Setting the Clock: the Planet way, the navy way, and the w..

On Apr 20, 6:15 pm, Loren Pechtel <lorenpech... RemoveThis @hotmail.invalid.com>
wrote:

> Which is why I say that a drive that leaves the universe, such as the
> hyperdrive of the Honorverse, is not subject to this restriction.

In view of another reply to this post, perhaps it would be better to
say "not _necessarily_ subject to this restriction", since the other
dimension in which FTL travel takes place *may* define a reference
frame relative to which all FTL journeys are forwards in time.

John Savard
 >> Stay informed about: Setting the Clock: the Planet way, the navy way, and the w.. 

On Apr 21, 5:34 am, Quadibloc <jsav....DeleteThis@ecn.ab.ca> wrote:
> On Apr 20, 6:15 pm, Loren Pechtel <lorenpech....DeleteThis@hotmail.invalid.com>
> wrote:
>
> > Which is why I say that a drive that leaves the universe, such as the
> > hyperdrive of the Honorverse, is not subject to this restriction.
>
> In view of another reply to this post, perhaps it would be better to
> say "not _necessarily_ subject to this restriction", since the other
> dimension in which FTL travel takes place *may* define a reference
> frame relative to which all FTL journeys are forwards in time.
>
> John Savard

The important thing to remember is that while such a reference frame
may exist, it is of little use if you cannot mathematically transpose
it back to the frames of reference that you are trying to reconcile in
a way that removes conflicts. A frame of reference that you cannot
refer to is a contradiction.
 >> Stay informed about: Setting the Clock: the Planet way, the navy way, and the w.. 

On Apr 21, 10:43 am, "rlbell.ns...@gmail.com" <rlbell.ns....TakeThisOut@gmail.com>
wrote:
> On Apr 21, 5:34 am, Quadibloc <jsav....TakeThisOut@ecn.ab.ca> wrote:
>
> > On Apr 20, 6:15 pm, Loren Pechtel <lorenpech....TakeThisOut@hotmail.invalid.com>
> > wrote:
>
> > > Which is why I say that a drive that leaves the universe, such as the
> > > hyperdrive of the Honorverse, is not subject to this restriction.
>
> > In view of another reply to this post, perhaps it would be better to
> > say "not _necessarily_ subject to this restriction", since the other
> > dimension in which FTL travel takes place *may* define a reference
> > frame relative to which all FTL journeys are forwards in time.

> The important thing to remember is that while such a reference frame
> may exist, it is of little use if you cannot mathematically transpose
> it back to the frames of reference that you are trying to reconcile in
> a way that removes conflicts.  A frame of reference that you cannot
> refer to is a contradiction.

It would transpose in the usual way of any other inertial reference
frame in SR. I'm not sure I grasp the basis of your objection. I'm
saying that one might have an FTL drive based on an unknown factor to
which the principle of relativity does not apply, so that it will not
allow FTL journeys that are backwards in time in reference frame S;
from S', some of them would look backwards in time when they are in
one spatial direction, but no causality violations could result.

John Savard
 >> Stay informed about: Setting the Clock: the Planet way, the navy way, and the w.. 

On Sun, 20 Apr 2008 08:11:01 -0800, Offbreed
<offbreed_106.TakeThisOut@hotmail.com> wrote:

>mike weber wrote:
>> On Sat, 19 Apr 2008 08:27:08 -0800, Offbreed
>>> Uh-huh. Einstein is applicable sub light. How do we know the equations
>>> are applicable FTL?
>>
>> Irrelevant; the "action at a distance" effect is part of the sub-light
>> universe.
>
>I guess I don't understand the "action at a distance" part, then. All
>you can do is "observe at a distance", and in the past.

With instantaneous travel/communications, you can perform what physics
describes as "action at a distance".
 >> Stay informed about: Setting the Clock: the Planet way, the navy way, and the w.. 

On Sun, 20 Apr 2008 22:31:30 -0700 (PDT), "rlbell.nsuid@gmail.com"
<rlbell.nsuid.DeleteThis@gmail.com> wrote:

>On Apr 20, 6:15 pm, Loren Pechtel <lorenpech....DeleteThis@hotmail.invalid.com>
>wrote:
>> On Sun, 20 Apr 2008 04:00:50 -0700 (PDT), Quadibloc
>>
>> <jsav....DeleteThis@ecn.ab.ca> wrote:
>> >But if your FTL drive obeys the laws of Special Relativity, so that
>> >its behavior is *exactly the same in all inertial reference frames*,
>> >then by jumping off from suitably fast-moving but slower than light
>> >starting points in both directions, one can appear to be moving
>> >backwards in time from Earth's vantage point on both legs of the
>> >journey, and arrive back on Earth up to eight years before you left,
>> >*even* with an FTL drive only capable of 1.01c *as viewed from the
>> >perspective of the slower than light frame the ship was in when it
>> >transitioned*.
>>
>> Which is why I say that a drive that leaves the universe, such as the
>> hyperdrive of the Honorverse, is not subject to this restriction.
>
>
>It isn't a "restriction". The effects that we are trying to describe
>are independent of how FTL travel is achieved. The only difference
>using a "exit the universe, travel a shorter distance, re-enter the
>universe, but still get to your destination before a light beam" drive
>makes is that your progress between departure and arrival are hidden
>from view. You still get there before you left.

