Why did the solar nebula begin to collapse to form the sun and planets if the forces of pressure and gravity were balanced?

Answer 1

We can't be certain of the exact sequence of events, but there are a few things we're pretty sure of. Because the Earth is made of iron, and silicon, and lead and gold and uranium, we know that the Earth and our solar system are "third generation", or later; we formed from the wreckage of earlier stars that went supernova. Supernova explosions are the ONLY way that these heavy elements can be formed. It probably took more than one supernova to create the heavy elements we find here.

From the gas and dust existing in space and thrown off from the supernovae, a nebula formed, and gradually began to condense under the influence of gravity. Here's where it gets interesting. Mathematical simulations of a condensing nebula doesn't seem to generate a solar system - UNLESS an external shock wave causes it to collapse. So it probably took one more supernova, and not too far away, to cause our solar system to form when it did.
Gravity.

Answer 2

The most likely scenario is that a nearby nova caused pressure waves in the interstellar medium, resulting in spots of critical density within the nebula, that then continued to collapse in on themselves.

Answer 3

The formation and evolution of the Solar System is estimated to have begun 4.6 billion years ago with the gravitational collapse of a small part of a giant molecular cloud. Most of the collapsing mass collected in the centre, forming the Sun, while the rest flattened into a protoplanetary disc out of which the planets, moons, asteroids, and other small Solar System bodies formed.

Answer 4

Gas and dust that make up nebula are made of matters. The matters of nebula are held together by gravity. There are lots of space in nebula between the particles. Gravitational attraction between the particles keeps them from drifting apart in a sphere.

Answer 5

The solar nebulae formed when the Universe was still in its first stages. A nebula is an interstellar cloud in outer space that is made up of dust, hydrogen and helium gas, and plasma. It is formed when portions of the interstellar medium collapse and clump together due to the gravitational attraction of the particles that comprise them.

Answer 6

a.All the planets' orbits lie roughly in the same plane.b.The Sun's rotational equator lies nearly in this plane.c.Planetary orbits are slightly elliptical, very nearly circular.d.The planets revolve in a west-to-east direction. The Sun rotates in the same west-to-east direction.e.The planets differ in composition. Their composition varies roughly with distance from the Sun: dense, metal-rich planets are in the inner part and giant, hydrogen-rich planets are in the outer part.f.Meteorites differ in chemical and geologic properties from the planets and the Moon.g.The Sun and most of the planets rotate in the same west-to-east direction. Their obliquity (the tilt of their rotation axes with respect to their orbits) are small. Uranus and Venus are exceptions.h.The rotation rates of the planets and asteroids are similar---5 to 15 hours, unless tides slow them down.i.The planet distances from the Sun obey Bode's law---a descriptive law that has no theoretical justification. However, Neptune is a significant exception to Bode's "law" .j.Planet-satellite systems resemble the solar system.k.The Oort Cloud and Kuiper Belt of comets.l.The planets contain about 90% of the solar system's angular momentum but the Sun contains over 99% of the solar system's mass.

Answer 7

conservation of energy,

as the pressure rises, the temp rises

Answer 8

Gravity

And whatever caused the Big Banger

Answer 9

It flattened as a natural consequence of collisions between particles in the nebula, changing random motions into more orderly ones.

Answer 10

When a gas contracts, its temperature will increase. In this case, the gas contracts due to the gravitation.