Even better --- they've just demonstrated the ability to go to GEO, which is about 14km/s from the Earth's surface. Lunar orbit is only another 2.4km/s, and the moon's surface another 1.6 on top of that!
Chances are that with the technology they have right now, that is, using a modified F9 with the GEO upper stage, they could send a probe on a free-return trajectory to the moon. Or even easier, an impactor. I suspect they won't; Elon Musk appears to have his sights firmly set on the upgraded F9 Heavy and the rocket-landing Dragon, and with that setup you could probably remote land a complete Dragon capsule. I'd be really interested to know what sort of delta vee the Dragon's internal rockets will have...
Luna-9's pictures were sent back using one of the standard encodings used for wireless newspaper photography transmission. During the transmission, the Jodrell Bank radio telescope in the United Kingdom was listening in (well, wouldn't you?) and the astronomers there recognised the encoding, phoned someone at the Daily Express, and as a result the first pictures from the surface of the moon ever were printed in a British newspaper while the USSR was still wondering what to do with them.
There is some speculation that the encoding scheme was picked deliberately to make sure this happened...
CCTV's live coverage showed a textbook landing and solar array deployment, including some very shiny live pictures from the descent imager. Next steps are self-testing, instrument deployment and releasing the rover, which they've said will take up to 24 hours. Although I'd imagine that they'll release images from the panoramic mast camera as soon as possible.
The RPi is an ARMv6, while this (along with pretty much every other modern ARM device) is an ARMv7. The ARMv6 has hardfloat but implements a slightly different version of the spec. Most OSes have standardised on the ARMv7 version which means that their code won't run on the ARMv6. So Debian armhf will run on this but will not run on the RPi: you have to use Raspbian instead, which is a version of Debian specifically compiled for the ARMv6. (Of course, Debian armel will run on both, but then you don't get any hardware floating point support.)
The Broadcom GPU is significantly awesome. It is, however, almost totally undocumented. There's a reverse engineering project which has mostly nailed down the instruction set, and there are even some C compilers for it (one of them is mine!) even though there's no gcc or LLVM support for it. You can write programs in C and run them on the bare metal. Unfortunately the GPU doesn't support double-precision float and the MMU is kinda weird, and it's probably going to be slower than the ARM for non-DSP-heavy code anyway, so it's unlikely you'll see Linux for it any time soon. But it's a beautiful, beautiful architecture to write code for. (And it's dual core! Not very many people know that...)
Back in 2009, a UK artist set up an... installation, I suppose you'd call it... which was 1301 flourescent lighting tubes in a field under a 400kV megagrid power line. It's worth checking the pictures out, as they're actually quite striking:
Note that in real life you do the gravity roll much earlier than you do in KSP --- this is to get the vehicle clear of the launchpad so that if you're not going to space today, the debris doesn't land on your technicians.
In KSP you leave the gravity roll quite late so that you waste as little fuel as possible pushing through the dense part of the atmosphere (I usually do it at 15km).
Yes, seriously. It's lightweight, it's free, it's integrated into Windows Update so it's really easy to get updates, and best of all it doesn't continually hassle you and go LOOK AT ME! LOOK AT ME! the way most of the other antivirus apps do. It just sits in your icon bar and does its job.
It's not brilliant, security-wise --- it's merely adequate --- but if you want something that hides itself away and gets on with things with a minimum of user panic, it's definitely the way to go.
I will see your pedantry, and raise you more pedantry: the stone is defined as 14 avoirdupois pounds; one avoirdupois pound is defined as 0.45359237 kg; therefore the stone is a unit of mass.
Yes, I was disappointed too. Still, we'll always have tons (which depending on the usage can be weight, mass, volume, energy, or power).
...Bitcoin is posing as a "thread" is hilarious on it's face.
Bitcoin raining down from the Red Star, threatening to destroy all life on our planet, and only an elite squad of fire-breathing US drone fighter aircraft can save us? I agree that this does seem a little hard to believe.
Oh, _The Moon Moth_ is brilliant. There's a (slightly mangled; there's a repeated section in the middle, but all the text is present) dodgy copy online here:
Definitely worth a read. (Apparently it's been adapted to a graphic novel; it seems a shame to miss out on the Vancian prose, though.)
Personally I have a soft spot for the Demon Princes novels. Classic tales of revenge, with a twist; you don't realise quite how much characterisation Vance sneaks in until after you've read them. Must reread...
I have heard that this is actually worse --- because the smaller fragments are more efficient at transferring heat to the atmosphere, while a single big impact will absorb a lot of energy into the crust and reflect a bunch more into space. So an asteroid-sized dust cloud hitting the Earth at 11km/s stands a good chance of igniting every flammable object in a thousand kilometre radius. But I can't find a reference for that.
