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question from about learning relativity...

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Message

birdman...

Posted: Wed Oct 28, 2009 7:09 pm

Guest

hey everyone - i was wondering about the best way of really, fully
understanding a few concepts in physics, one of them being the Special
Theory of Relativity. i studied it some i college and i remember
something about minkowski, the Lorentz transformation, Einstiens tidy
book (was it just called 'Relativity'?), and Maxwells Equations, but
i've lost all those books long ago.

So, i know Relativity is a big complicated topic, but might someone be
able to give me a roadmap, like a series of books or websites that
might get me started? My goal is to understand the stuff, so i am not
afraid of math. at the same time i don't want to get bogged down with
a bunch of numbers and formulas relating ot practical engineering
stuff, you know? That's the main reason i don't want to take a bunch
of Calc classes. From my experience, i learn a lot of formulas and
problem solving techniques, but don't get an intuitive grasp.

MY other goal is to understand Maxwells equations, so if anyone knows
how to get there, plaese let me know.

So, yeah, any help is most welcome.

- birdman.

waldofj...

Posted: Wed Oct 28, 2009 7:54 pm

Guest

On Oct 29, 1:09 am, birdman <bagofbi... at (no spam) gmail.com> wrote:
[quote]hey everyone - i was wondering about the best way of really, fully
understanding a few concepts in physics, one of them being the Special
Theory of Relativity. i studied it some i college and i remember
something about minkowski, the Lorentz transformation, Einstiens tidy
book (was it just called 'Relativity'?), and Maxwells Equations, but
i've lost all those books long ago.

So, i know Relativity is a big complicated topic, but might someone be
able to give me a roadmap, like a series of books or websites that
might get me started? My goal is to understand the stuff, so i am not
afraid of math. at the same time i don't want to get bogged down with
a bunch of numbers and formulas relating ot practical engineering
stuff, you know? That's the main reason i don't want to take a bunch
of Calc classes. From my experience, i learn a lot of formulas and
problem solving techniques, but don't get an intuitive grasp.

MY other goal is to understand Maxwells equations, so if anyone knows
how to get there, plaese let me know.

So, yeah, any help is most welcome.

- birdman.
[/quote]
here is a link to a series of 1/2 hour physics classes.
http://www.learner.org/resources/series42.html?pop=yes&pid=600#
It's not a great resource, many subjects are treated too
simplistically, but it has some good stuff nevertheless. Look to the
bottom for relativity related subjects.

dlzc...

Posted: Wed Oct 28, 2009 8:14 pm

Guest

Dear birdman:

On Oct 28, 10:09 pm, birdman <bagofbi... at (no spam) gmail.com> wrote:
....
[quote]So, i know Relativity is a big complicated
topic, but might someone be able to give me
a roadmap, like a series of books or
websites that might get me started?
[/quote]
There is a reading list here:
http://math.ucr.edu/home/baez/physics/Administrivia/rel_booklist.html
I recommend "Spacetime Physics" by Taylor and Wheeler as a starter.
Very little math, so you can warm up to the subject (and sharpen the
tools).

....
[quote]MY other goal is to understand Maxwells
equations, so if anyone knows how to get
there, plaese let me know.
[/quote]
I can't help here, sorry.

David A. Smith

Inertial...

Posted: Wed Oct 28, 2009 11:37 pm

Guest

"birdman" <bagofbirds at (no spam) gmail.com> wrote in message
news:91381f7c-7667-4532-b705-9111ba8173da at (no spam) v15g2000prn.googlegroups.com...
[quote]hey everyone - i was wondering about the best way of really, fully
understanding a few concepts in physics, one of them being the Special
Theory of Relativity.
[/quote]
Hard to say how to understand anything.

Learn as much as you can about it for a start, and make sure you can use it
appropriately.

Read some legitimate literature on relativity, and hopefully one explanation
(or a combination) will make sense and you'll have that
light-bulb-over-the-head moment and 'get' it.

