# B Relationship between mathematics and existing objects

1. Mar 27, 2017

### Mohd Abdullah

Hey guys,

Can the use of mathematics even describe or determines the real world? I mean, mathematical physicists always used and rely on math equations to abstract math "entities" like quantum field, virtual particles, quarks, gluons, etc. Can a physicist used math to determine the existence of, say, a small asteroid or a cat?

2. Mar 27, 2017

### Staff: Mentor

What do you mean by "determine the existence"? To know that there is an asteroid, or a cat, you have to observe them. To measure where they are, how large their mass is, and other properties, mathematics is used. Sometimes even the observation itself relies on more or less complex mathematics.

Quantum fields and so on are the best tools we have to describe the observed results of particle collisions and other interactions.

3. Mar 27, 2017

### Staff: Mentor

You don't need quantum mechanics or cosmology for that argument. Classical physics will do.

To drive to the next village 5 miles apart, you will need 10 minutes to get there, if you drive at 30 miles per hour.
From that you cannot conclude the existence of the car or the village. Nevertheless, it tells you when to start, if your invited for tea at a certain time. So mathematics helps you to get the answers. It cannot help you to get a car into existence.

This is a purely philosophical question at best, a religious one at worst. Both are topics we won't discuss here.

4. Mar 27, 2017

### Mohd Abdullah

I think we can determine the existence of an object without using mathematics. An object wouldn't be an object if it doesn't have shape. So, object is that which has shape.

An object that is exist is that which has a relative location. For example, the Moon has a location relative to Earth and Sun. Thus, Moon exists.

The existence and shape of Moon doesn't depend on anyone's observation. If someone said the existence of Moon depends on observation, that means as long as we don't see or can't observe the Moon, Moon doesn't exist but the Moon is actually there with its definite shape and relative location to other objects.

5. Mar 27, 2017

### Staff: Mentor

Not all objects are as easy to see as the Moon or a cat. Sometimes you need to analyze a lot of data to determine that there is an object. This analysis uses mathematical tools.
The object exists independent of our observations, but we need mathematics to discover it.

6. Mar 30, 2017

### Ion Aguirre

Most times, maths help for building what's named a "Model". A Model is a mathematical structure, founded on hypothesis and onservations, which predictions and results fit reality.
Many times, we have no means to know how reality "really" is. Then, our Model becomes the only available working tool and is taken as "true" or "good" until any prediction fails.
Without going to very deep theories, a thing as "obvious" as fluid mechanics is mostly supported by models that we know, are not perfect.
Why real flight tests are required for the final study of a new plane prototype ? Obviously, becouse the Models are not complete, or .... may even be they are wrong ....

For making predictions such as the existence of a cat, or a car, or yourself, the requirement is building the suitable model, and as far as I know, there is not such one.
Who knows ? May be somebody would arrive to the Model of Everything ?
A model predicted the Blackholes and Supernovae, a model predicted many of the subatomic particles we know now ..... may be, there is, anywere hidden in Nature, that model that explains why and how everything IS and works.