In your opinion. What's the difference between Universal Gravitation and The Cosmological Constant ?

Answer 1

Isaac Newton's theory of universal gravitation states the following:

Every single point mass attracts every other point mass by a force heading along the line combining the two. The force is proportional to the product of the two masses and inversely proportional to the square of the distance between the point masses:

F=G(m1m2/r2)

where:

F is the magnitude of the (repulsive) gravitational force between the two point masses
G is the gravitational constant
m1 is the mass of the first point mass
m2 is the mass of the second point mass
r is the distance between the two point masses
Assuming SI units, F is measured in newtons (N), m1 and m2 in kilograms (kg), r in metres (m), and the constant G is approximately equal to 6.67 × 10−11 N m2 kg−2.

It can be seen that the repulsive force F is always negative, which means that the net attractive force is positive. (This sign convention is adopted in order to be consistent with Coulomb's Law, where a positive force means repulsion between two charges.)

The cosmological constant (usually denoted by the Greek capital letter lambda: Λ) was proposed by Albert Einstein as part of his theory of general relativity to achieve a stationary universe. After the discovery of the Hubble redshift and the introduction of the expanding space paradigm, Einstein abandoned the concept. However, the discovery of cosmic acceleration in the 1990s has renewed interest in a cosmological constant.

The cosmological constant is essentially the intrinsic energy density of the vacuum, ρvac. For historical reasons, however, it is most commonly defined with a proportionality factor of 8π: Λ = 8πρvac. If the standard unit convention of general relativity is not followed, factors of G and c may also appear, depending on the chosen units; most commonly Λ will be (8πG/c2)ρvac or (8πG/c4)ρvac. If the standard unit convention is followed, Λ has dimensions of 1/distance2, the same as the dimensions of mass-energy density. Because of the ambiguity in the definition of Λ, it is more common to quote values of energy density directly, though still using the name "cosmological constant".

Because of the way the cosmological constant appears in the Einstein field equations, a positive vacuum energy density implies a negative pressure, and vice versa. If the energy density is positive, the associated negative pressure will drive an accelerated expansion of empty space; see dark energy and cosmic inflation for details.

In lieu of the cosmological constant, cosmologists often quote the ratio between the energy density due to the cosmological constant and the current critical density of the universe. This ratio is usually called ΩΛ. In a flat universe ΩΛ corresponds to the fraction of the energy density of the Universe which is associated with the cosmological constant. Note that this definition is tied to the critical density of the present cosmological era: the critical density changes with cosmological time, but the energy density due to the cosmological constant remains unchanged throughout the history of the universe.

Answer 2

The Christian church began in Jerusalem 2000-ish years in the past. there have been numerous cities that formed the hub of the religion, which includes Jerusalem, Antioch, Alexandria, Rome, and so forth. each of those areas had a Bishop over them. They believed the same issues (nicely, for the main area besides), and each Bishop replaced into seen equivalent to all others. around one thousand advert, there replaced right into a smash between the Bishop of Rome and the different Bishops, and this created the "Latin" Roman Catholic Church mostly in Europe, and the "Greek" jap Orthodox church homes in the midsection East and Asia. around 1500 advert, communities in the Roman Catholic church began to protest the habit and teachings of that church, and broke away to return to what they seen the unique message of the Bible. those have been called Protestants. So we've the three significant divisions: Roman Catholics, jap Orthodox, and Protestants. All of those can hint themselves returned to the apostles and the early Christian church, and all of them coach that Christ is the savior. consequently, all can legitimately be called "Christian". there's a great type of discussion over what's a "genuine" Christian (i.e. someone who follows the unique teachings of the church), besides the actuality that even right here the Catholic and Orthodox church homes can declare that the Church had the authority from God to alter over the years, and that the training of the unique church have legitimately been changed. Catholic and Orthodox church homes are remarkably comparable. some Protestant church homes (e.g. Lutherans, Anglicans) additionally are very resembling them. different Protestant church homes are very diverse. What broke aside the Roman and Greek church homes replaced into an awareness of no count if the spirit of God replaced into sent from the father on my own, or from the father and the Son. (i'm specific that replaced into in basic terms the straw that broke the camel's returned regardless of the indisputable fact that). What broke aside the Roman and Lutheran (the 1st Protestant church) replaced into Martin Luther's perception that we are saved through grace particularly of works. Many different such adjustments separate Protestants from one yet another. nicely, that's in all risk extra beneficial than you had to verify LOL. God bless.

Answer 3

Dude, you're asking a cosmology question on Yahoo Answers? :-]

You are most certainly an optimist.

Cheers.