And ask those who understand if there's anything you don't get, as they may
be able to help you

If you read the anti-relativity literature before you understand it, then
you may get some barriers in your brain to understanding what relativity
actually says.

After you've 'got' it, have a read of the anti-relativity stuff if you like,
so then you can critique what it has to say from a position of knowledge and
understanding.

[quote]i studied it some i college and i remember
something about minkowski, the Lorentz transformation, Einstiens tidy
book (was it just called 'Relativity'?), and Maxwells Equations, but
i've lost all those books long ago.
[/quote]
There are plenty of resources on-line. Maybe too much.

[quote]So, i know Relativity is a big complicated topic,
[/quote]
Special relativity is pretty straightforward and easy to get .. the math is
pretty simple for the most part.

General relativity is more complicated, and the math more difficult

So I'd start with SR. If you don't 'get' that, then you prob won't 'get'
the more complex GR

[quote]but might someone be
able to give me a roadmap, like a series of books or websites that
might get me started?
[/quote]
I know its not recommended as a source of reliable information .. but the
wikipedia pages on relativity are fairly good. And they have links to other
places.

I'm sure some others here can provide you with some good sites and/or books
to purchase/borrow.

[quote]My goal is to understand the stuff, so i am not
afraid of math.
[/quote]
That's good. As I said .. the math of SR is quite simple. What is trickier
to get your mind around is the physics that correspond to the math .. ie
what the SR math *means*.

[quote]at the same time i don't want to get bogged down with
a bunch of numbers and formulas relating ot practical engineering
stuff, you know? That's the main reason i don't want to take a bunch
of Calc classes. From my experience, i learn a lot of formulas and
problem solving techniques, but don't get an intuitive grasp.
[/quote]
Yeup .. that's often the hardest part.

[quote]MY other goal is to understand Maxwells equations, so if anyone knows
how to get there, plaese let me know.
[/quote]
There is some fairly complex math there as well. If you want to learn
maxwell's equations as part of learning relativity, its not essential to
know the details of the equations in order to get relativity. For example,
you don't need to know anything about how light propagates as an
electromagnetic wave in order to work with SR .. other than that it moves at
c, and that as with all wave, the product of wavelength and frequency gives
you speed.

[quote]So, yeah, any help is most welcome.
[/quote]
I don't think I can help much with specific places to look. But if you have
any questions or areas that confuse you, post them here and (if I see them)
I'll try to help.

Androcles...

Posted: Thu Oct 29, 2009 12:26 am

Guest

Inertial...

Posted: Thu Oct 29, 2009 12:35 am

Guest

Inertial...

Posted: Thu Oct 29, 2009 12:56 am

Guest

"Androcles" <Headmaster at (no spam) Hogwarts.physics_p> wrote in message
news:qBaGm.46566$R52.40141 at (no spam) newsfe24.ams2...
[quote]
"birdman" <bagofbirds at (no spam) gmail.com> wrote in message
news:91381f7c-7667-4532-b705-9111ba8173da at (no spam) v15g2000prn.googlegroups.com...
hey everyone - i was wondering about the best way of really, fully
understanding a few concepts in physics, one of them being the Special
Theory of Relativity. i studied it some i college and i remember
something about minkowski, the Lorentz transformation, Einstiens tidy
book (was it just called 'Relativity'?), and Maxwells Equations, but
i've lost all those books long ago.

So, i know Relativity is a big complicated topic, but might someone be
able to give me a roadmap, like a series of books or websites that
might get me started? My goal is to understand the stuff, so i am not
afraid of math. at the same time i don't want to get bogged down with
a bunch of numbers and formulas relating ot practical engineering
stuff, you know? That's the main reason i don't want to take a bunch
of Calc classes.

