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The Speeed of Light

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  The Speeed of Light The Starmaker <starmaker@ix.netcom.com> - 2018-04-02 13:58 -0700
    Re: The Speeed of Light Siri Cruise <chine.bleu@yahoo.com> - 2018-04-02 16:15 -0700
    Re: The Speeed of Light SolomonW <SolomonW@citi.com> - 2018-04-03 09:46 +1000
    Re: The Speeed of Light Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-02 22:32 -0500
      Re: The Speeed of Light Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-04-03 07:31 +0200
    Re: The Speeed of Light casagiannoni@optonline.net - 2018-04-04 14:23 -0400
    Re: The Speeed of Light Keith Stein <keithstein111@gmail.com> - 2018-04-08 20:02 +0100
      Re: The Speeed of Light Libor 'Poutnik' Stříž <poutnik@privacy.net> - 2018-04-08 22:03 +0200
        Re: The Speeed of Light Lofty Goat <rlwatkins@gmail.com> - 2018-05-05 22:16 -0500
      Re: The Speeed of Light Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-09 09:39 -0500
        Re: The Speeed of Light Keith Stein <keithstein111@gmail.com> - 2018-04-09 16:04 +0100
          Re: The Speeed of Light Libor Striz <poutnik4REMOVEnntp@CAPITALSgmail.com> - 2018-04-09 18:16 +0200
            GPS satellites. Jeff-Relf.Me  @. - 2018-04-09 10:45 -0700
              Re: GPS satellites. J. Clarke <jclarke.873638@gmail.com> - 2018-04-09 23:28 -0400
                GPS satellites. Jeff-Relf.Me  @. - 2018-04-09 20:49 -0700
                Re: GPS satellites. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-04-10 06:00 +0200
                Re: GPS satellites. Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-11 14:36 -0500
                  Re: GPS satellites. J. Clarke <jclarke.873638@gmail.com> - 2018-04-11 22:22 -0400
                    Re: GPS satellites. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-04-12 04:38 +0200
          Re: The Speeed of Light Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-09 14:00 -0500
          Re: The Speeed of Light Lofty Goat <rlwatkins@gmail.com> - 2018-04-09 21:10 -0500
            Re: The Speeed of Light Keith Stein <keithstein111@gmail.com> - 2018-04-10 17:56 +0100
              Re: The Speeed of Light Leo Sgouros <adravirgo@gmail.com> - 2018-04-10 09:59 -0700
              Re: The Speeed of Light Libor Striz <poutnik4REMOVEnntp@CAPITALSgmail.com> - 2018-04-10 20:40 +0200
              Re: The Speeed of Light Lofty Goat <rlwatkins@gmail.com> - 2018-04-10 14:23 -0500
                LET EXPERIMENT DECIDE ('cos i think Relativists are Charlatans eh!) Keith Stein <keithstein111@gmail.com> - 2018-04-10 21:28 +0100
              Re: The Speeed of Light Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-14 09:11 -0500
                Re: The Speeed of Light Keith Stein <keithstein111@gmail.com> - 2018-04-14 18:44 +0100
        Re: The Speeed of Light Whisper <beaver999@ozemail.com> - 2018-04-10 20:43 +1000
          Speed of light (was: The Speeed of Light) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-04-12 06:25 +0200
    Re: The Speeed of Light casagiannoni@optonline.net - 2018-04-08 19:51 -0400
      Re: The Speeed of Light Libor Striz <poutnik4REMOVEnntp@CAPITALSgmail.com> - 2018-04-09 06:43 +0200
        Re: The Speeed of Light Paul Colquhoun <newsposter@andor.dropbear.id.au> - 2018-04-09 16:52 +1000
          Re: The Speeed of Light Libor Striz <poutnik4REMOVEnntp@CAPITALSgmail.com> - 2018-04-09 09:23 +0200

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#489605 — The Speeed of Light

It is not a question that nothing travels faster
than the speed of light...but

why nothing travels faster than the speed of light, or..

what is the function of light to have to travel faster than anything else.


The function, or reason why light travels so fast is because...

if you plan to travel into the future before anybody else gets there..

light needs to get there first so that there is a future to be there when you get there.

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#489608

In article <5AC2995B.649C@ix.netcom.com>,
 The Starmaker <starmaker@ix.netcom.com> wrote:

> It is not a question that nothing travels faster
> than the speed of light...but
> 
> why nothing travels faster than the speed of light, or..
> 
> what is the function of light to have to travel faster than anything else.
> 
> 
> The function, or reason why light travels so fast is because...
> 
> if you plan to travel into the future before anybody else gets there..
> 
> light needs to get there first so that there is a future to be there when you 
> get there.

So light is anti-langoliers pooping out the future before we arrive?

