Term
| The Hubble’s law suggests that |
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Definition
| The recession velocity of a galaxy is proportional to the distance to it |
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Term
| The "critical density" of the Universe is defined as |
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Definition
| The density that determines whether the Universe will expands forever or re-collapse |
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Term
| _____ are the observational evidence of the Big Bang Theory |
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Definition
| Expansion of the Universe , Observation of the microwave background radiation , and Abundance of light elements in the Universe |
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Term
| Astronomers conclude that the Universe is flat because they |
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Definition
| they find that the angular distance between fluctuations in the cosmic background radiation of 1 degree is consistent with the prediction of the flat Universe model. |
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Term
| What is meant by the redshift? |
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Definition
| The spectral lines in the galaxy's spectrum are shifted to redder (longer) wavelengths. |
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Term
| The CMB is so cool now because |
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Definition
| The expansion of the Universe has cooled the radiation and stretched its wavelengths to microwave wavelength |
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Term
| The cosmic microwave background radiation represents |
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Definition
| a faint radio emission with the maximum power at the wavelength of 11 mm and is uniformly distributed across the sky and a remnant (relic) radiation from the Big Bang |
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Term
| A cosmological model of the Universe with density greater than the critical density |
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Definition
| will be closed and first expand, then slow down and contract into a Big Cranch |
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Term
| Cosmology as a science is based on the following |
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Definition
| The general relativity theory and The cosmological principle |
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Term
| What do astronomers infer from the motion of the distant galaxies? |
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Definition
| The Universe is expanding |
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Term
| First stars in the Universe were formed |
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Definition
| at around 1 million years after the Big Bang |
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Term
| The CMB was created as a result of |
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Definition
| The afterglow radiation left over from the Big Bang |
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Term
| Einstein's “Greatest Blunder' has to do with |
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Definition
| his failure to recognize the solution for an expanding universe by introducing a fudge term to make it static |
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Term
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Definition
| The repulsive force pushing space to expand with acceleration. |
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Term
| The Universe contains over ____ of dark energy |
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Definition
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Term
| Supernovae Type I are used to |
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Definition
| calculate distances to nearby and distant galaxies |
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Term
| Inflation theory of the Universe suggests |
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Definition
| a period of extremely rapid (exponential) expansion of the universe in the first 10-32 seconds after the Big Bang |
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Term
| A cosmological model of the Universe with density equal the critical density |
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Definition
| will be flat expanding forever |
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Term
| Cosmological principle suggests that |
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Definition
| The Universe has no center, no edges and no privileged directions in space |
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Term
| Suppose the Hubble constant turned out to be 140 km/sec/Mpc and not 70 km/sec/Mpc (the current value). How would that affect our estimate of the age of the Universe. |
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Definition
| The Universe would be about 7 billion yrs old |
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Term
| What force holds the Local Group together? |
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Definition
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Term
| Astronomers conclude that the Universe is expanding by observing |
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Definition
| The redshift in spectral lines of the galaxy’ spectrum. |
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Term
| About what temperature does the CMB have at the current epoch (time)? |
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Definition
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