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39 Cards in this Set
- Front
- Back
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Big Bang Theory |
Everything we see today began as an incredibely hot and dense collection of matter and radiation |
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Four Distinct Forces |
-Gravity -Electromagnetism -Strong Force -Weak Force |
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Electroweak Force |
The unified force of two of the four known fundamental reactions of nature |
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Grand Unified Theories |
Models that predict the merger of the electroweak |
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Planck Era |
-Represents times before the universe was 10(-43) second old -Sustainable energy fluctuations |
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GUT Era |
The merger of the strong, weak, and electromagnetic forces into a single GUT force |
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The Electroweak Era |
Marked the beginning of an era during which three three distinct forces operated: Gravity, The strong force, and the electroweak force |
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Particle Era |
-Spontaneous particle production -Protons and Antiprotons formed |
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Era of Nucleosynthesis |
-Gamma rays blasted apart nuclei -Fusion produced Helium from Hydrogen |
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The Era of Nuclei |
-Photons bounce from one electron to the next -Nucleas' manage to capture an electron to form a complete atom -The universe was filled with plasma of free electrons, H, and He |
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The Era of Atoms |
-When the universe consisted of a mixture of neutral atoms, atoms, and a large number of photons -Neutral Atoms formed |
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Cosmic Microwave Background |
Thermal radiation left over by the "Big Bang" |
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Olbers Paradox |
If the universe were infinite, unchanging, and filled with stars, the sky would be everywhere as bright as the surface of the sun, and it would not be dark at night |
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Dark Matter |
Name given to a mysterious mass in our galaxy |
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Dark Energy |
Mysterious force in our galaxy |
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Gravitational Lenses |
The theory that states matter bends light |
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What might dark matter must be made of? |
It could be made of either ordinary matter or exotic matter |
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Voids |
Giant empty regions that lie between chains and sheets of galaxies |
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Europa |
-Contains twice as much water as all earths oceans -Metallic Core -Rocky Interior |
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Habitable Zones |
Planets at intermediate distances from the sun |
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Climate Stability |
Due to tectonic plate activity |
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From what cosmic epoch do the photons in the cosmic background originate? |
The end of the era of nuclei |
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What evidence is there that there is dark matter in the milky way? |
We observe stars from the galactic center orbiting the galaxy at unexpectedly high speeds, higher speeds than they would have if they only felt the gravitational attraction from objects that we can see |
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Which of the following are the best candidates to search for planets that might harbor extraterrestrial life? |
Solar-Mass stars because they have both large habitable zones and a large stellar lifetime |
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Challenges of interstellar travel? |
High-speed interstellar travel would require Thousands of times as much energy as the world consumes each year |
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Fermi's Paradox |
Contradiction between high possibility of extraterrestrial civilization and the lack of contact or evidence of their existence |
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Ordinary Matter |
Planets & Failed/Dead stars |
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Exotic Matter |
-Weakly interacting massive particles -Mysterious neutrino mass particles |
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Orphan Planets |
-A planetary-mass object that orbits the galaxy directly -Ejected from planetary system |
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What caused protogalactic clouds to contract early in time? |
The Gravity of Dark Matter |
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Recollapsing Universe |
Lots of Dark Matter |
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Critical Universe |
Critical amount of dark matter |
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Coasting Universe |
Not enough dark matter |
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Accelerating Universe |
Not only is there not enough dark matter to stop expansion, but the expansion appears to be speeding up |
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What observed features of the universe motivated scientists to propose the big bang theory? |
The universe is expanding- galaxies have redshifts- and the expansion traces back to unique times in the past |
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Temperature in the early universe? |
The very early universe was so hot that energy was transformed into matter and matter into energy |
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Inflation |
During inflation tiny ripples in spacetime, that were smaller than a nucleas of an atom, stretched to the size of our solar system |
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What is the evidence for an accelerating expansion? |
The Four Expansion Models |
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Drake Equation |
An equation that predicts the amount of civilizations in the know universe |
