Thank goodness there was not an omniscience requirement. Yes we have all probably been wrong at times and at the time have been told we are wrong. Mostly it is very helpful and informative regardless of whether you support mainstream ideas or like to challenge them. Constructive criticism sharpens your focus and makes one re-evaluate ideas in far more depth (even if the end result is not a swing to mainstream thinking).

I came to this forum in Oct 2006 with a long winded post to reverse engineer a wormhole. I have learned a lot of mainstream physics here and that is why the forum exists. One of the first things I discovered is that neither the skeptical analysis nor the mathematics nor the physics in currently in use support the concept of time travel.

One day it is my hope that there will be some really good bad astronomy even if my reasons are not those of some others who also would like to see some really good bad astronomy, cheers

Nor do I. AFAIK, the only person in my family who ever knitted was my father the shrink!

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Any day you wake up on "the right side of the dirt" is a good day.

T. Anderson

You know Ken, you're very correct, there are so many cool things that are real that are great candidates for discussion, and this is definitely the place to discuss those things. And I'll keep that in mind in the future (note to self: people on board only interested in real stuff, don't post about PBIs even if you disagree with them and only want clarification that you are correct in disagreeing. This just isn't the place for that.)

So where do we draw the line? Is it ridiculous to ask what conditions might allow you to stand on a neutron star or speculate about what it might look like if you did, because quiet frankly, if you even think about getting too close the gravity will turn you into a nice layer of paint on the neutron star. So it is implausible, therefore not worthy of discussion.

There is no evidence whatsoever of life existing anywhere in the universe aside from Earth. So it is clearly ridiculous to discuss the matter because there isn't a shred of evidence to support the idea.

Why bother thinking about traveling close to the speed of light... we'll never do it.

Why bother wondering about what happens inside a black hole. We can observe that anyone who goes in doesn't come out, so it'll probably be a good idea to post No Swimming signs and leave it at that.

At what point do you clip curiosity and creativity? How well informed does a person need to be before they can post ideas about a topic?

(Don't take any of this reply personally, I'm not attacking you, I just wonder if anyone thinks about these things.)

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The only way of finding the limits of the possible is by going beyond them into the impossible.

Arthur C. Clarke

The Brain Science Podcast

So the thing that brought you here in the first place was a PBI and since then you have learned. I wonder how many people come to these boards because they are curious about some idea they had and would like validation or clarification of their idea and in the process learned more about the universe.

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The only way of finding the limits of the possible is by going beyond them into the impossible.

Arthur C. Clarke

The Brain Science Podcast

FriedPhoton, you seem to be thinking it is forbidden.

It is not.

It is just that if presenting an ATM idea, you are expected to back it up with evidence.
"I don't know" is an acceptable answer- why is that?

Because the discussion can be intriguing even if you cannot always pull evidence out of the hat.

When folks refuse to admit to not knowing, push theories in spite of being introduced to better evidence etc- that is where problems happen.

ETA: A lot of the examples you mentioned are, indeed, discussed on BAUT regularly.

I can't tell by how you worded this but are you implying that this is something that I do?

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The only way of finding the limits of the possible is by going beyond them into the impossible.

Arthur C. Clarke

The Brain Science Podcast

You might ask yourself that but I have never seen you do it.

I was referring to the frustrations felt by the more long standing members here.

I understand your complaints and perceptions too. I think, though, that you, like me, also tend to get carried away.

I think if you review any of these situations where it seems like I'm getting carried away you will see a gradual escalation from one post to the next that leads to those points... and you'll also note that I'm not talking to myself.

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The only way of finding the limits of the possible is by going beyond them into the impossible.

Arthur C. Clarke

The Brain Science Podcast

Oh, believe me, I know.

As much as one can talk one can listen though.

Is that your polite way of telling me to shut up?