The velocity you carry across the wall matters. The floating
reference frame of SR is gone and thus the time travel problem is
gone.
 >> Stay informed about: Setting the Clock: the Planet way, the navy way, and the w.. 

On Sun, 27 Apr 2008 09:42:42 -0700, Loren Pechtel
<lorenpechtel.TakeThisOut@hotmail.invalid.com> wrote:


>The velocity you carry across the wall matters. The floating
>reference frame of SR is gone and thus the time travel problem is
>gone.

Nope.

Since you begin and arrive in the same reference frame, that's where
it really comes in.

Rather like Doc SMith's "Bergenhols" inertialess drive - you still had
to opvercome the delta-vee (intrinsic velocity, as Doc called it)
between your departure point and your arrival point somewhere along
the line
 >> Stay informed about: Setting the Clock: the Planet way, the navy way, and the w.. 

On Sun, 27 Apr 2008 17:02:47 -0400, mike weber <fairportfan.RemoveThis@gmail.com>
wrote:

>On Sun, 27 Apr 2008 09:42:42 -0700, Loren Pechtel
><lorenpechtel.RemoveThis@hotmail.invalid.com> wrote:
>
>
>>The velocity you carry across the wall matters. The floating
>>reference frame of SR is gone and thus the time travel problem is
>>gone.
>
>Nope.
>
>Since you begin and arrive in the same reference frame, that's where
>it really comes in.
>
>Rather like Doc SMith's "Bergenhols" inertialess drive - you still had
>to opvercome the delta-vee (intrinsic velocity, as Doc called it)
>between your departure point and your arrival point somewhere along
>the line

I think it was Bergenholm.

That drive worked within our universe and utterly did not count
relativity. It would have fallen victim to the time travel issue.

What I'm saying is that the velocity you transition at matters. This
means there is some absolute reference point for velocity, you can't
pick any arbitrary frame like is required to produce the time travel
problem.

I'm also not convinced that the time travel problem is a real paradox
anyway. Sure, it lets you take a path that certain observers will say
is to the past. I don't think it will permit you to reach a point
before you set out, though.
 >> Stay informed about: Setting the Clock: the Planet way, the navy way, and the w.. 

On Mon, 28 Apr 2008 18:55:53 -0700, Loren Pechtel
<lorenpechtel DeleteThis @hotmail.invalid.com> wrote:

>On Sun, 27 Apr 2008 17:02:47 -0400, mike weber <fairportfan DeleteThis @gmail.com>
>wrote:
>

>>Rather like Doc SMith's "Bergenhols" inertialess drive - you still had
>>to opvercome the delta-vee (intrinsic velocity, as Doc called it)
>>between your departure point and your arrival point somewhere along
>>the line
>
>I think it was Bergenholm.

*sigh* Yes.
>
>That drive worked within our universe and utterly did not count
>relativity. It would have fallen victim to the time travel issue.
>
>What I'm saying is that the velocity you transition at matters. This
>means there is some absolute reference point for velocity, you can't
>pick any arbitrary frame like is required to produce the time travel
>problem.

Actually, you have that backward. The Bergenholm implies an absolute
frame of reference; otherwise "intrinsic velocity" wouldn't be a
problem.

In the universe described by relativity, there *is* no absolute frame
of reference.
>
>I'm also not convinced that the time travel problem is a real paradox
>anyway. Sure, it lets you take a path that certain observers will say
>is to the past. I don't think it will permit you to reach a point
>before you set out, though.

People who know more than i do about relativity say it will.
 >> Stay informed about: Setting the Clock: the Planet way, the navy way, and the w.. 

mike weber wrote:
> Actually, you have that backward. The Bergenholm implies an absolute
> frame of reference; otherwise "intrinsic velocity" wouldn't be a
> problem.

I don't think it was meant that way. As I recall, the intrinsic velocity
was the velocity something had before the inertialess drive kicked in.
(On the other hand, I have not read that series in many decades.)

> In the universe described by relativity, there *is* no absolute frame
> of reference.

Yet, a number of authors try to use an Einstein reference, but...

How many times do we see that some ship cannot keep accelerating because
it might hit a chunk of gravel at relativistic speeds? Doesn't that
imply a local "zero velocity", even if it is a mathematical average of
all particles and matter in the area?
 >> Stay informed about: Setting the Clock: the Planet way, the navy way, and the w.. 

