Search found 136 matches

by Earthshine
Thu Oct 30, 2008 9:52 pm
Forum: Telescopes and instruments
Topic: GSO Super Plossls
Replies: 0
Views: 1087

GSO Super Plossls

Are these effectively the same as the old Meade 3000 series?
by Earthshine
Tue Oct 28, 2008 9:31 pm
Forum: Telescopes and instruments
Topic: eq mounts .. mains or battery ?
Replies: 23
Views: 5804

Yes. The problem with just buying a set of say, AA batteries, is that they expire within a few hours of use, maybe even less. When you consider that most mounts will require a set of 8 batteries at about £6-£7 a set, it becomes very uneconomical. A good power tank is rechargable and should give you ...
by Earthshine
Tue Oct 28, 2008 9:27 pm
Forum: Telescopes and instruments
Topic: sky windows and binoculars
Replies: 12
Views: 4995

This looks quite good. I don't think they are available in the UK.

If its reasonably cheap, it might be a good idea to invest in one, but it really looks like a comfort thing. Offset the cost of one against a good tripod, which if positioned correctly can still give comfortable viewing.
by Earthshine
Tue Oct 28, 2008 9:00 pm
Forum: Telescopes and instruments
Topic: eq mounts .. mains or battery ?
Replies: 23
Views: 5804

Mains provides you with 240v AC, but your mount will require 12v DC most likely. Batteries provide low voltage DC and so will your power tank. If you decide to use the mains you will have to buy a DC adaptor that is effectively a step-down transformer to convert 240v AC into 12v DC. You will need to...
by Earthshine
Tue Oct 28, 2008 8:53 pm
Forum: Telescopes and instruments
Topic: sky windows and binoculars
Replies: 12
Views: 4995

By skywindows, I assume you mean a skylight in the roof of a house. I use bins a lot. Well worth using for general views of the night sky. The best sizes generally are: (Mag x Aperture) 10 x 50 15 x 70 20 x 80 20 x 100 25 x 100 I have a pair of 15 x 70's from Strathspey and they have Bak-4 coatings ...
by Earthshine
Mon Oct 27, 2008 9:46 pm
Forum: Telescopes and instruments
Topic: I took the plunge and it paid off
Replies: 0
Views: 1164

I took the plunge and it paid off

I finally sold both my SW f/5 200 Newt & HEQ5 mount and plumped for a Celestron Nexstar 4SE and I'm so pleased. I've just been out and set it up for the first time. I managed to get it to lock on to 3 stars using Skyalign and it worked first time, then I thought "Here goes" - used the hand control t...
by Earthshine
Sun Sep 21, 2008 3:02 pm
Forum: Telescopes and instruments
Topic: 80mm APO Refractors
Replies: 23
Views: 7064

orion f6.3 wrote:for good views and possibility of CCD the skywatcher, all that lets it down is the focuser locking ring, its a little harder to use than a WO type thumb screw, but as a cost point of view the skywatcher is hard to beat on any point. Orion
Thanks,

The SW seems to be the best choice so far :roll:
by Earthshine
Sat Sep 20, 2008 10:43 pm
Forum: Telescopes and instruments
Topic: 80mm APO Refractors
Replies: 23
Views: 7064

best what? weight, visual views, build quality, for CCD, easy of use, or as an overall scope. Orion As long as its below 3kgs (which they all are) weight isn't a problem. Basically, I mean from an optics quality point of view, for good visual images and possibly CCD. I'm asking which one would you ...
by Earthshine
Fri Sep 19, 2008 10:43 pm
Forum: Telescopes and instruments
Topic: 80mm APO Refractors
Replies: 23
Views: 7064

80mm APO Refractors

I'm looking for an 80mm APO refractor price range £350-£550.
by Earthshine
Wed Sep 17, 2008 7:00 pm
Forum: Telescopes and instruments
Topic: i Optron Alt-Az and Alt-Az-Eq GPS Mounts
Replies: 0
Views: 1172

i Optron Alt-Az and Alt-Az-Eq GPS Mounts

http://www.ioptron.com/products.aspx?subcatalog=16

Has anyone got one of these mounts? They look quite nifty for scopes up to 3kgs in weight.

I was thinking of purchasing one with a small (say 80mm) ED refractor.

Any comments?
by Earthshine
Sat Jul 05, 2008 6:30 pm
Forum: Astrophysics
Topic: Spacetravel...I still don't get it.
Replies: 85
Views: 29723

, but the acceleration of the second object will not be 'aware' of the speed of the first. Don't get this ? Would I be aware of the speed of a moving car if I stepped out in front of it ? Yes, in Newtonian physics this is true, but you are attempting here, to question arguably the best physicist th...
by Earthshine
Thu Jun 26, 2008 7:29 am
Forum: Astrophysics
Topic: A Practical Time Machine
Replies: 19
Views: 9489

Cliff wrote:Unless there were a bunch of very attractive ladies on board the space craft, I think I would rather watch paint dry.
The ladies of 'SHADO' were very nice (UFO from the 1970's), and those uniforms..... :shock: 8)
by Earthshine
Thu Jun 26, 2008 7:26 am
Forum: Astrophysics
Topic: Rudolfhendriques's thread.
Replies: 119
Views: 61076

I'm not saying it isn't due to mass, I'm just saying the black hole itself doesn't have the mass, the star causing it does. Oh, that's splitting hairs, surely? Don't we all take for granted, at least at this level, that a black hole refers to the singularity, the space surrounding it, the event hor...
by Earthshine
Wed Jun 25, 2008 7:27 pm
Forum: Astrophysics
Topic: Rudolfhendriques's thread.
Replies: 119
Views: 61076

A black hole does have mass. There is one at the centre of our own galaxy, and its mass is exerting a force on all the objects orbiting the galaxy centre. Because the hole can never be seen directly, its presence is inferred from the rate of rotation of the stars around it. They are moving so fast ...
by Earthshine
Wed Jun 25, 2008 6:18 pm
Forum: Astrophysics
Topic: Rudolfhendriques's thread.
Replies: 119
Views: 61076

Can you explain Joe why gravitational objects like this differ from one another? My understanding, limited as it may be, is that the black hole distorts spacetime more because its mass is more localised, so to speak. The star's mass is spread over a distance of several hundred thousand miles (the s...