The Impact on Time
19
Closed Timelike Curves
The Alan Machine
Preface
The Machine and the Question
1
Meet Alan
2
What Entropy Is
3
The Arrow of Time
Interlude: Does Time Flow?
Information Is Physical
4
Maxwell’s Demon and the Szilard Engine
5
Landauer’s Principle
6
Reversible Computing
7
Can a Mind Beat the Second Law?
Interlude: Three Demons
The Limits of the Machine
8
How Fast Can It Compute
9
How Much Can It Hold
10
Is Alan a Quantum Computer?
11
Laplace’s Demon
12
Black Holes and Information
Interlude: Are We Inside an Alan?
Reversing Entropy
13
Local Reversal
14
Life: The Original Local Reversal
15
Fluctuations and Recurrence
16
Global Reversal
Interlude: Would You Remember?
The Impact on Time
17
What Time Is
18
Would Time Run Backward
19
Closed Timelike Curves
20
The End of the Universe
Interlude: Can Alan Think?
Epilogue: What Alan Cannot Do
Building Alan
About Building Alan
CMOS: The Baseline
The Cost of Moving Data
Getting the Heat Out
Adiabatic and Reversible Logic
Superconducting Logic
Quantum Hardware
Thermodynamic and Probabilistic Computing
Neuromorphic Computing
Optical Computing
The Energy of a Token
Papers
About the Papers
References
Contributing
Appendices
A
Concepts
B
Notation
C
Constants
D
A Short Primer on Statistical Mechanics
E
Moderators and Curators
The Impact on Time
19
Closed Timelike Curves
19
Closed Timelike Curves
This chapter has not been written yet.
18
Would Time Run Backward
20
The End of the Universe