The Philosophy of Time Travel: Can You Change the Past?
Exploring the paradoxes and implications of time travel through a hypothetical scenario involving changing a past event. The concept of time manipulation, logical contradictions, and their impact on altering personal history are examined in a thought-provoking manner.
Uploaded on Sep 06, 2024 | 3 Views
Download Presentation
Please find below an Image/Link to download the presentation.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author. Download presentation by click this link. If you encounter any issues during the download, it is possible that the publisher has removed the file from their server.
E N D
Presentation Transcript
Guess Whos Back: The Philosophy of Time Travel Food and Talk March 15, 2022
Can I go back in time and change my high school haircut? Assumptions 1. Time travel is physically possible 2. A logical contradiction cannot be true
How might this work? time March 15, 2007 March 15, 2022 Methods of time travel: Discontinuous: I enter a time machine, set the date, and instantaneously get teleported back to that date Worry: is that still me? Continuous: I enter a time machine, hit reverse, and start moving backward through the timeline Worry: how do I get moving forward again in 2007?
What happens? March 15, 2022 March 15, 2007 Chris thinks, Gosh that was a bad haircut. I should go back and change it. Chris enters a time machine, discontinuously travels back to March 15, 2007. Chris arrives, finds younger Chris Chris convinces younger Chris to get a different haircut
What happens? March 15, 2022 March 15, 2007 Chris doesn tthink, Gosh that was a bad haircut. I should go back and change it. Chris doesn t enter a time machine. Younger Chris, without the advice of older Chris, gets the bad haircut.
What happens? On March 15, 2022: Chris both does and does not think Gosh that was a bad haircut. I should go back and change it. On March 15, 2022: Chris both does and does not enter a time machine. On March 15, 2007: Chris both does and does not meet younger Chris. On March 15, 2007: Younger Chris both does and does not get a different haircut.
What happens? We have logical contradictions all over the place A logical contradiction cannot be true. So it must not be possible for me to go back in time and change my haircut
Different timelines Timeline 1 Timeline 2 March 15, 2007: younger Chris has a bad haircut. March 15, 2022: older Chris thinks Gosh that was a bad haircut. I should go back and change it. March 15, 2022: older Chris gets in a time machine and travels to Timeline 2. March 15, 2007: younger Chris briefly has a bad haircut; older Chris shows up and convinces him to get a different haircut. March 15, 2022: younger Chris is now not young, and is thankful that he got a haircut. Older Chris is now much older.
Different timelines This two-timeline scenario seems possible (but only with a discontinuous method of travel). But it s not genuine time travel. It s travel to a different world entirely. Everything that happened in Timeline 1 still happened. Nothing is changed about the past of Timeline 1 by hopping over to Timeline 2.
The argument formalized X can do P is true if and only if there is a possible world in which X does P. There is no possible world in which Chris goes back in time and changes the haircut he had in 2007. So Chris cannot go back in time and change the haircut he had in 2007. Alas.
Is time travel physically possible? If time travel isn t physically possible, my argument is even stronger: I can t go back and change my haircut because the laws of nature do not allow for time travel in the first place. Physicists and philosophers of physics debate whether time travel is physically possible.
Time travel in physics Spacetime Diagram Spacetime with Temporal Loops time space time space
