On 1/18/2023 12:25 PM, VSim wrote:
> On Wednesday, January 18, 2023 at 7:31:54 AM UTC+2, Dimensional Traveler wrote:
>> On 1/17/2023 4:35 PM, VSim wrote:
>>> On Tuesday, January 17, 2023 at 6:30:28 PM UTC+2, Ross Presser wrote:
>>>>
>>>> Because if there's a time machine, somebody WILL change the past. And
>>>> if that change didn't disable time travel, it'll get changed "again".
>>>> And "again". Until "finally" someone changes the past in a way that
>>>> erases the time machine invention. "After" that, no more changes.
>>>
>>> I'll discuss this based on my own model.
>>> First, even after the time machine invention erasure, it can be reinvented.
>>> Second, it probably won't happen. Every time somebody changes the past, they'll be very careful to take a lot of knowledge with them in the time machine, including how to build a time machine.
>>>
>>>> Scare quotes around those words because they only make sense if there's
>>>> some kind of memory that outlasts changing the past, which has always
>>>> seemed impossible to me.
>>>
>>> Not at all. The time travelers have their memory and all that's written or otherwise recorded with them in the time machine. And, if it's done seriously, as I said there will be necessarily *a lot* of knowledge there.
>>>
>> BUT the change to the timeline would mean the those books, electronic
>> files, what have you's, would never have been created to be sent back in
>> time!
>
> No it doesn't. Not in my model. They were created in the old timeline and sent to the new one with the time machine.

Then that's not time travel, that's universe hopping.

--
I've done good in this world. Now I'm tired and just want to be a cranky
dirty old man.

On Thursday, January 19, 2023 at 12:26:15 AM UTC+2, Dimensional Traveler wrote:
> On 1/18/2023 12:25 PM, VSim wrote:
> > On Wednesday, January 18, 2023 at 7:31:54 AM UTC+2, Dimensional Traveler wrote:
> >> On 1/17/2023 4:35 PM, VSim wrote:
> >>> On Tuesday, January 17, 2023 at 6:30:28 PM UTC+2, Ross Presser wrote:
> >>>>
> >>>> Because if there's a time machine, somebody WILL change the past. And
> >>>> if that change didn't disable time travel, it'll get changed "again".
> >>>> And "again". Until "finally" someone changes the past in a way that
> >>>> erases the time machine invention. "After" that, no more changes.
> >>>
> >>> I'll discuss this based on my own model.
> >>> First, even after the time machine invention erasure, it can be reinvented.
> >>> Second, it probably won't happen. Every time somebody changes the past, they'll be very careful to take a lot of knowledge with them in the time machine, including how to build a time machine.
> >>>
> >>>> Scare quotes around those words because they only make sense if there's
> >>>> some kind of memory that outlasts changing the past, which has always
> >>>> seemed impossible to me.
> >>>
> >>> Not at all. The time travelers have their memory and all that's written or otherwise recorded with them in the time machine. And, if it's done seriously, as I said there will be necessarily *a lot* of knowledge there.
> >>>
> >> BUT the change to the timeline would mean the those books, electronic
> >> files, what have you's, would never have been created to be sent back in
> >> time!
> >
> > No it doesn't. Not in my model. They were created in the old timeline and sent to the new one with the time machine.
> Then that's not time travel, that's universe hopping.

I don't know about universe hopping. There's no other universe involved. Everything happens in ours.
What I described is time travel. I'm not going to repeat it here. If you want to see what it's about you'll have to read it on my site.

----
My own time travel model, which permits paradox-free travel to the past and changing the past:
http://mhtt.50webs.com