You want to drive a car but you don't to be bogged down getting
a license?
I want to know how the Easter Bunny lays chocolate eggs but I
don't want to be bogged down with factories and moulding
machines.
Ok, here's a roadmap to relativity.
http://www.androcles01.pwp.blueyonder.co.uk/QUESTION.htm
[/quote]
I'll take you through his page (which isn't what he said it is, of coruse)

At the top is a formula from Einstein's paper. It is part of the derivation
of how one can derive how measurements of time and space vary between
observers. This is based on the common sense definition of how synchronized
clocks behave, combined with the postulate the the speed of light is the
same for all observers.

As he shows it is saying the the time for light to go (in some frame) from
fixed point A to fixed point B is the half the time for light to go from A
to B and back to A, which is pretty much obvious when SR says light travels
at a fixed speed in all directions. So if it travels twice as far, it takes
twice as long.

He then quotes Einstein's definition of what it means for clocks at fixed
point A and fixed point B to be synchronised. ie that they show the time for
light (or any fixed speed signal) to go from A to B is the same time as for
it to go in the reverse direction.

Androcles has a problem with that .. though he cannot seem to express what
the problem is, hence his sarcastic comment in yellow. He also says its a
postulate, but its not, it is just a common sense description of what
properly synchronized clocks should do.

There is a link there to Einstiens paper at the fourmilab site. Maybe worth
a read.

He then has an animation whose relationship to what goes before or after is
not at all clear.

He then has a couple of animations and claims what it clearly show that
accompany a presentation of simultaneity of simultaneity, though on their
own without explanation, they aren't terribly meaningful.

Then he has a big QUESTION.

"Why did Einstein say
the speed of light from A to B is c-v,
the speed of light from B to A is c+v,
the "time" each way is the same?"

Of course, Einstein did not say that.. he said the speed of light from A to
B is c and the speed from B to A is c. That's the whole point of the second
postulate .. the speed of light is one value, c, in all frames of reference.

Of course, closing speed between light and some object moving in a frame of
reference will be different to c, as common sense tells us.

He then shows some mostly appropriate responses from others to his deceptive
question. He also points out the Einsteins paper doesn't use the word
"inertial" .. which is correct. That terms was not in use then .. he
instead use the phrase "frames of reference for which the equations of
mechanics hold good" .. which we would nowadays call an inertial frame of
reference.

Helmut Wabnig...

Posted: Thu Oct 29, 2009 2:06 am

Guest

On Wed, 28 Oct 2009 22:09:13 -0700 (PDT), birdman
<bagofbirds at (no spam) gmail.com> wrote:

[quote]hey everyone - i was wondering about the best way of really, fully
understanding a few concepts in physics, one of them being the Special
Theory of Relativity. i studied it some i college and i remember
something about minkowski, the Lorentz transformation, Einstiens tidy
book (was it just called 'Relativity'?), and Maxwells Equations, but
i've lost all those books long ago.

So, i know Relativity is a big complicated topic, but might someone be
able to give me a roadmap, like a series of books or websites that
might get me started? My goal is to understand the stuff, so i am not
afraid of math. at the same time i don't want to get bogged down with
a bunch of numbers and formulas relating ot practical engineering
stuff, you know? That's the main reason i don't want to take a bunch
of Calc classes. From my experience, i learn a lot of formulas and
problem solving techniques, but don't get an intuitive grasp.

MY other goal is to understand Maxwells equations, so if anyone knows
how to get there, plaese let me know.

So, yeah, any help is most welcome.

- birdman.
[/quote]

Read the Google archives of sci.physics.relativity and sci.physics,
lots of stuff here :-)

w.

Helmut Wabnig...

Posted: Thu Oct 29, 2009 2:12 am

Guest

On Thu, 29 Oct 2009 17:56:36 +1100, "Inertial" <relatively at (no spam) rest.com>
wrote:

[quote]"Androcles" <Headmaster at (no spam) Hogwarts.physics_p> wrote in message
news:qBaGm.46566$R52.40141 at (no spam) newsfe24.ams2...

