Science > Physics > Androcles' long-winded solution to the mosquito problem
| Topic: |
Science > Physics |
| User: |
"Randy Poe" |
| Date: |
07 Jan 2005 02:51:33 PM |
| Object: |
Androcles' long-winded solution to the mosquito problem |
Androcles wrote:
"Randy Poe" <poespam-trap@yahoo.com> wrote in message
news:1105046914.966673.254950@z14g2000cwz.googlegroups.com...
MY equation applies equally well to a bouncing ball or a mosquito
From the standpoint of an observer on the road, we
can say the following.
Same velocity in both directions:
- light
- sound through stationary air
- mosquito
Different velocity in each direction:
- sound through enclosed (moving) air
- bouncing ball
The equation I was talking about applies in the first
case (same ground speed in both directions). No equation
applies to both.
As I hope you realized by now, by the time you wrote down
the actual solution to the mosquito problem, you ended
up with my equation. Or have you not realized yet
that you worked out L/(u-v) + L/(u+v)?
If not, your equation is worthless.
The time for the round trip, on the plane, in the bus, on the back
of the flatbed truck, no matter what vehicle we use, is
t = 2d/c. Right or wrong?
Wrong. See your solution for the mosquito.
- Randy
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| User: "Androcles" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
07 Jan 2005 04:24:28 PM |
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"Randy Poe" <poespam-trap@yahoo.com> wrote in message
news:1105131093.202251.210310@z14g2000cwz.googlegroups.com...
Androcles wrote:
"Randy Poe" <poespam-trap@yahoo.com> wrote in message
news:1105046914.966673.254950@z14g2000cwz.googlegroups.com...
MY equation applies equally well to a bouncing ball or a mosquito
From the standpoint of an observer on the road, we
can say the following.
Same velocity in both directions:
- light
- sound through stationary air
- mosquito
What, 16 seconds one way and 4 seconds the other?
Was 20 round trip you calculated, wasn't it?
So the time to get to Joe is half of that, 16 seconds.
32 feet out, 32 feet back, total 64 feet, time 20 seconds,
64/20 = 3.2 fps, right?
I thought McCullough said 5 fps... How come you changed it?
Everyone knows 20/2 = 16, right?
Different velocity in each direction:
- sound through enclosed (moving) air
- bouncing ball
The equation I was talking about applies in the first
case (same ground speed in both directions). No equation
applies to both.
As I hope you realized by now, by the time you wrote down
the actual solution to the mosquito problem, you ended
up with my equation. Or have you not realized yet
that you worked out L/(u-v) + L/(u+v)?
If not, your equation is worthless.
The time for the round trip, on the plane, in the bus, on the back
of the flatbed truck, no matter what vehicle we use, is
t = 2d/c. Right or wrong?
Wrong. See your solution for the mosquito.
Ah... I see what you are getting at.
See, Sam and Joe (and the mosquito) have hitched a ride
in the back of an ENCLOSED truck that is moving along at 3 fps.
The length of the truck is 32 feet, and the mosquito, flying along
at 3.2 fps with respect to the truck, takes 10 seconds each way.
If he flew at 5 fps, then it only takes him 64/5 = 12.2 seconds
round trip.
So we both disagree with question, right? The mosquito can't be
flying at 5 fps.
Oh wait! I forgot the time dilation!!!!
It takes 20 seconds in the ground frame and 12.2 seconds in
the truck frame!
tau = 20 * sqrt(1 - 3^2/5^2)
= 20 * 0.8
= 16 seconds.
Hmm... not quite, but closer.
Dang... I forgot the length contraction.. that should do it.
See, the velocity of mosquitoes is 5 fps in all frames of reference.
Its a POSTULATE, McCullough said so.
Androcles says...
Insufficent data.
McCullough has not specified what the 5 feet/second is relative to.
McCullough.
It doesn't matter, as long as you measure all these quantities in
the same frame:
1. The speed of Joe and Sam in that frame is 3 feet/second.
2. The speed of the mosquito in that frame is 5 feet/second.
3. The distance between Joe and Sam in that frame is 32 feet.
Happy now?
Androcles.
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| User: "Franz Heymann" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
08 Jan 2005 05:37:42 AM |
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"Androcles" <dummy@dummy.net> wrote in message
news:w_DDd.66045$48.49527@fe1.news.blueyonder.co.uk...
I spare you the shame of having that amount of ignorance displayed yet
again by snipping it.
Androcles, you really have to face up to it. You cannot weigh a
pennyworth of mint balls
and give the kid the right change.
What makes you think you are empowered to waffle abour SR?
[snip]
Franz
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| User: "Daryl McCullough" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
07 Jan 2005 04:45:19 PM |
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Androcles says...
See, the velocity of mosquitoes is 5 fps in all frames of reference.
Its a POSTULATE, McCullough said so.
No, I didn't. I said that there is *one* frame in which the mosquito
moves at 5 fps. I didn't say that it had that speed in very frame
of reference. The problem doesn't involve more than one frame of
reference. The speed of the mosquito, the speed of the walkers,
the distance between the walkers, the time for the round trip,
*all* these quantities are measured in the *same* reference frame.
--
Daryl McCullough
Ithaca, NY
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| User: "Androcles" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
08 Jan 2005 05:06:07 AM |
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"Daryl McCullough" <daryl@atc-nycorp.com> wrote in message
news:crn3dv021if@drn.newsguy.com...
Androcles says...
See, the velocity of mosquitoes is 5 fps in all frames of reference.
Its a POSTULATE, McCullough said so.
No, I didn't.
I said that there is *one* frame in which the mosquito
moves at 5 fps.
So? I went on to prove that the mosquito flies at 5fps in ALL frames.
I used Einstein's math, its quite easy.
c is the speed of the mosquito, w is the speed of Joe and Sam.
It follows, further, that the velocity of mosquitoes c cannot be altered
by composition with a velocity less than that of mosquitoes.
"For this case we obtain V = (c+w)/(1+w/c) = c."- Einstein.
Look:
5 = (5+ 3)/(1+ 3/5)
Surely you agree, this is only high school algebra, for heaven's sake.
I didn't say that it had that speed in very frame
of reference.
No, but I proved it is. Einstein showed me how, and we all know he
was right, don't we?
The problem doesn't involve more than one frame of
reference.
LOL! Of course it does.The stationary frame time is 20 seconds
round trip, but for the mosquito, who travels 2 * 32 = 64 feet
in 20 seconds, he would have a speed of 64/20 = 3.2 fps, which is
less that 5 fps, so that can't be right. Now, 64/5 = 12.2 seconds,
which is the time in the Sam and Joes frame of reference. Their
wristwatches runs slow, it's called time dilation.