On Apr 28, 8:52 pm, mike weber <fairport... DeleteThis @gmail.com> wrote:
> On Mon, 28 Apr 2008 18:55:53 -0700, Loren Pechtel
>
> <lorenpech... DeleteThis @hotmail.invalid.com> wrote:
> >On Sun, 27 Apr 2008 17:02:47 -0400, mike weber <fairport... DeleteThis @gmail.com>
> >wrote:
>
> >>Rather like Doc SMith's "Bergenhols" inertialess drive - you still had
> >>to opvercome the delta-vee (intrinsic velocity, as Doc called it)
> >>between your departure point and your arrival point somewhere along
> >>the line
>
> >I think it was Bergenholm.
>
> *sigh* Yes.
>
>
>
> >That drive worked within our universe and utterly did not count
> >relativity. It would have fallen victim to the time travel issue.
>
> >What I'm saying is that the velocity you transition at matters. This
> >means there is some absolute reference point for velocity, you can't
> >pick any arbitrary frame like is required to produce the time travel
> >problem.
>
> Actually, you have that backward. The Bergenholm implies an absolute
> frame of reference; otherwise "intrinsic velocity" wouldn't be a
> problem.
>
> In the universe described by relativity, there *is* no absolute frame
> of reference.

The Universe described in the Lensmen series has no connection to any
universe described by relativity.

In the lensmen universe, newtonian mechanics reigned supreme and all
non-accelerating frames of reference agreed with each other. Space
and time were disjoint quantities. The speed of light was not a
limit. The most devastating thing known was the chemical explosive,
heptadetonate (before they started lobbing planets and found two
planets with superluminal intrinsic vectors 180 degrees apart).
 >> Stay informed about: Setting the Clock: the Planet way, the navy way, and the w.. 

On Mon, 28 Apr 2008 22:52:34 -0400, mike weber <fairportfan.DeleteThis@gmail.com>
wrote:

>>What I'm saying is that the velocity you transition at matters. This
>>means there is some absolute reference point for velocity, you can't
>>pick any arbitrary frame like is required to produce the time travel
>>problem.
>
>Actually, you have that backward. The Bergenholm implies an absolute
>frame of reference; otherwise "intrinsic velocity" wouldn't be a
>problem.

No. Intrinsic velocity is simply the velocity you have. Any
acceleration you do under the Bergenholm has no effect, when you turn
it off you have exactly the same velocity you had when you turned it
on.
 >> Stay informed about: Setting the Clock: the Planet way, the navy way, and the w.. 

On Mon, 28 Apr 2008 19:47:05 -0800, Offbreed
<offbreed_106 RemoveThis @hotmail.com> wrote:

>mike weber wrote:
>> Actually, you have that backward. The Bergenholm implies an absolute
>> frame of reference; otherwise "intrinsic velocity" wouldn't be a
>> problem.
>
>I don't think it was meant that way. As I recall, the intrinsic velocity
>was the velocity something had before the inertialess drive kicked in.
>(On the other hand, I have not read that series in many decades.)

I think you're right. The drive utterly suppresses interia (I suspect
a more realistic description is that it suppresses mass.) Under this
drive the ship instantly assumes a velocity consistent with the energy
being applied to it. The drive pushes you, friction with the
interstellar medium slows you.

Of course this is utterly incompatible with relativity as the
equilibrium point is FTL and not only that, the particles in the way
that are being knocked aside to slow it themselves are being pushed
FTL.

>How many times do we see that some ship cannot keep accelerating because
>it might hit a chunk of gravel at relativistic speeds? Doesn't that
>imply a local "zero velocity", even if it is a mathematical average of
>all particles and matter in the area?

No, it implies that objects in a neighborhood have a velocity. If we
were all moving at .99c it wouldn't make any difference.
 >> Stay informed about: Setting the Clock: the Planet way, the navy way, and the w.. 

On Mon, 28 Apr 2008 19:47:05 -0800, Offbreed
<offbreed_106 DeleteThis @hotmail.com> wrote:

>mike weber wrote:
>> Actually, you have that backward. The Bergenholm implies an absolute
>> frame of reference; otherwise "intrinsic velocity" wouldn't be a
>> problem.
>
>I don't think it was meant that way. As I recall, the intrinsic velocity
>was the velocity something had before the inertialess drive kicked in.
>(On the other hand, I have not read that series in many decades.)

Well, yeah - but it had to be in relation to an absolute frame of
reference so that it could reassert itself at the other end.

And that something was the ether, the motionless medium through which
electro-magnetic radiation propagates, the existence of which was
more-or-less disproven by the Michaelson-Morley experiments, which
some handwaving by Doc explained away.
>
>> In the universe described by relativity, there *is* no absolute frame
>> of reference.
>
>Yet, a number of authors try to use an Einstein reference, but...
>
>How many times do we see that some ship cannot keep accelerating because
>it might hit a chunk of gravel at relativistic speeds? Doesn't that
>imply a local "zero velocity", even if it is a mathematical average of
>all particles and matter in the area?

No, it implies a relative velocity of ship and local object.

Consider this: In the Einsteinian universe, if one ship is travelling
at .9C in one direction, and another is travelling at .9C on a direct
reciprocal, their closing velocity is *not* 1.8C, it's something
greater than .9C, but less than C.

Likewise, if one of those ships projects a laser beam forward, that
laser beam will be propagating forward relative to that ship at C,
but it will be seen from an outside observer as propagating at exactly
C.
 >> Stay informed about: Setting the Clock: the Planet way, the navy way, and the w..