Things you always wanted to know the answer to [Vol. 5]
Discussion
98elise said:
It's significantly cheaper then that these days!
Spacex will do 50kg for 300k on their rideshare service. You can even book it on line like an Uber
https://www.spacex.com/rideshare
That's to low earth orbit, for example around the ISS's altitude of 400km. To get to orbit from a space elevator you'd need to go to geosynchronous orbit which is around 36,000km, so way more expensive to get to. A quick calc reckons about 4km/s dV to get from LEO to GEO. A Falcon 9 can put 22.8 tonnes to LEO, but only 8.3 tonnes to geostationary transfer orbit, and that 8.3 tonnes would still need around 2km/s dV to get in to GEO, which for a conventional rocket would mean 4-5 tonnes for fuel. So I guess in the region of 10-20 times more expensive than LEO, but yes my original figure was way out. Spacex will do 50kg for 300k on their rideshare service. You can even book it on line like an Uber
https://www.spacex.com/rideshare
I think I meant $100M/tonne, which would roughly line with the above figures. 300k for 50kg is 6M/tonne, so 100M to GEO would be a factor of about 16.
...and yes I've spent far too much time playing Kerbal Space Program
Edited by RizzoTheRat on Wednesday 19th June 11:53
bigpriest said:
Doofus said:
See also Berkshire, Wiltshire, Cheshire, Shropshire.
I think Chestershire was a thing once, like Lancastershire but the people from the North West are too busy being cool to mess around with overly-long names. beagrizzly said:
Are motorbikes really loud because there are science and engineering reasons why they can't be properly silenced, or because 'look at me, look at me, look at me'?
I suspect that the quieter you make them, the bigger the silencer needs to be, which increases the weight, which reduces the power-to-weight ratio. And also alters the weight balance. So it is probably a compromise and a case of getting away with the minimum.
There is an element of that, plus a lot of manufactures manage to make the standard pipes so ugly more people change them. But there's an awful lot of people who just think loud exhausts are cool and don't realise the people staring at them are thinking "what a dick" rather "wow that's cool". (I recommend the southpark episode with the Harleys for and exploration of that attitude). Plus theres the "loud pipes save lives" brigade who still haven't figured out that they're no where near as loud from in front as they are from behind, and that modern cars are very well sound proofed.
hidetheelephants said:
If chainsaws can be silenced such that they still weigh less than my 30 year old tree murderer yet be much quieter, it's just "look at me". Adding a couple kg to a bike makes no practical difference when it has a power to weight ratio of 1hp:1kg.
... and if weight in the wrong place is a concern then having a huge lardarse sitting on top is probably not the best idea.RizzoTheRat said:
Is there some kind of global agreement about postal services, and in particular free/prepaid postage?
I've just filled in my postal vote and it says no stamp required, so presumably that must be from any country? Or are there different versions they send to some countries?
I was thinking the same thing yesterday with my postal vote. The letter could be being posted from anywhere in the world so I would expect a variation in costI've just filled in my postal vote and it says no stamp required, so presumably that must be from any country? Or are there different versions they send to some countries?
hidetheelephants said:
If chainsaws can be silenced such that they still weigh less than my 30 year old tree murderer yet be much quieter, it's just "look at me". Adding a couple kg to a bike makes no practical difference when it has a power to weight ratio of 1hp:1kg.
I'm Intrigued by these quiet chainsaws?I've 4 of the things including a fairly decent nearly new Husqvarna and they're all noisy b
ds which can be heard for miles around whenever I fire it up!RizzoTheRat said:
Is there some kind of global agreement about postal services, and in particular free/prepaid postage?
I've just filled in my postal vote and it says no stamp required, so presumably that must be from any country? Or are there different versions they send to some countries?
I don't know the answer, but I know there is something called the Universal Postal Union which is a UN-backed global organisation for countries to collaborate regarding postal mail, so my guess would be there is something arranged via the UPU for countries to honour freepost beteween them.I've just filled in my postal vote and it says no stamp required, so presumably that must be from any country? Or are there different versions they send to some countries?
beagrizzly said:
Are motorbikes really loud because there are science and engineering reasons why they can't be properly silenced, or because 'look at me, look at me, look at me'?
They're really loud to attract the kind of people who like really loud things.I owned an Aprilia a few years ago and it too loud to ride out in the country...and I'd bought it for long fast rides in the Peak District. i mean I didn't really want a stealth bike, but this thing came with an Akropovic as standard and after a while just sounded ridiculous.
Yes. If it is going to get UK plates, it must conform to UK regs. We had to have white parking lights up front instead of amber, side indicator lights added, amber turn signals in the rear, and a red fog light fitted in the rear. Oh, and the headlights need to be reaimed. If you are around an RAF base where the USAF works, you will see some Frakenstein looking conversions.
US parking lights are amber up front. Side indicators are a lot more common these days, but used to be US cars didn't have side indicators. US manufactured cars usually have the rear turn signals as part of the brake assembly, so they are red. And US cars don't have rear fog lights.
US parking lights are amber up front. Side indicators are a lot more common these days, but used to be US cars didn't have side indicators. US manufactured cars usually have the rear turn signals as part of the brake assembly, so they are red. And US cars don't have rear fog lights.
Clockwork Cupcake said:
beagrizzly said:
Are motorbikes really loud because there are science and engineering reasons why they can't be properly silenced, or because 'look at me, look at me, look at me'?
I suspect that the quieter you make them, the bigger the silencer needs to be, which increases the weight, which reduces the power-to-weight ratio. And also alters the weight balance. So it is probably a compromise and a case of getting away with the minimum.
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