Astronomy Flashcards
What should baryonic matter (physics) only include?
matter composed of baryons
What does it mean that by definition baryonic matter should only include matter composed of baryons
it should include protons, neutrons and all the objects composed of them (i.e. atomic nuclei)
What should baryonic matter exclude?
Things such as electrons and neutrinos which are actually leptons
What is a lepton?
a subatomic particle, such as an electron, muon, or neutrino, which does not take part in the strong interaction.
What portion of dark matter is considered likely to be baryonic?
Only a small portion
As “dark matter”, baryonic dark matter is undetectable by its _____________, but its presence can be inferred from gravitational effects on visible matter.
Emitted radiation
As “dark matter”, baryonic dark matter is undetectable by its emitted radiation, but its presence can be inferred from ____________ on visible matter.
Gravitational effects
Dark matter is a type of matter that may constitute about ____________of the total matter in the universe. It has not been directly observed, but its gravitational effects are visible in a variety of astrophysical observations.
80%
Dark matter is a type of matter that may constitute about 80% of the total matter in the universe. It has not been directly observed, but its ____________ are visible in a variety of astrophysical observations.
gravitational effects
___________ that filled the universe a mere second after the big bang make up a third component of the cosmos alongside dark matter and dark energy.
New Scientist 14 April 2018
Neutrinos
Neutrinos that filled the universe a mere second after the _________ make up a third component of the cosmos alongside dark matter and dark energy.
Big bang
Neutrinos that filled the universe a mere second after the big bang make up a third component of the cosmos alongside dark matter and ___________.
Dark energy
Moments after the ___________ our universe was a seething sea of particles, packed together and constantly bouncing off one another. Among the first to break free from this dense plasma as the universe expanded were neutrinos, which then formed the cosmic neutrino background. These neutrinos are everywhere but impossible to detect because of their low energies.
New Scientist 14 April 2018
big bang
Moments after the big bang our universe was a seething sea of particles, packed together and constantly bouncing off one another. Among the first to break free from this dense plasma as the universe expanded were ___________, which then formed the cosmic neutrino background. These neutrinos are everywhere but impossible to detect because of their low energies.
New Scientist 14 April 2018
Neutrinos
Moments after the big bang our universe was a seething sea of particles, packed together and constantly bouncing off one another. Among the first to break free from this dense plasma as the universe expanded were neutrinos, which then formed the cosmic neutrino background. These neutrinos are everywhere but impossible to detect because of their ____________.
New Scientist 14 April 2018
low energies
According to the ____________, about 30,000 years after the big bang, random quantum fluctuations led to some regions having more dark matter than others. Normal matter gravitationally fell towards these pockets only to rebound away as photons in the dense plasma pushed against particles of matter. Thin dense shells of normal matter began speeding away from each pocket of dark matter like sound waves from a popped balloon.
New Scientist 14 April 2018
Standard model of cosmology
According to the standard model of cosmology, about ____________________, random quantum fluctuations led to some regions having more dark matter than others. Normal matter gravitationally fell towards these pockets only to rebound away as photons in the dense plasma pushed against particles of matter. Thin dense shells of normal matter began speeding away from each pocket of dark matter like sound waves from a popped balloon.
New Scientist 14 April 2018
30,000 years after the big bang
According to the standard model of cosmology, about 30,000 years after the big bang, random quantum fluctuations led to some regions having more dark matter than others. Normal matter gravitationally fell towards these pockets only to rebound away as _____________ in the dense plasma pushed against particles of matter. Thin dense shells of normal matter began speeding away from each pocket of dark matter like sound waves from a popped balloon.
New Scientist 14 April 2018
photons
According to the standard model of cosmology, about 30,000 years after the big bang, random quantum fluctuations led to some regions having more dark matter than others. Normal matter gravitationally fell towards these pockets only to rebound away as photons in the dense plasma pushed against particles of matter. Thin dense shells of normal matter began speeding away from each pocket of _____________ like sound waves from a popped balloon.
New Scientist 14 April 2018
Dark matter
Shells of _________s did the same. These were larger than the shells of normal matter because ________s are lighter and travel faster. The gravitational influence of the __________ shells subtly changed the size and shape of the shells of normal matter.
New Scientist 14 April 2018
neutrino
Shells of neutrinos did the same. These were larger than the shells of normal matter because neutrinos are lighter and travel faster. The ________________ of the neutrino shells subtly changed the size and shape of the shells of normal matter.
New Scientist 14 April 2018
Gravitational influence
Shells of neutrinos did the same. These were larger than the shells of normal matter because neutrinos are lighter and travel faster. The gravitational influence of the neutrino shells subtly changed the size and shape of the shells of __________.
New Scientist 14 April 2018
normal matter
When the __________ cooled enough to stop both types of shells from propagating outward, about 380,000 years after the big bang, they were frozen in time. The shells became regions where more galaxies eventually formed because they were denser than other areas of space.
New Scientist 14 April 2018
universe
When the universe cooled enough to stop both types of shells from propagating outward, about 380,000 years after the ________, they were frozen in time. The shells became regions where more galaxies eventually formed because they were denser than other areas of space.
New Scientist 14 April 2018
Big bang