On 1/18/2023 3:01 PM, VSim wrote:
> On Thursday, January 19, 2023 at 12:26:15 AM UTC+2, Dimensional Traveler wrote:
>> On 1/18/2023 12:25 PM, VSim wrote:
>>> On Wednesday, January 18, 2023 at 7:31:54 AM UTC+2, Dimensional Traveler wrote:
>>>> On 1/17/2023 4:35 PM, VSim wrote:
>>>>> On Tuesday, January 17, 2023 at 6:30:28 PM UTC+2, Ross Presser wrote:
>>>>>>
>>>>>> Because if there's a time machine, somebody WILL change the past. And
>>>>>> if that change didn't disable time travel, it'll get changed "again".
>>>>>> And "again". Until "finally" someone changes the past in a way that
>>>>>> erases the time machine invention. "After" that, no more changes.
>>>>>
>>>>> I'll discuss this based on my own model.
>>>>> First, even after the time machine invention erasure, it can be reinvented.
>>>>> Second, it probably won't happen. Every time somebody changes the past, they'll be very careful to take a lot of knowledge with them in the time machine, including how to build a time machine.
>>>>>
>>>>>> Scare quotes around those words because they only make sense if there's
>>>>>> some kind of memory that outlasts changing the past, which has always
>>>>>> seemed impossible to me.
>>>>>
>>>>> Not at all. The time travelers have their memory and all that's written or otherwise recorded with them in the time machine. And, if it's done seriously, as I said there will be necessarily *a lot* of knowledge there.
>>>>>
>>>> BUT the change to the timeline would mean the those books, electronic
>>>> files, what have you's, would never have been created to be sent back in
>>>> time!
>>>
>>> No it doesn't. Not in my model. They were created in the old timeline and sent to the new one with the time machine.
>> Then that's not time travel, that's universe hopping.
>
> I don't know about universe hopping. There's no other universe involved. Everything happens in ours.
> What I described is time travel. I'm not going to repeat it here. If you want to see what it's about you'll have to read it on my site.
>
Your model is based on "things from later in time will still be there
even though the time line was changed before then." If the time line
gets changed then it will have "always" been that way. You are assuming
there is a delay or a propagation of the change thru time that takes
time. Why would there be? And how fast would that propagation travel?
At the speed of time? A time traveler would be changing the very thing
you are measuring "when" the change "catches up" with the "future" with.

Essentially, the creation of the "new" time line removes the "old" time
line from existence through out ALL of spacetime. It was never there,
EVER, once the time line was/is/has been changed. (This is basically a
problem with ALL time travel stories, the assumption there is a "before"
and an "after" in something that we don't have the language for.)

--
I've done good in this world. Now I'm tired and just want to be a cranky
dirty old man.

On Thursday, January 19, 2023 at 3:02:09 AM UTC+2, Dimensional Traveler wrote:
> On 1/18/2023 3:01 PM, VSim wrote:
> > I don't know about universe hopping. There's no other universe involved. Everything happens in ours.
> > What I described is time travel. I'm not going to repeat it here. If you want to see what it's about you'll have to read it on my site.
> >
> Your model is based on "things from later in time will still be there
> even though the time line was changed before then." If the time line
> gets changed then it will have "always" been that way. You are assuming
> there is a delay or a propagation of the change thru time that takes
> time. Why would there be? And how fast would that propagation travel?
> At the speed of time? A time traveler would be changing the very thing
> you are measuring "when" the change "catches up" with the "future" with.
>
> Essentially, the creation of the "new" time line removes the "old" time
> line from existence through out ALL of spacetime. It was never there,
> EVER, once the time line was/is/has been changed. (This is basically a
> problem with ALL time travel stories, the assumption there is a "before"
> and an "after" in something that we don't have the language for.)
> --
> I've done good in this world. Now I'm tired and just want to be a cranky
> dirty old man.

Have you read it ? At least up to and including "The easy way". It's very little.

In article <7cc7f4c6-ff07-4885-a24f-a96789b3c028n@googlegroups.com>,
Ross Presser <rpresser@gmail.com> wrote:
>On Monday, January 16, 2023 at 4:08:34 PM UTC-5, Dorothy J Heydt wrote:
>
>> Dorothy wrote a time travel story in which the protgonist keeps being
>> sent back until he takes an action that prevents changing the past.
>
>Niven proposed a "law" in "The Theory and Practice of Time Travel"
>(1973): If the universe of discourse permits the possibility of time
>travel and of changing the past, then no time machine will be invented
>in that universe.
>
>(I can well believe that Mrs. Heydt knew of Niven coining this "law" when
>she wrote her story. If she did not, then, well, it's a logical
>conclusion she reached on her own.)
>
>Because if there's a time machine, somebody WILL change the past. And
>if that change didn't disable time travel, it'll get changed "again".
>And "again". Until "finally" someone changes the past in a way that
>erases the time machine invention. "After" that, no more changes.

