Old Stuff
How many stars are there in the Solar System?
One!
What is the one way we know of that dark matter interacts with regular matter?
Through the gravitational force
How do we know the universe is expanding? In other words, how can we tell that almost all other galaxies are moving away from us?
We are measuring the Doppler shift of galaxies and find that most are redshifted (moving away from us).
What physicist first came up with the scientific idea that the universe had a beginning?
Georges LeMaitres
What do astronomers mean by calling it "dark" energy?
It means they don't know what it is.
How far will light travel in 1 month?
1 light month
What was strange about the galaxies the Vera Rubin was observing?
They seemed to be rotating much faster than expected.
What baked good did we use to represent the expansion of the universe?
Raisin bread.
What did Arno Penzias and Robert Wilson's radio static turn out to be?
The Cosmic Microwave Background Radiation
What do we think is happening to the Hubble constant as a result of Dark Energy? In other words, how is the expansion rate of the universe impacted by dark energy?
We think the Hubble Constant is increasing over time a.k.a. accelerating.
On the magnitude scale, every 5 magnitudes is equivalent to ___________ times in brightness?
100x brightness
Why is dark matter important in regards to the large-scale structure of the universe?
During the early stages of structure formation, gravity causes regular matter (gas, etc.) and dark matter to coalesce, or "clump up". Due to gas pressure, the hot regular matter resists being clumped up. Since dark matter has no gas pressure, it proceeds to clump up. Later, when the hot gas cools down, gravity will be able to clump it up too, and it will be gravitationally pulled towards the dark matter clumps that already formed. In this way, dark matter provides the framework for large-scale structure, and the regular matter clumps up around this framework.......or something similar to that
Who discovered that the universe is expanding?
Edwin Hubble (and Milton Humason)
Who coined the term "Big Bang"
Fred Hoyle
How do we think the universe will most likely end?
Most likely a "Big Chill" scenario.
If the Earth were moved out to 3x its current distance from the Sun, how much dimmer would the Sun appear?
9x dimmer (Inverse Square Law)
About what percentage of a galaxy's total mass is actually dark matter rather than "regular" matter?
About 85%
What does Hubble's Law say about nearby galaxies vs farther galaxies?
Farther galaxies are receding (moving away from us) faster than nearby galaxies.
What do we call the period of time soon after the Big Bang during which, as Alan Guth proposed, the universe increased exponentially in size in a fraction of a second?
Inflation
What will happen to our view of other galaxies in the distant future?
They will pass beyond our cosmic horizon and we won't ever see them again.
What do we call the most distant galaxies we can see?
Quasars (Quasi-stellar radio sources)
What does WIMPs stand for?
Weakly Interacting Massive Particles
What is the current value of the Hubble Constant?
About 70 km/sec/Mpc.
What do we call the period of time during the Big Bang that our physics cannot describe?
The Planck Epoch
What is the diameter of the universe a.k.a. how far across is the universe?
About 93 billion light-years across.