General relativity is a metric theory of gravity, now verified to high precision via observations of the binary pulsar. As the temperature continued to drop, nuclear reactions occurred, converting protons first into deuterium and subsequently into the two forms of helium nuclei by the same reactions that now occur in stellar interiors: This allowed light to shine through aboutyears after the Big Bang.
A critical case universe has an intermediate helium abundance. For the real universe with a rate of expansion as observed Hubble Constant there are three possibilities. Whether dark energy is a type of dynamical fluid, heretofore unknown to physics, or whether it is a property of the vacuum of empty space, or whether it is some modification to general relativity is not yet known.
First, the cosmologists were very ingenious. The Big Bang was once a fireball. This is a clear prediction for closure of the universe.
ESA and the Planck Collaboration. In this case, the density must be the critical density given by where H o is the Hubble constant measured in the present day universe due to the gravitational deceleration, its value does change over time.
More energy means that the pressure of an elastic string is negative. Once the nuclear fuel supply of hydrogen, helium, and carbon is exhausted, the star soon runs out of fuel. There is no explanation for dark energy; it can simply be regarded as a contribution to the energy of the vacuum.
How Old is the Universe? The lightest supersymmetric particle or neutralino is such a possible stable relic. At some time in the history of the universe, the density of the radiation dropped below the density of the real mass see Figure.
Cosmic Blackbody Radiation Only about 10 percent of the dark matter in the universe is baryonic. These decayed or combined as the universe got cooler. The cosmic microwave background has demonstrated isotropy to a level of order 1 part inHowever, as the temperature drops further, all the strongly interacting particles annihilate into radiation.
One consequence is that the universe switched from deceleration under the influence of the gravitational attraction of matter to acceleration under the influence of the gravitational repulsion of the dark energy.
Ordinary gas pressure acts as a source of gravity. But all this leaves unanswered the question of what powered inflation.
To this must be added about 1 billion years for the delay between the Big Bang and the formation of the globular cluster, to give an age for the universe of some 14 billion years. One could now begin to reconstruct the thermal history of the universe.
In the "multiverse" model, different universes would coexist with each other like bubbles lying side by side. Cosmic Acceleration and Dark Energy What causes the acceleration?
Missions Study Cosmic Background Radiation NASA has launched two missions to study the cosmic background radiation, taking "baby pictures" of the Universe onlyyears after it was born.
This "stuff" has been dubbed dark energybut to give it a name is not to understand it. A lesser mass density in the universe means less deceleration, and the critical case universe has an intermediate deceleration.Org provides the latest news on astronomy, space, earth an analysis of the big bang theory in astronomy science and space exploration.
The Big Bang Theory is the leading explanation about how the universe began. At its simplest, it talks about the universe as we know it starting with a small singularity, then inflating over the next billion years to the cosmos that we know today.
What has become known as the Big Bang theory originally was an attempt by George Gamow and his coworkers to explain the chemical elements in the universe.
In this, the theory was incorrect because elements actually are synthesized in the interiors of stars, but the theory is still successful in. The Big Bang is the dominant (and highly supported) theory of the origin of the universe. In essence, this theory states that the universe began from an initial point or singularity which has expanded over billions of years to form the universe as we now know it.
The mathematical underpinnings of the Big Bang theory include Albert Einstein's general theory of relativity along with standard theories of fundamental particles. Today NASA spacecraft such as the Hubble Space Telescope and the Spitzer Space Telescope continue measuring the expansion of the Universe.
May 15, · Space has been expanding in all directions at the speed of light from the time of the big bang, when light interacts with negative-space it creates positive-space!
negative space is infinite yet we can never measure it because it only exists outside the realm of what is possible for us to explore 5/5(1).Download