"birdman" <bagofbirds at (no spam) gmail.com> wrote in message
news:91381f7c-7667-4532-b705-9111ba8173da at (no spam) v15g2000prn.googlegroups.com...
hey everyone - i was wondering about the best way of really, fully
understanding a few concepts in physics, one of them being the Special
Theory of Relativity. i studied it some i college and i remember
something about minkowski, the Lorentz transformation, Einstiens tidy
book (was it just called 'Relativity'?), and Maxwells Equations, but
i've lost all those books long ago.

So, i know Relativity is a big complicated topic, but might someone be
able to give me a roadmap, like a series of books or websites that
might get me started? My goal is to understand the stuff, so i am not
afraid of math. at the same time i don't want to get bogged down with
a bunch of numbers and formulas relating ot practical engineering
stuff, you know? That's the main reason i don't want to take a bunch
of Calc classes.

You want to drive a car but you don't to be bogged down getting
a license?
I want to know how the Easter Bunny lays chocolate eggs but I
don't want to be bogged down with factories and moulding
machines.
Ok, here's a roadmap to relativity.
http://www.androcles01.pwp.blueyonder.co.uk/QUESTION.htm

I'll take you through his page (which isn't what he said it is, of coruse)

At the top is a formula from Einstein's paper. It is part of the derivation
of how one can derive how measurements of time and space vary between
observers. This is based on the common sense definition of how synchronized
clocks behave, combined with the postulate the the speed of light is the
same for all observers.

As he shows it is saying the the time for light to go (in some frame) from
fixed point A to fixed point B is the half the time for light to go from A
to B and back to A, which is pretty much obvious when SR says light travels
at a fixed speed in all directions. So if it travels twice as far, it takes
twice as long.

He then quotes Einstein's definition of what it means for clocks at fixed
point A and fixed point B to be synchronised. ie that they show the time for
light (or any fixed speed signal) to go from A to B is the same time as for
it to go in the reverse direction.

Androcles has a problem with that .. though he cannot seem to express what
the problem is, hence his sarcastic comment in yellow. He also says its a
postulate, but its not, it is just a common sense description of what
properly synchronized clocks should do.

There is a link there to Einstiens paper at the fourmilab site. Maybe worth
a read.

He then has an animation whose relationship to what goes before or after is
not at all clear.

He then has a couple of animations and claims what it clearly show that
accompany a presentation of simultaneity of simultaneity, though on their
own without explanation, they aren't terribly meaningful.

Then he has a big QUESTION.

"Why did Einstein say
the speed of light from A to B is c-v,
the speed of light from B to A is c+v,
the "time" each way is the same?"

Of course, Einstein did not say that.. he said the speed of light from A to
B is c and the speed from B to A is c. That's the whole point of the second
postulate .. the speed of light is one value, c, in all frames of reference.

Of course, closing speed between light and some object moving in a frame of
reference will be different to c, as common sense tells us.

He then shows some mostly appropriate responses from others to his deceptive
question. He also points out the Einsteins paper doesn't use the word
"inertial" .. which is correct. That terms was not in use then .. he
instead use the phrase "frames of reference for which the equations of
mechanics hold good" .. which we would nowadays call an inertial frame of
reference.

[/quote]
When c is and has to be always "c" and not more or less
any formulas containing terms with c +/- v are wrong by postulate.

w.

Inertial...

Posted: Thu Oct 29, 2009 2:19 am

Guest

"Helmut Wabnig" <hwabnig at (no spam) .- --- -. dotat> wrote in message
news:dfjie5d6kiqgpckhu36kaqqgfjehioe6l6 at (no spam) 4ax.com...
[quote]On Thu, 29 Oct 2009 17:56:36 +1100, "Inertial" <relatively at (no spam) rest.com
wrote:

"Androcles" <Headmaster at (no spam) Hogwarts.physics_p> wrote in message
news:qBaGm.46566$R52.40141 at (no spam) newsfe24.ams2...

