How did scientists arrive at the conclusion about the earth's characteristics?

Question

How did scientists arrive at the conclusion about the earth's characteristics?

Answer 1

Theory, hypothesis, observation and testing.  it is a continuing process.

Which characteristics are you specifically thinking about?

Answer 2

The conclusions that scientists have reached about Earth's characteristics were made after scientific investigation.  Example:  The study of the speed and direction of earthquake-created seismic waves, which travel through the interior of the Earth, led to the conclusion that the Earth's inner core is solid but the outer core is liquid.

Answer 3

Through years and years of study. Through millions of scientist, working around the clock, proving these things to be true. A scientist just doesn't say "Hey, the Earth is round" and then it is excepted. They have to prove their theory is true. In many cases, it took many scientist, lifetimes to prove the idea as fact.

Answer 4

this question is quite familiar.....you study in science high? are u Filipino????

example no. 1 (about earth's shape)

Now that we have access to space, the easiest way to prove the Earth is spherical is to leave it and view it from a distance. Astronauts and space probes have done just that. Every picture of Earth ever taken shows only a circular shape, and the only geometric solid which looks like a circle from any direction is a sphere.

One of the oldest proofs of the Earth's shape, however, can be seen from the ground and occurs during every lunar eclipse. The geometry of a lunar eclipse has been known since ancient Greece. When a full Moon occurs in the plane of Earth's orbit, the Moon slowly moves through Earth's shadow. Every time that shadow is seen, its edge is round. Once again, the only solid that always projects a round shadow is a sphere.

example no 2 (earth's size)

two centuries before the birth of Christ, Eratosthenes devised a way to determine the size of the earth

Eratosthenes calculated a remarkably accurate measurement of the circumference of earth by doing an experiment. His idea was to think of the earth as an orange cut in half, and if you walked along the edge of the orange, your path would be circular. Since he couldn't walk around the world, he determined that if he could divide the cross-section of the earth into equal-size wedges, like pizza slices, he would only need to measure one of the arcs from one of the wedges (the length of the pizza crust of one slice) and multiply that by the number of arcs (number of pizza slices).

    * For example, if a pizza is cut into 8 equal slices, and the crust from one of the slices measures 2", the circumference of the pizza would be 16":

          o 8 (slices) x 2" = 16"

    * Now to apply this to the earth, if a cross-section of the earth at its widest point could be divided into 10 equal wedges, and the arc from one of the wedges measured 4,000 km, then the circumference of the earth would be 40,000 km:

          o 10 (wedges) x 4,000 km = 40,000 km

In order to make an accurate calculation of the circumference of the earth using this method, you would therefore need to divide the earth's cross-section into a number of equal-size wedges and then, measure the arc of one of the wedges. However, how did Eratosthenes determine how many equal-size wedges to divide the cross-section of the earth, and how did he make measure the arc of one of the sections?

In order to answer the first question, Eratosthenes used Geometry. If you could determine the angle that one of the wedges makes at the center of the cross-section, you could figure out out how many wedges make up the circle. Let's take a look at the following example:

    Central Angle In the circle to the left, angle ABC, also known as the central angle, is 60 degrees. Since there are 360 degrees in a circle, then there are 6 slices in this "pie" (360/60 = 6). That means that 6 arcs (AC) would fit around the globe. Now, all you need to know is the distance of AC and you would be in business!

However, finding this central angle in a cross-section of the earth seems just as impossible as finding the diameter; but, as it turns out, this was Eratosthenes' brilliant insight. He discovered it by studying shadows!