(Hal Heydt)
No machine involved. The story is "Paradox Lost". It was in
MZB's Fantasy Magazine, Issue #2, 1989. I haven't checked, but
it should be in _Stories You Never Heard Of_, which is on her web
site.

Ross Presser wrote:
> Dorothy J Heydt wrote:
>
>> Dorothy wrote a time travel story in which the protgonist keeps being
>> sent back until he takes an action that prevents changing the past.
>
> Niven proposed a "law" in "The Theory and Practice of Time Travel"
> (1973): If the universe of discourse permits the possibility of time
> travel and of changing the past, then no time machine will be invented
> in that universe.
>
> (I can well believe that Mrs. Heydt knew of Niven coining this "law" when
> she wrote her story. If she did not, then, well, it's a logical
> conclusion she reached on her own.)
>
> Because if there's a time machine, somebody WILL change the past. And
> if that change didn't disable time travel, it'll get changed "again".
> And "again". Until "finally" someone changes the past in a way that
> erases the time machine invention. "After" that, no more changes.
>
> Scare quotes around those words because they only make sense if there's
> some kind of memory that outlasts changing the past, which has always
> seemed impossible to me.
>
> https://www.goodreads.com/book/show/39679824-the-theory-and-practice-of-time-travel

"Brevity is the soul of wit." You say it much more succinctly than
Niven.
Time itself is a slippery concept. Open questions to readers: Do
Earthlings suffer from temporalcentrism (in more than one way)? Do
notions of Kochab and Miza as Indestructible betray privileged conceit?
My mind associates your scare quote metaverse with Ouspensky's sixth
dimension. YMMV.

Danke,

--
Don.......My cat's )\._.,--....,'``. https://crcomp.net/reviews.php
telltale tall tail /, _.. \ _\ (`._ ,. Walk humbly with thy God.
tells tall tales.. `._.-(,_..'--(,_..'`-.;.' Make 1984 fiction again.

In article <fl43sh99ftjniqjc0rm39b90bkmfabrhtt@4ax.com>,
Paul S Person <psperson@old.netcom.invalid> wrote:
>I once saw a film where an Arab-American businessman, on discovering
>that the teleportation device was really a time-travel device, decided
>to go back and (it developed) wipe out Jesus and the Twelve in
>Gethsemane. Of course others went back to try to stop it.

Arab-American? Was he supposed to be Muslim? Jesus was spoken
of by Mohammed as a great prophet, though of course, he considered
Christianity to be a corruption of Jesus' teaching. Some
historians have referred to Islam as a Christian heresy.

An actual Muslim wanting to get rid of the historical Jesus is
a major suspension of disbelief thing right there.

Of course, not all Arabs are any sort of religious believer.
If the Arab-American was an atheist of the Sam Shepard sort,
I could see it.

And, it does sound like it's a rather silly movie.

--
Mike Van Pelt | "I don't advise it unless you're nuts."
mvp at calweb.com | -- Ray Wilkinson, after riding out Hurricane
KE6BVH | Ike on Surfside Beach in Galveston

On Wednesday, January 18, 2023 at 6:02:09 PM UTC-7, Dimensional Traveler wrote:

> Essentially, the creation of the "new" time line removes the "old" time
> line from existence through out ALL of spacetime.

Well, according to _one_ view of how time travel would work.

One view is that the old time line goes on just fine, and the new time line is
just an addition: i.e. The Man Who Folded Himself by David Gerrold.

Another is that the new time line replaces the old time line for the future
of the world, but the time traveller and his time machine, not being in the
future of the change when it happens, but in its present, are unaffected.

This view makes sense, because in that view, all causes and effects are
local.

John Savard

On Sunday, January 22, 2023 at 12:59:32 AM UTC+2, Quadibloc wrote:
> On Wednesday, January 18, 2023 at 6:02:09 PM UTC-7, Dimensional Traveler wrote:
>
> > Essentially, the creation of the "new" time line removes the "old" time
> > line from existence through out ALL of spacetime.
> Well, according to _one_ view of how time travel would work.

An absurd one.

