11 Modern Cosmology
217
were good. But his father was away again on his favourite
hobby horse.
This time, however, the boy had a prepared response. He
reached across for The Little Star Gatherer, and rose from his
chair. At the door, he turned back towards his father, and called:
“Hey, Ba, did I tell you our sports teacher thinks I should try out
for the football team? He said I show a lot of promise. Never
know. Might even get good enough to be a pro one day.” He
closed the door quickly to hide his grin, and strode smirking
down the passage to his own room.
∗ ∗ ∗
Danh’s question is a good one. Wormholes, or tunnels connecting different
events in space–time, are valid solutions of Einstein’s field equations. They
do however raise the problem of time travel, where travellers might go back
into the past and kill their parents, thereby threatening their own existence.
Perhaps fortunately, there is no experimental evidence for the existence of
wormholes.
11.2 The First 380,000 Years
In the last Chapter we have been diligent in our attempt not to stray too far
from established theories in a search for an explanation of what is arguably
the oldest and most puzzling question ever to have confronted humanity: how
did the universe in which we live begin? This question is basic for all religions:
physics cannot simply ignore it, and take refuge behind the defence that a
direct observation of the Big Bang is impossible. However, when venturing
to explore this region, caution is necessary, controversy unavoidable, and
frankness laudable.
Although many people are working diligently in this field, it is openly
admitted that the physics immediately following the Big Bang is completely
unknown. Unfortunately, that period contains the original central singularity at the origin of the universe. It is where the two main cathedrals of
modern physics, Quantum Mechanics and General Relativity—one probabilistic and the other deterministic in nature—are mutually inconsistent.
We have discussed this conflict already in Chap. 9. Physicists have tended
to skate around this issue, applying Quantum Mechanics when dealing with
small particles, and General Relativity when gravity is the dominating force.
217
were good. But his father was away again on his favourite
hobby horse.
This time, however, the boy had a prepared response. He
reached across for The Little Star Gatherer, and rose from his
chair. At the door, he turned back towards his father, and called:
“Hey, Ba, did I tell you our sports teacher thinks I should try out
for the football team? He said I show a lot of promise. Never
know. Might even get good enough to be a pro one day.” He
closed the door quickly to hide his grin, and strode smirking
down the passage to his own room.
∗ ∗ ∗
Danh’s question is a good one. Wormholes, or tunnels connecting different
events in space–time, are valid solutions of Einstein’s field equations. They
do however raise the problem of time travel, where travellers might go back
into the past and kill their parents, thereby threatening their own existence.
Perhaps fortunately, there is no experimental evidence for the existence of
wormholes.
11.2 The First 380,000 Years
In the last Chapter we have been diligent in our attempt not to stray too far
from established theories in a search for an explanation of what is arguably
the oldest and most puzzling question ever to have confronted humanity: how
did the universe in which we live begin? This question is basic for all religions:
physics cannot simply ignore it, and take refuge behind the defence that a
direct observation of the Big Bang is impossible. However, when venturing
to explore this region, caution is necessary, controversy unavoidable, and
frankness laudable.
Although many people are working diligently in this field, it is openly
admitted that the physics immediately following the Big Bang is completely
unknown. Unfortunately, that period contains the original central singularity at the origin of the universe. It is where the two main cathedrals of
modern physics, Quantum Mechanics and General Relativity—one probabilistic and the other deterministic in nature—are mutually inconsistent.
We have discussed this conflict already in Chap. 9. Physicists have tended
to skate around this issue, applying Quantum Mechanics when dealing with
small particles, and General Relativity when gravity is the dominating force.