sordavie

So, you have a problem with me jumping to the conclusion that leejo is a layman in physics but not with leejo's jumping to the conclusion that tim maudlin is a layman in physics?

At least it's much less likely that a philosopher of physics is a layman in physics than someone on the tacticalgamer forums.

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leejo

You sure seem to get upset when credentials are questioned or not shown the proper respect. What up with that?

I said thanks for the link, I'll read it, and on first blush it seems to be making a typical layman's mistake by imposing mental modeling on the quantum world. You respond with a lot of assumptions about what I think and by saying he's one of the top practitioners of the philosophy of physics. He and the top clogger of physics and painter of physics and mime of physics could form a super band and stop crime or something. Which is a not very funny way of wondering why not be a physicist of physics? It's also a not very funny way of saying "so what?"

There are a zillion books out there like Dancing Wu Li Masters, The Tao of Physics, etc., that make slightly over the top claims about the philosophical implications of quantum mechanics. This paper reads just like them. They're really cool and on one level yes the theory does allow for the strange behavior these facile books and this paper discuss. But once you get into the theory, and when you consider all the manifest problems with the physics of time travel at the macroscopic level...well that was my question - is this just some mental self-love or are physicists really saying interesting things about this? From what I can see, this writer is an accomplished philosopher of physics, and I don't doubt his skilz, but I don't see how he's advanced the subject or that the physics supports the idea of time travel any more than the last time I checked in.

sordavie

This is an entry in an encyclopedia of philosophy. The audience is directed at philosophers who are not specialists in physics. So, of course it is more in laymans terms than not. You asked for primary sources from the physicists who argue that time travel is consistent with modern physics. This is why I said to look at the works he's listed in his bibliography. I did not say that the body of the encyclopedia article would you what you were looking for. Which is why I'm disturbed that you're complaining that the encylopedia entry makes a conceptual oversimplification, that you then assume the author also makes. You wouldn't assume that a physicist relies only on cusory understandings of quantum mechanics if you read an encyclopedia entry he wrote for the general audience. Would you?

You said
I replied:

In particular, I did not reply: "here's an encylopedia article that will explain things in terms of what physicists think" or "here's an encylopedia article by a physicist, explaining what he thinks." The point in directing you towards the bibliography is to direct you towards the primary sources.

Of course it will be disturbing if the first thing you reply back with is:

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jepzilla

As far as I'm aware, every attempt to show that time travel is possible goes like this:

1. Someone finds a weird solution to general relativity allowing for time travel.
2. Quantum mechanics bitch-slaps them.

SmokingTarpan

Although I don't agree with this view of time travel, even if I did I'd have a problem because it requires the laws of genetics to be tossed by the wayside.

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[squadl]
"I am the prettiest african-american, vietnamese..cong..person." -SugarNCamo

leejo

@sordavie

You have made statements about things I have said that are not true. For example, find where I have made any comment about what's-his-face's understanding of physics. Find where I have assumed that the author makes the same oversimplification his paper makes. Etc. You have put a lot of words in my mouth, and that surprises me given your training.

In your first post you implied that you are "in the know" somewhat regarding what physicists are saying about time travel ("Scientists take the possibility of closed causal loops seriously"). I was curiouis and asked to see what you've read. You wondered aloud So do YOU really understand what's going on? I don't see where you qualified your understanding of the physics around time travel until I pushed you on it. Also, next time someone asks you for supporting material, maybe you could skip the part about wondering whether to send the dumb version or not Send both maybe. That way the person gets what they need and you come off as doubly helpful and respectful.

I do apologize for the confusion around the article you forwarded. I see now that you did suggest that I read the cited material not the article itself. I missed that part. FWIW I'm extremely sleep-deprived these days and also pressing on some tight deadlines, so I'm probably missing some details and coming across more abruptly than my usual charming self. Please remember that I haven't slept in a month.

Also, FWIW, Feynman, Friedman, Wheeler - these are some heavy hitters in the world of quantum mechanics and I have spent hundreds of hours reading their work. I'm not familiar with all of the works cited, so I guess we can all take my thoughts with a considerable grain of salt.

Moving on.

leejo

By the way, time travel FORWARD in time is certainly possible. You just have to travel very close to the speed of light. This violates no physical law and in fact happens all the time. Everytime you fly in an airplane, you travel very slightly forward in time relative to everyone who remained on the earth's surface. This is because you're less affected by the earth's gravity and you are traveling slightly closer to the speed of light. Granted the amount of time travel is very small, but it's measurable.

It's going backwards that's the problem.

sordavie

Right leejo, i never claimed I knew the physics of time travel. Which is why I mentioned that although my example might not be possible at the actual universe, there's reasons to think that if the laws of nature were different, it would be possible at that universe. How different would the laws of nature have to be? I don't know. But, it's enough for my purposes. And, it's enough to get a coherent bizarre story off the ground.

In any case, I don't think I ever implied that was "in the know" about the physics of time travel. My first posts merely says that physicists take the possibility of time travel seriously, thinking that it's consistent with the best science we have. I don't see how that implies anything about my knowledge of physics other than that I think a number of physicists take take the possibility of time travel seriously. I could just be reporting something I read from newscientist or time magazine or I could be a physcist who works on it. That statement just doesn't imply anything about how much physics I know. It's a statement about what physicists take seriously, not a statement about physics.

Part of the problem with linking the primary sources here is that they aren't available publicly on the net. Which is why I didn't link to both. Unless you have access to these academic journals online, it's going to be useless to link you to them. www.jstor.com/AHFDUFLKSJ... is not going to help anyone who can't access Jstor. Which is why I merely pointed at the bibliography of a site that everyone can link to. And, if people want to goto their local university library to find that stuff, they're welcome to.

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leejo

From what I can see this little sidetrack got started when I had the temerity to comment on a philosopher-of-physic's paper and you chose to go hostile for some reason.

For what it's worth, if we're not worried about whether or not reality can tolerate a scenario, can we talk about my threesome with Halle Berry and Charlise Theron instead of this one? As you say, it is conceivable and conceivability is a good guide to possibility. A freakin' men to THAT.

SmokingTarpan

Might want to pick someone else, all she ever does is cry. I swear.

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[squadl]
"I am the prettiest african-american, vietnamese..cong..person." -SugarNCamo

Rincewind

You've never met leejo have you? Because she obviously has.

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~~ Veritas simplex oratio est ~~
No matter how far a wizard goes, he will always come back for his hat. --T. Pratchett

<---- You know you're getting old when you rely on your forum meta-data to remind you how old you are.

Required Reading for all TG sandboxers

leejo

I was going to say. Crying is a pretty common reaction to knocking boots with the leejo.

Quest Shady

HA HA HA.... We all get it in the end so to speak...with or without time travel...

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