Why did the era of nuclei end when the?
6) Why did the era of nuclei end when the universe was about 300,000 years old? A) Neutrinos and electrons were finally able to escape the plasma of the early universe and no longer heated the other particles.
Why is the nucleosynthesis era so important in determining the chemical composition of the universe?
Answer: The era of nucleosynthesis is important because during this time all the primordial hydrogen and helium was created from the nuclear fusion process. Except for the few percent of matter that stars later fused into heavier elements, the chemical composition of the universe remains unchanged today.
Why can’t Current theories describe what happened during the Planck era?
Why can't current theories describe what happened during the Planck era? We do not yet have a theory that links quantum mechanics and general relativity. unify the strong force and the electromagnetic and weak forces. Two, gravity and the GUT force.
Why did the era of nuclei end when the universe was about 380000?
Why did the era of nuclei end when the universe wasabout 380,000 years old? The universe had expanded and cooled enough for stable,neutral atoms to form.
What happened during the Era of nuclei?
In the Era of Nuclei, between 3 minutes and 500,000 years, the Universe's temperature dipped, causing fusion to stop. What is this? The nuclei formation ended, leaving the Universe with ionized atoms. During this epoch, the temperature of the Universe is between 10^9 Kelvins and 3000 Kelvins.
What happened in the nuclei Era?
Era of Nuclei. Nuclear reactions could occur until about 3 minutes after the Big Bang. At this point the temperature became too low for them to continue. However, the temperature remained high enough to keep all the atoms ionized (electrons free from the nuclei) until about 300,000 – 500,000 years past the beginning.
What event made it possible for photons to begin to travel freely through the universe when the universe was about 380000 years old?
What event made it possible for photons to begin to travel freely through the universe when the universe was about 380,000 years old? The universe had expanded and cooled enough for electrons to combine with nuclei to form neutral atoms.
What happens to gas as it freely expands?
The combined mass of the two particles is completely transformed into energy (photons). What happens to gas as it freely expands? It gets more dense and heats.
What happened during the Planck era?
The Planck era is defined as the time when the universe was the size of the Planck length, 10−33 cms, and less, and the universe's age was 10−43 sec, the Planck time, and less. It is the earliest epoch we identify after the Big Bang. The Planck temperature at the end of the epoch was about 1032 degrees Kelvin.
What happened in particle era?
During this era, particles continually were created and destroyed until, by 0.001 s (one millisecond), the universe had expanded and cooled far enough (to 1012 K) that creation and destruction of this kind ended. For some reason, the universe created slightly more matter particles than anti-matter particles.
What happened during the era of nuclei?
In the Era of Nuclei, between 3 minutes and 500,000 years, the Universe's temperature dipped, causing fusion to stop. What is this? The nuclei formation ended, leaving the Universe with ionized atoms. During this epoch, the temperature of the Universe is between 10^9 Kelvins and 3000 Kelvins.
What happened in the era of atoms?
The Era of Atoms (380,000 years – 1 billion years or so) began as the universe finally cooled and expanded enough for the nuclei to capture free electrons, forming fully-fledged, neutral atoms. Previously trapped photons were finally free to move through space, and the universe became transparent for the first time.
What happened during the matter era?
In the Big Bang theory, the era that started when the gravitational effect of matter began to dominate the effect of radiation pressure. Although radiation is massless, it has a gravitational effect which increases with the intensity of the radiation.
When did the photons in the cosmic microwave background first travel freely through the universe?
– Photons could first travel freely when the universe was about 380,000 years old and had a temperature of about 3,000 K. These photons are what we see today—almost 14 billion years later—as the cosmic microwave background.
What is meant by free expansion?
the expansion of a gas into an evacuated space without the transfer of heat or the performance of work.
Is free expansion possible?
The free expansion of a gas is an irreversible process; in principle, the temperature of a gas undergoing a free expansion is not a meaningful quantity. When we talk about an isothermal free expansion of a gas, we mean that the final temperature is the same as the initial temperature.
What happened during the Quark era?
During the quark epoch the universe was filled with a dense, hot quark–gluon plasma, containing quarks, leptons and their antiparticles. Collisions between particles were too energetic to allow quarks to combine into mesons or baryons.
What happened during the era of Nuclei?
In the Era of Nuclei, between 3 minutes and 500,000 years, the Universe's temperature dipped, causing fusion to stop. What is this? The nuclei formation ended, leaving the Universe with ionized atoms. During this epoch, the temperature of the Universe is between 10^9 Kelvins and 3000 Kelvins.
What happened during the quark Era?
During the quark epoch the universe was filled with a dense, hot quark–gluon plasma, containing quarks, leptons and their antiparticles. Collisions between particles were too energetic to allow quarks to combine into mesons or baryons.
What happened during Era of atoms?
The Era of Atoms (380,000 years – 1 billion years or so) began as the universe finally cooled and expanded enough for the nuclei to capture free electrons, forming fully-fledged, neutral atoms. Previously trapped photons were finally free to move through space, and the universe became transparent for the first time.
What happened in the quark epoch?
During the quark epoch the universe was filled with a dense, hot quark–gluon plasma, containing quarks, leptons and their antiparticles. Collisions between particles were too energetic to allow quarks to combine into mesons or baryons.
What happened during quark epoch?
During the quark epoch the universe was filled with a dense, hot quark–gluon plasma, containing quarks, leptons and their antiparticles. Collisions between particles were too energetic to allow quarks to combine into mesons or baryons.
What happened during radiation era?
The period from about 10−43 s (the Planck era) to 30 000 years after the Big Bang. During this time, the expansion of the Universe was dominated by the effects of radiation or high-speed particles (at high energies, all particles behave like radiation).
During which age of the universe do photons begin to move freely?
This was the moment of first light in the universe, between 240,000 and 300,000 years after the Big Bang, known as the Era of Recombination. The first time that photons could rest for a second, attached as electrons to atoms. It was at this point that the universe went from being totally opaque, to transparent.
What happens in free expansion of gas?
Free expansion of a gas occurs when it is subjected to expansion in a vacuum (pex=0). During free expansion of an ideal gas, the work done is 0 be it a reversible or irreversible process. Where ∆U represents the change in internal energy, q is the heat given by the system and w is the work done on the system.
What happens in free expansion?
The Joule expansion (also called free expansion) is an irreversible process in thermodynamics in which a volume of gas is kept in one side of a thermally isolated container (via a small partition), with the other side of the container being evacuated.
Why free expansion is irreversible?
When the gas expanded, its entropy increased. The compress/cool process can move that new entropy to the environment, but it can't make that new extra entropy go away. So the process is not reversible: there's no way to put everything back.
When did quarks become confined to normal particles?
The quark epoch ended when the universe was about 10−6 seconds old, when the average energy of particle interactions had fallen below the binding energy of hadrons. The following period, when quarks became confined within hadrons, is known as the hadron epoch.
What happened in the hadron era?
The short period from about 10−6 s to 10−5 s after the Big Bang when heavy atomic particles such as protons, neutrons, pions, and kaons were formed. Before the start of the hadron era, quarks behaved as free particles. The process by which hadrons formed from these quarks is called the quark–hadron phase transition.
What happened during lepton era?
In physical cosmology, the lepton epoch was the period in the evolution of the early universe in which the leptons dominated the mass of the Universe. It started roughly 1 second after the Big Bang, after the majority of hadrons and anti-hadrons annihilated each other at the end of the hadron epoch.