer at CogSci.SE Aug 2, 2012 at 14:42

Trial and error.

The CNS is very much a living, changing organ system - much more so before you are an adult. While you are a child your neurons fire, muscles contract, and force is exerted on objects - then your CNS modifies itself (either through redistribution of neural contacts or growth of new neurons spurned by chemical changes) to account for the results.

This is why "practice makes perfect." As you continuously perform a task, like throwing a ball, your body is keeping track of the results. Did X muscle fibers contracting in Y muscles overshoot your buddy? You register the failure and compensate by utilizing X-N muscle fibers that contract in Y muscles until you consistently satisfy your goal.

Your CNS is keeping track of everything, all the time. There isn't a single instant in your life - asleep or awake - that's not being monitored, so your body has copious amounts of data to work with when making its estimates.

This is also why simulations take time to adapt to, even if the person is fully aware of the basics behind the physics involved.

First of all a little detail : laws of physics describe what is going on, they are not what is actually going on. Beeing able to make nearly precise predictions about the outcome of a certain action is what those formulas are about, as well as getting a feeling of how and why it actually happens this way. I would bet that neither Newton nor Einstein or any great head of physics ever tried to predict a real life action by the mathematics they know.

The key to understand how organisms predict actions is heuristics. So you and any organism on earth uses other intuitively calculated values for predicting actions. You can easily predict that every object you throw in the air will fall to the ground whether you are a physicist or not.

Prof. Gigerenzer explained this phenomena at this presentation at 36:50 unfortunately this is in German, but maybe the pictures he shows help a little bit. https://youtu.be/IderadHRCu8

An easy example: a dog that is trying to catch a thrown freesbee in the air does not know anything about mathematics. But dogs actually seem to be pretty good at predicting where a freesbee is in a good position to get caught while it is still in the air. How they do this? A dog is focusing the freesbee at a certain angle to themselve at which it would be good to get caught when they are close enough. They then ran fast or slow, always keeping the same angle, not the same distance, to the freesbee. No matter the parabola of the freesbee as long as the dog keeps the angle all is fine. When the freesbee comes close enough to get caught, the dog bites and catches the freesbee.

Do we do unconscious mathematics? Yes kind of easy sensoric heuristics. Do we do unconscious mathematics like physics? Definetly not, as I said Newton and others are formulas that work well to EXPLAIN what happens, they are not what is actually happening.

• +1 for the first sentence. Exactly what I was going to comment. Jan 28, 2018 at 17:02

And just to be different.

You are looking at 30 million years of evolution and natural selection to be able to gauge distance and relative position in 3 dimensional space accurately. The penalty of making a mistake is death by falling out of a tree. http://anthro.palomar.edu/earlyprimates/early_2.htm

As for throwing... that is another 3 million years of evolution on how to use such a tool. The penalty for missing a target... well I am guessing it is to be eaten or have your child eaten by one or more predators. https://en.wikipedia.org/wiki/Oldowan

Humans are good at throwing things... better than good. Human can throw fast and accurately. Our shoulder joints have undergone natural selection such that humans have weird shoulder blades compared to other great ape. http://www.natureworldnews.com/articles/16572/20150909/ape-human-evolution-more-clues-revealed-shoulders.htm

If there was enough selection pressure to reshape the shoulder of an ape to enable it to throw rocks (projectiles) fast, I am sure that was equal pressure on the software side to make sure said rock hits its intended target.