Is physics a science?

John Polasek

2009-11-10 15:46:59 UTC

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On Tue, 10 Nov 2009 00:42:12 -0000, "Androcles"

On Sun, 8 Nov 2009 18:19:41 -0000, "Androcles"

On Sun, 8 Nov 2009 00:08:42 -0000, "Androcles"

On Sat, 7 Nov 2009 19:05:36 -0000, "Androcles"

snip

Errors are always intolerable, John.
Saying "wavelength doesn't stretch" is pretty meaningless.

It's just to highlight the fact that most attempts at analysis of
the Doppler effect struggle to show that the wavelength stretches
during the process, see for example Weisstein and therefore end up
with the wrong results.

All velocities are relative, and since you are not comfortable with
algebra I've drawn a picture to prove wavelengths are relative too.
Loading Image...

Algebraically, if
c = \lambda * \nu
or, easier, c = w*f
then w is a length and f is a frequency,
and since frequency = 1/duration
then
c = length/duration = x/t and dx/dt is a velocity.
Doppler isn't really all that difficult, many people have more
difficulty with relative motion.
You should really try my little quiz below.
A) http://tinyurl.com/lv2fl7
B) http://tinyurl.com/njgouh
C) http://tinyurl.com/klkfc9
D) http://tinyurl.com/l6lt4g
1) applies to light (in vacuum) and sound (in air)
2) applies to light but not sound
3) applies to sound but not light
4) applies to neither light nor sound

I looked at a couple of your cartoons have to say they're neither
instructive nor correct.

I looked at your reply and I have to say you are ineducable.

They have a hypnotic effect after 30 seconds.

Interesting, I've never hypnotised anyone before.

In #B, the source of the sound is moving ahead at the same speed as
the sound wave itself. I can't immediately picture that.

B is exactly the same as A, seen from the ship's frame of reference.
It is VERY correct. That you cannot picture it is your problem.
Haven't you ever been in a car or train or plane and seen the world
go by?

Equations are good, vector diagrams are good, but cartoons are just
entertaining.

Cartoons are instructive to an engineer creating a moving world
on your TV screen or computer monitor, but not much use to an
ineducable moron that can't understand algebra, such as you.

For example, favor me with one equation that is made
evident by its corresponding cartoon.

Certainly.
For A, f_at_star = f.
f_at_ship = f_at_star * (1+v/c)
since v = c by choice,
f_at_ship = f_at_star *(1 + c/c)
= f_at_star *(1 + 1/1)
= f_at_star *(1 + 1)
= f_at_star *2
The frequency is doubled. This is true for both light and sound.
For sound the car is approaching a stationary fire siren.

Thus we have a match, A to 1.
For B, f_at_ship = f_at_star *(1 + v/c).
since v = c by choice,
f_at_ship = f_at_star *(1 + c/c)
= f_at_star *(1 + 1/1)
= f_at_star *(1 + 1)
= f_at_star *2
The frequency is doubled.
If the wind were blowing into the ship at speed v then
B would also apply to sound, but it isn't.
Thus we have a match, B to 2.
For C, f_at_star is still f, but
f_at_ship = f_at_star /(1-v/c)
= f_at_star /(1-1/1)
= f_at_star/0, but division by zero is undefined.
For sound, this is a sonic boom. The plane travels
through the air at the same speed as the sound.
It is NOT true for light, there is no aether.
Thus we have a match, C to 3.
For D, the ship cannot affect the emission speed of light or sound.
"It follows from these results that to an observer approaching a source of
light with the velocity c, this source of light must appear of infinite
intensity." -- Fuckin' Idiot Einstein.
Thus we have a match, D to 4.
Equations are good, vector diagrams are good, but the cretin Polasek is
just
entertaining.
You've been favoured. You are too fuckin' stupid to do anything with it.

Alright, I'll help you out with your cartoons.
Your equations for A and B are correct, C and D are not.

In #B, the source of the light is moving ahead at the same speed as
the photons themselves (NOT). You can't immediately picture that
because all speeds are relative and you are too stupid to realise that
the speed of photons relative to the star is c and the speed of photons
relative to the ship is c+v. Not only that, but ANYONE can
measure the distance (in pixels) and the time (in microseconds)
because computers (including yours) are damned accurate at
measuring time, and speed is distance/time.
All my equations are Doppler's equations and are correct.
I don't need your fucking help, you can stick it up your arse.

But you should really use my correct form,
f/f0 = 1 - Ddot/c same as A, B Ddot = dD/dt

Babbling iD.iot!
For #C,
f = f0 * c/(c-v) = f0 * c/0 because c = v and c-v = 0,
but division by zero is undefined.
A fuckwit like you has never experienced a sonic boom.
Go crack a whip, you'll hear one.

where Ddot is the rate of separation and not really a velocity.

Bwhahahahahahahahaha!
You are as fuckin' crazy as the morons that call it a "closing speed."
Of course it's a velocity.
http://www.merriam-webster.com/dictionary/velocity
2 : the rate of change of position along a straight line with respect to
time : the derivative of position with respect to time
We now have a fuckin' ignorant wanker wants to disagree with
the dictionary!

Ddot
is more inclusive and averts explanations as to polarity, and you
could do with one diagram what you have done with two.

I made two very deliberately for people with more than half a brain.
You have an extra 'd' and are missing two 'i's in "Ddot". It's "iDiot".

Look at C, where you set v = c, you failed to recognize that C, per
extensio, must use the same algebra as B because it is just another
instance of B except for value.

Tell it to Doppler, Ddot iDiot.

But you chose to help things out in C by inverting the algebra, aided
by the intuition suggested in your nifty diagram which, you think,
plainly shows that the wavelengths are squashed to zero by the star
that's moving at the velocity of light to get
f/f0 = 1/(1-v/c) (an invention)
incorrectly yielding infinite frequency for v = c.
But if we take Eq. B and set v = .9999+*c we get f/f0 = 1.999+, in
the limit, C should be 2.00, not infinity.

You are totally hopeless.
f = f0 ( c+/-v)/ ( c+/-u)
where v is the velocity of the observer relative to the air
and u is the velocity of the source relative to the air.

Forget air, we have enough trouble with empty space. It looks like
you're using wiki's air formula when it suits you.

C and D are also both defective

That's it, I've had enough. You are a complete idiot,
you know nothing about Doppler. Fuck off.

I agree, further discussion would be fruitless, but I still have to
point out two things.
You should have the same answer for B & C where both stars are moving
at the velocity of light. (what?!)
Except that in B the star was stationary for a while, then began
moving at the velocity c, (what?!!) while in C, the star and its
emission started simultaneously at c (what?!!). The answers should be
the same, 2X, not infinity.
I can see you have never derived any of this. See how easy it is:
N = f0(t - D/c) cycles, time-delayed
f = dN/dt = f0(1 - Ddot/c) cycles/second
so velocity is just a change of position rate, a kinematic quantity,
not a dynamic one (see Goldstein).
John Polasek