Memory Systems, the Epistemic Arrow of Time, and the Second Law
The epistemic arrow of time is the fact that our knowledge of the past seems to be both of a different kind and more detailed than our knowledge of the future. Just like with the other arrows of time, it has often been speculated that the epistemic arrow arises due to the second law of thermodynamic...
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| Format: | Article |
| Language: | English |
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MDPI AG
2024-02-01
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| Series: | Entropy |
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| Online Access: | https://www.mdpi.com/1099-4300/26/2/170 |
| _version_ | 1797298260202749952 |
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| author | David H. Wolpert Jens Kipper |
| author_facet | David H. Wolpert Jens Kipper |
| author_sort | David H. Wolpert |
| collection | DOAJ |
| description | The epistemic arrow of time is the fact that our knowledge of the past seems to be both of a different kind and more detailed than our knowledge of the future. Just like with the other arrows of time, it has often been speculated that the epistemic arrow arises due to the second law of thermodynamics. In this paper, we investigate the epistemic arrow of time using a fully formal framework. We begin by defining a memory system as any physical system whose present state can provide information about the state of the external world at some time other than the present. We then identify two types of memory systems in our universe, along with an important special case of the first type, which we distinguish as a third type of memory system. We show that two of these types of memory systems are time-symmetric, able to provide knowledge about both the past and the future. However, the third type of memory systems exploits the second law of thermodynamics, at least in all of its instances in our universe that we are aware of. The result is that in our universe, this type of memory system only ever provides information about the past. We also argue that human memory is of this third type, completing the argument. We end by scrutinizing the basis of the second law itself. This uncovers a previously unappreciated formal problem for common arguments that try to derive the second law from the “Past Hypothesis”, i.e., from the claim that the very early universe was in a state of extremely low entropy. Our analysis is indebted to prior work by one of us but expands and improves upon this work in several respects. |
| first_indexed | 2024-03-07T22:33:21Z |
| format | Article |
| id | doaj.art-265bad0176c5406a8ac0416a3de38c1f |
| institution | Directory Open Access Journal |
| issn | 1099-4300 |
| language | English |
| last_indexed | 2024-03-07T22:33:21Z |
| publishDate | 2024-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Entropy |
| spelling | doaj.art-265bad0176c5406a8ac0416a3de38c1f2024-02-23T15:15:47ZengMDPI AGEntropy1099-43002024-02-0126217010.3390/e26020170Memory Systems, the Epistemic Arrow of Time, and the Second LawDavid H. Wolpert0Jens Kipper1Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501, USAPhilosophy Department, University of Rochester, Rochester, NY 14627, USAThe epistemic arrow of time is the fact that our knowledge of the past seems to be both of a different kind and more detailed than our knowledge of the future. Just like with the other arrows of time, it has often been speculated that the epistemic arrow arises due to the second law of thermodynamics. In this paper, we investigate the epistemic arrow of time using a fully formal framework. We begin by defining a memory system as any physical system whose present state can provide information about the state of the external world at some time other than the present. We then identify two types of memory systems in our universe, along with an important special case of the first type, which we distinguish as a third type of memory system. We show that two of these types of memory systems are time-symmetric, able to provide knowledge about both the past and the future. However, the third type of memory systems exploits the second law of thermodynamics, at least in all of its instances in our universe that we are aware of. The result is that in our universe, this type of memory system only ever provides information about the past. We also argue that human memory is of this third type, completing the argument. We end by scrutinizing the basis of the second law itself. This uncovers a previously unappreciated formal problem for common arguments that try to derive the second law from the “Past Hypothesis”, i.e., from the claim that the very early universe was in a state of extremely low entropy. Our analysis is indebted to prior work by one of us but expands and improves upon this work in several respects.https://www.mdpi.com/1099-4300/26/2/170second law of thermodynamicspsychological arrow of timeBrownian bridgememory systemsrecords |
| spellingShingle | David H. Wolpert Jens Kipper Memory Systems, the Epistemic Arrow of Time, and the Second Law Entropy second law of thermodynamics psychological arrow of time Brownian bridge memory systems records |
| title | Memory Systems, the Epistemic Arrow of Time, and the Second Law |
| title_full | Memory Systems, the Epistemic Arrow of Time, and the Second Law |
| title_fullStr | Memory Systems, the Epistemic Arrow of Time, and the Second Law |
| title_full_unstemmed | Memory Systems, the Epistemic Arrow of Time, and the Second Law |
| title_short | Memory Systems, the Epistemic Arrow of Time, and the Second Law |
| title_sort | memory systems the epistemic arrow of time and the second law |
| topic | second law of thermodynamics psychological arrow of time Brownian bridge memory systems records |
| url | https://www.mdpi.com/1099-4300/26/2/170 |
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