"birdman" <bagofbirds at (no spam) gmail.com> wrote in message
news:91381f7c-7667-4532-b705-9111ba8173da at (no spam) v15g2000prn.googlegroups.com...
hey everyone - i was wondering about the best way of really, fully
understanding a few concepts in physics, one of them being the Special
Theory of Relativity. i studied it some i college and i remember
something about minkowski, the Lorentz transformation, Einstiens tidy
book (was it just called 'Relativity'?), and Maxwells Equations, but
i've lost all those books long ago.

So, i know Relativity is a big complicated topic, but might someone be
able to give me a roadmap, like a series of books or websites that
might get me started? My goal is to understand the stuff, so i am not
afraid of math. at the same time i don't want to get bogged down with
a bunch of numbers and formulas relating ot practical engineering
stuff, you know? That's the main reason i don't want to take a bunch
of Calc classes.

You want to drive a car but you don't to be bogged down getting
a license?
I want to know how the Easter Bunny lays chocolate eggs but I
don't want to be bogged down with factories and moulding
machines.
Ok, here's a roadmap to relativity.
http://www.androcles01.pwp.blueyonder.co.uk/QUESTION.htm

I'll take you through his page (which isn't what he said it is, of coruse)

At the top is a formula from Einstein's paper. It is part of the
derivation
of how one can derive how measurements of time and space vary between
observers. This is based on the common sense definition of how
synchronized
clocks behave, combined with the postulate the the speed of light is the
same for all observers.

As he shows it is saying the the time for light to go (in some frame) from
fixed point A to fixed point B is the half the time for light to go from A
to B and back to A, which is pretty much obvious when SR says light
travels
at a fixed speed in all directions. So if it travels twice as far, it
takes
twice as long.

He then quotes Einstein's definition of what it means for clocks at fixed
point A and fixed point B to be synchronised. ie that they show the time
for
light (or any fixed speed signal) to go from A to B is the same time as
for
it to go in the reverse direction.

Androcles has a problem with that .. though he cannot seem to express what
the problem is, hence his sarcastic comment in yellow. He also says its a
postulate, but its not, it is just a common sense description of what
properly synchronized clocks should do.

There is a link there to Einstiens paper at the fourmilab site. Maybe
worth
a read.

He then has an animation whose relationship to what goes before or after
is
not at all clear.

He then has a couple of animations and claims what it clearly show that
accompany a presentation of simultaneity of simultaneity, though on their
own without explanation, they aren't terribly meaningful.

Then he has a big QUESTION.

"Why did Einstein say
the speed of light from A to B is c-v,
the speed of light from B to A is c+v,
the "time" each way is the same?"

Of course, Einstein did not say that.. he said the speed of light from A
to
B is c and the speed from B to A is c. That's the whole point of the
second
postulate .. the speed of light is one value, c, in all frames of
reference.

Of course, closing speed between light and some object moving in a frame
of
reference will be different to c, as common sense tells us.

He then shows some mostly appropriate responses from others to his
deceptive
question. He also points out the Einsteins paper doesn't use the word
"inertial" .. which is correct. That terms was not in use then .. he
instead use the phrase "frames of reference for which the equations of
mechanics hold good" .. which we would nowadays call an inertial frame of
reference.

When c is and has to be always "c" and not more or less
any formulas containing terms with c +/- v are wrong by postulate.
[/quote]
No .. as, for example, closing speed can be c +/- v.

Please, don't misinform what the original poster is trying to learn.

eric gisse...

Posted: Thu Oct 29, 2009 2:30 am

Guest

birdman wrote:

[quote]hey everyone - i was wondering about the best way of really, fully
understanding a few concepts in physics, one of them being the Special
Theory of Relativity.
[/quote]
Read a book.

The internet is, overall, the wrong answer.

[quote]i studied it some i college and i remember
something about minkowski, the Lorentz transformation, Einstiens tidy
book (was it just called 'Relativity'?), and Maxwells Equations, but
i've lost all those books long ago.
[/quote]
Fortunately the world has continued to make books, and there are several
good ones published since Einstein's time. Taylor's "Spacetime Physics" is a
good one from what I understand, if you want to limit yourself to SR.

