180 FAQs about Big Bang Cosmology (The Astronomy Cafe)

1. Is there any connection between the Higgs field and dark matter?
2. Does Big Bang theory predict a cosmic background radiation different than the 2.7 K actually found?
3. Where can I read more about how the universe will evolve trillions of years from now?
4. What kind of shape does a 10-dimensional universe have?
5. How many dimensions does our universe have?
6. What is the probability that Big Bangs and Big Crunches will continue indefinitly?
7. How is the temperature of the Cosmic Background Radiation calculated to be 2.7 K?
8. What are the 4 dimensions to space, and why can't a 6-D universe exist?
9. Could the Big Bang have been the beginning of a black hole in an external universe?
10. What is the universe made of?
11. How many fundamental particles are in the universe?
12. Does the fact that there is no primordial abundance of elements heavier than lithium support Big Bang theory?
13. Where in the universe did the Big Bang happen?
14. If quantum fluctuations happen 'in time' how could they have existed before the Big Bang when time was first created?
15. What determined the ratio of hydrogen to helium in the universe?
16. How is the critical density of the universe estimated?
17. Are universes with more than 3+1 dimensions unstable, theoretically?
18. Due to relativity, wouldn't it make sense that some places in the universe are older than the others?
19. Have astronomers really discovered stars or galaxies that are older than the universe?
20. Is the universe closer to 15 or 8 billion years, and why don't we know this exactly?
21. How old is the Universe?
22. How do you define the boundary between the 4 large dimensions to space-time and the 6 'compact' ones?
23. How do you reconcile the fact that the Big Bang was a black hole that expanded?
24. Did the Big Bang really happen?
25. What alternate theories of the universe are being actively tested today?
26. How were the physical constants fine tuned to make our kind of universe possible?
27. What are the basic ideas and issues in contemporary Inflationary cosmology?
28. What are the three most recent theories about 'missing mass'?
29. Did the laws that govern quantum fluctuations exist prior to the Big Bang?
30. Are gamma ray bursts produced by neutron stars colliding with black holes?
31. Why do scientist's keep hammering on the Big Bang. It's only a theory, not divine truth. So why not give it up and try a new idea?
32. Aren't the proponents of Big Bang theory allowing wishful thinking to prevail over logic?
33. Where can amateur cosmologists post their ideas?
34. Why do you cosmologists get so sentimental about religious issues, and just admit to everyone that you do not see God in your data at all?
35. Was there really no time at all before the Big Bang?
36. If the universe emerged from a region the size of a pin head, where else could that have come from than from God?
37. How is the age of the universe determined?
38. Does Hawking's imaginary time idea have any impact on Guth's repulsive gravity theory for Inflationary cosmology?
39. What is the upper limit for the energy of the Big Bang?
40. Didn't the 'maximum entropy' state happen soon after the Big Bang?
41. If the Big Bang singularity dwarfed a black hole singularity, why did anything ever escape?
42. With special relativity, how long did the famous 10^-33 seconds after the Big Bang actually last?
43. Can the Big Bang be reconciled with the idea of advanced and retarded waves in electrodynamics?
44. If the density of the universe is now 100x less than needed to make it a black hole, wasn't it 100x higher when the universe was younger?
45. What is nothingness?
46. Could virtual particles make up dark matter?
47. When was matter created after the Inflationary Epoch?
48. What does proton decay have to do with the heat death of the universe?
49. In your list of 10 things supporting Big Bang theory, why do they not also support other ideas too?
50. Did the Big Bang happen in a medium, or in a vacuum?
51. Could dark matter be distributed smoothly in the universe?
52. Was the 'Cosmic Egg' a black hole?
53. Where did the initial momentum come from that caused the universe to expand?
54. What is the real evidence that there was a beginning of time?
55. Does general relativity allow for toroidal cosmological models?
56. If the Big Bang expanded adiabatically at constant entropy, why is the entropy now increasing as required by the Arrow of Time?