> One view is that the old time line goes on just fine, and the new time line is
> just an addition: i.e. The Man Who Folded Himself by David Gerrold.

That's forking universes. That's not time travel.

> Another is that the new time line replaces the old time line for the future
> of the world, but the time traveller and his time machine, not being in the
> future of the change when it happens, but in its present, are unaffected.

Can you name a story by this model ?

----
My own time travel model, which permits paradox-free travel to the past and changing the past:
http://mhtt.50webs.com

On Sat, 21 Jan 2023 20:06:39 -0000 (UTC), Mike Van Pelt
<usenet@mikevanpelt.com> wrote:

>In article <fl43sh99ftjniqjc0rm39b90bkmfabrhtt@4ax.com>,
>Paul S Person <psperson@old.netcom.invalid> wrote:
>>I once saw a film where an Arab-American businessman, on discovering
>>that the teleportation device was really a time-travel device, decided
>>to go back and (it developed) wipe out Jesus and the Twelve in
>>Gethsemane. Of course others went back to try to stop it.
>
>Arab-American? Was he supposed to be Muslim? Jesus was spoken
>of by Mohammed as a great prophet, though of course, he considered
>Christianity to be a corruption of Jesus' teaching. Some
>historians have referred to Islam as a Christian heresy.

He turned out to be /very/ Muslim.

CS Lewis, IIRC, said that Islam is the /greatest/ (most successful)
Christian heresy, being essentially a variant of Arianism. Arianism
greatly modified and elaborated, to be sure.

>An actual Muslim wanting to get rid of the historical Jesus is
>a major suspension of disbelief thing right there.

I suspect their wingnuts have a few members who would like that.

One of them died as the bad thief on a neighboring cross assuring
Jesus that He was a fake. Sadly, the guy was not around to witness the
Resurrection.

>Of course, not all Arabs are any sort of religious believer.
>If the Arab-American was an atheist of the Sam Shepard sort,
>I could see it.

Sorry to disappoint you.

>And, it does sound like it's a rather silly movie.

In many ways, yes. And definitely on the low-budget side. But the idea
was a good one.

It ends, BTW, with the heroes 20 years or so in the future -- in the
middle of Armageddon. Clearly a teaser for a sequel.

Feel free to regard the very concept of a sequel as a threat.
--
"In this connexion, unquestionably the most significant
development was the disintegration, under Christian
influence, of classical conceptions of the family and
of family right."

In article <93e1fb42-5f20-4cf3-8d2c-6302a08da0cbn@googlegroups.com>,
Quadibloc <jsavard@ecn.ab.ca> wrote:
>On Wednesday, January 18, 2023 at 6:02:09 PM UTC-7, Dimensional Traveler wrote:
>
>> Essentially, the creation of the "new" time line removes the "old" time
>> line from existence through out ALL of spacetime.
>
>Well, according to _one_ view of how time travel would work.
>
>One view is that the old time line goes on just fine, and the new time line is
>just an addition: i.e. The Man Who Folded Himself by David Gerrold.

This one avoids paradoxes, but has the feature of every time travel
episode creating an entire new cosmos _ex nihilo_. The energy
requirements would seem to be rather large.

--
Mike Van Pelt | "I don't advise it unless you're nuts."
mvp at calweb.com | -- Ray Wilkinson, after riding out Hurricane
KE6BVH | Ike on Surfside Beach in Galveston

In article <tqmqic$3os0g$1@dont-email.me>,
Mike Van Pelt <usenet@mikevanpelt.com> wrote:
>In article <93e1fb42-5f20-4cf3-8d2c-6302a08da0cbn@googlegroups.com>,
>Quadibloc <jsavard@ecn.ab.ca> wrote:
>>On Wednesday, January 18, 2023 at 6:02:09 PM UTC-7, Dimensional Traveler wrote:
>>
>>> Essentially, the creation of the "new" time line removes the "old" time
>>> line from existence through out ALL of spacetime.
>>
>>Well, according to _one_ view of how time travel would work.
>>
>>One view is that the old time line goes on just fine, and the new time line is
>>just an addition: i.e. The Man Who Folded Himself by David Gerrold.
>
>This one avoids paradoxes, but has the feature of every time travel
>episode creating an entire new cosmos _ex nihilo_. The energy
>requirements would seem to be rather large.
>

Fiat Lux..
--
columbiaclosings.com
What's not in Columbia anymore..

