What do scientists think the universe started as?

The Big Bang was the moment 13.8 billion years ago when the universe began as a tiny, dense, fireball that exploded. Most astronomers use the Big Bang theory to explain how the universe began.

Why do scientists think that the universe will expand forever?

If the density of the universe is less than this critical density, then the geometry of space is “open” and “negatively curved” like the surface of a saddle. If so, the universe has no bounds, and will expand forever.

What lies in the center of the universe?

There is no centre of the universe! According to the standard theories of cosmology, the universe started with a “Big Bang” about 14 thousand million years ago and has been expanding ever since. Yet there is no centre to the expansion; it is the same everywhere.

What does the shape of the universe depend on?

The shape of the universe depends on its density. If the density is more than the critical density, the universe is closed and curves like a sphere; if less, it will curve like a saddle.

Does the universe curve like a flat piece of paper?

If the density is more than the critical density, the universe is closed and curves like a sphere; if less, it will curve like a saddle. But if the actual density of the universe is equal to the critical density, as scientists think it is, then it will extend forever like a flat piece of paper. (Image credit: NASA/WMAP Science team.)

How do we know that the Earth is a sphere?

OK, so how do we know — scientifically — that the Earth is a sphere? At a very basic level, we can see the Earth’s curvature through satellites that we’ve launched into space. Additionally, through the use of high-powered telescopes, we’ve been able to examine planets both in our solar system and beyond, and all of them are spherical in shape.

What would the Big Bang result in a sphere shape?

I would think that the Big Bang would result in a sphere shape mass of energy, light, matter, heat, radiation, etc. and whatever else expanding outward while maintaining the shape of the sphere. The meaning of the Big Bang has been very often misunderstood.