wulfrun
-
Posts
821 -
Joined
-
Last visited
Content Type
Profiles
Forums
Gallery
Events
Blogs
Posts posted by wulfrun
-
-
I store a 150PL in my shed. I put a plastic bag over each end (over the tube cap on that end), retained with a large elastic band. I also always put the EP plug in. Haven't had it all that long but it hasn't suffered (yet!). The bags keep any spiders out. It's not exactly sealed, so it can "breathe" a bit. My EPs live in the house.
-
1
-
1
-
-
33 minutes ago, mark81 said:
I didnt see it. I never see them.. I've actually never seen a fireball despite looking for 20 years...
There are a few sites that log fireballs, I thinks it's meteorsky.co.uk. Check that out in a day or two and see what pops up..
Mark
I've seen a few over a good many years - high up, short, white-streak sort. This one looked very different and I just stood there wondering if it was real and I had actually seen what I thought I had. I'll have look at that site, thanks, might clear it up.
Edit: could this be the site?
https://ukmeteornetwork.co.uk/
Can't find anything at the URL you gave.
-
Not sure if this is the right forum place for it but just now I saw an impressive meteor. Time was 7.40pm, near as. I was just standing out in the garden wondering what I might get to see and happened to be looking up, maybe 10 degrees W of Polaris but lower, maybe 45 degrees Alt. Saw a fireball streak, ending towards the handle-end of the dipper. Not end-of-the-worldly spectacular but not the usual quick streak either, orange glow and a trail that lasted a fraction of a second. Anyone else just happen to see it?
-
1
-
-
If it's ferritic stainless i.e. iron-containing, which is pretty certain if there's rust, put some phosphoric acid on it. You can buy phosphoric acid from aquatics suppliers (often called pH-down). Beware, it's seriously evil stuff so you'll need rubber gloves and eye-protection. Wash it off with water and dry carefully. It'll turn the rust into iron phosphate, passivating it but turning it black. As suggested, a lacquer of some sort afterwards would be good but the phosphated areas will not rust again.
-
2
-
-
Yes, it does look like velcro is one of the better ideas - just better velcro, or better adhesive on it anyway. One idea I can see: use 3 smaller pieces on the three corners of the blue box BUT remove the screws first and put them through the velcro afterwards. Then put a small piece of felt or whatever over the actual screw-heads - as protection against them scratching things. At least that would stop it parting company completely. I'd say 3 pieces on the corners would give enough security.
Can't think of anything else, maybe someone else can apply better lateral-thinking though.
EDIT: actually you wouldn't need the felt as the screw-heads would only be against the other half of the velcro
-
1
-
-
A photo of the relevant parts might come in handy, showing what you're trying to achieve. There's likely to be a solution somewhere.
-
2
-
-
3 minutes ago, jadcx said:
Yeah 😕 I did clean with alcohol first, but I just can't bring myself to get the emery paper, not on such lovely blue aluminium. But I totally understand that it wold most likely be much more successful.
Ah ok, so not just shiny but anodized or painted. I can see your reluctance! Isn't there somewhere else or somewhere unobtrusive?
-
Shiny and new isn't usually a good surface for sticky stuff. If you're willing to deface your new gear, abrade the area with some emery cloth/scotchbrite or similar, clean with alcohol (not the booze sort!), allow to dry and apply the velcro. You'll have a lot better chance that way.
-
2
-
-
On the eyepieces, the SVbony ones are so cheap you could buy one just to figure out your most useful FLs, then buy better/premium fixed ones for those "spots". You could then either keep the SVbony as a grab-and-go when you don't want to mess around or sell it on. It suffers from a narrower FOV at the longer end but you already have a 25mm that will do that end a bit better. I have the SVbony 7-21 and the Hyperflex 7.2-21.5 and they are both handy and pretty good, especially for the price.
EDIT: the Ebay link above is the seller I used for mine and I can recommend them.
EDIT 2: The Hyperflex is currently in stock at FLO, https://www.firstlightoptics.com/ovl-eyepieces/hyperflex-72mm-215mm-eyepiece.html
-
Before purchasing, I'd recommend some homework, try this excellent site:
Go to the "choosing and using" tab. There are good recommendations on there about what to buy and what to avoid, plus ideas within price ranges.
-
Not sure that's quite fair. GR is accepted as the best model yet. The "fudge-factor" of dark matter is because they've yet to figure out whether (a) GR is wrong or incomplete or (b) GR is right but dark matter is something real. I think the scientific community has an open mind about what the explanation is. Worth remembering that a theory like GR is still a theory and accepted until there's definitive proof it's wrong. No scientific theory is ever accepted as truth - just something which hasn't yet been proven incorrect.
-
Pretty calm & cold here too but I agree with Tiny Clanger, it doesn't look very good conditions in reality. Jupiter & Saturn were a bit low and a bit near to getting obscured by nearby houses. Had a quick look through the binoculars and couldn't even see Jupiter's moons. The moon had a bit of a haze so I didn't bother getting the 'scope out, don't think it would've been any better a view of anything.
-
I had a go on Mars about a week ago, with the Hyperflex 7.2-21.5 and Svbony 7-21 zooms in a SW150PL (1200mm f/8). Neither of them gave me enough magnification really (didn't have a barlow to add at the time) but I fancy I could just make out a tiny bit of detail at the shortest FL (x170-ish). Seeing and clarity did seem very good but I'm not experienced enough to say that with conviction. By comparison, I thought the Hyperflex had a slight edge on sharpness but so slight that I'm not quite sure, could have even been seeing varying in between changes. I found the Hyperflex a little smoother and easier to zoom (maybe due to the larger barrel) but both were slightly hampered by having a helical focuser-holder - meaning you have to hold the main barrel to operate the zoom, or lose focus badly - which slows things down a bit.