[quote]
So, i know Relativity is a big complicated topic
[/quote]
Not nearly as much as either what you think, or what people on this
newsgroup would like you to assume.

[quote], but might someone be
able to give me a roadmap, like a series of books or websites that
might get me started? My goal is to understand the stuff, so i am not
afraid of math.
[/quote]
Good.

[quote]at the same time i don't want to get bogged down with
a bunch of numbers and formulas relating ot practical engineering
stuff, you know? That's the main reason i don't want to take a bunch
of Calc classes. From my experience, i learn a lot of formulas and
problem solving techniques, but don't get an intuitive grasp.

MY other goal is to understand Maxwells equations, so if anyone knows
how to get there, plaese let me know.
[/quote]
If you are serious about E&M, Griffiths for undergraduate E&M and then
Jackson for graduate level E&M.

[quote]
So, yeah, any help is most welcome.

- birdman.[/quote]

Androcles...

Posted: Thu Oct 29, 2009 2:33 am

Guest

"dlzc" <dlzc1 at (no spam) cox.net> wrote in message
news:faead17d-b5ba-4db7-881f-aa8733f96a93 at (no spam) j19g2000yqk.googlegroups.com...
Dear birdman:

On Oct 28, 10:09 pm, birdman <bagofbi... at (no spam) gmail.com> wrote:
....
[quote]So, i know Relativity is a big complicated
topic, but might someone be able to give me
a roadmap, like a series of books or
websites that might get me started?
[/quote]
There is a reading list here:
http://math.ucr.edu/home/baez/physics/Administrivia/rel_booklist.html
I recommend "Spacetime Physics"

========================================
Bwhahahahahahahaha!
I recommend "See Spot Run" for Smiffy.

Ref: http://www.fourmilab.ch/etexts/einstein/specrel/www/figures/img22.gif

What kind of lunacy prompted Einstein to say
the speed of light from A to B is c-v,
the speed of light from B to A is c+v,
the "time" each way is the same?

Inertial...

Posted: Thu Oct 29, 2009 4:09 am

Guest

"Androcles" <Headmaster at (no spam) Hogwarts.physics_p> wrote in message
news:NscGm.3813$%f1.2625 at (no spam) newsfe15.ams2...
[quote]
"dlzc" <dlzc1 at (no spam) cox.net> wrote in message
news:faead17d-b5ba-4db7-881f-aa8733f96a93 at (no spam) j19g2000yqk.googlegroups.com...
Dear birdman:

On Oct 28, 10:09 pm, birdman <bagofbi... at (no spam) gmail.com> wrote:
...
So, i know Relativity is a big complicated
topic, but might someone be able to give me
a roadmap, like a series of books or
websites that might get me started?

There is a reading list here:
http://math.ucr.edu/home/baez/physics/Administrivia/rel_booklist.html
I recommend "Spacetime Physics"

========================================
Bwhahahahahahahaha!
I recommend "See Spot Run" for Smiffy.

Ref:
http://www.fourmilab.ch/etexts/einstein/specrel/www/figures/img22.gif

What kind of lunacy prompted Einstein to say
the speed of light from A to B is c-v,
the speed of light from B to A is c+v,
the "time" each way is the same?
[/quote]
Which he never said

eric gisse...

Posted: Thu Oct 29, 2009 4:16 am

Guest

Inertial wrote:
[...]

[quote]
Which he never said
[/quote]
Androcles has truly been the homeless guy ranting on the corner for several
years now.

birdman...

Posted: Thu Oct 29, 2009 8:59 am

Guest

wow! Thanks so much to you all for the helpful responses. i have my
work cut out for me (which is what i wanted!) Educational materials
have sure come a long way since my undergrad days (mid nineties) and i
look forward to digging in!

-birdman

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