Believing only what you can see locally is wrong
Pythagoras’ theorem is that any number can be expressed by two smaller numbers according to the relationship c2=a2+b2. This was originally solved in Euclidean geometry, space with a curvature of zero, as the hypotenuse of a triangle. The relationship is true for a triangle in any geometry, including non Euclidean. It is just that under other geometries, the formula for the hypotenuse of a triangle is different because the sum of the angles in a triangle will be different. If the sum of the angles in a triangle is greater than 180 degrees, the curvature is positive and the non-Euclidean geometry is spherical. If the sum of the angles in a triangle is equal to 180 degrees, the curvature is 0, flat, and the geometry is Euclidean. If the sum of the angles in a triangle is less than 180 degrees, the curvature is negative and the non-Euclidean geometry is hyperbolic.
In Euclidean space, with a curvature of zero, the formula for
a hypotenuse is
c=sqrt(a2+b2)
But this is only the formula in Euclidean space. The Flat Earth
fallacy is because while locally space is Euclidean, the Earth is a large
sphere, with a radius R, has positive curvature, and the formula for a hypotenuse
which is its Great Circle Distance is
cos
(c/R)=cos(a/R)*cos (b/R)
When the radius of the
sphere is exceptionally large compared to c, a, and b, this is virtually indistinguishable
from the formula in Euclidean space, i.e. locally space is Euclidean but over
the entire surface of the Earth the geometry is spherical.
If the curvature is negative,
hyperbolic, the formula is
c=ln(cosh(a)cosh(b)±sinh(a)sinh(b))
Mabkhout[1]
proposed that the universe is globally hyperbolic and locally flat. If Einstein’s
equations are solved for universally flat space, then dark matter and dark energy
must be invoked in order to be
consistent with cosmic inflation immediately after the Big Bang; to solve the paradox of rotating galaxies; to solve
for the apparent difference in the size and the age of the observable universe;
and to result in an expanding universe. If the universe is globally hyperbolic,
then all of these issues can be resolved without invoking unseen dark energy or
matter. Additionally gravity may be only an apparent force and the time dilation,
length contraction, relativistic mass transform would not be the Lorentz transform, but would be
γ=1+ln(
Just because something is true locally, it is not necessarily so that it is true globally.
[1]
Mabkhout,
Salah A. "The infinite distance horizon and the hyperbolic inflation in
the hyperbolic universe." Phys. Essays 25.1 (2012): 112.