SilverAstro

That reminds me didnt M.Palin (from the Architects Sketch and other MontyP delights) navigate from pole to pole once upon a time ?

  ^

y'all be pleased to know that I have found a bottle, and (it was) full of Butcombe Bitter

Happy

4 minutes ago, johnfosteruk said:

I think you need to be inside, but that presents a whole other set of challenges,

but it doesnt have an inside and outside, errrr, does it ? And if it did and you drank all the beer through a straw would it collapse under the pressure of all the air outside, ma heed hertz.

17 minutes ago, Dave In Vermont said:

How abouts a "Polytetrahedron-Earth Society? 

Or just a Polyhedral Earth ?

as a wee lad I was fascinated by and made models of the Platonic Solids and then branched out into more complex nets, just think I could have been an architect !

18 minutes ago, johnfosteruk said:

 capacity!

and get a following.

Capacity ! did you mean that, I dont know how to define the capacity of one of they Klein bottles, nor how to drink out of one, I dare not do a facebook page, I have enough trouble following myself at times :

in fact I think my transmogrified furry friend looks a bit puzzled as well, + I have rectified the true representation of the cloud over my bit of Europe  :-

7 minutes ago, johnfosteruk said:

could be the answer to Schrodinger.

But then there'd have to be a top and bottom so actually you're right.

Arrrghh ! ( or should that be meeew ) your bending my mind

Oh I got it - a Mobius earth ! flat all the way round and no need to lift the lid to look inside , or do I mean a Klein bottle

and it is (still) raining, so I (still) maintain that is a fraudulent card

25 minutes ago, johnfosteruk said:

however I thought I'd have a laugh:

THEREFORE, the Earth must be a cylinder. Change the name of this page to The Cylindrical Earth Society immediately.

hehee

But then it would be flat,,, on the top and bottom

I can not decide if they are serious or just persist to annoy astrologers

2 minutes ago, ollypenrice said:

I'd prefer, 'If the Earth were flat...' but it isn't...

Ah yes, thought provoking, but does not the addition "but it isnt" turn it into an oxymoron or somfink, me engineer not linguist

In case I am in danger of upsetting the Hubble team, I crossed out 'figured' in ref to it being superbly well figured to completely the wrong profile. Yea, I know, tediously old joke, I plead rain-on-the-brain malady.

2 minutes ago, xtreemchaos said:

that's not a bottle, its the hubble optic telescope .. charl.

However I think you are mistaken, that bottle is too finely   figured  crafted to be a Hubble ?

That card in the op is a fake, it shows no rain   is this rain ever going to stop ?

Point of order onerable members :-

quote " If the Earth WAS flat" /quote, what is with this past tense, shirley  "the Earth Is flat" would be more   correct  errrr in keeping with, beliefs in certain quarters. Or perhaps they think it was but have now accepted that it is in fact a cube ?

6 minutes ago, Knight of Clear Skies said:

The scale is well off in that picture - the bottle of wine should be a similar size to the cat.

but what about some gravitational lensing distortion with all that dark matter swirling ?

Are we not forgetting - - that we now know everything is floating in a sea of Dark Matter giving everything that interacts with the Higgs field buoyancy. No more need of turtles ? and no more falling off the edge.

On 08/03/2017 at 13:10, bobro said:

 So, after a bit of internet searching, a magazine article dating back to 1991 with an optical design for CCs was found.

sounds like an interesting read, have you a link ?

4 hours ago, JOC said:

 when you move your head the position of the red dot varies - I guess the notion is that I should get the red dot bang in the middle of the finder,

Talk about learning as you go LOL  SGL threads are wonderful! 

they sure are

I may be speaking out of turn here cos I've not used my RDF, (not fitted it,  I squint along the ota and that is near enough to get my object in a low power field, or close enough ! ) and if I've got it wrong someone will be along in a min. but  : -

I think the RDF is meant to give a dot which does not move   relative to the stars  , ie. when you move your head the dot will move in the circle of the housing but so do the stars, so when you plonk the dot ( sorry got a bit technical there ) on a star it will stay there as you move your head. It does not have to be in the centre of the housing, nor need your head be.

No parallax because the dot is an image at infinity in the same plane as the stars.

EDIT I've just unpackaged my rdf ( 'specially for you ) and tried it on a tree at the other side of the garden and yep, the dot remains coincident with the branch as I shift them both within the frame as I move my head. within the limits of the parameters of the experiment

47 minutes ago, JOC said:

 and had sent back their base and got the squeak fixed.

 had some neat software (I need to find out what this was and I hope its free) that picked frames from the footage and stacked them

ah yes I remember that and similar reports of 'polystyrene' against blackboard noises fingers etc xxed that you are not without too long, I too know about the idle fingers - cloudy nights syndrome !

