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 Post subject: Re: Quantum of Light and my Parrot.Posted: Thu Aug 11, 2011 9:40 am

Joined: Wed Feb 02, 2011 9:37 pm
Posts: 834
Location: Cardiff
Hi again.
Relativity theory is such a break from 'normal' physics that I think a crash course in the latter would not help much.
Einstein published two major works : 'Special Relativity' in 1905 and 'General Relativity' in 1915.
What I described in outline in my earlier post referred exclusively to 'Special Relativity'. This looks at the distortions in space and time that are experienced by an observer travelling in a straight line at some unchanging speed.
General Relativity includes the effects of acceleration, or gravity, and explores curvature of space-time, and is really a lot more difficult to follow. The maths required to grapple with GR is way beyond me. (I have tried).
To get a general idea of what SR (special relativity) is about, you don't really need any maths, or basic physics, at all. You just need to be able to picture 3 objects moving in space, each at a steady speed, and all moving along the same straight line, but all at different speeds relative to each other..
The main points you need to bear in mind are;
1. We cannot discover an absolutely fixed background against which speeds can be measured.
2. the speed of light is the same for all observers.
Looking first at point 1. Normally we measure speed against what we think of as a fixed background. For example if a car's speedo says 70, that means the car is travelling at 70mph along the road. We think of the road as fixed. We dont take into account that the earth itself is moving around the sun, or that the sun is moving around the galaxy, or that the galaxy itself... etc etc. So how fast is the car 'really' moving?
The answer is, no-one can discover a 'true' answer Effectively, we might as well say there is no 'true' answer. Movement can only be measured relative to something else.
Now consider point 2. For a very long time, all but the most advanced physicists had to either take Einstein's word for this 'weird' statement, or else do some very difficult and precise experiments to discover for themselves that it is correct. Nowadays millions of people, all around the world, use extremely high precision instruments to test this. It's called GPS. (Global Positioning by Satellite) All aeroplanes and ships have them, and most small boats. These days cars and trucks usually have them too. And in fact, this technology demonstrates, millions of times a day, at millions of places all around the planet, that both SR and GR are correct.
So now we have two statements, both of which we can trust as much as we can trust any statement made by science; and all we have to do is think through the consequences.

If you and I had a neat little spaceship each, equipped with identical, and highly accurate, instruments, we could fly millions of miles away from any planet, and do an experiment.
Say we start a long way apart, and fly towards each other. Your instruments tell you I'm flying towards you at 10 million metres per second. My instruments tell me you are flying towards me at 10 million metres per second. I think I am not moving relative to myself, obviously, and you think you are not moving relative to yourself. And of course we are both correct about this. We cannot find any fixed background against which we can definitely say that one of us is moving at some fixed speed and the other is moving at some other fixed speed. But at least we agree that our ' closing speed' is 10 million metres per second.
Now a photon whizzes past my spaceship, towards yours. My instruments measure its speed at 300 million metres per second, relative to me. So I would expect your instruments to measure its speed at 310 million metres per second, relative to you. (Because you and the photon appear to be flying towards each other, I might expect your speeds to 'add up', the way the speeds of two cars in a head-on collision 'add up'.)
Now another photon whizzes past my ship, this one coming from the direction of your ship. Again my instruments measure the speed of this photon at 300 million metres per second. So I expect you would have measured that photon to be passing your ship at 290 million metres per second. (Because I think you are travelling in the same direction as the photon, I might expect your speed to be 'subtracted from' the photon's speed, the way your 60mph was subtracted from the ambulance's 90mph, to measure the ambulance going 30 mph faster than you.)
In fact you will measure the speeds of both these photons at 300 million metres per second relative to your ship; the same speed I measured them at, relative to my ship.
What is going on? Where is the 10 million metres per second difference in our speeds? Why doesn't it show up as a 10 million metres per second difference in our measurement of the photon's speed?
The answer must be that, because the speed of light is the same for all observers, and speed is only a relation of distance (ie space) and time, it is space and time that are measured differently by different observers.
This resolves Socratus's question about the apparent contradiction between the absolute speed of light and the relativity of space. It's not a contradiction; the one is a consequence of the other.
Hope this helps.
PS Still open for questions

Last edited by Thundril on Thu Aug 11, 2011 11:33 am, edited 5 times in total.

