Philip B

I am currently working on a project about the optical design of some of the worlds largest telescopes. I have come across an 'EE' scale relating to image quality (EE50) and EE(80) which seems to be quoted in terms of arc seconds. Anybody know how this scale is defined and what the EE means?

Sorry for asking a serious question on here for a change but can anyone give me a concise to the point explanation for the shape or locus of the main sequence curve on the HR diagram. In particular the reason for the levelling out section in the central region.

I currently use a Lunt LS60T Ha dedicated solar telescope which is really excellent. I use it for both visual observing as well as imaging.

What would be the advantage of adding a second filter (double stacking) this telescope and what would I see that I can't see now?

With the need for a flat field of view (i.e. coma free), which type of telescope would you choose between an apochromatic refractor (e.g. Meade 5000 or Skywatcher Equinox) or a Maksutov Cassegrain (E.g Skywatcher Skymax Pro)

The refractor might be better because of the clear aperture, the reflector though has the larger aperture.

I have had an 06 plate Mondeo Titanium X fitted with the OEM 18" 7 spoke alloys since May.

My problem is that I don't know how to get the wheels off. The wheel nuts on this particular model are hidden behind a chrome finished plastic cover which obviously needs to come off before the wheel itself can be removed. There is a slot in this plastic cover which it seems a flat blade screwdriver or similar could be inserted into as a lever. However the cover doesn't seem to want to come off easily and I don't want to force it.

Anyone help?

I have just purchased a new package off the Internet, but now realised that my existing contract does not come up to the minimal 18 month term till the end of May.

My question is does by new contact start automatically from the date of purchase, or not until I actually insert the sim and connect to the network? I am not going to open the packaging until I know for sure.

many thanks in advance

If just for once people on here could stop asking stupid and meaningless questions and start using this very useful page to actually ask questions that those reading can browse through and learn something instead of wasting it.

What triangular roadsign also implies a change of speed limit?