I've seen 100% satisfactory resolutions to the Twin Paradox and the
Barn-Pole paradox, but am unable to find anyone who can resolve the
Bug-Rivet SR paradox described he
http://hyperphysics.phy-astr.gsu.edu.../bugrivet.html

-KJS

Ken and Vicki wrote:
I've seen 100% satisfactory resolutions to the Twin Paradox and the
Barn-Pole paradox, but am unable to find anyone who can resolve the
Bug-Rivet SR paradox described he
http://hyperphysics.phy-astr.gsu.edu.../bugrivet.html

It's really the same as the barn-and-pole paradox, in the variant
in which the person at rest wit respect to the barn waits until the
pole is inside and closes the door.

Here's a hint: in the bug's frame of reference, what happens
to the tip of the rivet when the head hits the wall? Remember,
the information that the head has hit the wall can't travel
down the rivet faster than light.

Steve Carlip

"Ken and Vicki" escribió en el mensaje
...
I've seen 100% satisfactory resolutions to the Twin Paradox and the
Barn-Pole paradox, but am unable to find anyone who can resolve the
Bug-Rivet SR paradox described he
http://hyperphysics.phy-astr.gsu.edu.../bugrivet.html

-KJS

A plaussible scenario in lack of more data:

the bug dies smashed, and the rivet is destroyed, breaking in two or more
pieces. This paradox does have to do with the relativity of the
simultaneity, but it also has to do with the signals travelling at speed
less than c. Let's see it briefly:

1) bug PoV: the rivet is small, but it is not stoped because the signals
when hitting the external part of the wall cannot reach the front of the
rivet. The rivet breaks, and the front continues travel and kills the bug.

2) Rivet PoV: the bug is smashed first, and later the wider part of the
river hits the external part of the wall. The rivet is fragmented, but the
bug died first.

In both cases, the bug dies and the rivet is broken into 2 pieces. The
relativity of simultaneity is a part of the scenario, but also the
impossibility of the end of the rivet to "communicate" to the front that it
has to stop, making the rivet to break into 2 pieces. (We consider the wall
being more "solid"). Other plaussible scenarios will also not yield any
paradox at all.

"Cesar Sirvent" wrote in message
s...

"Ken and Vicki" escribió en el mensaje
...
I've seen 100% satisfactory resolutions to the Twin Paradox and the
Barn-Pole paradox, but am unable to find anyone who can resolve the
Bug-Rivet SR paradox described he
http://hyperphysics.phy-astr.gsu.edu.../bugrivet.html

-KJS

A plaussible scenario in lack of more data:

the bug dies smashed, and the rivet is destroyed, breaking in two or more
pieces. This paradox does have to do with the relativity of the
simultaneity, but it also has to do with the signals travelling at speed
less than c. Let's see it briefly:

1) bug PoV: the rivet is small, but it is not stoped because the signals
when hitting the external part of the wall cannot reach the front of the
rivet. The rivet breaks, and the front continues travel and kills the bug.

2) Rivet PoV: the bug is smashed first, and later the wider part of the
river hits the external part of the wall. The rivet is fragmented, but the
bug died first.

In both cases, the bug dies and the rivet is broken into 2 pieces. The
relativity of simultaneity is a part of the scenario, but also the
impossibility of the end of the rivet to "communicate" to the front that
it
has to stop, making the rivet to break into 2 pieces. (We consider the
wall
being more "solid"). Other plaussible scenarios will also not yield any
paradox at all.




The two answer offered so far are WAY unsatisfactory!!!

This paradox is not about deceleration times or tensile strength! Dispense
with all that naggage at once. ALL that this paradox is about is that from
the rivet's PoV, the bug gets squashed before the head of the rivet is
stopped by the wall; the math is clearly shown at the original GSU posting,
and is correct, and accounts for Relativity of Simultaneity, and yet the bug
gets squashed from that Pov but NOT from the other (the wall's) PoV. Nor is
the bug squashed if the velocity is low. A paradox truly persists, and I
challenge some minds to RESOLVE it squarely on the side of STR! [Because I
wholeheartedly believe in said theory.]

-KJS

"Ken and Vicki" wrote in message
...
I've seen 100% satisfactory resolutions to the Twin Paradox ...

The Twin Paradox isn't resolved. Here's the triplet clock paradox....

