Second Time Around

Steve, if you read the entire article you'll see that: ".....reducing contrails by 73% would raise fuel costs by just 0.11% and overall operating costs by just 0.08%. They also noted that rerouting aircraft under such a scenario would only involve 14% of all flights."

Yes, it does of course depend on atmospheric conditions. I didn't quote the entire article but this extract is relevant: ".......used weather and satellite data to create software models and AI prediction tools to determine whether it was feasible to divert planes from airspace that would lead to contrail formation. They found that it appeared possible to reduce contrail formation by approximately 54%."

From article in The Conversation: "When several planes fly in the same general area over the same period of time, the contrails can combine, leading to the formation of cirrus clouds, which can act like a blanket, holding in heat." The article was entitled "Study finds rerouting of airplanes to reduce contrails not as expensive as thought." It seems as though a huge reduction in contrails is possible at minimal cost. The original article is at https://techxplore.com/news/2024-03-rerouting-airplanes-contrails-expensive-thought.html?utm_source=nwletter&utm_medium=email&utm_campaign=daily-nwletter

Yep, we had reduced water pressure and had bottled water delivered. We didn't have to use it though. Others a few miles away weren't so lucky and had no water at all. Thankfully the situation isn't as bad as 2000 when levels were even higher, and many properties a few villages away were flooded by groundwater rather than rivers.

Ernest's bench tests are partly based on eyepieces supplied to him, mainly I believe by members of his forum. If I remember correctly, he described the Mk III Baader zoom as "battered", which is why it may not have performed well. The supposedly optically identical Mk IV came out much better, and I'm certainly pleased with mine. The Baader is still not as good as my APM, that also has a wider (and constant) 66 degree field of view. The APM is more expensive though. Considerably more expensive still is the Leica. I haven't tried this as it doesn't accept a Dioptrx astigmatism corrector. Perhaps the best value for money is the Svbony 7-21mm zoom, that came out well in Ernest's bench tests. No, it's not as good as the Baader, but it's a fraction of the price. It's currently on sale direct from Svbony at just £32.76!

The Solarquest accepts Vixen dovetails.

The inexpensive Solarquest mount will both find and track the sun for you. Max payload is given as 4kgs on European sites, 5kgs on US sites. My 72mm ED at f/6 works fine on it. https://www.firstlightoptics.com/skywatcher-mounts/sky-watcher-solarquest-solar-tracking-mount.html

Or get a 2x Barlow lens. Some of these can also be used at 1.5x as well by unscrewing the black cell at the bottom and screwing it into the filter thread of an eyepiece. This would give you magnifications of 39x and 52x with your 25mm eyepiece, plus 97x and 130x with your 10mm eyepiece. FLO do such a model for just £27. Go to https://www.firstlightoptics.com/barlows/astro-essentials-125-2x-barlow-with-t-thread.html

This is my understanding of the difference between Barlows and Powermates (Televue's name for focal extenders). The reason focal extenders have 4 elements is that they have to first make the rays from the objective parallel. Barlows don't do this so can be just 2 elements. Therefore because of the extra elements focal extenders are more expensive, although not necessarily better. Having said that Powermates are made to a very high standard. However, as said, there are also some very good Barlow lenses on the market. Apart from the ones already mentioned, the 2.7x APM is very highly regarded by experts. Mine is excellent, although I've never used a Powermate so am not qualified to make a comparison. As mentioned above, Barlow lenses increase the amount of eye relief, which may be good or bad. Also on some long focal length eyepieces they may create vignetting. One other point to bear in mind is that the amplification power of a Powermate is fixed or nearly so. On the other hand, with many Barlows it can be changed to give a multitude of amplifications, so Barlows are more flexible.

The bases are the best part of the OOUK Dobs. They're made of aluminium so are lighter than steel or plywood let alone particleboard. They also have a smaller footprint that enables them to be carried close to your body. Both of these features make them much easier to carry. Indeed, I can go up to a 10 inch OOUK Dob, but only an 8 inch with Chinese makes. The only mod I've done is adding a pair of kitchen door handles. OOUK make these bases to order to fit any Dob, not just their own. Expensive yes, but well worth it.

