zed_three

Everything I can find says red aurora is due to low concentrations of oxygen at higher altitude, whereas green aurora is due to higher concentrations at lower altitude. That's quite an unsatisfying explanation though.

What exactly is the mechanism for exciting different wavelengths at different altitudes?

I'm not sure if I'm just being dim, but I tried following the notepad tutorial: https://doc.qt.io/qt-5/qtwidgets-tutorials-notepad-example.html and got as far as adding the Text Edit widget. The tutorial says that the header should then include a bunch of slots like:

private slots:
    void newDocument();

    void open();

    void save();

    void saveAs();

but they don't appear for me? I'm guessing there's some step missing like "add the toolbar widget", but I can't see any obvious widgets like that.

Have I gone wrong somewhere, or is the tutorial missing something?

I'm looking to upgrade my pretty old HD monitor to something a bit nicer, and I'm just completely overwhelmed by all the options. I've got a GTX 1080 Ti and a budget of about £300 ($370). It looks like I can get either 144Hz or 4K, but not both. I don't play many fast-paced games, so I'm leaning towards a higher-res monitor.

Any advice on what to actually look for?

I can't make it any more and would hate for the tickets to go to waste. Face value is £64 for the pair, send me a message

I've got a slightly damaged Honda CB500 that's been sat in my backyard for way too long. It currently doesn't start, but it is a Honda, so I doubt it would take much to get it going again, I just don't have the time or funds myself.

Any recommendations for places to sell it? I've seen a fair few damaged bikes on ebay, but there's also these "we buy any bike" sites. Anybody with experience selling a bike for spares that can give me any tips?

There's a library I'd like to use which is written using PyGtk, with a fork using PyQt4 instead. I thought I'd have a bash at merging the two projects, in order to make development easier. I've not done much GUI development before, so I was hoping to find another project which uses multiple GUI backends to study how they do it.

Unfortunately, Matplotlib is the only project I can find which does so, and it's rather complex. Are there any other examples out there that might be easier to understand?