If I just listened, I wouldn't post, then there would be nothing for people to tear down, their lives would lose meaning, and ultimately they would probably take their own lives in utter despair... so look at my posting as more of a life-saving service than just some idiot wasting his time defending the most pointless minutia in each of his postings.

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The only way of finding the limits of the possible is by going beyond them into the impossible.

Arthur C. Clarke

The Brain Science Podcast

I don't take it personally, don't worry. I am simply making the point that all of the "examples" you gave are based in actual science, and discussing them brings up actual observations and findings (about things like the surfaces of neutron stars, or what happens when objects move at high speed, or what can we say about the likelihood of life elsewhere.). Time travel is not. You can pretend that this a difficult "line to draw", but it's not difficult at all, it's the line between what is real and what is purely imaginary, between science and science fiction. I'm not singling you out-- many people post about time travel. I'm saying that it's just silly, that's all. I've heard many things on this forum that were readily branded as "silly", such as belief systems in miracles, or alternative medicine, or a host of other issues that have so far extablished zero scientifically supportable content. And so it is with time travel. If it is interest in that issue that has brought someone seeking scientific knowledge, why should I not tell them the truth about it? I don't claim all knowledge in science, but I know magic when I see it.

Ken, I don't disagree with you at all. I feel the same way about time travel, and I think that is the point that everyone is missing. I said I thought I heard that someone came up with some theory that was being taken seriously at some level. The person who brought it up originally was a guy I know who majored in physics. I felt that if he took something seriously, with his educational background, that there must be more people who believed there was something to this "theory", whatever it was.

I just wanted to know what the "theory" was, and felt that if the theory was getting widespread attention that someone here might have heard about it. I never said I believed, or would believe, the theory any more than I would have said I believe in unicorns (although I do believe the outside of the universe is filled with popcorns).

I just wanted to know what it was... that's all.

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The only way of finding the limits of the possible is by going beyond them into the impossible.

Arthur C. Clarke

The Brain Science Podcast

Ummm... No.

And I officially give up posting in this thread now. No matter what I say you seem to attribute opposite meanings to it

I think that was the problem-- by not citing anything specific there, it was easy to just read in what point you were actually asking about. To my knowledge, there is no time travel theory that is "taken seriously", though time travel continues to be a topic at the fringe of science where it intersects with pure science fiction.
The problem is, no "theory" can be taken seriously without observational evidence. It just reverses the order of the logic. We observe a universe where time travel is not possible for a macroscopic object, let alone a surviving animal, so if a theory says it is then it is a thousand times more likely that the theory is wrong than that it will lead to observations of time travel. It is surprising indeed how many people miss that simple logic, even physics majors.
Personally, I've no idea. There are many solutions of relativity that can be interpreted as time-travel solutions, but none of them apply in reasonable circumstances for macroscopic objects, and none of them even address issues of survivability. It seems like an obvious case of over-extrapolating a theory into a realm where it was never intended, whatever the "theory" is.
Then we're in complete agreement.

You believe the outside of the universe is filled with popcorn too! Cool. Now to convince the other 6.6 billion... I better get busy.

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The only way of finding the limits of the possible is by going beyond them into the impossible.

Arthur C. Clarke

The Brain Science Podcast

The theory is General Releativity. It called a Morris-Thorne wormhole after Mike Morris and Kip Thorne who first worked out the properties in 1988. They also found that such wormholes could become time machines if one mouth of the wormhole was acclerated with respect to the other using time dilation from special relativity. Within General Relativity, these type of time machines are called closed timelike curves. Unfortunately, Morris-Thorne wormholes were not traversable. Mike Visser found a different class of traverable wormholes in 1989.

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Some try to tell me, thoughts they cannot defend,... - Moody Blues.

Thank you! Whew!

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The only way of finding the limits of the possible is by going beyond them into the impossible.

Arthur C. Clarke

The Brain Science Podcast

Note that such solutions to general relativity equations are a far cry from time travel, because of the staggeringly limiting assumptions that will have gone into them. They're still miracles.