Two of the clocks fly off in spaceships and run only while in inertial
motion & turn off while accelerating. They fly off in opposite directions
relative to the earth & have identical velocities -- relative to the earth.
They return after 1 light year as measured by the clocks local to their
ships. According to SR, when they arrive back on Earth one of the clocks
should be "old" and the other "young". In fact, because the velocity of one
ship relative to the other is greater than that relative to earth, they
should both be "older" than the stay at home clock & the same age as each
other.

Regards

Jack Martinelli

http://www.martinelli.org

"Ken and Vicki" escribió en el mensaje
...

"Cesar Sirvent" wrote in message
s...

"Ken and Vicki" escribió en el mensaje
...
I've seen 100% satisfactory resolutions to the Twin Paradox and the
Barn-Pole paradox, but am unable to find anyone who can resolve the
Bug-Rivet SR paradox described he
http://hyperphysics.phy-astr.gsu.edu.../bugrivet.html

-KJS

A plaussible scenario in lack of more data:

the bug dies smashed, and the rivet is destroyed, breaking in two or
more
pieces. This paradox does have to do with the relativity of the
simultaneity, but it also has to do with the signals travelling at speed
less than c. Let's see it briefly:

1) bug PoV: the rivet is small, but it is not stoped because the signals
when hitting the external part of the wall cannot reach the front of the
rivet. The rivet breaks, and the front continues travel and kills the
bug.

2) Rivet PoV: the bug is smashed first, and later the wider part of the
river hits the external part of the wall. The rivet is fragmented, but
the
bug died first.

In both cases, the bug dies and the rivet is broken into 2 pieces. The
relativity of simultaneity is a part of the scenario, but also the
impossibility of the end of the rivet to "communicate" to the front that
it
has to stop, making the rivet to break into 2 pieces. (We consider the
wall
being more "solid"). Other plaussible scenarios will also not yield any
paradox at all.




The two answer offered so far are WAY unsatisfactory!!!

This paradox is not about deceleration times or tensile strength! Dispense
with all that naggage at once. ALL that this paradox is about is that from
the rivet's PoV, the bug gets squashed before the head of the rivet is
stopped by the wall;

The rivet cannot be stopped by the wall. Information cannot travel faster
than light, and the part in contact with the wall must say to the front of
the rivet "hey, you, please STOP!!"... but the front cannot receive this
message because it goes too fast... consequence, the front does not stop, it
breaks, and killls the disgraceful bug. No paradox, end of the story.

Happy New Year 2004

the math is clearly shown at the original GSU posting,
and is correct, and accounts for Relativity of Simultaneity, and yet the
bug
gets squashed from that Pov but NOT from the other (the wall's) PoV. Nor
is
the bug squashed if the velocity is low. A paradox truly persists, and I
challenge some minds to RESOLVE it squarely on the side of STR! [Because I
wholeheartedly believe in said theory.]

-KJS

"Cesar Sirvent" wrote in message
s...

"Ken and Vicki" escribió en el mensaje
...

"Cesar Sirvent" wrote in message
s...

"Ken and Vicki" escribió en el mensaje
...
I've seen 100% satisfactory resolutions to the Twin Paradox and the
Barn-Pole paradox, but am unable to find anyone who can resolve the
Bug-Rivet SR paradox described he
http://hyperphysics.phy-astr.gsu.edu.../bugrivet.html

-KJS

A plaussible scenario in lack of more data:

the bug dies smashed, and the rivet is destroyed, breaking in two or
more
pieces. This paradox does have to do with the relativity of the
simultaneity, but it also has to do with the signals travelling at
speed
less than c. Let's see it briefly:

1) bug PoV: the rivet is small, but it is not stoped because the
signals
when hitting the external part of the wall cannot reach the front of
the
rivet. The rivet breaks, and the front continues travel and kills the
bug.

2) Rivet PoV: the bug is smashed first, and later the wider part of
the
river hits the external part of the wall. The rivet is fragmented, but
the
bug died first.

In both cases, the bug dies and the rivet is broken into 2 pieces. The
relativity of simultaneity is a part of the scenario, but also the
impossibility of the end of the rivet to "communicate" to the front
that
it
has to stop, making the rivet to break into 2 pieces. (We consider the
wall
being more "solid"). Other plaussible scenarios will also not yield
any
paradox at all.




The two answer offered so far are WAY unsatisfactory!!!

This paradox is not about deceleration times or tensile strength!
Dispense
with all that naggage at once. ALL that this paradox is about is that
from
the rivet's PoV, the bug gets squashed before the head of the rivet is
stopped by the wall;

The rivet cannot be stopped by the wall. Information cannot travel faster
than light, and the part in contact with the wall must say to the front of
the rivet "hey, you, please STOP!!"... but the front cannot receive this
message because it goes too fast... consequence, the front does not stop,
it
breaks, and killls the disgraceful bug. No paradox, end of the story.

