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Nigel

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2 minutes ago, chrisp65 said:

Relatively low in the sky, to the west, we currently have Venus and Jupiter. Venus is the brighter one.

That won’t be happening again in our lifetime.

I've been out every night this week to see them and it's been cloudy every time! Damn you weather!

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Just now, Lichfield Dean said:

I've been out every night this week to see them and it's been cloudy every time! Damn you weather!

Should be good tonight shouldn’t it? Absolutely clear sky here.

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2 minutes ago, chrisp65 said:

Oh, bugger.

Just been trying to persuade the gang in Worcester to get out and have a look… wonder if they’ve got a chance?

BBC weather map has Worcester on the edge of the cloud cover, so they probably have a reasonable chance.

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9 minutes ago, chrisp65 said:

Oh, bugger.

Just been trying to persuade the gang in Worcester to get out and have a look… wonder if they’ve got a chance?

Better hurry though, will be dipping below the horizon soon!

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2 hours ago, chrisp65 said:

Relatively low in the sky, to the west, we currently have Venus and Jupiter. Venus is the brighter one.

That won’t be happening again in our lifetime.

I had to stop the car (on a small road) and get out and watch it for a bit. The two where super-bright and it looked awesome.

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9 hours ago, sidcow said:

Possibly Perovskite for solar panels

Just a quick comment there is little chance from a commodity point of view.

The mineral is a calcium titanium oxide. The mineral is relatively common. When solar panel people talk about perovskite they are referring to the crystal structure and pretty much does not include calcium or titanium. So when making these solar panels it is more a technology issue than scarcity/commodity.

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So spacex have launched a satellite powered by a Quantum Drive (no, not the one from The Orville). It's a reactionless drive similar to the EmDrive from a few years ago, although not exactly the same. If it works ... well it kind of means a lot of physics will need looking at again and it'll also mean a revolution in space propulsion (no more rocket equation).

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2 hours ago, Lichfield Dean said:

So spacex have launched a satellite powered by a Quantum Drive (no, not the one from The Orville). It's a reactionless drive similar to the EmDrive from a few years ago, although not exactly the same. If it works ... well it kind of means a lot of physics will need looking at again and it'll also mean a revolution in space propulsion (no more rocket equation).

Does it? What acceleration are they claiming at what energy cost? Presumably they can't test it on Earth because the acceleration is less than gravity.

If it's going to mean the end of rockets, why's it being launched on a rocket?

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49 minutes ago, limpid said:

Does it? What acceleration are they claiming at what energy cost? Presumably they can't test it on Earth because the acceleration is less than gravity.

If it's going to mean the end of rockets, why's it being launched on a rocket?

Won't mean an end to rockets, as you'd need them to get the thing into space. But once in space you won't need to factor in the fuel for its own propulsion. So yeah, point taken.

As for how much it'll help in space... Well it remains to be seen what sort of thrust they can get out of this thing (my bet is it'll be zero thrust) but even if it does work I don't know what they expect they may be able to achieve. I've seen reports that they think they can get thrust massively more than an ion engine for a fraction of the weight.

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59 minutes ago, Lichfield Dean said:

Won't mean an end to rockets, as you'd need them to get the thing into space. But once in space you won't need to factor in the fuel for its own propulsion. So yeah, point taken.

As for how much it'll help in space... Well it remains to be seen what sort of thrust they can get out of this thing (my bet is it'll be zero thrust) but even if it does work I don't know what they expect they may be able to achieve. I've seen reports that they think they can get thrust massively more than an ion engine for a fraction of the weight.

But they can test thrust on Earth down to tiny fractions of Newtons (in a vacuum if necessary). Feels like a scam to me. I wonder when they'll start selling shares.

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