wulfrun

@Kev M I suggest reading the derivation for E = mc², it will lead you to the proof. Any particle with no mass* is forced to travel at the speed of light and does not experience time. I can suggest a good book, "Why Does E = mc²?"by Geoff Forshaw (Foreshaw?)/Brian Cox. It's reasonably non-mathematical but fairly intensive. *technically, rest-mass not just "mass". As for point-particles, I think the word "particles" is a bit misleading. It conjures up the idea of (say) tiny billiard-balls or some such, which is wrong because they couldn't be zero size. Just consider them as "things", with measurable properties.

Most of England & Wales have been sitting under a near-still "cloud" of pollution/haze for a week or so, so I'd say it's likely to be atypical. I've certainly noticed poor transparency even in light-polluted Midlands. Scotland seems to have fared better though (no consolidation).

You live & learn, I'd never heard of them! Certainly never seen one in the wild.

I suppose London's light pollution is so bad it'll not make it much worse - not that that should be an excuse. Pity the poor souls living in sight of it. I see they'll be offered black-out blinds "as a last resort" though, how thoughtful 😛 Wonder what it'll be known as, locally...the bunion? The carbuncle? Or probably something less polite! Whatever happened to the polluter being responsible for fixing things? Imagine if a chemical company proposed to pollute the water-table and offered filters "as a last resort" as a solution. I wonder if that would be acceptable!

Can't comment on other aspects but question 4, FLO sell one which is decently made: https://www.firstlightoptics.com/adapters/t-rings.html You'll need a nose piece to go with it as well: https://www.firstlightoptics.com/adapters/astro-essentials-1-25-inch-t-mount-camera-nosepiece-adapter.html Make sure the camera can "shoot without lens". It probably can but double-check. Some cameras will refuse to fire unless they can detect a lens or it's been set to allow it (i.e. the setting must exist!). I have a G2 where it's a menu setting and a G9 that simply allows it by default, no setting required. If you can't afford other gear, I'd say give it a go for £27! You may need a Barlow to achieve focus, depending on the scope and the focuser range, again I can't advise on your examples. My Newts won't reach focus without one.

Recycling at its best 👍

Try slackening the three allen-headed screws a fraction, that should take the pressure off the centre screw.

Yes, although most (all?) are 3rd-party makers and not Olympus/Panasonic.

This might be what you're looking for then: https://www.firstlightoptics.com/zwo-accessories/zwo-t2-to-micro-four-thirds-adaptor.html Note the requirement for the lens to have a manual-focus capability.

Yes, FLO sell a m4/3 adapter that takes standard 42mm threaded (T2), 1+1/4" nose pieces (which they also sell). EDIT: actually, I think I may have mis-read the question, you want to connect a m4/3 LENS to a nose piece??

Not even vaguely jealous over here are we? 😉

First time out in a while due to the weather. I popped out for a couple of hours with the Virtuoso 114P. Didn't put anything larger out as the chilly wind made me unsure how long I'd cope! I spent most of the time spotting clusters, some old and some new-to-me - all taken from "tonight's best" in Synscan app. Pleiades, Hyades, starfish, wild duck, double cluster, spiral cluster and 37-cluster (I really can't "get" the 37 in it!) were all attempted and a couple were failed on with the small aperture/LP. Needless to say, I had a good look at the ever-irresistible M42 Orion nebula, had a stare at what little I can see in my local LP of the Andromeda galaxy and then tried Bode's (M81) and Cigar (M82) galaxies - I just detected the former (unexpectedly) but no hint of the latter. Having the newly-added go-to I tried my luck on the Leo triplet but I've failed to see them in the 150 so wasn't surprised to fail again. Probably too early in the night/year anyway but nothing ventured etc. Came in pretty cold but happy that the go-to functionality allows me to find faint stuff that I can't find without a scope, so a worthwhile addition.

I considered that but didn't want to realise later it was for some purpose I'd not realised!

A friend reckons it's shaped like a fish...OK, squint a lot and I follow that idea. What did you do with (seeming like) 10m of surplus belting?

I forgot to post this one, it arrived a couple days ago. Thought it was about time to invest in some comfort...

Nice scope to inherit! Don't rush to be cleaning the mirror until you're sure, there are various threads on here and tutorials if you need them though. Post a photo of the mirror and folk will give you an idea how badly it needs cleaning. Looks like the focuser rubbers have gone AWOL but nothing to be concerned about, a couple of big o-rings or similar can replace them.

Postie brought me this, courtesy of the classifieds and an impeccable service from @Clavius D Needless to say, last night was clear with howling wind but today is just grim!

Firstly, identify the problem else you may only fix it by accident. It may help to put a plastic bag/shower cap or similar over the primary end (if it's open) but the chances are a closed-tube will dew the secondary long before the primary. You can get heaters for secondaries too. Heating the tube doesn't sound helpful, it's likely to cause air currents that will blur your view.

Assuming you're sure it's not the seeing etc, less likely to be the primary but quite possible to be the secondary or eyepieces dewing. I've had the secondary dew up in my smaller scopes, partly because it's less recessed in them. The 150PL, on the other hand, rarely suffers from it. At the risk of ruining your night-vision, shine a small torch across the face of the secondary, look down the focuser tube - if it looks milky it'll be dew. If your dob is the truss-tube, do you have light shroud? A truss dob with no shroud has a pretty exposed secondary. You could also add a foam-matt tube "extension" on the front as well or invest in a portable low-power "hairdryer" type blower if nothing else works.

A word of caution, apologies if this is patronising you (if you use RC Li-Po packs you'll probably know already): be careful not to over-discharge the pack accidentally. If you do, you'll ruin it. RC electronics will know and cut the power but a mount designed for D-cells won't care how low they go. I use a 3S pack for my SW Virtuoso but I plug a low-voltage alarm into the balance lead. It shows green for good and red for low, one per cell and shrieks if any cell goes too low. The alarm is readily available from RC gear stockists etc.

Easily solved, turn it off. It does work extremely well in "normal" use. Haven't tried it on an OTA so I can't comment on how well it works but the G9 does have an 80Mp sensor-shift combined-image output too.

Had a vague recollection that that was where I heard it! Blimey, that's well before any PC.

Or stop trying to launch them when a storm's due? Can't remember where the quote is from but my initial thought was "oh dear, what a shame, how sad". Also, what a waste of resources but that applies to the rest of them!

I know for a fact you aren't the first and I'm sure you won't be the last!

Unless I'm mistaken, it's the third support and is spring-loaded. Not a knob at all, twiddling it around does nothing and won't damage anything either.