No, they wouldn't --- acceleration due to gravity is independent of the mass of the body. (The force due to gravity is GMm/r^2; acceleration is a=F/m; therefore the acceleration due to gravity is GMm/mr^2. The two m factors cancel out.)
What would happen is the nuke would push the fragments apart. These would continue to diverge, but would follow much the same course as the original asteroid. Whether they've been deflected enough to miss the Earth --- which is, of course, a really big target --- depends entirely on how hard the nuke pushed them and how long they travel before impact.
In order for the station to reenter, you'd have to change its orbital velocity by a substantial amount. The interwebs suggests that it's about 150m/s (that's about 300 mph for the metrically challenged).
To change the ISS's velocity that much in a single impact would destroy the entire station. I don't even think the ISS is capable of being deorbited without additional hardware; the Progress supply drones it currently uses to adjust its orbit carry very little thruster fuel. (Just enough to deorbit the Progress itself, plus some spare.)
Personally, the main bit which caused me to roll my eyes is right at the beginning, where the two astronauts admire the sunset, tumbling uncontrollably, while facing in entirely the wrong direction...
Using words I recognize as nonsense isn't the sole problem. It's vocabulary collisions.
I had precisely this problem the other day, when talking to someone about DVCSes. It took about five minutes (of face-to-face conversation, mind; five minutes is a lot) to figure out that git and hg use the word 'revert' to refer to fundamentally different operations.
It would have been less confusing if he'd just said 'I don't know what that word means'. It was the fact that he thought he knew what I meant, but didn't, which was causing the problems...
How do these images compare to the absurdly high resolution images provided by the HiRISE camera on the Mars Reconnaissance Orbiter? The PR images look fairly small scale.
It's always struck me a bit odd that we seem to have vastly higher resolution pictures of Mars from space than we do of Earth; and Earth's, like, right here...
You might find Andrew Plotkin's Pocket Storm interesting: http://zarfhome.com/pocketstorm/ It's an iOS app that will produce a procedurally generated soundscape of a summer storm. By default the whole thing takes an hour; it's tweakable.
(That's a turnkey version of the storm module for his Boodler ambient sound generation engine, wrapped in an iOS app. Boodler itself is in relatively portable Python and is open source. And scriptable. So you can build your own soundscapes with it. There's a zillion different Boodler soundscapes available.)
I had totally forgotten about the MSP430 --- thanks for the reminder; ordered one. I don't have an application in mind but it'll be fun to play with...
I'm particularly intrigued to see they do a bundle of two MSP430 LaunchPads and two low-power RF modules for $23.30. That looks like it would make a very interesting way to experiment with ultra-low-power radio at about $10 a node.
TI's got a lot of interesting stuff. The devkit in a watch looks fun. Pity it's (a) not a dot matrix LCD and (b) out of stock. It's also a pity their website is so broken...
This is a very old idea, although most countries don't need to build artificial islands to do it. For example, the Ben Cruachan pumped storage plant in Scotland uses two lochs at different levels. Energy is stored by pumping water from the low one to the high one.
Pumped storage power stations are typically used for short-term handling of power spikes; if you get sudden load on the electricity network, you can spin up a pumped storage plant in minutes --- sometimes seconds if you know that a spike is due and can prepare --- while traditional oil, coal and nuclear can take hours. So the pumped storage plant handles the load while the big power stations rev up.
Drawbacks involve not being very efficient ---Wikipedia says 70-80% --- and they don't store that much energy. Ben Cruachan, for example, can only generate 440MW for 22 hours before running dry. They're also environmentally rather poor (although not nearly as bad as the alternatives, which are usually fast-start gas turbines, of course).
Using an artificial island is an interesting idea. If you're using off-shore wind farms then the power generation is local and you save on infrastructure and transmission costs; you avoid destroying valuable mountainside (although at the expense of destroying valuable sea bottom); it's close to the coastal cities which would be using the power... does anyone have a link to more technical information? Like how big it is? The linked article is almost entirely content-free.
You can't change the prototype of an object once it's been constructed (ignoring platform-specific extensions). I'm used to Lua, which has a much more orthogonal prototype mechanism, and have a whole stable of neat algorithms involving object prototypes... most of which require setting the prototype only after the object itself has been created.
Slashdot Mirror
Even better --- they've just demonstrated the ability to go to GEO, which is about 14km/s from the Earth's surface. Lunar orbit is only another 2.4km/s, and the moon's surface another 1.6 on top of that!