Don't you know that moving clocks run slow?
The speed of the mosquito, the speed of the walkers,
the distance between the walkers, the time for the round trip,
*all* these quantities are measured in the *same* reference frame.
Well, if you ONLY want the time in the stationary frame, sure.
But the time in Sam and Joe's frame is 12.2 seconds.
Einstein's math prove it.
What goes wrong is when Sam stops to tie his shoelace
while still walking toward Joe at 3 fps.
½[tau(0,0,0,t)+tau(0,0,0,t+x'/(c-v)+x'/(c+v))] = tau(x',0,0,t+x'/(c-v))
There is only one place (0,0,0) for the mosquito to return to Sam, see?
This is high school algebra. Did you go to high school? Einstein failed
his high school, did you know that?
Androcles.
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| User: "Daryl McCullough" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
08 Jan 2005 09:03:43 AM |
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Androcles says...
"Daryl McCullough" <daryl@atc-nycorp.com> wrote in message
news:crn3dv021if@drn.newsguy.com...
Androcles says...
See, the velocity of mosquitoes is 5 fps in all frames of reference.
Its a POSTULATE, McCullough said so.
No, I didn't.
I said that there is *one* frame in which the mosquito
moves at 5 fps.
So? I went on to prove that the mosquito flies at 5fps in ALL frames.
So you lied when you said "Its a POSTULATE, McCullough said so".
I used Einstein's math, its quite easy.
Not for you, obviously. You didn't derive anything.
c is the speed of the mosquito, w is the speed of Joe and Sam.
No. I didn't say that the mosquito had speed c. I didn't say
that the speed of the mosquito was a universal constant. You
are just getting hopelessly confused.
This problem didn't involve relativity at all. It didn't involve
coordinate transformations. It didn't involve the composition
of velocities. It was a simple problem of algebra. You haven't
been able to do it.
The problem doesn't involve more than one frame of
reference.
LOL! Of course it does.
No, it doesn't. It is simply an algebra problem.
The stationary frame time is 20 seconds
round trip, but for the mosquito
The problem doesn't ask for what things look like
from the rest frame of the mosquito. It asked for
the round-trip time as measured in the frame of
the ground.
The speed of the mosquito, the speed of the walkers,
the distance between the walkers, the time for the round trip,
*all* these quantities are measured in the *same* reference frame.
Well, if you ONLY want the time in the stationary frame, sure.
That's exactly what I want. I'm just asking you to understand
a simple algebra problem.
--
Daryl McCullough
Ithaca, NY
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| User: "Androcles" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
08 Jan 2005 12:10:03 PM |
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"Daryl McCullough" <daryl@atc-nycorp.com> wrote in message
news:crosof01ul2@drn.newsguy.com...
Androcles says...
"Daryl McCullough" <daryl@atc-nycorp.com> wrote in message
news:crn3dv021if@drn.newsguy.com...
Androcles says...
See, the velocity of mosquitoes is 5 fps in all frames of reference.
Its a POSTULATE, McCullough said so.
No, I didn't.
I said that there is *one* frame in which the mosquito
moves at 5 fps.
So? I went on to prove that the mosquito flies at 5fps in ALL frames.
So you lied when you said "Its a POSTULATE, McCullough said so".
Not at all. You postulated that the speed of the mosquito is 5 fps.
I added "all frames of reference" since you refused to specify a frame
when I asked.
I used Einstein's math, its quite easy.
Not for you, obviously. You didn't derive anything.
Sure I did. You are being silly.
c is the speed of the mosquito, w is the speed of Joe and Sam.
No. I didn't say that the mosquito had speed c. I didn't say
that the speed of the mosquito was a universal constant. You
are just getting hopelessly confused.
Not at all. I was using Einstein's math, that's all.
The velocity of the mosquito plays the part, physically, of the
velocity of light.
You really are floundering if you think you'll trip me on that one.
It was you that created the analogy as I was discussing the issue
with Poe.
This problem didn't involve relativity at all.
Sure it does. u-v, u+v are relative velocities.
It didn't involve
coordinate transformations.
Sure it does.
(xi3,tau3) = (0,20)
is a transform from
(60, 20) in the ground frame.
It didn't involve the composition
of velocities.
You can't derive that. Poe's been trying for 3 weeks and he's
no further now than when he started. Still, if you want to have
a go at it, be my guest.
I can promse you that you'll fail. I'm not accepting the speed of
an object has two speeds in the moving frame to prove it has one
speed in the moving frame.
It was a simple problem of algebra. You haven't
been able to do it.
Don't be silly. Of course I can divide 80 by 5 and get 16.
The problem doesn't involve more than one frame of
reference.
LOL! Of course it does.
No, it doesn't. It is simply an algebra problem.
The stationary frame time is 20 seconds
round trip, but for the mosquito
The problem doesn't ask for what things look like
from the rest frame of the mosquito. It asked for
the round-trip time as measured in the frame of
the ground.
Well, in case you missed it:
80/5 = 16 and 20/5 = 4.
The speed of the mosquito, the speed of the walkers,
the distance between the walkers, the time for the round trip,
*all* these quantities are measured in the *same* reference frame.
Well, if you ONLY want the time in the stationary frame, sure.
That's exactly what I want. I'm just asking you to understand
a simple algebra problem.
The answer is 80/5, 20/5 in the ground frame
and 32/2,32/8 in the moving frame.
Now you have both.
Androcles.
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| User: "Daryl McCullough" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
08 Jan 2005 04:01:35 PM |
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Androcles says...
See, the velocity of mosquitoes is 5 fps in all frames of reference.
Its a POSTULATE, McCullough said so.
So you lied when you said "Its a POSTULATE, McCullough said so".
Not at all. You postulated that the speed of the mosquito is 5 fps.
I didn't postulate that it was 5 in all frames of reference.
Not at all. I was using Einstein's math, that's all.
You were using it incorrectly. Nonsensically, to be precise.
The velocity of the mosquito plays the part, physically, of the
velocity of light.
No, it doesn't. It's just a speed.
This problem didn't involve relativity at all.
Sure it does. u-v, u+v are relative velocities.
No, in this problem, they are closing velocities. That, as
I explained is the rate at which the distance between
two objects changes, as measured in a *third* reference
frame. Relative velocity, in contrast, is the velocity
of one object, as measured in the frame of the other
object.
For the problem at hand, the concept of relative
velocity does not appear.