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 Post subject: Re: Quantum of Light and my Parrot.Posted: Thu Aug 11, 2011 10:37 am

Joined: Wed Oct 17, 2007 2:31 am
Posts: 10543
Not sure if it helps but we can also prove his theories a bit more simply by putting extremely accurate clocks on the ground and in a very fast jet and just comparing times after a while.

Here's a comedy one I've always thought about, why do pilots and those who do things that involve great lengths of their lives travelling at speed always look so young for their age?

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 Post subject: Re: Quantum of Light and my Parrot.Posted: Thu Aug 11, 2011 11:02 am

Joined: Wed Feb 02, 2011 9:37 pm
Posts: 834
Location: Cardiff
Arising_uk wrote:
Not sure if it helps but we can also prove his theories a bit more simply by putting extremely accurate clocks on the ground and in a very fast jet and just comparing times after a while.

Yep, that's been done several times, with caesium clocks in sattelites.. Astronauts really are slightly younger than they would have been had they not flown.
I don't think it's simpler than verfiying that your GPS actually works

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 Post subject: Re: Quantum of Light and my Parrot.Posted: Thu Aug 11, 2011 11:21 am

Joined: Wed Oct 17, 2007 2:31 am
Posts: 10543
Anyhoo. Its all LIES as its the FSM that does all the tweaking to make it turn out as we believe and I have the pirates to prove it!! Now where's that parrot gone?

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 Post subject: Re: Quantum of Light and my Parrot.Posted: Thu Aug 11, 2011 11:41 am

Joined: Wed Feb 02, 2011 9:37 pm
Posts: 834
Location: Cardiff
Arising_uk wrote:
Anyhoo. Its all LIES as its the FSM that does all the tweaking to make it turn out as we believe and I have the pirates to prove it!! Now where's that parrot gone?

It's gone to join the choir invisible! That's why, as I pointed out in an earlier post, the black geese are in mourning.

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 Post subject: Re: Quantum of Light and my Parrot.Posted: Thu Aug 11, 2011 3:08 pm

Joined: Wed Oct 17, 2007 2:31 am
Posts: 10543
Thundril wrote:
... I don't think it's simpler than verfiying that your GPS actually works
Do me a favour!!! You come and bloody tell Orange maps that!!!!

Oo! Have I just disproved GR?

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 Post subject: Re: Quantum of Light and my Parrot.Posted: Thu Aug 11, 2011 3:45 pm

Joined: Sat Oct 24, 2009 7:00 am
Posts: 429
Location: Israel
#
In other words, the absolute value of the speed of light
doesn't contradict the relativity of time and space;
on the exact contrary, it is the absolute speed of light which proves it.
/ Thundril /
between the absolute speed of light and the relativity of space.
It's not a contradiction; the one is a consequence of the other.
/ Thundril /
====.
#
The book: Albert Einstein and the Cosmic World Order
/ Six lectures delivered at the University
of Michigan in the Spring of 1962 /
by Cornelius Lanczos / The lecture № 3 /
=============.
Cornelius Lanczos (served as assistant to Einstein during
the period 1928–29 ) wrote:
SRT was created on two postulates.
First postulate – there isn’t absolute speed of movement.
Every movement is relative.
Second postulate – the speed of light ( quantum of light)
is constant.
Lanczos wrote: from the first point of view it seems that
to unite these two different postulates is impossible,
trying to do this is absolute nonsense. (!)
But . . . . It was be done. (!)
. . It was needed the Einstein’s courage to do this unity. (!)
How did Einstein connected them ? (!)
1
He solved this problem saying that Newton’s absolute space
and time are relative.
2
And these two postulates can be unite in spacetime - 4D.
3
As the result we can see different occurrences :
( for example: not only the physical parameters of particles
can change but space and time too )

And Lanczos wrote: now we are accustomed to this conception
and never, not for the world give up from such manner of thinking.
==================.
Very well ! !
There is only small problem in this conception:
What is the negative 4D spacetime ?
Nobody knows.
! !
============.
In my opinion : the Einstein’s SRT explains that we have two
( 2) kinds of reality: Newtonian and Minkowski and the
Quantum of Light who travels between them.
===.
Best wishes.
==============.