Chances are that with the technology they have right now, that is, using a modified F9 with the GEO upper stage, they could send a probe on a free-return trajectory to the moon. Or even easier, an impactor. I suspect they won't; Elon Musk appears to have his sights firmly set on the upgraded F9 Heavy and the rocket-landing Dragon, and with that setup you could probably remote land a complete Dragon capsule. I'd be really interested to know what sort of delta vee the Dragon's internal rockets will have...
Luna-9's pictures were sent back using one of the standard encodings used for wireless newspaper photography transmission. During the transmission, the Jodrell Bank radio telescope in the United Kingdom was listening in (well, wouldn't you?) and the astronomers there recognised the encoding, phoned someone at the Daily Express, and as a result the first pictures from the surface of the moon ever were printed in a British newspaper while the USSR was still wondering what to do with them.
There is some speculation that the encoding scheme was picked deliberately to make sure this happened...
CCTV's live coverage showed a textbook landing and solar array deployment, including some very shiny live pictures from the descent imager. Next steps are self-testing, instrument deployment and releasing the rover, which they've said will take up to 24 hours. Although I'd imagine that they'll release images from the panoramic mast camera as soon as possible.
The RPi is an ARMv6, while this (along with pretty much every other modern ARM device) is an ARMv7. The ARMv6 has hardfloat but implements a slightly different version of the spec. Most OSes have standardised on the ARMv7 version which means that their code won't run on the ARMv6. So Debian armhf will run on this but will not run on the RPi: you have to use Raspbian instead, which is a version of Debian specifically compiled for the ARMv6. (Of course, Debian armel will run on both, but then you don't get any hardware floating point support.)
The Broadcom GPU is significantly awesome. It is, however, almost totally undocumented. There's a reverse engineering project which has mostly nailed down the instruction set, and there are even some C compilers for it (one of them is mine!) even though there's no gcc or LLVM support for it. You can write programs in C and run them on the bare metal. Unfortunately the GPU doesn't support double-precision float and the MMU is kinda weird, and it's probably going to be slower than the ARM for non-DSP-heavy code anyway, so it's unlikely you'll see Linux for it any time soon. But it's a beautiful, beautiful architecture to write code for. (And it's dual core! Not very many people know that...)
Back in 2009, a UK artist set up an... installation, I suppose you'd call it... which was 1301 flourescent lighting tubes in a field under a 400kV megagrid power line. It's worth checking the pictures out, as they're actually quite striking:
http://io9.com/5204842/a-field-of-light-sabers-powered-by-ambient-electricity
The total amount of power used here would be negligible, of course. But I'm surprised they didn't come down on him for improper disposal of mercury...
No wonder I find most of the posts incomprehensible! I'm reading it in ISO 8859-15...
That's half the fun!
Note that in real life you do the gravity roll much earlier than you do in KSP --- this is to get the vehicle clear of the launchpad so that if you're not going to space today, the debris doesn't land on your technicians.
In KSP you leave the gravity roll quite late so that you waste as little fuel as possible pushing through the dense part of the atmosphere (I usually do it at 15km).
Yes, seriously. It's lightweight, it's free, it's integrated into Windows Update so it's really easy to get updates, and best of all it doesn't continually hassle you and go LOOK AT ME! LOOK AT ME! the way most of the other antivirus apps do. It just sits in your icon bar and does its job.
It's not brilliant, security-wise --- it's merely adequate --- but if you want something that hides itself away and gets on with things with a minimum of user panic, it's definitely the way to go.
I will see your pedantry, and raise you more pedantry: the stone is defined as 14 avoirdupois pounds; one avoirdupois pound is defined as 0.45359237 kg; therefore the stone is a unit of mass.
Yes, I was disappointed too. Still, we'll always have tons (which depending on the usage can be weight, mass, volume, energy, or power).
Her son Todd has taken over. Apparently they're not bad, although I stopped reading new Pern books years ago.
...Bitcoin is posing as a "thread" is hilarious on it's face.
Bitcoin raining down from the Red Star, threatening to destroy all life on our planet, and only an elite squad of fire-breathing US drone fighter aircraft can save us? I agree that this does seem a little hard to believe.
Oh, _The Moon Moth_ is brilliant. There's a (slightly mangled; there's a repeated section in the middle, but all the text is present) dodgy copy online here:
http://www.unexploredworlds.com/RealPulp/htm/rpulp145.htm
Definitely worth a read. (Apparently it's been adapted to a graphic novel; it seems a shame to miss out on the Vancian prose, though.)
Personally I have a soft spot for the Demon Princes novels. Classic tales of revenge, with a twist; you don't realise quite how much characterisation Vance sneaks in until after you've read them. Must reread...
