Author:
(1) Andrew Knight, J.D. (aknight@alum.mit.edu).
Table of Links
VI. CONCLUSION
When we assume that zero change to the past implies zero change to the present, we impose the information structure of the present universe onto its past structure – that is, we assume that everything will turn out the same, except for those events (and their chaotic interactions) that were changed in the past. Unfortunately for aspiring time travelers, this notion is false.
Traveling into the past logically requires changing the present, no matter how careful one is to avoid a temporal paradox. Hopes to travel into the past without changing the present, such as by avoiding any physical interaction within the past, are unfounded. Because all serious proposals for time travel into the past inherently assume Eq. 1, which has been shown false on a priori logical grounds, their treatment as scientific proposals are pseudoscientific.
[1] Pienaar, J.L., Ralph, T.C. and Myers, C.R., 2013. Open timelike curves violate Heisenberg’s uncertainty principle. Physical Review Letters, 110(6), p.060501.
[2] Godel, K., 1949. An example of a new type of cosmological solutions of Einstein’s field equations of gravitation. Reviews of Modern Physics, 21(3), p.447.
[3] Morris, M.S., Thorne, K.S. and Yurtsever, U., 1988. Wormholes, time machines, and the weak energy condition. Physical Review Letters, 61(13), p.1446.
[4] Deser, S. and Jackiw, R., 1992. Physical cosmic strings do not generate closed timelike curves. Physical Review Letters, 68(3), p.267.
[5] Deutsch, D., 1991. Quantum mechanics near closed timelike lines. Physical Review D, 44(10), p.3197.
[6] Hartle, J.B., 1994. Unitarity and causality in generalized quantum mechanics for nonchronal spacetimes. Physical Review D, 49(12), p.6543.
[7] Politzer, H.D., 1994. Path integrals, density matrices, and information flow with closed timelike curves. Physical Review D, 49(8), p.3981.
[8] Goldwirth, D.S., Perry, M.J., Piran, T. and Thorne, K.S., 1994. Quantum propagator for a nonrelativistic particle in the vicinity of a time machine. Physical Review D, 49(8), p.3951.
[9] Hawking, S., 2009. A brief history of time: from big bang to black holes. Random House.
[10] Hawking, S.W., 1992. Chronology protection conjecture. Physical Review D, 46(2), p.603.
[11] Thorne, K., 1995. Black Holes & Time Warps: Einstein’s Outrageous Legacy. WW Norton & Company.
[12] Popper, Karl, 1962. Conjectures and refutations. The growth of scientific knowledge, New York: Basic Books.
[13] Boekholt, T.C.N., Portegies Zwart, S.F. and Valtonen, M., 2020. Gargantuan chaotic gravitational threebody systems and their irreversibility to the Planck length. Monthly Notices of the Royal Astronomical Society, 493(3), pp.3932-3937.
This paper is available on arxiv under CC BY 4.0 Deed license.