Since then it's been either solid cloud or more-cloud-than-sky so I've not had another chance - and a Baader x2.25 barlow has arrived so fingers crossed!
-
2
-
-
The moon also doesn't orbit directly above the equator, in addition to being in elliptical orbit. The motion is complex and not a sinewave, even though the deviation isn't huge. It's enough to throw a "simple" analysis off though.
-
1
-
-
I wonder if all this modern LED outdoor lighting shouldn't come with a prominent warning that light pollution is a problem and can actually be an offence. Yes, I know, who reads manuals/boxes? Maybe a prominent label on the box, a bit like health warnings on fags (perhaps not so unpleasant, mind). I know it won't stop the issue but it might make some folk pause and think. Better than nothing anyway. Plus, people can't plead ignorance either.
Maybe there should just be legislation that limits the power, it's certainly about time something was done to confront the issue. Interestingly, there is (or was, I'm not sure which) EU legislation to limit the power of vaccuum cleaners, in the name of efficiency. We also have legislation governing maximum standby power of devices, for the same reason. If they can do that, why cannot they limit insecurity lights and also make them conform to approved designs?
-
1
-
-
The postman brought me a new zoom EP yesterday and I'm expecting a couple of other EPs today, off FLO. So yes, you can all cheerfully blame me for the continuing clouds around this neck of the woods. I probably started it off just over a week ago by buying a scope off another member on here.
-
2
-
-
12 minutes ago, Luke said:
If it's THAT good for photography, it begs the question as to why all professional photo-journalists haven't got one? Maybe I'm just too cynical but I suspect the reason is what I expect: it's rubbish!
-
I'm tempted to say that if you expect the performance of a $3k scope for 48-quid you deserve the inevitable outcome. Consumer protection laws say I'm wrong though. Looks like the figures on it say 40x60, I wonder if either of them is believable.
-
2 minutes ago, vlaiv said:
That is actually very profound statement.
When we think of the time, we think of it as passing at exact intervals - always "flowing" at the same pace. But that is of course not true. Even without relativity, we can only say that things happen concurrently - like two physical processes happening at the same time - clock hand moving one second (smallest measurable interval) and something else happening. Almost like in steps. But do steps "last" the same amount of "time" or is only assumption that we can make - events happen in sequence - they are ordered - we only know what is before and after and that divides events to past and future with respect to certain event.
But then steps in relativity and we find out that order of events is not guaranteed. One observer can measure event A to happen before event B and another observer can measure opposite - event B happening before event A. So even our sequence is no longer valid assumption - only thing that is left is fact that everything did not happen at once
Almost. There is also causality; two observers must agree on the order of events if one causes the other. For an example, every observer must agree that your father was born before you were.
-
4 minutes ago, LukeSkywatcher said:
Back to original Q.
I've read a theory that the universe will expand as far as it can before retracting in on itself again. Explosion and implosion. It will be like a YoYo.
Who knows.
I don't think that idea holds water anymore. Current "best guess" is that it'll continue to expand at an ever-increasing rate and eventually just become, essentially, a vacuum. Gravity will have lost. At least, that's my understanding of the current ideas.
-
1
-
-
Slightly over your budget but I found this in stock as of now:
https://www.bristolcameras.co.uk/p-skywatcher-heritage-100p-telescope.htm
I have no experience of the store. As a starter, you could do worse although it's not likely to provide "wow" views of planets. The table-top Dob style has already been commented on for its cons but if needs must...
-
As a small aside - Betelgeuse has exploded, not the star (as far as we know) but an oil tanker named after it:
https://en.wikipedia.org/wiki/Whiddy_Island_disaster
Somewhat ironic, not to diminish the awfulness of the disaster.
-
1
-
-
Recently, Neowise, which has rekindled my astronomy interest. Ever, probably the total eclipse of 1999, for which I was not quite in the umbra region but it went very dark and I managed a series of shots leading up to and beyond totality. Just a chip of the sun showing.
-
2
-
-
Suggestions: first - PATIENCE - if you break the stubs off you'll be in a worse position (obvious, I know). Try and get a small butane blowtorch on the alloy (?) parts and keep the stubs as cool as possible. Use something like mole-grips or, where there's enough thread left, get two nuts and lock them tightly against each other. Technique is everything; if you can get them to move, even a tiny bit - STOP - re-tighten slightly and repeat, rock them back and forth going slowly in favour of "undo". Penetrating oil (like Plus-Gas, not WD40) will help, get something on the stubs now and leave it at least for a day before you even start trying. Diesel works well as a penetrating fluid but take care with that blowtorch then.
A light smear of coppaslip or equivalent (copper grease) on the new screws will reduce the chance of siezure in future, as will wrapping the threads with teflon plumber's tape - if you can get the threads back with it in place. I would replace them with allen-headed blacked screws if you can get them (should be easily available). If you have access to someone with engineering stuff, a "plug" tap run into the threads would be well worth the trouble, to clean the threads out.
-
1
-
1
-
Dark matter - fudge factor?
in Physics, Space Science and Theories
Posted
I think this is correct, there is no need to do anything more complex than Newtonian physics for the majority of space exploration. GR needs to be accounted for in things like SatNav and comms satellites.
I think gravity persists simply because it's convenient to think of it that way and it's adequate for a great deal of processing, predictions and so on. That's also true for other areas of science, it's simpler to think of things in certain ways even when we know it isn't actually true. Atomic orbitals anyone? Electricity a bit like water in plumbing?