Mass Ratio and Lagrange Points

Web page URL:http://www.merlyn.demon.co.uk/$lag-pts.htm is a draft
component for URL:http://www.merlyn.demon.co.uk/gravity4.htm. It's
core is a graphic showing how the five Lagrange points move as mass is
transferred from one large body to the other, and how it all rotates.

Current MSIE 8 cannot show the graphic. Current Opera (10.10) cannot
show text on the graphic. Current, but not necessarily recent, Firefox,
Safari, and Chrome show the graphic with its text. JavaScript is
required.

The graphic is being slowly changed, particularly in labelling, to look
more like the large M=9 one in gravity4.htm.

Any comments and suggestions while I am still working on it?

It has just occurred to me that, to show moving Lagrange points for
elliptical orbits rather than circular ones, I may only need to alter
the separation variable as a function of angle and to make some circles
into ellipses. But that needs more thought. Festina lente.



FYI, the fairly new HTML component canvas is rather useful for
preparing and presenting diagrams which are computed rather than
sketched - see also
URL:http://www.merlyn.demon.co.uk/js-grphx.htm, from which one can
save the graphic as a PNG.



See also BBC page
http://news.bbc.co.uk/1/low/technology/8537763.stm, on browsers;
and http://spaceweather.com/ for bus-stop astronomy.

--
(c) John Stockton, nr London, UK. Turnpike v6.05 MIME.
Web URL:http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms & links;
Astro stuff via astron-1.htm, gravity0.htm ; quotings.htm, pascal.htm, etc.
No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News.

"Dr J R Stockton" wrote in message
nvalid...

Web page URL:http://www.merlyn.demon.co.uk/$lag-pts.htm is a draft
component for URL:http://www.merlyn.demon.co.uk/gravity4.htm. It's
core is a graphic showing how the five Lagrange points move as mass is
transferred from one large body to the other, and how it all rotates.

Neat!

Current MSIE 8 cannot show the graphic. Current Opera (10.10) cannot
show text on the graphic. Current, but not necessarily recent, Firefox,
Safari, and Chrome show the graphic with its text. JavaScript is
required.

Current Opera is 10.5, baby! HTML5 support and new JavaScript engine, yeah.

The graphic is being slowly changed, particularly in labelling, to look
more like the large M=9 one in gravity4.htm.

Any comments and suggestions while I am still working on it?

If I have one suggestion, it would be to have the option of changing the
background colour to black (better yet, have the script detect the user's
default system colours, if that's possible).

It all amounts to planetary epicycles by default,something they did
away with with Copernicus and entirely with Kepler.

Try again.

On Mar 1, 10:54*pm, Dr J R Stockton
wrote:
Web page URL:http://www.merlyn.demon.co.uk/$lag-pts.htm is a draft
component for URL:http://www.merlyn.demon.co.uk/gravity4.htm. *It's
core is a graphic showing how the five Lagrange points move as mass is
transferred from one large body to the other, and how it all rotates.

Current MSIE 8 cannot show the graphic. *Current Opera (10.10) cannot
show text on the graphic. *Current, but not necessarily recent, Firefox,
Safari, and Chrome show the graphic with its text. *JavaScript is
required.

The graphic is being slowly changed, particularly in labelling, to look
more like the large M=9 one in gravity4.htm.

Any comments and suggestions while I am still working on it?

It has just occurred to me that, to show moving Lagrange points for
elliptical orbits rather than circular ones, I may only need to alter
the separation variable as a function of angle and to make some circles
into ellipses. *But that needs more thought. *Festina lente.

FYI, the fairly new HTML component canvas is rather useful for
preparing and presenting diagrams which are computed rather than
sketched - see also
URL:http://www.merlyn.demon.co.uk/js-grphx.htm, from which one can
save the graphic as a PNG.

See also BBC page
*http://news.bbc.co.uk/1/low/technology/8537763.stm, on browsers;
and http://spaceweather.com/ for bus-stop astronomy.

--
*(c) John Stockton, nr London, UK. *Turnpike v6.05 *MIME.
*Web *URL:http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms & links;
* Astro stuff via astron-1.htm, gravity0.htm ; quotings.htm, pascal.htm, etc.
*No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News.