No, wait, now I get. Langoliers are klein bottles with their mouths in the past 
and their poopholes in the future. They are constantly eating past time, 
refurbishing it, and pooping it out as future time. The universe is just the 
three dimensional surface of the four dimensional klein bottles.

It makes so much sense now.

-- 
:-<> Siri Seal of Disavowal #000-001. Disavowed. Denied. Deleted.    @
'I desire mercy, not sacrifice.'                                    /|\
I'm saving up to buy the Donald a blue stone      This post         / \
from Metebelis 3. All praise the Great Don!       insults Islam.  Mohammed

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#489609

On Mon, 02 Apr 2018 13:58:03 -0700, The Starmaker wrote:

> It is not a question that nothing travels faster
> than the speed of light...but
> 
> why nothing travels faster than the speed of light, or..
> 
> what is the function of light to have to travel faster than anything else.
> 
> 
> The function, or reason why light travels so fast is because...
> 
> if you plan to travel into the future before anybody else gets there..
> 
> light needs to get there first so that there is a future to be there when you get there.

Not really.


Its not actually a requirement of modern physics that nothing goes faster
then light, what relativity does forbid is that ordinary matter can ever
reach the speed of light, because it would require infinite energy but this
theory does not rule out “tachyons” that can only travel faster than light.

The problem is that relativity has that if information can go faster then
light then *Causality* is lost.

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#489619

On 4/2/18 3:58 PM, The Starmaker wrote:
> [... much silliness and nonsense]

There are two quite different meanings of the symbol "c" [#], which have 
confused you (and myriad other newbies and wannabes).

   * c(1) is the speed that appears in the Lorentz transform.

   * c(2) is the vacuum speed of light.

Note that c(1) is the limiting speed for timelike (massive) objects, not 
c(2) as you seem to think. c(1) is locally invariant, and is the only 
speed at which massless objects can travel.

At present, to the best of our knowledge c(1) = c(2); the limit on the 
mass of photons is extremely small, but is not zero. This numerical 
equality seems to be rather a coincidence, as these two meanings are 
QUITE different. If it should happen that photons are not actually 
massless, then c(1) != c(2) and lots of physics books would have to be 
re-written. Folks like you would no longer get confused by this 
particular subtlety (but of course many others remain).

	[#] Due to the historical accident of Einstein using
	electrodynamics to discover Special Relativity, while
	logically their relationship is the other way 'round:
	SR is geometry, which is much more fundamental and
	pervasive than electrodynamics.

Tom Roberts

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#489622

    [Next time, please set Followup-To when crossposting.]

Tom Roberts wrote:

> There are two quite different meanings of the symbol "c" [#], which have
> confused you (and myriad other newbies and wannabes).
> 
>    * c(1) is the speed that appears in the Lorentz transform.
> 
>    * c(2) is the vacuum speed of light.
> 
> Note that c(1) is the limiting speed for timelike (massive) objects, not
> c(2) as you seem to think. c(1) is locally invariant, and is the only
> speed at which massless objects can travel.
> 
> At present, to the best of our knowledge c(1) = c(2); […]

Count me as one of the “newbies” then.  This discussion brings me back to
my earlier question, which you had answered in an evasive, unsatisfactory 
way back then.  So I ask again:

Do you mean that, for example,

  t' = γ (t − v∕c² x)

would have to be written precisely

  t' = γ (t − v∕c₀² x)

*regardless* of the medium in which the relative motion occurs?

A simple “yes” or “no” will suffice for now.  TIA.


PointedEars
-- 
Q: What happens when electrons lose their energy?  
A: They get Bohr'ed.

(from: WolframAlpha)

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#489673

Speed of light for all observers
 = constant c = 3E8 M/Sec .

Perceived wavelength when source is receding 
 is increased. i.e. red shift.

All in accordance with Einstein's Relativities.

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#489868

The speed of light in vacuum is a silly concept,
because what can this speed be relative to ?

But since there is FINITE DENSITY EVERYWHERE,
there is no need to solve this conundrum.

LIGHT TRAVELS RELATIVE TO THE STUFF IT IS TRAVELING THROUGH,
AS DOES EVERY OTHER TYPE OF WAVE TOO.

Don't tell me i'm wrong, rather tell me what experiment proves what i 
say is not true eh!

keith stein

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#489871

Dne 08/04/2018 v 21:02 Keith Stein napsal(a):
> The speed of light in vacuum is a silly concept,
> because what can this speed be relative to ?

Any speed relates to a coordinate system.
So does speed of light in vacuum.
> 
> But since there is FINITE DENSITY EVERYWHERE,
> there is no need to solve this conundrum.

As it is solved already.
There is strong convergence toward vacuum,
as I pointed out in other post.
> 
> LIGHT TRAVELS RELATIVE TO THE STUFF IT IS TRAVELING THROUGH,
> AS DOES EVERY OTHER TYPE OF WAVE TOO.

