Galactic Habitable Zone
Zones that do not fall in the Galatic Habitable Zone are called dead zones
Galatic Habitable Zone is primarily a function of distance from the galactic center
(rotational center of the Milky Way galaxy)
When distance increases:
91. What was the critical discovery made using the COBE satellite that supported the Big Bang
theorys explanation of galaxy formation?
The Cosmic Background Explorer satellite used its Differential Microwave Radiometer to map
the entire sky and saw a vari
150. After about how long after the Big Bang should galaxy-sized structures been built up?
The first objects would have formed when the universe was only a few hundred million years
old. By the time the universe was a billion years old galaxy-sized struct
165. Why would stellar collisions be more common in the Degenerate era than in the Stelliferous
era? Are collisions between stars common in the Stelliferous era?
As dead stars trace through their orbits, direct collisions sporadically take place, with abo
77. How did the Steady State Theory proponents react to the news that Pope Pius XII supported
the Big Bang hypothesis, viewing it as a scientific interpretation of genesis? Can this reaction be
considered a scientific argument against the Big Bang?
87. What is the difference between microwaves and radio waves?
Radio waves are the longest wavelengths within the electromagnetic spectrum. Microwaves are
shorter than radio waves with wavelengths of a few millimeters or centimeters.
88. Why was the disco
Stars and Nebulae
40. What was the connection between the nebulae and the question about the size and
distribution of stars in the Universe?
Some thought the nebulae were young stars surrounded by clouds of debris situated within the
Milky Way, which was
Speed of Light and Time dilation
19. What did Einstein conclude about the speed of light?
Einstein concluded that light travels at a constant velocity of 300,000 km/s relative to the
observer. This means that whoever is measuring the speed of light always
48. Why is the science of spectroscopy important in astronomy?
With spectroscopy we can determine the temperatures of stars as well as the stars chemical
49. What is the wave model of light? How do light waves of the various colors in a rainbow
135. Why does the value of seem to be fine-tuned to have a Universe with the complex
forms of life found on Earth? In other words, what would the evolution of the Universe been like
if was too low or too high?
is now at least .3. This implies that was ve
Relativity and Astronomical Models
8. Which model of the Universe, Earth-centered, or Aristarchus/Copernicus Sun-centered, made
more accurate predictions for the motions of the planets?
In the 16th century, the Ptolemaic model made more accurate predictio
The Early Universe
68. Why do astronomers conclude that the bulk of the helium in the Sun could not have been
Even if it were possible for the Sun to fuse two hydrogen nuclei into a helium nucleus, it would
only be a very light and unstable
36. What is the inverse square law of light? What is the distinction between how bright a star
appears and how much light a star emits each second?
The physical law stating that a specified physical quantity or strength is inversely proportional to
112. What is the age of the Milky Way galaxy?
The oldest star in the Galactic halo was estimated to be about 13.2 billion years old.
113. What is the observational evidence that supports the claim that new stars still form in the
ANSWER THIS Q.
What explanations could possibly account for this discrepancy between our physical theories and
actual physical phenomena in the world? To answer the question, we must take into account the
three separate categories which are distinct in revealing ways. F
Testing the Rare Earth Hypothesis
There are two tests that can be conducted to test the Rare Earth Hypothesis
o the first test would be to try to detect the presence of microbial life in
other bodies in the solar system; this would support the idea that m
The possible frameworks for the development of our nave mental models could be everyday
experiences leading to information acquisition specifically about certain objects in certain
situations or induction about the behavior of related objects from general
The presence of an impetus force stems from the presence of the frictional force being invisible
to the observer. Because friction is operating on the physical system, the observer sees its effect
on the toy car (slowing down and ultimately stopping) but
Nave Physics in a Dynamic Universe
Jonathan Sunny Laxmi
How is our nave physics mistaken (according to Clement and others)? How do we get by in life
if we make these mistakes? Why dont we get eaten or fall off cliffs much more often than we do?
Even if one cannot define the forces in theory behind physical phenomena occurring in reality,
one can still know the output behavior of the physical phenomena. This simple example makes it
evident that humans may not necessarily know theoretically the me
From an evolutionary perspective, we see that natural selection would ensure reproductive
success for those who used their limited cognitive resources to hold information most relevant to
survival and reproductive ability and who group relevant informatio
The Formation of Nuclei and Atoms:
As with galaxy measurements, the total matter density determined by deuterium abundance
shows that the matter density is only a few percent of the critical density.
Galaxy Formation and Evolution:
Galaxies are believed t
The Formation of Nuclei and Atoms:
The time during which nuclei and electrons combined to form atoms is referred to as the
decoupling epoch. This is when the cosmic background radiation originated.
The Inflationary Universe:
The horizon problem: When obse
160. What is the Chandrasekhar limit?
White dwarfs cannot be made too massive. An overweight white dwarf will explode. As a white
dwarf becomes heavier, it becomes smaller and denser, and a larger pressure is required to hold
up the star against the oppos
82. How did the Steady state theory proponents explain the formation and the abundances of the
Hoyle predicted the excited carbon state which would have 7.65 more MeV than the normal
carbon state as Helium 4 and Beryllium 8 combined in a short s
95. All decades are 10 years long. Are all cosmological decades of equal length?
No. 20th cosmological decade is 1020 whereas 21st cosmological decade is 1021. The later the
cosmological decade the longer it is.
96. During the first second of the Universe
106. What are the candidates for dark matter?
In light of stellar observations and the theory of nucleosynthesis, the universe must contain two
to eight times more mass in baryons than is accounted for in ordinary stars. As a result, some
portion of the b
170. Towards the end of the Degenerate era, what might provide a source of energy to white
dwarfs that they would subsequently radiate away into space?
Dark matter annihilation.
171. By the 40th cosmological decade, what will have happened to the degenera
145. The size of the temperature variations in the CMB is comparable to a number referred to in
Just Six Numbers as Q. Describe this number.
Structures in the cosmos like stars, galaxies, and clusters of galaxies are all held together by
gravity. We can e
99. What is the physical significance of the critical density, c, of the Universe? How is the
critical density related to the Hubble constant? What is the relation between the critical density
and the density parameter, ?
We observe the spatial geometry o