It didn't involve
coordinate transformations.
Sure it does.
No, it doesn't. It is pure algebra: given
1. u = D_m/T_sj
2. v = D_j/T_sj
3. D_m = D_j + L
solve for T_sj. There is no coordinate transformation
involved.
It didn't involve the composition of velocities.
You can't derive that
Composition of velocities is *irrelevant* for this
problem. Bringing it up shows that you don't understand
simple algebra.
I'm not accepting the speed of an object has two speeds
in the moving frame to prove it has one speed in the
moving frame.
This problem doesn't involve the moving frame at all.
It was a simple problem of algebra. You haven't
been able to do it.
Don't be silly. Of course I can divide 80 by 5 and get 16.
Then why can't you derive the correct result, without
bringing in relativity, relative velocities, Einstein,
composition of velocities, blah, blah, blah?
The problem doesn't ask for what things look like
from the rest frame of the mosquito. It asked for
the round-trip time as measured in the frame of
the ground.
Well, in case you missed it:
80/5 = 16 and 20/5 = 4.
I didn't ask for the answer, I asked for a *derivation*.
You haven't given that yet.
--
Daryl McCullough
Ithaca, NY
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| User: "Androcles" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
08 Jan 2005 06:59:56 PM |
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"Daryl McCullough" <daryl@atc-nycorp.com> wrote in message
news:crpl7v01abj@drn.newsguy.com...
Androcles says...
See, the velocity of mosquitoes is 5 fps in all frames of
reference.
Its a POSTULATE, McCullough said so.
So you lied when you said "Its a POSTULATE, McCullough said so".
Not at all. You postulated that the speed of the mosquito is 5 fps.
I didn't postulate that it was 5 in all frames of reference.
Not at all. I was using Einstein's math, that's all.
You were using it incorrectly. Nonsensically, to be precise.
It IS nonsense.
Anyone that thinks
tau [(16+4] /2 = tau(16) doesn't have a clue.
Plugging the x, y and z coordinates in is assinine.
The velocity of the mosquito plays the part, physically, of the
velocity of light.
No, it doesn't. It's just a speed.
At least I'm not claiming "the velocity of light in our theory
plays the part, physically, of an infinitely great velocity."
Reference :
http://www.fourmilab.ch/etexts/einstein/specrel/www/
The speed of light is just a speed too, unless you can
produce some magic to make it something else.
Ask Harry Potter or Einstein to show you how.
This problem didn't involve relativity at all.
Sure it does. u-v, u+v are relative velocities.
No, in this problem, they are closing velocities.
I don't care what name you give to it. All velocities are
relative.
That, as
I explained is the rate at which the distance between
two objects changes, as measured in a *third* reference
frame.
You don't know what a frame is. The three frames
in this situation are
A rock in the road at rest in the ground frame.
Sam and Joe at rest in the moving frame.
The mosquito at rest in the mosquito frame.
There are no other frames, and you asked for a
calculation in the ground frame.
What you did is use the Galilean Transforms
to make a calculation in the moving frame,
x' = x-vt,
t' = t.
Relative velocity, in contrast, is the velocity
of one object, as measured in the frame of the other
object.
Sam measures the velocity of the mosquito
as 2 fps and -8 fps. He doesn't care how fast the ground
is passing beneath him. He is only looking at the mosquito,
the distance it travels and his watch. Relative to Sam,
those ARE the velocities. NOTHING is moving at
5 fps in Sam's frame. You and Poe are using Sam's calculation
after you've applied the Galilean Transform. You never realized
that is what you were doing, did you?
You don't know what a frame is.
For the problem at hand, the concept of relative
velocity does not appear.
Nonsense, you've used 2 fps and 8 fps relative to Sam.
It didn't involve
coordinate transformations.
Sure it does.
No, it doesn't.
Yes it does. You don't know what a frame is.
It didn't involve the composition of velocities.
You can't derive that
Composition of velocities is *irrelevant* for this
problem. Bringing it up shows that you don't understand
simple algebra.
It is irrelevant for anything, pure nonsense.
I'm not accepting the speed of an object has two speeds
in the moving frame to prove it has one speed in the
moving frame.
This problem doesn't involve the moving frame at all.
Yes it does, you are using the fixed distance L in the
moving frame and the 2 speeds u-v and u+v in the moving frame.
You don't know what a frame is.
It was a simple problem of algebra. You haven't
been able to do it.
Don't be silly. Of course I can divide 80 by 5 and get 16.
Then why can't you derive the correct result, without
bringing in relativity, relative velocities, Einstein,
composition of velocities, blah, blah, blah?
Of course I have the correct result.
You don't know what a frame is.
The problem doesn't ask for what things look like
from the rest frame of the mosquito. It asked for
the round-trip time as measured in the frame of
the ground.
Well, in case you missed it:
80/5 = 16 and 20/5 = 4.
I didn't ask for the answer, I asked for a *derivation*.
You haven't given that yet.
Why should I bother, it is only high school algebra.
vt is the distance the mosquito moves,
ut is the distance Sam moves
L is the fixed distance Joe is from Sam.
vt = ut+L. Solve for t.
You don't know what a frame is.
Have I explained to you now?
Androcles.
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| User: "Daryl McCullough" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
09 Jan 2005 12:39:16 AM |
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Androcles says...
Sam measures the velocity of the mosquito
as 2 fps and -8 fps.
As I've said several times, that is irrelevant
to solving the problem. However, if you're going
to keep bringing it up, I want to ask you *how*
you know that. It is *not* true by definition.
A *physical* assumption is needed to be able
to compute the speed as measured by Sam, given
the speed as measured from the ground.
That's what I'm trying to get you to understand:
what part is pure algebra, and what part requires
assumptions about the laws of physics. To go from
The moquito has velocity u and Sam has velocity v,
as measured in the frame of the ground
to
The mosquito has velocity u-v, as measured in Sam's
frame.
requires knowledge of *physics*, not just knowledge of
algebra. In particular, in the frame of the ground, we have
the distance the mosquito travels
is 80 feet in 16 seconds in one
direction and 20 feet in 4 seconds
in the other direction
To be able to calculate speeds in Sam's frame (which you don't
need to do to solve the problem), you need to know how Sam's
measurement of distance relates to measurements of distance on
the ground. You need to know how Sam's measurement of time
relates to the measurements of time on the ground. Those are
*physical* assumptions. The assumption that you (and Galilean
relativity) makes is that measurements of time are absolute:
If the time the mosquito travels is 16 seconds in one frame,
then it is 16 seconds in *every* frame. What basis do you have
for believing that?