I have heard that this is actually worse --- because the smaller fragments are more efficient at transferring heat to the atmosphere, while a single big impact will absorb a lot of energy into the crust and reflect a bunch more into space. So an asteroid-sized dust cloud hitting the Earth at 11km/s stands a good chance of igniting every flammable object in a thousand kilometre radius. But I can't find a reference for that.
No, they wouldn't --- acceleration due to gravity is independent of the mass of the body. (The force due to gravity is GMm/r^2; acceleration is a=F/m; therefore the acceleration due to gravity is GMm/mr^2. The two m factors cancel out.)
What would happen is the nuke would push the fragments apart. These would continue to diverge, but would follow much the same course as the original asteroid. Whether they've been deflected enough to miss the Earth --- which is, of course, a really big target --- depends entirely on how hard the nuke pushed them and how long they travel before impact.
In order for the station to reenter, you'd have to change its orbital velocity by a substantial amount. The interwebs suggests that it's about 150m/s (that's about 300 mph for the metrically challenged).
To change the ISS's velocity that much in a single impact would destroy the entire station. I don't even think the ISS is capable of being deorbited without additional hardware; the Progress supply drones it currently uses to adjust its orbit carry very little thruster fuel. (Just enough to deorbit the Progress itself, plus some spare.)
Personally, the main bit which caused me to roll my eyes is right at the beginning, where the two astronauts admire the sunset, tumbling uncontrollably, while facing in entirely the wrong direction...
Using words I recognize as nonsense isn't the sole problem. It's vocabulary collisions.
I had precisely this problem the other day, when talking to someone about DVCSes. It took about five minutes (of face-to-face conversation, mind; five minutes is a lot) to figure out that git and hg use the word 'revert' to refer to fundamentally different operations.
It would have been less confusing if he'd just said 'I don't know what that word means'. It was the fact that he thought he knew what I meant, but didn't, which was causing the problems...
Indeed. System crashes in rocketry tend to be... messier... than they are in IT.
How do these images compare to the absurdly high resolution images provided by the HiRISE camera on the Mars Reconnaissance Orbiter? The PR images look fairly small scale.
It's always struck me a bit odd that we seem to have vastly higher resolution pictures of Mars from space than we do of Earth; and Earth's, like, right here...
You might find Andrew Plotkin's Pocket Storm interesting: http://zarfhome.com/pocketstorm/ It's an iOS app that will produce a procedurally generated soundscape of a summer storm. By default the whole thing takes an hour; it's tweakable.
(That's a turnkey version of the storm module for his Boodler ambient sound generation engine, wrapped in an iOS app. Boodler itself is in relatively portable Python and is open source. And scriptable. So you can build your own soundscapes with it. There's a zillion different Boodler soundscapes available.)
Unfortunately it requires you to run an SQL server and PHP, both of which require admin overhead to maintain. Does look nice, though.
Please, please don't post links to these without at least warning people...
I had totally forgotten about the MSP430 --- thanks for the reminder; ordered one. I don't have an application in mind but it'll be fun to play with...
I'm particularly intrigued to see they do a bundle of two MSP430 LaunchPads and two low-power RF modules for $23.30. That looks like it would make a very interesting way to experiment with ultra-low-power radio at about $10 a node.
TI's got a lot of interesting stuff. The devkit in a watch looks fun. Pity it's (a) not a dot matrix LCD and (b) out of stock. It's also a pity their website is so broken...
This is a very old idea, although most countries don't need to build artificial islands to do it. For example, the Ben Cruachan pumped storage plant in Scotland uses two lochs at different levels. Energy is stored by pumping water from the low one to the high one.
Pumped storage power stations are typically used for short-term handling of power spikes; if you get sudden load on the electricity network, you can spin up a pumped storage plant in minutes --- sometimes seconds if you know that a spike is due and can prepare --- while traditional oil, coal and nuclear can take hours. So the pumped storage plant handles the load while the big power stations rev up.
Drawbacks involve not being very efficient ---Wikipedia says 70-80% --- and they don't store that much energy. Ben Cruachan, for example, can only generate 440MW for 22 hours before running dry. They're also environmentally rather poor (although not nearly as bad as the alternatives, which are usually fast-start gas turbines, of course).
Using an artificial island is an interesting idea. If you're using off-shore wind farms then the power generation is local and you save on infrastructure and transmission costs; you avoid destroying valuable mountainside (although at the expense of destroying valuable sea bottom); it's close to the coastal cities which would be using the power... does anyone have a link to more technical information? Like how big it is? The linked article is almost entirely content-free.
You can't change the prototype of an object once it's been constructed (ignoring platform-specific extensions). I'm used to Lua, which has a much more orthogonal prototype mechanism, and have a whole stable of neat algorithms involving object prototypes... most of which require setting the prototype only after the object itself has been created.