57. Why si the Big Bang described as a singularity when Einstein himself said that physical singularities do not exist?
58. Could another Big Bang ever happen inside our own universe, thereby destroying it?
59. How did the first molecules assemble in space to start the Big Bang?
60. Why can't we see where the Big Bang started?
61. Is there an easy way to describe Big Bang cosmology?
62. Why does the rest mass of a neutrino make any difference to cosmology?
63. Have electric and magnetic fields played any role in the large scale structure of the universe?
64. What are the simplest things we know about the Big Bang?
65. Do you see any relationship between the subatomic microcosm and the macroscopic universe?
66. At the instant of the Big Bang, was Heisenberg's Uncertainty Principle violated?
67. How could a quantum vacuum state have produced our universe when the universe has such regular physical laws rather than random things just happening?
68. Is there really any order in the universe, or is it all the result of random patterns that happen from time to time?
69. If every star had 9 planets like Jupiter, would this account for the missing mass in the universe?
70. Why can't a universe with more than 4 dimensions have life?
71. What is the relationship between the terms 'universe', 'knowable universe' and 'visible universe'?
72. Why is there no anti-matter in the universe in equal amounts to matter?
73. If we looked far enough out in space, could we actually see the Big Bang itself?
74. What do you mean by 'multiple universes' given the definition of the word universe?
75. What is quantum cosmology?
76. How many atoms are there in our universe?
77. Can you name 10 things that contradict Big Bang theory?
78. What will happen to cosmology when physicists discover the Theory of Everything?
79. How can we still see the cosmic background radiation when its source has vanished, and all radiation has to have a source?
80. If time did not exist before the Big Bang, can we really say that it exists now?
81. Is there a net gravitational force directed back towards where the Big Bang happened that could cause re-collapse?
82. What is the Big Crunch?
83. How does superstring theory affect our understanding of the cosmos?
84. If the Big Bang started out as a ball of compressed matter ,why do some objects now rotate clockwise and counter-clockwise?
85. Does an infinite universe imply that a planet like the Earth is not unique?
86. What were the key observations that eliminated previous theories of the universe?
87. Have scientists proven that other universes exist?
88. Was the formation of the universe at the Big Bang a 'negative entropy' process?
89. Is it really true that the laws of physics are randomly selected at the Big Bang?
90. How does 'bulk viscosity' affect the evolution of the universe?
91. How could the universe have been spatially infinite even at the Big Bang?
92. Is there any scientific or observational evidence to support the idea that nothing existed before the Big Bang?
93. Did Einstein know of Hubble's theory of an expanding universe and take this into account in his theory?
94. If there was no universe before the Big Bang, does that mean that the universe is not a bounded container with a well-defined boundary?
95. If space has a boundary, then how could a 'void' have existed before the Big Bang when there was no universe?
96. Does space have a boundary because it has a finite age since the Big Bang?
97. If the universe recollapses, will it become the same kind of atom-sized singularity it started-out as in the Big Bang?
98. Where did the first rocks come from that made the Big Bang happen?
99. If the universe collapsed to a point what happens to the Weyl tensor?
100. In an oscillating universe, can some information survive to become the seeds for the irregularities we see in our universe?
101. What is the relationship between the energy of the vacuum and the Cosmological Constant?
102. Why did nature produce a Big Bang at all?
103. What do you think of plasma cosmology?
104. Since the universe must have been inside its own Schwarschild radius after the Big Bang, how did it get out?
105. How did the first stars form after the Big Bang?
106. Why don't astronomers believe that God could have jump started the universe rather than some random quantum fluctuation?
107. What is the compelling evidence that demands that the universe was smaller than an atom when the Big Bang happened?
108. What is the status of theories that propose that the Big Bang never happened?
109. If there is matter in the universe other than in galaxies, why isn't the universe opaque?
110. Is chaos theory applicable to cosmology and events near the Big Bang?
111. How can astronomers measure the temperature of the cosmic background radiation when it is billions of light years away from us?
112. Why don't the temperatures of all the stars in the Milky Way affect the temperature of the cosmic background radiation at 2.7 K?
113. Isn't the real question all advocates of Big Bang theory should answer is what caused the Big Bang?
114. How did the creation of the universe depend on Beryllium-8?
115. What is the history of a single proton from the Big Bang to the present?
116. Astronomer Michael Strauss proved that Big Bang theory is inconsistent with new data to the 95 percent confidence limit. Why still believe in Big Bang theory?