--
Daryl McCullough
Ithaca, NY
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| User: "Androcles" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
09 Jan 2005 10:54:52 AM |
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"Daryl McCullough" <daryl@atc-nycorp.com> wrote in message
news:crqjik01b0r@drn.newsguy.com...
Androcles says...
Sam measures the velocity of the mosquito
as 2 fps and -8 fps.
As I've said several times, that is irrelevant
to solving the problem.
Then don't use it.
However, if you're going
to keep bringing it up, I want to ask you *how*
you know that.
When you've learned what a frame is, you'll understand.
All the time you persist in making a fool of yourself
pretending that you have not converted from the ground frame
to the moving frame to obtain t, you never will.
It is *not* true by definition.
Prove it.
A *physical* assumption is needed to be able
to compute the speed as measured by Sam, given
the speed as measured from the ground.
Oh, that is easy enough. Sam sees the mosquito travel
the full distance of 32 ft from Joe in 4 seconds, by his watch.
he doesn't bother looking at the ground at all. He simply
says 32/4 = 8 fps. That's his definition. v = d/t. Perhaps
you've heard of it. To difficult for you?
I'm getting bored.
Bye.
Androcles.
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| User: "Daryl McCullough" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
10 Jan 2005 06:03:43 AM |
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Androcles says...
"Daryl McCullough" <daryl@atc-nycorp.com> wrote
Androcles says...
Sam measures the velocity of the mosquito
as 2 fps and -8 fps...
A *physical* assumption is needed to be able
to compute the speed as measured by Sam, given
the speed as measured from the ground.
Oh, that is easy enough. Sam sees the mosquito travel
the full distance of 32 ft from Joe in 4 seconds, by his watch.
How do you know that? You know that in the *ground* frame,
the distance between Sam and Joe is 32 feet. How does it
follow that the distance is 32 feet in Sam's frame? You
know that the time for the flight from Joe to Sam is 4
seconds in the ground frame. How does it follow that it
is 4 seconds in Sam's frame?
--
Daryl McCullough
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| User: "Androcles" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
10 Jan 2005 06:55:10 AM |
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"Daryl McCullough" <daryl@atc-nycorp.com> wrote in message
news:crtquv026n5@drn.newsguy.com...
Androcles says...
"Daryl McCullough" <daryl@atc-nycorp.com> wrote
Androcles says...
Sam measures the velocity of the mosquito
as 2 fps and -8 fps...
A *physical* assumption is needed to be able
to compute the speed as measured by Sam, given
the speed as measured from the ground.
Oh, that is easy enough. Sam sees the mosquito travel
the full distance of 32 ft from Joe in 4 seconds, by his watch.
How do you know that?
It's called the Galilean Transform.
You used it.
vt = ut +L.
vt - ut = (ut+L) - ut.
= L.
You know that in the *ground* frame,
the distance between Sam and Joe is 32 feet.
Who cares? That won't find the time of flight of the mosquito.
How does it
follow that the distance is 32 feet in Sam's frame?
It is called the Galilean Transform.
x' = x-vt.
32 = 80 - 3*16.
You
know that the time for the flight from Joe to Sam is 4
seconds in the ground frame. How does it follow that it
is 4 seconds in Sam's frame?
You said so. So did Poe.
You are arguing with yourself now.
Androcles.
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| User: "Daryl McCullough" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
10 Jan 2005 07:48:06 AM |
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Androcles says...
"Daryl McCullough" <daryl@atc-nycorp.com> wrote
Sam measures the velocity of the mosquito
as 2 fps and -8 fps...
A *physical* assumption is needed to be able
to compute the speed as measured by Sam, given
the speed as measured from the ground.
Oh, that is easy enough. Sam sees the mosquito travel
the full distance of 32 ft from Joe in 4 seconds, by his watch.
How do you know that?
It's called the Galilean Transform.
How do you know that the Galilean Transform is correct?
You
know that the time for the flight from Joe to Sam is 4
seconds in the ground frame. How does it follow that it
is 4 seconds in Sam's frame?
You said so. So did Poe.
No. I said that it was 4 seconds in the ground frame. I
have never made any statements about Sam's frame or the
frame of the mosquito.
--
Daryl McCullough
Ithaca, NY
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| User: "Androcles" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
10 Jan 2005 09:53:13 AM |
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"Daryl McCullough" <daryl@atc-nycorp.com> wrote in message
news:cru12m02nts@drn.newsguy.com...
Androcles says...
"Daryl McCullough" <daryl@atc-nycorp.com> wrote
Sam measures the velocity of the mosquito
as 2 fps and -8 fps...
A *physical* assumption is needed to be able
to compute the speed as measured by Sam, given
the speed as measured from the ground.
Oh, that is easy enough. Sam sees the mosquito travel
the full distance of 32 ft from Joe in 4 seconds, by his watch.
How do you know that?
It's called the Galilean Transform.
How do you know that the Galilean Transform is correct?
You
know that the time for the flight from Joe to Sam is 4
seconds in the ground frame. How does it follow that it
is 4 seconds in Sam's frame?
You said so. So did Poe.
No. I said that it was 4 seconds in the ground frame. I
have never made any statements about Sam's frame or the
frame of the mosquito.
Yes you did, to computed two velocities and one distance.
That is the moving frame computation.
The ground frame computation is one velocity and two distances.
Good thing time is invariant, huh?
Androcles.
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| User: "Daryl McCullough" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
10 Jan 2005 10:14:58 AM |
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Androcles says...
"Daryl McCullough" <daryl@atc-nycorp.com> wrote
No. I said that it was 4 seconds in the ground frame. I
have never made any statements about Sam's frame or the
frame of the mosquito.
Yes you did, to computed two velocities and one distance.
Okay, once again. You agree that as measured in the ground
frame,
ut = L + vt
for the journey from Sam to Joe.
But you think that it is necessary to do a transformation
to the *moving* frame in order to solve for t?
--
Daryl McCullough
Ithaca, NY
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| User: "Androcles" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
10 Jan 2005 12:14:06 PM |
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"Daryl McCullough" <daryl@atc-nycorp.com> wrote in message
news:cru9m20hv3@drn.newsguy.com...
Androcles says...
"Daryl McCullough" <daryl@atc-nycorp.com> wrote
No. I said that it was 4 seconds in the ground frame. I
have never made any statements about Sam's frame or the
frame of the mosquito.
Yes you did, to computed two velocities and one distance.
Okay, once again. You agree that as measured in the ground
frame,
ut = L + vt
for the journey from Sam to Joe.