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 Post subject: Re: Quantum of Light and my Parrot.Posted: Thu Aug 11, 2011 6:39 pm

Joined: Wed Feb 02, 2011 9:37 pm
Posts: 834
Location: Cardiff
Arising_uk wrote:
Thundril wrote:
... I don't think it's simpler than verfiying that your GPS actually works
Do me a favour!!! You come and bloody tell Orange maps that!!!!

Oo! Have I just disproved GR?

Einstein vs Tom Tom. Hmmm. Tricky, that.

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 Post subject: Re: Quantum of Light and my Parrot.Posted: Thu Aug 11, 2011 6:45 pm

Joined: Wed Feb 02, 2011 9:37 pm
Posts: 834
Location: Cardiff
socratus wrote:
#

In my opinion : the Einstein’s SRT explains that we have two
( 2) kinds of reality: Newtonian and Minkowski and the
Quantum of Light who travels between them.
===.
Best wishes.
==============.

In my opinion we have two perceptions of reality, - Newtonian and Relativistic.
We use the simplest perception that suffices for our purposes in any given situation.
I don't think the Newtonian universe is a different place. Nor do I think Minkowski space is actually a different place.
I think there is just the one reality. We have a lot of different ideas about it, (none of them perfect) and some of these ideas are more useful than others.

= = = Best wishes to you too, Israel.

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 Post subject: Re: Quantum of Light and my Parrot.Posted: Fri Aug 12, 2011 5:40 am

Joined: Sat Oct 24, 2009 7:00 am
Posts: 429
Location: Israel
I don't think the Newtonian universe is a different place.
Nor do I think Minkowski space is actually a different place.
/ Thundril /
===.
Henceforth, space by itself, and time by itself,
and only a kind of union of the two will preserve
an independent reality.
/ H. Minkowski.. /
#
‘ space by itself, and time by itself, ‘ – are Newtonian
#
‘only a kind of union of the two will preserve
an independent reality.’ – is Minkowski.
#
‘Are’ and ‘Is’ are not the same. They are different.
#
You can see the Minkowski space in attachments.
===.

 Attachments: File comment: Minkowski negative 4D Space. 300px-World_line_svg.png [ 41.81 KiB | Viewed 999 times ]
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 Post subject: Re: Quantum of Light and my Parrot.Posted: Fri Aug 12, 2011 11:50 am

Joined: Wed Feb 02, 2011 9:37 pm
Posts: 834
Location: Cardiff
The Minkowski light-cones image is a really good way of visualising how some events can be 'elsewhere' (that is, effectively non-existent) with respect to some other events. It is a really clear (IMO) representation of the timeline of an individual 'observer'. For most purposes though, here in our ordinary human lives, the Newtonian space, with its Euclidean 3d space, and its separate and seemingly Universal time, is quite good enough. The trajectory of a spacecraft visiting two or three planets, and even 'slingshotting' around moons, can all be calculated using Newtonian physics. The Newtonian view of space and time isn't "wrong".
These, the Minkowski and Newtonian views, are two different ways of understanding reality.
Reality didn't change at the beginning of the 20th century; our understanding of reality took a huge leap, but it's still the same Universe.
Just as the Americas existed before 'we discovered them', string theory, M-theory, or some other, will at some point present a cosmology even richer than Minkowski's description. Does that mean there will then be three Realities? Or that there always were three Realities, only we didn't know it? Or that Minkowski's ideas have now become untrue?
Or shall we carry on with the idea that there is just the one 'reality', and now and then we find another way of thinking about it?

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 Post subject: Re: Quantum of Light and my Parrot.Posted: Sat Aug 13, 2011 1:34 am

Joined: Sat Oct 24, 2009 7:00 am
Posts: 429
Location: Israel
Thundril wrote:
These, the Minkowski and Newtonian views, are two different ways of understanding reality.

What is Newtonian reality ?
The Classic physics , Euclidian geometry and
Galileo transformations.
What is Minkowski reality ?
SRT, Pseudo Euclidian geometry and
Lorentz transformations.

These, the Minkowski and Newtonian views,
are two different ways of understanding reality.
/ Thundril /
Correct.
And we need to understand their unity.
Their unity is possible to understand only through Quantum of Light.
==.

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