How we located on earth..?

Question

Couple of Simple/Silly Questions?

1. If earth is a sphere ? how exactly we are loacted? When we see from space all the land and oceans appear on the face of the earth! does it mean that we are 2D space.? hope my question is clear?

2. If earth rotates on its axis? Why we are not rotation along wiht it?

Answer 1

The surface of a sphere is a 2-D figure, embedded in 3-D space. The Earth is a 3-D object (almost a sphere) and we are 3-D things living on (or very near) its surface.

Positions on Earth are given by a coordinate system called latitudes and longitudes.

Because the Earth rotates around an axis, it is possible to define two poles: the points where the axis of rotation intersects the surface. If the Earth were a perfect sphere, we would then identify a great circle exactly 90 degrees from the poles and this line would be the equator. Then, smaller circles, parallel to the equator, would mark the latitudes. Latitude 10 N is the small circle located 10 degrees north of the equator. Of course, latitude 90 N is the North pole.

In practice, the celestial sphere was the first to get a coordinate system (declination and Right Ascension). Declinations are determined just as explained above (the celestial sphere appears to rotate around its poles, which are projections of Earth's poles, since the apparent movement of the celestial sphere is a reflection of Earth's spin).

Latitudes on Earth are defined by the declination that passes directly at the zenith (the point overhead). This takes care of the fact that the Earth's shape is almost-but-not-quite a sphere.

Longitudes are great circles that cross the equator at a right angle, and go through both poles. All meridians (as these lines are called) meet at the poles. They could be measured from any place (there is no prefered place) and, for a time, each country decided what was the 0 longitude for its maps.

A little over a 100 years ago, all countries decided on calling the meridian that goes through the observatory in Greewich (near London, UK) Longitude 0, and calculate a location's longitude from that meridian.

In nautical astronomy, Earth is treated as a sphere and its surface is treated as a 2-D object. Spherical trigonometry is used to solve spherical triangles.

In geometry (and other branches of mathematics), the sphere is a 3-D object and the surface of the sphere is simply the collection of all points (x, y, z), in 3-D, such that
x^2 + y^2 + z^2 = R^2
where R is the radius of the sphere and (0,0,0) is the centre of the sphere.

So, we are not in 2-D space, even though we can use equations designed for 2-D sub-spaces.

The Earth rotates and everything on Earth rotates with it. It is just that with one rotation per day, it is not always the most noticeable motion.

If you stood at the North pole and kept facing the same way (e.g., looking at the same star), you would turn on the spot at a rate of approx. 15 degrees per hour.

If you were at the equator and kept your eye on a star on the celestial equator, this star would appear to rise in the East, pass directly overhead and set in the West; you could imagine this star continuing on its circle, being directly below your feet 6 hours after setting. The star is not moving, you are doing a slow (very slow) tumble around the Earth's axis.

You don't feel it because the movement is too slow. You could calculate the centrifugal force caused by Earth's rotation on your body. It is a very small amount.

Answer 2

Hell is not physically located within the Earth, obviously! If you were able to drill to the center of the Earth, you would not discover Hell because it does not really exist anywhere, including in another dimension -- unless, of course, you believe in Hell, in which case, either answer could be true. The center of the Earth is (supposedly) molten iron, thus would be an ideal locale for Hell! However, since Heaven (if existent) occupies another dimension, presumably, you would expect the same then to apply to Hell because the two are opposites. You will have to resolve the answer of your own question; no one here can give you a definitive reply as no one has ever returned from Hell to describe its location!

Answer 3

The universe it "flat" but still very 3D. we just se a side of the earth from space. Go stare at a basketball. Then turn it.

We are rotating. Everything is rotating with the earth so we do not notice it.