Correct.
But you think that it is necessary to do a transformation
to the *moving* frame in order to solve for t?
Not necessary, no, but that is what you did.
You assumed t was invariant and simply did some trivial
high school manipulation, and computed t = L/(u-v). That
IS the computation in the moving frame, whether you say
it isn't or not. You applied the Galilean Transform, L = x-ut.
It's ok to do that, so long as t is invariant.
Are you saying time is invariant in all frames of reference?
Androcles.
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| User: "Daryl McCullough" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
10 Jan 2005 12:21:24 PM |
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Androcles says...
"Daryl McCullough" <daryl@atc-nycorp.com> wrote>> Okay, once again. You agree
that as measured in the ground
frame,
ut = L + vt
for the journey from Sam to Joe.
Correct.
But you think that it is necessary to do a transformation
to the *moving* frame in order to solve for t?
Not necessary, no, but that is what you did.
You are making no sense. I never *mentioned* measurements in Sam's
frame at *all*. All computations were in the frame of the ground.
You assumed t was invariant and simply did some trivial
high school manipulation, and computed t = L/(u-v).
I didn't assume *anything* about the value of t in Sam's frame.
So I didn't assume that t was invariant. All quantities are as
measured in the ground frame.
--
Daryl McCullough
Ithaca, NY
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| User: "Androcles" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
10 Jan 2005 01:32:12 PM |
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"Daryl McCullough" <daryl@atc-nycorp.com> wrote in message
news:cruh3401941@drn.newsguy.com...
Androcles says...
"Daryl McCullough" <daryl@atc-nycorp.com> wrote>> Okay, once again.
You agree
that as measured in the ground
frame,
ut = L + vt
for the journey from Sam to Joe.
Correct.
But you think that it is necessary to do a transformation
to the *moving* frame in order to solve for t?
Not necessary, no, but that is what you did.
You are making no sense. I never *mentioned* measurements in Sam's
frame at *all*.
Using the Galilean Transform without mentioning it doesn't mean
I can't mention it. That is what you did.
All computations were in the frame of the ground.
No, can't be, the ground frame has two distances and one
speed.
You used the Galilean transform without mentioning it.
In fact you are so stooopid, you did it without even realizing it.
You assumed t was invariant and simply did some trivial
high school manipulation, and computed t = L/(u-v).
I didn't assume *anything* about the value of t in Sam's frame.
Of course you did. Not consciously, perhaps, but then,
you are not really conscious, are you?
So I didn't assume that t was invariant. All quantities are as
measured in the ground frame.
Nonsense.
Anyway, I'm not playing ths pantomime any more,
saying "Oh yes you did" and "Oh no I didn't".
You did, and that's the end of it.
*plonk*
Androcles.
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| User: "Dirk Van de moortel" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
10 Jan 2005 01:35:08 PM |
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"Androcles" <dummy@dummy.net> wrote in message news:0LAEd.100137$Z7.37207@fe2.news.blueyonder.co.uk...
"Daryl McCullough" <daryl@atc-nycorp.com> wrote in message
news:cruh3401941@drn.newsguy.com...
Androcles says...
"Daryl McCullough" <daryl@atc-nycorp.com> wrote>> Okay, once again.
You agree
that as measured in the ground
frame,
ut = L + vt
for the journey from Sam to Joe.
Correct.
But you think that it is necessary to do a transformation
to the *moving* frame in order to solve for t?
Not necessary, no, but that is what you did.
You are making no sense. I never *mentioned* measurements in Sam's
frame at *all*.
Using the Galilean Transform without mentioning it doesn't mean
I can't mention it. That is what you did.
All computations were in the frame of the ground.
No, can't be, the ground frame has two distances and one
speed.
You used the Galilean transform without mentioning it.
In fact you are so stooopid, you did it without even realizing it.
You assumed t was invariant and simply did some trivial
high school manipulation, and computed t = L/(u-v).
I didn't assume *anything* about the value of t in Sam's frame.
Of course you did. Not consciously, perhaps, but then,
you are not really conscious, are you?
So I didn't assume that t was invariant. All quantities are as
measured in the ground frame.
Nonsense.
Anyway, I'm not playing ths pantomime any more,
saying "Oh yes you did" and "Oh no I didn't".
You did, and that's the end of it.
*plonk*
At *last* :-)))
Randy is next. Bet?
Dirk Vdm
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| User: "Randy Poe" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
10 Jan 2005 02:14:16 PM |
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Androcles wrote:
So I didn't assume that t was invariant. All quantities are as
measured in the ground frame.
Nonsense.
Here are the quantities:
v = mosquito velocity (measured in the ground frame).
u = Joe velocity (measured in the ground frame).
t = time (measured in the ground frame).
L = Joe-Sam distance (measured in the ground frame).
Looks to me like that's the complete list of quantities,
and that all are measured in the ground frame. So I
don't see why the statement "all quantities are as measured
in the ground frame" is nonsense.
- Randy
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| User: "Androcles" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
10 Jan 2005 05:40:28 PM |
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"Randy Poe" <poespam-trap@yahoo.com> wrote in message
news:1105388056.703161.32160@f14g2000cwb.googlegroups.com...
Androcles wrote:
So I didn't assume that t was invariant. All quantities are as
measured in the ground frame.
Nonsense.
Here are the quantities:
v = mosquito velocity (measured in the ground frame).
u = Joe velocity (measured in the ground frame).
t = time (measured in the ground frame).
No it wasn't. It was computed.
L = Joe-Sam distance (measured in the ground frame).
Looks to me like that's the complete list of quantities,
and that all are measured in the ground frame. So I
don't see why the statement "all quantities are as measured
in the ground frame" is nonsense.
- Randy
I've explained this to you before, but you refuse to acknowledge
it.
The ground frame has but one speed, 5 fps, and two distances,
80 ft and 20 ft.
The moving frame computation has two speeds, 2 fps and 8 fps,
but only one distance.
You used one distance and two speeds.
It logically follows that the computation you used was the moving frame
computation. End of discussion.
Androcles.
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| User: "Daryl McCullough" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
10 Jan 2005 06:09:13 PM |
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Androcles says...
"Randy Poe" <poespam-trap@yahoo.com> wrote
Here are the quantities:
v = mosquito velocity (measured in the ground frame).
u = Joe velocity (measured in the ground frame).
t = time (measured in the ground frame).
No it wasn't. It was computed.
L = Joe-Sam distance (measured in the ground frame).
Looks to me like that's the complete list of quantities,
and that all are measured in the ground frame. So I
don't see why the statement "all quantities are as measured
in the ground frame" is nonsense.