Cant help with the usbcamera / software  but will be watching with interest.

Apols to all Challengers for this little diversion.

27 minutes ago, JOC said:

I am minus my telecope stand until it is repaired,

Oh dear, what happened, I have missed this 'tale of woe' ? hope it is soon sorted for you.

26 minutes ago, laser_jock99 said:

You'd be surprised at how many 'townies' move into rural properties seeking the country dream and are then scared by the darkness. The 'For Sale' sign comes down and the 24 hour 'insecurity lights' go up shortly after. Many a rural location has been blighted in this way......

Exactly, I have seen it here, all the 'oldies' that were here in this dark rural location (since ohhh at least the 50s I think) have died off and their nice little cottages have been 'snapped up' and 'improved' over the years - lights every few yards up the driveways, lights on each and every corner of house and garage, there are two that are progressively lighting up some 'feature' trees !

Tell me about it !, but no I am not surprised at allatall   The only saving grace is that there are several hundred yards between me and my nearest (with no chance of planning permissions betwixt  either ) and I have layers of hedges to make doubly sure !!

Adding the "dark skies" bit to the general advert may be a double-edged sword, it may be seen to advantage by 1 in 1000, but it may put off the other 999 who all want street lighting near by, and till then hadnt realised how dark some bits of Spain can be !

I think better to add it to astromomy forums and any other specialist sites you can find  ??

2 hours ago, JOC said:

 on the internet finding the diagrams

Well it seems that the internet is a bit short on diagrams of what is going on with Barlows

Here is a Chinese one that addresses the variable spacing / x magnification

http://www.skylook.org/info/info-tw/info_2106.html

good luck with Google translate

It gives two examples of the insert distance (A) 25 or 3mm resulting in magnifications of 2x and 3.1x

The magnification of the Barlow mirror is changed with its position (distance A). Example:

Set the focal length of Barlow f = 50 mm, A = 25 mm.
The imaging distance must be B = f 'A / (f - A) = 50' 25 / (50 - 25) = 50 mm
Magnification = B / A = 50 mm / 25 mm = 2 times

Let f be still 50 mm but A increase to 34 mm.
Imaging distance B = 50 '34 / (50 - 34) = 106 mm
Magnification = B / A = 106 mm / 34 mm = 3.1 times

27 minutes ago, JOC said:

spend the night on the internet

actually fine explanations!

I'll let Louis speak for himself but you may be assured that mine is,  LOL !

But seriously though, ask and it shall be given,  but later I'm cooking, , , unless Louis wants to draw some pictures

else - we give the hints you do the research , mind you dont get too engrossed, keep a sharp eye out for a parting of the clouds !  I wouldnt want to be responsible for you missing that !!

By attaching the barlow lens element to the eyepiece you are reducing its penetration into the light cone from the primary, hence the reduction in x,  compared to when it is mounted in its tube ( if or not the change is to exactly 1.5x depends upon the construction of the eyepiece and hence the exact positioning of the negative element )

Similar, if you construct an extra long barlow tube to carry the lens further in you can get 2.5x or even 3x etc, but the further in ( the greater the x) you begin to get extra distortions.

3 hours ago, JOC said:

 No contest,

had an unusual emotional reaction to - Enola Gay - I wasn't quite sure what to make of her,

Very interesting, thanks.

Yep I'd have done the same, no contest.

I didnt realise she was preserved ! Hmmm, not sure about that ,, and the person I really feel sorry for is Enola Gay herself, dont think she would want to be remembered this way / in this context

back to the challange : according to the NASA def. then  just about everything is in orbit about something ! Except I suppose things that are attached (like the shuttle?) to other orbiting things !!

I'd better get back to work on my time-lapse of Vesta > > >

1 hour ago, happy-kat said:

be interesting to know keep rate on discovery with ED80

+1

2 hours ago, The Admiral said:

Congrats Nige , but a bit confused . Star discovery, polar aligned, new mount? Must have missed something (there've been a lot of posts!). Do I take it that your EQ3 is the new mount? And you're going over to the dark side?

Me too, sounds very dark, did this get passed by the committee one wonders.  Can Nige be split in two ? and post as Nigel 1G and Nigel 2G depending which mode he is in ? LOL!

congrats Nige, as the others, I look forward to your new first lights. Going by what you have achieved with the moded Discovery they should be awsome.