117. At the Big Bang, why didn't the matter turn into a swarm of black holes instead of an expanding plasma?
118. How does 'dimensional phase change' drive Inflation and the Big Bang?
119. What is the contribution of virtual particles to the mass of the universe?
120. If Inflation produced only 1 monopole in our universe, why bother looking for it?
121. What is the difference between an open and a closed universe?
122. Couldn't a higher value for the speed of light in the past explain many paradoxes in modern cosmology?
123. How did galaxies form from a smooth, uniformly-expanding Big Bang state?
124. Did the birth of the Universe violate the Conservation of Energy?
125. Do you believe in the Big Bang theory, or Creation?
126. If the universe oscillates, will we line on and on for eternity?
127. What did the dense matter soon after the Big Bang look like?
128. How far back in time can you see with a telescope?
129. If I tell you how the universe works, how can I be sure I get credit for my theory?
130. If the universe is uniform and infinite what would cause it to collapse?
131. What are all of the rungs in the cosmological distance ladder?
132. What are cosmic strings and superstrings?
133. Where did the chemicals come from that are in outer space?
134. Did physical laws exist before the Big Bang?
135. If gravity causes objects to rotate, wouldn't the universe be rotating?
136. When the universe collapses will the night sky turn bright?
137. What fraction of the universe is made up of anti-matter?
138. Have other Big Bangs happened before?
139. If the cosmic background is so smooth, why is matter in galaxies so clumpy?
140. What does the recent announcement of their being 5 times more galaxies than previously known, do for the missing mass problem?
141. Why wasn't the Big Bang a black hole?
142. What is a space time continuum?
143. What ever happened to the rival theories to Big Bang cosmology?
144. What is the latest on the nature and existence of 'dark matter'?
145. Do people send you their ideas for new theories about the universe?
146. Can you list 10 or more observational facts supporting Big Bang Theory?
147. Why was there a slight imbalance between matter and antimatter just after the Big Bang?
148. If proton decay occurs, does this prove that a state of maximum entropy is the natural state of the universe?
149. Do you agree with the idea that the visible universe was once smaller than an atom?
150. Do the different estimates for the age of the universe imply that the speed of light may have changed?
151. Do you believe in Big Bang theory?
152. Where does the 2.7 K cosmic radiation come from. Cold matter in space?
153. Could you tell me what the basic ideas in cosmology are?
154. Why is the temperature of the universe 2.7 K and not absolute zero?
155. If the universe is closed now, was it also closed before the Big Bang?
156. Was the Big Bang a singularity that expanded to fill up a pre-existing void?
157. If gravity is so strong, why couldn't it keep the Big Bang from exploding apart?
158. Could you tell me what the arrows of time are in relation to cosmology?
159. Are the spaces between galaxies filled with stars or gas?
160. If the pre-Big Bang state was timeless, what is the best guess as to what it was like?
161. What is the mass equivalent of all forms of energy in the universe?
162. Can virtual particles still be created in a vacuum where the temperature is absolute zero?
163. Are there any places in the universe where the temperature is lower than 2.7 K?
164. Is the amount by which light is bent important in cosmology?
165. How is it that, according to general relativity, space can be curved?
166. Is it your view that the universe is finite or infinite?
167. If the universe is finite, what's outside?
168. How can the density of a cosmological scalar field decrease less than the matter density as the universe expands?
169. What does it mean for a closed, finite universe to be a part of an undefinable, mysterious embedding space that is beyond observation?
170. How long ago did the Big Bang take place?
171. If a black hole has enough gravity to keep matter from escaping, how could matter have escaped the Big Bang?
172. What is the cosmological significance of neutrinos having a small, but non-zero, mass?
173. Does the term Big Bang only refer to what is inside our universe?
174. What existed in space before the Big Bang?
175. What is out past the farthest reaches of where the universe has expanded into?
176. Is there a connection between the laws of the microcosm and the structure of the universe?
177. If the universe is infinite, then its total mass should be zero. Does this mean there is negative mass to cancel out the positive mass found in stars and galaxies?
178. If stars come in clusters, and galaxies come in clusters too, could our universe come in clusters with other universes?
179. Could our universe be a quark in another, bigger universe?
180. How can our universe have Third generation stars if it is only 10-15 billion years old?

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