- Randy
I've explained this to you before, but you refuse to acknowledge
it. The ground frame has but one speed, 5 fps, and two distances,
80 ft and 20 ft.
The moving frame computation has two speeds, 2 fps and 8 fps,
but only one distance.
You used one distance and two speeds.
It logically follows that the computation you used was the moving frame
computation. End of discussion.
So, Randy, if you subtract two quantities to get a third, you
are performing a Galilean transform. So every time you balance
your checkbook you are secretly doing coordinate transformations.
--
Daryl McCullough
Ithaca, NY
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| User: "Franz Heymann" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
11 Jan 2005 02:17:05 PM |
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"Daryl McCullough" <daryl@atc-nycorp.com> wrote in message
news:crv5f90frc@drn.newsguy.com...
Androcles says...
"Randy Poe" <poespam-trap@yahoo.com> wrote
Here are the quantities:
v = mosquito velocity (measured in the ground frame).
u = Joe velocity (measured in the ground frame).
t = time (measured in the ground frame).
No it wasn't. It was computed.
L = Joe-Sam distance (measured in the ground frame).
Looks to me like that's the complete list of quantities,
and that all are measured in the ground frame. So I
don't see why the statement "all quantities are as measured
in the ground frame" is nonsense.
- Randy
I've explained this to you before, but you refuse to acknowledge
it. The ground frame has but one speed, 5 fps, and two distances,
80 ft and 20 ft.
The moving frame computation has two speeds, 2 fps and 8 fps,
but only one distance.
You used one distance and two speeds.
It logically follows that the computation you used was the moving
frame
computation. End of discussion.
So, Randy, if you subtract two quantities to get a third, you
are performing a Galilean transform. So every time you balance
your checkbook you are secretly doing coordinate transformations.
If I were Randy I would sue you for defamation of character
{:-))
Franz
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| User: "Daryl McCullough" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
09 Jan 2005 12:11:35 AM |
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Androcles says...
You were using it incorrectly. Nonsensically, to be precise.
It IS nonsense.
Anyone that thinks
tau [(16+4] /2 = tau(16) doesn't have a clue.
That comment shows you don't understand what you are
talking about. Nobody has said that, except you.
The velocity of the mosquito plays the part, physically, of the
velocity of light.
No, it doesn't. It's just a speed.
At least I'm not claiming "the velocity of light in our theory
plays the part, physically, of an infinitely great velocity."
We're not talking about Einstein, we're talking about
a simple problem involving a travelling mosquito.
That, as I explained is the rate at which the distance between
two objects changes, as measured in a *third* reference
frame.
You don't know what a frame is.
This problem only involves one frame, the frame of the ground.
Your bringing up other frames just shows how confused you are.
The three frames in this situation are
A rock in the road at rest in the ground frame.
That's the frame this problem is concerned with.
Sam and Joe at rest in the moving frame.
That is irrelevant to this problem.
The mosquito at rest in the mosquito frame.
That is also irrelevant. All calculation are
done in the coordinate system of the ground
There are no other frames, and you asked for a
calculation in the ground frame.
What you did is use the Galilean Transforms
to make a calculation in the moving frame,
x' = x-vt,
t' = t.
I didn't use any coordinate transformations at *all*.
I used a single coordinate system throughout. As I
said, you are deeply confused about simple algebra.
We have these facts
D_j = the distance travelled by Joe, as measured
in the ground frame.
D_m = the distance travelled by the mosquito,
as measured in the ground frame
v = the speed of Joe, as measured in the ground frame
u = the speed of the mosquito, as measured in the ground frame.
T = time for the mosquito to travel from Sam to Joe
What we know is:
1. D_m = D_j + L
2. D_m = uT
3. D_j = vT
There is no tranformation to the moving frame of the mosquito.
There is only solving a system of three equations. It's *algebra*.
And you are thoroughly confused by it.
Relative velocity, in contrast, is the velocity
of one object, as measured in the frame of the other
object.
Sam measures the velocity of the mosquito
as 2 fps and -8 fps.
Who says? That's irrelevant to solving this problem.
We're not solving the problem in Sam's frame, we're
solving it in the frame of the ground.
For the problem at hand, the concept of relative
velocity does not appear.
Nonsense, you've used 2 fps and 8 fps relative to Sam.
All distances, times, and velocities are relative to the
ground. It's simple algebra.
Yes it does. You don't know what a frame is.
Frames don't come into play in this problem. It's
a problem of pure algebra.
This problem doesn't involve the moving frame at all.
Yes it does,
No, it doesn't. Look at the equations again:
1. D_m = L + D_j
2. D_m = u T
3. D_j = v T
D_m, L, D_j are all distances measured in the frame of the ground.
T is a time measured in the frame of the ground.
u and v are velocities as measured in the frame of the ground.
There is no need to refer to *any* measurements in any other frame.
I didn't ask for the answer, I asked for a *derivation*.
You haven't given that yet.
Why should I bother, it is only high school algebra.
Too advanced for you? Okay, I'll solve it for you. You take the
first equation, plug it into the second to get
L + D_j = u T
Now, use the third equation to eliminate D_j. You get
L + v T = u T
Now, get all the Ts to one side:
L = (u-v)T
Divide through by (u-v)
L/(u-v) = T
See, isn't that simple? You don't need to use velocities
relative to any moving frame. You just need algebra.
--
Daryl McCullough
Ithaca, NY
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| User: "Androcles" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
09 Jan 2005 10:44:21 AM |
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"Daryl McCullough" <daryl@atc-nycorp.com> wrote in message
news:crqhun01582@drn.newsguy.com...
Androcles says...
You were using it incorrectly. Nonsensically, to be precise.
It IS nonsense.
Anyone that thinks
tau [(16+4] /2 = tau(16) doesn't have a clue.
That comment shows you don't understand what you are
talking about. Nobody has said that, except you.
McCullough knowing what he is talking about:
The transformation equations are
t' = gamma (t - vx/c^2)
t'' = gamma (t + vx/c^2)
So
t1' = t1'' = 0
t2' = 2 (4.619 - .866 * 4) = 2.31
T_out = 2.31 - 0 = 2.31
t2'' = 2 (4.619 + .866 * 4) = 16.166
t3'' = 2 (9.238 + .866 * 0) = 18.476
T_return = 18.476 - 16.166 = 2.31
T_total = T_out + T_return = 4.62
That's the *correct* calculation, Androcles.
