How do we know the age of the universe?

Astronomers estimate the age of the universe in two ways: 1) by looking for the oldest stars; and 2) by measuring the rate of expansion of the universe and extrapolating back to the Big Bang; just as crime detectives can trace the origin of a bullet from the holes in a wall.

What evidence do we have that dark energy exists?

While Lee’s team asserts that the redshift of these supernovae is the strongest evidence for dark energy (and that additional evidence for dark energy is flawed), it is not the only evidence. Two other main sources of evidence are cosmic microwave background (CMB) and baryon acoustic oscillations (BAO).

What happens in a closed universe?

If space has positive curvature, there is more than enough mass to stop the present expansion of the universe. Thus, at some point in the future the galaxies will stop receding from each other and begin approaching each other as the universe collapses on itself. This is called a closed universe.

What is meant by a closed universe?

Definitions of closed universe. (cosmology) a universe that is spatially closed and in which there is sufficient matter to halt the expansion that began with the big bang; the visible matter is only 10 percent of the matter required for closure but there may be large amounts of dark matter.

What would happen to the universe without dark energy?

If wanted the Universe to have the same exact amount of matter in it, but with no dark energy, our Universe would have expanded faster early on, and would be expanding slower today.

What evidence is there about dark energy and the universe?

The evidence for dark energy is indirect but comes from three independent sources: Distance measurements and their relation to redshift, which suggest the universe has expanded more in the latter half of its life.

What is a closed universe assignment?

constructing a first-semester closed-universe assignment, a legal writing professor faces a series of choices— general topic, jurisdiction, cases, issues, and more.” & Writing 58, 58 (1995) (“The design of assignments is perhaps the most important pedagogical activity in teaching legal research and writing.”).

Is the universe flat or closed?

However, a new look at the cosmic background radiation — the echo of the first light of the Universe — shows everything around us may have a closed shape, like a sphere. The Lambda-Cold Dark Matter (LCDM) model is, currently, our best understanding of the visible Cosmos. One of the fundamental conclusions of this model is that the Universe is flat.

What is the shape of the universe?

The Universe is thought to (likely) have one of three intrinsic shapes —a closed round sphere, a negative saddle shape, or a flat sheet — and most physics leans toward the flat Universe. Image credit: NASA Run, Run, Run, Run Away…

Is the universe homogeneous or isotropic?

Answer Wiki. As closely as we can measure, the observable universe is approximately a sphere and we are at the center of it. The standard assumptions of cosmology is that the universe is isotropic and homogeneous.

What did Galileo discover about the universe?

Galileo sparked the birth of modern astronomy with his observations of the Moon, phases of Venus, moons around Jupiter, sunspots, and the news that seemingly countless individual stars make up the Milky Way Galaxy.