Happy New Year 2004

the math is clearly shown at the original GSU posting,
and is correct, and accounts for Relativity of Simultaneity, and yet the
bug
gets squashed from that Pov but NOT from the other (the wall's) PoV. Nor
is
the bug squashed if the velocity is low. A paradox truly persists, and I
challenge some minds to RESOLVE it squarely on the side of STR! [Because
I
wholeheartedly believe in said theory.]

-KJS





Cesar:
Your point is well-taken indeed! but it fails to address the *primary*
paradox which the scenario was drawn up to present.

"Jack Martinelli" wrote in message
...

"Ken and Vicki" wrote in message
...
I've seen 100% satisfactory resolutions to the Twin Paradox ...

The Twin Paradox isn't resolved. Here's the triplet clock paradox....

Two of the clocks fly off in spaceships and run only while in inertial
motion & turn off while accelerating. They fly off in opposite directions
relative to the earth & have identical velocities -- relative to the
earth.
They return after 1 light year as measured by the clocks local to their
ships. According to SR, when they arrive back on Earth one of the clocks
should be "old" and the other "young". In fact, because the velocity of
one
ship relative to the other is greater than that relative to earth, they
should both be "older" than the stay at home clock & the same age as each
other.

Regards

Jack Martinelli

http://www.martinelli.org

Thanks but I know better than to see a paradox in that presentment of yours.
The Twin Paradox and your Triple Paradox are fully resolved without any need
for General Relativity, accelerations, G-forces and all that. Like so many,
you fail to resolve the apparent paradox because you choose to simply
*ignore* relativistic clock dissynchronicity (usually termed "Relativity of
Simultaneity"). In your Triple Paradox, the returning clocks will agree with
one another and both will be younger than Earth's. Time dilation does not
stand alone, nor does length contraction, nor does clock dissynchronicity...
rather, they all THREE work dependent upon one another in the Lorentz
Transform to make for Relativity to be a consistent truism.

Your confusion results from ignoring that relativistic clock
dissynchronicity is direction-dependent. Time dilation isn't
direction-dependent, and length contraction certainly isn't
direction-dependent, but
the Relativity of Simultaneity is most DEFINITELY direction-dependent! When
the space-travelling clocks (or brothers) reverse direction out in space,
YES, they can still be thought of as relativistically stock still while it
is Earth that is in motion -- but if it is Earth that is doing the moving,
then
her direction has clearly been reversed, and ALL of the clocks along that
"real estate" that comprise the Earth frame have all-of-a-sudden switched
orientation of their clock dissynchronicity. Each of the various
space-travelling clocks (or brothers) can rely soley upon the immediate
*local*
clock of that Earth frame to serve as a basis for any extropolating to
discern Earth's clock reading; and where that extrapolating went backward in
time on the one hand, after the direction reverse the extrapolating must
point *forward* in time.

-KJS

Ken and Vicki:

The two answer offered so far are WAY unsatisfactory!!!

This paradox is not about deceleration times or tensile strength!

No, but it is about no signal beimg able to propagate faster than
light. It is therefore impossible for the end of the rivet to come
to rest with respect to the head of the rivet in less time than it
takes light to propagate down the length of the rivet.

Dispense with all that naggage at once. ALL that this paradox is
about is that from the rivet's PoV, the bug gets squashed before the
head of the rivet is stopped by the wall; the math is clearly shown
at the original GSU posting, and is correct, and accounts for
Relativity of Simultaneity, and yet the bug gets squashed from that
Pov but NOT from the other (the wall's) PoV. Nor is the bug squashed
if the velocity is low. A paradox truly persists, and I challenge
some minds to RESOLVE it squarely on the side of STR! [Because I
wholeheartedly believe in said theory.]

You are insisting that the scenario violate special relativity.
That is why you have the paradox. Don't insist that special relativity
explain signals propagating faster than light and the paradox will
go away.

"Ken and Vicki" wrote in message ...


The two answer offered so far are WAY unsatisfactory!!!

ALL that this paradox is about is that from
the rivet's PoV, the bug gets squashed before the head of the rivet is
stopped by the wall;

and from the bug's point of view the bug gets squashed after
the head of the rivet hits the wall.

What is the problem?

Martin Hogbin