--
Daryl McCullough
Ithaca, NY
Here's how a spreadsheet figures it.x v t = x/v tau=(t-xv)*gamma
tau=(t+xv)*gamma
4.000 0.100 40.000 39.799 inbound time
-4.000 -0.100 40.000 40.604 outbound time
Playing with the sign of x and v.
-4.000 0.100 -40.000 wrong, time doesn't run backwards
4.000 -0.100 -40.000 wrong, time doesn't run backwards
Total 80.403 years
x v t = x/v tau=(t-xv)*gamma tau=(t+xv)*gamma
4.000 0.866 4.619 2.310 inbound time
-4.000 -0.866 4.619 16.164 outbound time
Total 18.474 years
x v t = x/v tau=(t-xv)*gamma tau=(t+xv)*gamma
4.000 0.999 4.004 0.179 inbound time
-4.000 -0.999 4.004 178.930 outbound time
Total 179.109 years
We see that this approximates the Galilean computation with small v =
0.1, exceeds the Galilean computation with larger v = 0.866, and that
the faster you go (v = 0.999), the later you arrive.
The velocity of the mosquito plays the part, physically, of the
velocity of light.
No, it doesn't. It's just a speed.
At least I'm not claiming "the velocity of light in our theory
plays the part, physically, of an infinitely great velocity."
We're not talking about Einstein, we're talking about
a simple problem involving a travelling mosquito.
I am.
That, as I explained is the rate at which the distance between
two objects changes, as measured in a *third* reference
frame.
You don't know what a frame is.
This problem only involves one frame, the frame of the ground.
Your bringing up other frames just shows how confused you are.
There is only one speed, 5 fps and two distances in the ground frame.
You bringing up 2 fps and 8 fps (and one distance, 32 ft)
in the moving frame very clearly shows just who is confused.
You STILL don't know what a frame is.
The three frames in this situation are
A rock in the road at rest in the ground frame.
That's the frame this problem is concerned with.
Sam and Joe at rest in the moving frame.
That is irrelevant to this problem.
So why are you using two speeds for the mosquito and 32 ft distance?
You STILL don't know what a frame is.
The mosquito at rest in the mosquito frame.
That is also irrelevant. All calculation are
done in the coordinate system of the ground
So why are you using two speeds for the mosquito and 32 ft distance?
You STILL don't know what a frame is, and you are certainly no
match for a spreadsheet.
There are no other frames, and you asked for a
calculation in the ground frame.
What you did is use the Galilean Transforms
to make a calculation in the moving frame,
x' = x-vt,
t' = t.
I didn't use any coordinate transformations at *all*.
I used a single coordinate system throughout. As I
said, you are deeply confused about simple algebra.
We have these facts
D_j = the distance travelled by Joe, as measured
in the ground frame.
80 ft
D_m = the distance travelled by the mosquito,
as measured in the ground frame
80 ft.
v = the speed of Joe, as measured in the ground frame
3 fps
u = the speed of the mosquito, as measured in the ground frame.
5 fps
T = time for the mosquito to travel from Sam to Joe
In either frame, 16 seconds.
vt = ut + L.
5*16 = 3*16 + 32.
80 = 48+32.
That's the ground frame calculation.
What we know is:
1. D_m = D_j + L
2. D_m = uT
3. D_j = vT
There is no tranformation to the moving frame of the mosquito.
There is only solving a system of three equations. It's *algebra*.
And you are thoroughly confused by it.
Me? No way. Converting from the ground frame to the moving frame,
1: L = x - vt. (=32)
2: V1 = u+v (=8)
3: V2 = u-v. (=2)
Calculating in the moving frame,
32/2 + 32/8 = 20.
Calculating in the ground frame,
80/5 + 20/5 = 20.
You calculated in the moving frame.
It's only *algebra* that converts coordinates
and speeds from one frame to the other.
You are confused. I am not.
You converted.
You STILL don't know what a frame is.
Relative velocity, in contrast, is the velocity
of one object, as measured in the frame of the other
object.
Sam measures the velocity of the mosquito
as 2 fps and -8 fps.
Who says?
I did. It is only *algebra*
That's irrelevant to solving this problem.
We're not solving the problem in Sam's frame, we're
solving it in the frame of the ground.
Why did you use it then?
You STILL don't know what a frame is.
For the problem at hand, the concept of relative
velocity does not appear.
Nonsense, you've used 2 fps and 8 fps relative to Sam.
All distances, times, and velocities are relative to the
ground. It's simple algebra.
The only speed in the ground frame is 5 fps.
You STILL don't know what a frame is.
Converting is simple algebra.
Yes it does. You don't know what a frame is.
Frames don't come into play in this problem. It's
a problem of pure algebra.
You STILL don't know what a frame is.
Converting is pure algebra.
This problem doesn't involve the moving frame at all.
Yes it does,
No, it doesn't. Look at the equations again:
1. D_m = L + D_j
2. D_m = u T
3. D_j = v T
D_m, L, D_j are all distances measured in the frame of the ground.
T is a time measured in the frame of the ground.
u and v are velocities as measured in the frame of the ground.
There is no need to refer to *any* measurements in any other frame.
32/2 and 32/8 is what YOU used,
I used 80/5 and 20/5.
You STILL don't know what a frame is.
Converting is pure algebra, and that what you did. Converted.
I didn't ask for the answer, I asked for a *derivation*.
You haven't given that yet.
Why should I bother, it is only high school algebra.
Too advanced for you? Okay, I'll solve it for you. You take the
first equation, plug it into the second to get
L + D_j = u T
Now, use the third equation to eliminate D_j. You get
L + v T = u T
Now, get all the Ts to one side:
L = (u-v)T
You've just converted to the moving frame, u-v = 2.
Obviously understanding what a frame is is too advanced for you.
Divide through by (u-v)
(the moving frame velocity of the mosquito)
L/(u-v) = T
See, isn't that simple?
Of course it is simple. Convert to the moving frame
and calculate T, that's what you did, but you are too simple-minded
to realize it.
You don't need to use velocities
relative to any moving frame. You just need algebra.
So why did you use the TWO moving frame velocities of the mosquito,
then?
The moment you say v-u (you have it backwards as u-v) you are
converting to the moving frame.
Obviously understanding what a frame is is too advanced for you.
Androcles.
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| User: "Daryl McCullough" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
10 Jan 2005 06:16:19 AM |
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Androcles says...
"Daryl McCullough" <daryl@atc-nycorp.com> wrote in message
news:crqhun01582@drn.newsguy.com...
Androcles says...
You were using it incorrectly. Nonsensically, to be precise.