Telescope Express in Germany hold good stocks of OOUK products. Go to https://www.teleskop-express.de/en/orion-uk

I used dovetail plates from StarPal on AliExpress, who sell multiple sizes. I've posted a link elsewhere in the topic. However, for the second Starsense Explorer I've got I've had a 3D printed adapter made. This is even better. Go to https://www.thingiverse.com/thing:4868065

The Stella Mira 0.6x reducer wouldn't come to focus with my 72ED. However, FLO will refund you if it doesn't work with your scope.

This is what I posted in another topic about 7x50s - although I'm not suggesting you're old! 🙂 "As you said, as you age your maximum pupil size will almost certainly diminish and so you won't benefit from the full 50mm aperture. This would of course need a pupil size of 50 divided by 7, so over 7mm. As I'm sure you know, but others might not, that's more typical of a youngster. The same applies when you're in towns and cities where the extra lights mean that even a young person's pupils are most unlikely to open to 7mm. If in either circumstance your pupil size opens to only say 5mm you might as well buy 7x35 binoculars. These will be smaller and lighter, and also probably have a wider field of view. Another point to consider is that experiments have shown that magnification is even more important than aperture in seeing faint stars. This has been discussed at length on the Cloudy Nights binocular forum. However, as you said, if you go up to 10x50s they'll be harder to hold steady. Short of buying expensive image stabilised binoculars, a good compromise might be 8x40s or 8x42s. Strangely enough, many of these will have a wider field of view than 7x50s. Indeed, in practice, many 10x50s have a wider field of view than 7x50s."

I believe only some had a problem and this was rectified. Mine's been fine I'm glad to say. In fact, my Mount Zero is superb in so many ways! Apparently, the reason they're no longer available is a patent violation. Whether this will be solved or not I don't know. Anyone?

That's the best star strails pic I've ever seen! Stunning!

Very strange! I haven't come across anyone who believes in astrology these days who actually looks up into the night sky. Could this simply be a definition that hasn't been amended over time? BTW, I find the results of the following 2015 Yougov survey encouraging, and in fact rather surprising: "Overall, the rate of belief in the predictive power of astrology, is 8% in Britain and 14% in the United States. Notably only 82% of British people and only 65% of Americans are definitive “NOs” on this question – the rest are unsure."

Just to follow on from my last post, one of the first books I read as a teenager was Webb's Celestial Objects for Common Telescopes. That led to my love of DSOs, and because these were published observations (mainly with a 3.7 inch refractor) I do consider them science.

We of course might be theoretical scientists, but are we entitled to call ourselves observational scientists if we don't record our observations rather than just stargaze? What do others think?

Following from the stargazer v astronomer topic why do you observe? I have several reasons. For instance I may be trying to split a close double. However, the overwhelming reason is to appreciate the beauty of the the skies (no, not clouds!). It's the same reason that I like admiring beautiful scenery here on planet earth.

Good point!

If I describe what I am to those outside our hobby I say stargazer. If I say astronomer all too often I get asked what sign am I. Too many of the general public still confuse astronomy and astrology.

Sorry you've not had a reply yet but I expect it's because we need more information. I'm a great fan of Starsense Explorer scopes. This is because the main reason for newcomers giving up is that they can't find objects. The Starsense Explorer technology makes this easy. However, the LT-114AZ model can't be recommended. This is because it's a "Bird-Jones" design, that everyone here will steer you away from as they give poor quality images and are difficult to collimate. If you tell us more about your observing needs such as how far you've got to carry the scope, whether you have a sturdy table to put it on etc, we can help more. Is it just the planets you want to look at or are after you after a scope that will also show nebulae and galaxies etc? Are you in an urban area or out in the country? The more you can tell us the better. We'd also need your budget, but whatever it is I'm sure we'll be able to come up with something!

I love that stool!

Be aware that are several ways of measuring the quality of a mirror. For instance, I think I've right in saying that some scopes that are described as 1/8th wave may be no better than "diffraction limited". Anyone? If you decide on an OOUK scope bear in mind that they have very long lead times, that also frequently slip. It seems as though OOUK don't have the best reputation for customer service, and many would recommend you buy from one of their retailers, Telescope Service in Germany, who usually have OOUK scopes in stock. The OOUK mirrors are reputed to be better than mass market ones. Certainly I'm very pleased with mine. However, I can't comment further myself as I've not had any mass market ones to compare with.