Mike Van Pelt <usenet@mikevanpelt.com> wrote in
news:tqmqic$3os0g$1@dont-email.me:

> In article
> <93e1fb42-5f20-4cf3-8d2c-6302a08da0cbn@googlegroups.com>,
> Quadibloc <jsavard@ecn.ab.ca> wrote:
>>On Wednesday, January 18, 2023 at 6:02:09 PM UTC-7, Dimensional
>>Traveler wrote:
>>
>>> Essentially, the creation of the "new" time line removes the
>>> "old" time line from existence through out ALL of spacetime.
>>
>>Well, according to _one_ view of how time travel would work.
>>
>>One view is that the old time line goes on just fine, and the
>>new time line is just an addition: i.e. The Man Who Folded
>>Himself by David Gerrold.
>
> This one avoids paradoxes, but has the feature of every time
> travel episode creating an entire new cosmos _ex nihilo_. The
> energy requirements would seem to be rather large.
>
Or those alternate timelines have always existed (along with every
other conceivable timeline), and time travel isn't time travel, it's
just dimension jumping that looks like time travel.

--
Terry Austin

"Terry Austin: like the polio vaccine, only with more asshole."
-- David Bilek

Jesus forgives sinners, not criminals.

On 1/23/23 17:37, Ted Nolan <tednolan> wrote:
> In article <tqmqic$3os0g$1@dont-email.me>,
> Mike Van Pelt <usenet@mikevanpelt.com> wrote:
>> In article <93e1fb42-5f20-4cf3-8d2c-6302a08da0cbn@googlegroups.com>,
>> Quadibloc <jsavard@ecn.ab.ca> wrote:
>>> On Wednesday, January 18, 2023 at 6:02:09 PM UTC-7, Dimensional Traveler wrote:
>>>
>>>> Essentially, the creation of the "new" time line removes the "old" time
>>>> line from existence through out ALL of spacetime.
>>>
>>> Well, according to _one_ view of how time travel would work.
>>>
>>> One view is that the old time line goes on just fine, and the new time line is
>>> just an addition: i.e. The Man Who Folded Himself by David Gerrold.
>>
>> This one avoids paradoxes, but has the feature of every time travel
>> episode creating an entire new cosmos _ex nihilo_. The energy
>> requirements would seem to be rather large.
>>
>
> Fiat Lux..

As I remember it, the time travel during the ending bit of Narbonic was
said to require an entire universe worth of energy(drained from another
universe where they were sure the people did not care as much about
living as we do) so that would work out.

On 1/24/2023 9:52 AM, Magewolf wrote:
> On 1/23/23 17:37, Ted Nolan <tednolan> wrote:
>> In article <tqmqic$3os0g$1@dont-email.me>,
>> Mike Van Pelt  <usenet@mikevanpelt.com> wrote:
>>> In article <93e1fb42-5f20-4cf3-8d2c-6302a08da0cbn@googlegroups.com>,
>>> Quadibloc  <jsavard@ecn.ab.ca> wrote:
>>>> On Wednesday, January 18, 2023 at 6:02:09 PM UTC-7, Dimensional
>>>> Traveler wrote:
>>>>
>>>>> Essentially, the creation of the "new" time line removes the "old"
>>>>> time
>>>>> line from existence through out ALL of spacetime.
>>>>
>>>> Well, according to _one_ view of how time travel would work.
>>>>
>>>> One view is that the old time line goes on just fine, and the new
>>>> time line is
>>>> just an addition: i.e. The Man Who Folded Himself by David Gerrold.
>>>
>>> This one avoids paradoxes, but has the feature of every time travel
>>> episode creating an entire new cosmos _ex nihilo_.  The energy
>>> requirements would seem to be rather large.
>>>
>>
>> Fiat Lux..
>
> As I remember it, the time travel during the ending bit of Narbonic was
> said to require an entire universe worth of energy(drained from another
> universe where they were sure the people did not care as much about
> living as we do) so that would work out.

So where did the energy to create our "real" universe come from?

--
I've done good in this world. Now I'm tired and just want to be a cranky
dirty old man.