It IS nonsense.
Anyone that thinks
tau [(16+4] /2 = tau(16) doesn't have a clue.
That comment shows you don't understand what you are
talking about. Nobody has said that, except you.
McCullough knowing what he is talking about:
The transformation equations are
t' = gamma (t - vx/c^2)
t'' = gamma (t + vx/c^2)
So
t1' = t1'' = 0
t2' = 2 (4.619 - .866 * 4) = 2.31
T_out = 2.31 - 0 = 2.31
t2'' = 2 (4.619 + .866 * 4) = 16.166
t3'' = 2 (9.238 + .866 * 0) = 18.476
T_return = 18.476 - 16.166 = 2.31
T_total = T_out + T_return = 4.62
That's the *correct* calculation, Androcles.
Here's how a spreadsheet figures it
I gave you a derivation. You don't need a spreadsheet. And
your spread sheet calculation gave nonsensical results because
you don't know what you are doing.
We're not talking about Einstein, we're talking about
a simple problem involving a travelling mosquito.
I am.
But you don't know what you are talking about.
What we know is:
1. D_m = D_j + L
2. D_m = uT
3. D_j = vT
There is no tranformation to the moving frame of the mosquito.
There is only solving a system of three equations. It's *algebra*.
And you are thoroughly confused by it.
Me? No way. Converting from the ground frame to the moving frame,
The fact that you bring up the moving frame shows how confused
you are. You don't need anything other than the three above
facts to solve the problem. You don't need to know anything
about the moving frame.
Sam measures the velocity of the mosquito
as 2 fps and -8 fps.
Who says?
I did. It is only *algebra*
No, it's not. It's algebra *plus* Galilean relativity.
--
Daryl McCullough
Ithaca, NY
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| User: "Androcles" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
10 Jan 2005 06:59:27 AM |
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"Daryl McCullough" <daryl@atc-nycorp.com> wrote in message
news:crtrmj028ss@drn.newsguy.com...
Androcles says...
"Daryl McCullough" <daryl@atc-nycorp.com> wrote in message
news:crqhun01582@drn.newsguy.com...
Androcles says...
You were using it incorrectly. Nonsensically, to be precise.
It IS nonsense.
Anyone that thinks
tau [(16+4] /2 = tau(16) doesn't have a clue.
That comment shows you don't understand what you are
talking about. Nobody has said that, except you.
McCullough knowing what he is talking about:
The transformation equations are
t' = gamma (t - vx/c^2)
t'' = gamma (t + vx/c^2)
So
t1' = t1'' = 0
t2' = 2 (4.619 - .866 * 4) = 2.31
T_out = 2.31 - 0 = 2.31
t2'' = 2 (4.619 + .866 * 4) = 16.166
t3'' = 2 (9.238 + .866 * 0) = 18.476
T_return = 18.476 - 16.166 = 2.31
T_total = T_out + T_return = 4.62
That's the *correct* calculation, Androcles.
Here's how a spreadsheet figures it
I gave you a derivation. You don't need a spreadsheet. And
your spread sheet calculation gave nonsensical results because
you don't know what you are doing.
LOL! Go on, make a fool of yourself publicly.
We're not talking about Einstein, we're talking about
a simple problem involving a travelling mosquito.
I am.
But you don't know what you are talking about.
So you imagine.
What we know is:
1. D_m = D_j + L
2. D_m = uT
3. D_j = vT
There is no tranformation to the moving frame of the mosquito.
There is only solving a system of three equations. It's *algebra*.
And you are thoroughly confused by it.
Me? No way. Converting from the ground frame to the moving frame,
The fact that you bring up the moving frame shows how confused
you are. You don't need anything other than the three above
facts to solve the problem. You don't need to know anything
about the moving frame.
So you imagine.
Sam measures the velocity of the mosquito
as 2 fps and -8 fps.
Who says?
I did. It is only *algebra*
No, it's not. It's algebra *plus* Galilean relativity.
L = x-vt isn't only algebra, huh?
You are an ineducable fool, McCullough.
Androcles
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| User: "Daryl McCullough" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
10 Jan 2005 07:44:34 AM |
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Androcles says...
What we know is:
1. D_m = D_j + L
2. D_m = uT
3. D_j = vT
There is no tranformation to the moving frame of the mosquito.
There is only solving a system of three equations. It's *algebra*.
And you are thoroughly confused by it.
Me? No way. Converting from the ground frame to the moving frame,
The fact that you bring up the moving frame shows how confused
you are. You don't need anything other than the three above
facts to solve the problem. You don't need to know anything
about the moving frame.
So you imagine.
You imagine differently? You think that it is impossible
to solve a system of three equations without using a coordinate
transformation?
--
Daryl McCullough
Ithaca, NY
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| User: "Androcles" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
10 Jan 2005 09:46:44 AM |
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"Daryl McCullough" <daryl@atc-nycorp.com> wrote in message
news:cru0s202ndb@drn.newsguy.com...
Androcles says...
What we know is:
1. D_m = D_j + L
2. D_m = uT
3. D_j = vT
There is no tranformation to the moving frame of the mosquito.
There is only solving a system of three equations. It's *algebra*.
And you are thoroughly confused by it.
Me? No way. Converting from the ground frame to the moving frame,
The fact that you bring up the moving frame shows how confused
you are. You don't need anything other than the three above
facts to solve the problem. You don't need to know anything
about the moving frame.
So you imagine.
You imagine differently?
I KNOW I can handle algebra and frames, and I know you have no
idea what a frame is.
You think that it is impossible
to solve a system of three equations without using a coordinate
transformation?
You can solve for t if you assume it is invariant.
You don't think it is, so your equation is wrong.
Androcles.
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| User: "Daryl McCullough" |
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| Title: Re: Androcles' long-winded solution to the mosquito problem |
10 Jan 2005 10:19:37 AM |
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Androcles says...
I KNOW I can handle algebra and frames, and I know you have no
idea what a frame is.
What I know is that you don't need to know anything about frames
or Galilean transformations in order to solve for t in terms of
L, u and v given
1. D_m = D_j + L
2. u t = D_m
3. v t = D_j
You think that it is impossible
to solve a system of three equations without using a coordinate
transformation?
You can solve for t if you assume it is invariant.
Invariant means that it has the same value in all frames. Since
we're only computing it in *one* frame, it isn't necessary to
assume it is invariant.
Once again, do you think it is impossible to solve a system
of three equations and three unknowns without using a coordinate
transformation, and without making assumptions about invariance?
--
Daryl McCullough
Ithaca, NY
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