On Mar 2, 2:58*pm, "MakeMak" wrote:
"Dr J R Stockton" wrote in erlyn.invalid...



Web page URL:http://www.merlyn.demon.co.uk/$lag-pts.htm is a draft
component for URL:http://www.merlyn.demon.co.uk/gravity4.htm. *It's
core is a graphic showing how the five Lagrange points move as mass is
transferred from one large body to the other, and how it all rotates.

Neat!


Ah,the guys who preceded Newton were many times more interesting than
you lot -

http://books.google.com/books?id=RyB...0tides&f=false

The only reason empiricists and their langrange/epicycle thingies
thrive is due to the lack of astronomers.



Current MSIE 8 cannot show the graphic. *Current Opera (10.10) cannot
show text on the graphic. *Current, but not necessarily recent, Firefox,
Safari, and Chrome show the graphic with its text. *JavaScript is
required.

Current Opera is 10.5, baby! *HTML5 support and new JavaScript engine, yeah.

The graphic is being slowly changed, particularly in labelling, to look
more like the large M=9 one in gravity4.htm.

Any comments and suggestions while I am still working on it?

If I have one suggestion, it would be to have the option of changing the
background colour to black (better yet, have the script detect the user's
default system colours, if that's possible).

In uk.sci.astronomy message , Tue,
2 Mar 2010 13:58:02, MakeMak posted:

"Dr J R Stockton" wrote in message
. invalid...

Web page URL:http://www.merlyn.demon.co.uk/$lag-pts.htm is a draft
component for URL:http://www.merlyn.demon.co.uk/gravity4.htm. It's
core is a graphic showing how the five Lagrange points move as mass is
transferred from one large body to the other, and how it all rotates.

Neat!

Current MSIE 8 cannot show the graphic. Current Opera (10.10) cannot
show text on the graphic. Current, but not necessarily recent, Firefox,
Safari, and Chrome show the graphic with its text. JavaScript is
required.

Current Opera is 10.5, baby! HTML5 support and new JavaScript engine, yeah.

Available, maybe; but not offered by "Check for updates" in my 10.10. I
don't go for beta versions or anything resembling them.


The graphic is being slowly changed, particularly in labelling, to look
more like the large M=9 one in gravity4.htm.

Any comments and suggestions while I am still working on it?

If I have one suggestion, it would be to have the option of changing the
background colour to black (better yet, have the script detect the user's
default system colours, if that's possible).

I greatly dislike black backgrounds, except for directly viewing the
Universe at night.

I could allow colour selection without much difficulty - but I'd need to
change the text to match. I might be able to access system colours, but
not directly - OTOH I see no reason to think that choosing some of them
will reliably give a suitable set. Default colouring needs to match an
existing diagram done in Paint.

I should be able to easily change plot size - all drawing is already
scaled from a single number, and fonts can be scaled.

This newsreader detects, but does not read, items from oriel36.

--
(c) John Stockton, Surrey, UK. Turnpike v6.05 MIME.
Web URL:http://www.merlyn.demon.co.uk/ - FAQish topics, acronyms, & links.
Proper = 4-line sig. separator as above, a line exactly "-- " (RFCs 5536/7)
Do not Mail News to me. Before a reply, quote with "" or " " (RFCs 5536/7)

In uk.sci.astronomy message
..invalid, Tue, 2 Mar 2010 23:43:32, Dr J R Stockton
posted:

Web page URL:http://www.merlyn.demon.co.uk/$lag-pts.htm is a draft
component for URL:http://www.merlyn.demon.co.uk/gravity4.htm. It's
core is a graphic showing how the five Lagrange points move as mass is
transferred from one large body to the other, and how it all rotates.


I should be able to easily change plot size - all drawing is already
scaled from a single number, and fonts can be scaled.

All done. Also, handles elliptical orbits. The controls are changed.

However, are there simple forms for distance(t) and/or angle(t) for an
elliptical orbit as seen from a focus ? Currently, I iterate the angle
approximately and get the distance from that.

--
(c) John Stockton, nr London, UK. Turnpike v6.05 MIME.
Web URL:http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms & links;
Astro stuff via astron-1.htm, gravity0.htm ; quotings.htm, pascal.htm, etc.
No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News.