Shouting is not more true than whispering.

Light travels relative to any coordinate system,
implicit or explicit, like any other wave.

> 
> Don't tell me i'm wrong, rather tell me what experiment proves what i
> say is not true eh!

The education experiment.

-- 
Poutnik ( The Pilgrim, Der Wanderer )

A wise man guards words he says,
as they say about him more,
than he says about the subject.

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#491772

On Sun, 8 Apr 2018 22:03:23 +0200, Libor 'Poutnik' St?íž wrote:

> ... The education experiment.

Many people should perform this experiment much more often.

-- 
Goat / RLW

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#489918

On 4/8/18 2:02 PM, Keith Stein wrote:
> The speed of light in vacuum is a silly concept,
> because what can this speed be relative to ?

Like ALL speeds, it is relative to the coordinates used to measure it.

By convention, physicists use locally inertial coordinates unless otherwise 
specified. Around here that convention is not so well established (mostly 
because many people don't understand the need for it).

Tom Roberts

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#489919

On 09/04/2018 15:39, Tom Roberts wrote:
> On 4/8/18 2:02 PM, Keith Stein wrote:
>> The speed of light in vacuum is a silly concept,
>> because what can this speed be relative to ?
> 
> Like ALL speeds, it is relative to the coordinates used to measure it.

:)  What is 'silly' Mr.Roberts is to believe that the velocity of any 
given light beam could possibly be the same value 'c' relative to all 
inertial coordinates, irrespective of how those coordinates are moving 
relative to each other.

> By convention, physicists use locally inertial coordinates unless 
> otherwise specified. Around here that convention is not so well 
> established (mostly because many people don't understand the need for it).
> 
> Tom Roberts
> 

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#489923

Keith Stein <keithstein111@gmail.com> Wrote in message:
> On 09/04/2018 15:39, Tom Roberts wrote:
>> On 4/8/18 2:02 PM, Keith Stein wrote:
>>> The speed of light in vacuum is a silly concept,
>>> because what can this speed be relative to ?
>> 
>> Like ALL speeds, it is relative to the coordinates used to measure it.
> 
> :)  What is 'silly' Mr.Roberts is to believe that the velocity of any 
> given light beam could possibly be the same value 'c' relative to all 
> inertial coordinates, irrespective of how those coordinates are moving 
> relative to each other.

Welcome to the silly nature. It does not care if what it does is
 silly. 

The observer independent speed is nothing, compared to behaviour
 of quantum objects. 

Silly behaviour cannot be properly  described by models that are
 not silly enough  for common sense.



-- 
Libor Striz aka Poutnik ( a pilgrim/wanderer/wayfarer)


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

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#489933 — GPS satellites.

> common sense.

GPS satellites are the perfect way to explain relativity,
because everyone can relate to it.

On Earth, the satellite's signal is BlueShifted by gravity
and RedShifted by its velocity, relative to earth's core.

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#489976 — Re: GPS satellites.

On Mon, 09 Apr 2018 10:45:53 -0700 (Seattle), Jeff-Relf.Me  @. wrote:

>> common sense.
>
>GPS satellites are the perfect way to explain relativity,
>because everyone can relate to it.
>
>On Earth, the satellite's signal is BlueShifted by gravity
>and RedShifted by its velocity, relative to earth's core.

While that is true, the relativistic correction in GPS satellites is
in the timebase, not the transmission frequency.

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#489977 — GPS satellites.

> > GPS satellites are the perfect way to explain relativity,
> > because everyone can relate to it.
> > 
> > On Earth, the satellite's signal is BlueShifted by gravity
> > and RedShifted by its velocity, relative to earth's core.
> 
> While that is true, the relativistic correction in GPS satellites
> is in the timebase, not the transmission frequency.

Relativity is used to adjust the frequency of the orbiting clocks;
c, the speed of light, is a known constant;
so time and distance are easily derived.

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#489978 — Re: GPS satellites.

J.  Clarke amok-crossposted to 4 newsgroups:
^^
Your first name belongs there.

> On Mon, 09 Apr 2018 10:45:53 -0700 (Seattle), Jeff-Relf.Me  @. wrote:
>> GPS satellites are the perfect way to explain relativity,
>> because everyone can relate to it.
>>
>> On Earth, the satellite's signal is BlueShifted by gravity
>> and RedShifted by its velocity,

It is _not_ written “BlueShifted” or “RedShifted”.

>> relative to earth's core.
> 
> While that is true,

In a manner of speaking.  Because gravity does not exist in general 
relativity, and the satellites’ velocity is measured relative to the ground 
receiver (approximately, in the ECI frame, which has nothing to do with 
“earth’s core” but with the *center* of the *geoid* through which the 
planet’s rotational axis passes).

