Interpretation of negative values in the real world

[Macoleco]

I have always wondered if negative values have a meaning, and we just havent discovered how to use them.

For example, if we make an exercise about accelerated movement, and we obtain 2 values for time from a quadratic equation: one positive, and one negative. We are taught to ignore the negative value because it makes no sense in the real world. But is it really true?

I feel mathematics always tell us something. We just need to discover how to interpret negative values.

[vorlon13]

The square root of -1 is used in electronics and electrical engineering.

[robvalue]

I have always wondered if negative values have a meaning, and we just havent discovered how to use them.

For example, if we make an exercise about accelerated movement, and we obtain 2 values for time from a quadratic equation: one positive, and one negative. We are taught to ignore the negative value because it makes no sense in the real world. But is it really true?

I feel mathematics always tell us something. We just need to discover how to interpret negative values.

Sure, the solutions could potentially mean something in certain situations. The reason we ignore some of them is because they are outside the scope of the practical problem. Mapping the real world onto (whole) functions is not one to one; we are picking out a portion of the function which represents our situation. The rest of the function represents potential extrapolation beyond those boundaries, which may not be accurate (or even possible). You probably know all this, but anyhow You can't cut away 12cm from a 10cm piece of wood, or take -3s to come to a stop.

It is weird and fascinating, I agree. You could think of the other solutions as things that would happen in an alternate reality that was able to follow the path of the function outside the boundaries for which it is currently possible.

[vorlon13]

"Negative energy" is a real thing in the evaporation process of black holes.

Stephen Hawking seddso.

[Macoleco]

The square root of -1 is used in electronics and electrical engineering.

This is true. As an electrical engineering I have worked with imaginary functions. But we always end up coming back to frequency or time. We never stay on the imaginary world. My teacher said that it is not possible to interpret "s", the complex frequency. Now, I do not completely agree since as I said, may be we just dont understand it yet. But the imaginary numbers are more of a tool rather than an intepretation.

[vorlon13]

Sparky school for me being a very far time in the past indeed . . . .