It is possible that the extra 7 dimensions of space in string theory, (that are not perceived), are mathematical deception. This mathematical deception first appeared with 5 dimensional Kaluza-Klein Theory.

String theory is possibly deception, derived from adding dimensions of space to the already existing 3 dimensions of space one dimension at a time at 90 degree angles to the previous dimension.

That string theory is possibly invalid is stated at the end of the wikipedia article on string theory.
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Complexity of mathematical description does not equate to wrongness.

There is no way to test *any* cosmological hypothesis…unless you had a really big lab and billions of years of time on your hands.

If M-theory explains things more efficiently than other theories, what's the problem? If someone proves that it is incorrect or inaccurate, then it will be discarded for the better explanation.
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In its most recent form, it consists of six level contests from pre-algebra through calculus, run in the fall and spring of each academic year. Over 500 students and dozens of schools now participate.

Cistercian has a proud history of excellence in the McNabb, from its inception when Cistercian won the first team and individual contest, through the present, when in the past academic year, Cistercian captured 5 of the 12 team championships.
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http://www.cistercian.org/school/faculty/RNewcomb/mcnabb_team_results_fall_and_spr19992000.htm

Acceleration doesn't need to be taught in calculus. A calculus course could be completely abstract, without reference to the real world. But, calculus has found an extremely wide range of application, so it makes sense to bring in the applications in a calculus course, not least because those taking the course may want to apply to real world problems (physicists, engineers, even business men), but it also helps heuristically if it relates to the real world, things that are tangible and 'knowable'.
That is to say, calculus does not depend on physics. Calculus to be completely abstract. But it is quite unlikely that physics would have gotten far without calculus. Just about every branch of physics can be dealt with within the framework of calculus- dynamics, kinematics, hydraulics…- you name it. Some topics in physics would even be impossible without calculus, such as variable acceleration. Even in quantum mechanics, where (almost) everything is discrete, calculus plays an important role.
But, one could say that certain physics problems which required an analysis with calculus, sort of spurred on the developement of calculus, in a similar way that engineering problems pushed physics forward (think Fourier Series etc.).

Why does calculus find so much application in physics? Calculus basically deals with infinitesimal changes- changes that are not zero, but smaller than any imaginable real number. In physics (reality) the universe operates with infinitesimal changes. So calculus (specifically, infinitesimal calculus) works splenidly with the real world where things can be analysed infinitesimally. And such infinitesimal analyses covers the (usual) situation where the quantity in question is not constant, or not even changing at a constant rate, which would not be possible without calculus.
And that would explain why calculus and physics are difficult. Calculus requires thinking about infinitesimal changes, which sound quite contradictory and mind-boggling. Calculus is unlike any other branch in mathematics. Also, physics requires a sort of "visualisation" and intuition about physical reality.
One must also remember that the topics covered in one physics or calculus course (at university) may have taken thinkers and scientists centuries, and even millenia, to come to grips with, and all that thought is condensed into a semester or one year.

It makes you think….
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Me

PHYSICS , LIKE ALL OTHER SCIENCE SUBJECT, IS BASED ON REASONING OF CAUSE AND EFFECT OF NATURAL PHENOMENON . THE REASONING IS BEST EXPLAINED BY MATHEMATICAL PRINCIPLES . MATHEMATICS AGAIN IS BASED ON PHILOSOPHICAL TRUTHS FORMULATED IN NUMBERS.
SOME NUMBERS ARE DESCRETE AND WE USE THEM IN OUR DAY TO DAY LIFE AND EASILY UNDERSTOOD . TRANSITION OF ONE NUMER TO ANOTHER IS EXPLAINED BY DECIMALS. FOR FINER TRANSITION WE NEED SOME CONTINUOS FUNCTION WHICH MAY REPRESENT CONTINUITY OF NATURAL PHENOMENON AT ANY TIME INSTANT . CALCULUS DEALS WITH SUCH FUNCTIONS OF VARIABLES ANALYTICALLY .
SOME PERSONS ARE GOOD WITH REAL DIGITAL MATHEMATICS BUT NOT SO COMFORTABLE WITH ANALYTICAL ONE JUST LIKE SOME ARE GOOD AS SCIENTISTS , SOME ARE BETTER AS BUSSINESSMAN.
Those with analytical bend of mind will be more comfortable with calculus and physics among intelligent student community.
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v = d (s) / dt

a = d (v) / dt

v = rate of change of position, with respect to time

accel = rate of change of vel., with respect to time

These are concepts which are easy to understand.
It's applying mathematical formulation to physical scenarios in the real world that i find difficult. Hence your question I suppose
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