That is, while the signal from a satellite to the ground will always be 
blueshifted due to a positive difference in spacetime curvature, the signal 
can *equally* be blueshifted due to relative motion of the satellite 
*towards* the observer or vice-versa.

> the relativistic correction

There are many misconceptions regarding GNSSs like GPS (we have discussed 
them all here in sci.physics.relativity).  What do *you* mean by 
“relativistic correction”?

> in GPS satellites is in the timebase,

What do you mean by “timebase”?

> not the transmission frequency.

Correct.  Both the gravitational redshift/blueshift and the relativistic 
Doppler shift are negligibly small here.


F’up2 sci.physics.relativity

PointedEars
-- 
Q: Where are offenders sentenced for light crimes?  
A: To a prism.

(from: WolframAlpha)

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#490090 — Re: GPS satellites.

On 4/9/18 10:28 PM, J. Clarke wrote:
> the relativistic correction in GPS satellites is
> in the timebase, not the transmission frequency.

Hmmmm. Your wording is ambiguous, and can be interpreted as either true or false.

The "timebase" of a GPS satellite is an atomic clock divided down to 
10.22999999543 MHz (this includes the primary relativistic corrections). The 
satellite's transmission frequencies are determined as integral multiples of 
that frequency. So the transmission frequencies have relativistic corrections 
included, but those corrections were applied to the timebase which determines them.

The result is that on the ground the L1 and L2 signals have frequencies 
1575.420000000 MHz and 1227.600000000 MHz, because they were transmitted from 
the satellite at slightly lower frequencies (as measured on the satellite).

Tom Roberts

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#490119 — Re: GPS satellites.

On Wed, 11 Apr 2018 14:36:27 -0500, Tom Roberts
<tjroberts137@sbcglobal.net> wrote:

>On 4/9/18 10:28 PM, J. Clarke wrote:
>> the relativistic correction in GPS satellites is
>> in the timebase, not the transmission frequency.
>
>Hmmmm. Your wording is ambiguous, and can be interpreted as either true or false.
>
>The "timebase" of a GPS satellite is an atomic clock divided down to 
>10.22999999543 MHz (this includes the primary relativistic corrections). The 
>satellite's transmission frequencies are determined as integral multiples of 
>that frequency. So the transmission frequencies have relativistic corrections 
>included, but those corrections were applied to the timebase which determines them.
>
>The result is that on the ground the L1 and L2 signals have frequencies 
>1575.420000000 MHz and 1227.600000000 MHz, because they were transmitted from 
>the satellite at slightly lower frequencies (as measured on the satellite).

The frequencies are carriers, their being off a fraction makes no
difference in the functioning of the system.  The timing is what makes
the system work.

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#490122 — Re: GPS satellites.

J.  Clarke wrote:
^^
Your first name belongs there.

> The frequencies are carriers,

I beg your pardon?

> their being off a fraction makes no difference in the functioning of the
> system. 

Correct.  Fortunately, nobody said or implied otherwise.

> The timing is what makes the system work.
      ^^^^^^
Again you are using words in an uncommon way.  How do *you* define “timing” 
here?  More to the point: How do *you* think does GPS work?

And with your reply, *please* do not crosspost to 4 newsgroups (without 
Followup-To) *again*.  TIA.


F’up2 sci.physics.relativity

PointedEars
-- 
Heisenberg is out for a drive when he's stopped by a traffic cop. 
The officer asks him "Do you know how fast you were going?" 
Heisenberg replies "No, but I know where I am."
(from: WolframAlpha)

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#489939

On 4/9/18 10:04 AM, Keith Stein wrote:
> On 09/04/2018 15:39, Tom Roberts wrote:
>> On 4/8/18 2:02 PM, Keith Stein wrote:
>>> The speed of light in vacuum is a silly concept,
>>> because what can this speed be relative to ?
>>
>> Like ALL speeds, it is relative to the coordinates used to measure it.
> 
> :)  What is 'silly' Mr.Roberts is to believe that the velocity of any given 
> light beam could possibly be the same value 'c' relative to all inertial 
> coordinates, irrespective of how those coordinates are moving relative to each 
> other.

No. What is truly SILLY (and STUPID) is you thinking that your GUESSES are 
better and more important than actual experiments.

Nature does what she does, regardless of whether that seems "silly" to some 
ill-informed humans like yourself.

Moreover, this is not really "silly" at all, it is just that you are IGNORANT: 
Special Relativity explicitly showed how it is possible, and actual experiments 
have confirmed it is indeed how nature behaves.

	Basically you are claiming "I, Keith Stein, am smarter and
	more knowledgeable about physics than every physicist of
	the past century." -- THAT is indeed SILLY (and STUPID).

Tom Roberts

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