I suggest you dig up reprint volumes of classic Silver Age comics. The original Spiderman stories, the original Iron Man stories, etc.
In those days, the comics were striving to not violate the "comics code" and they contained very little death, no actual swear words, and generally had a lighter tone than modern comics.
These days, comics are marketed toward teen males; horrible things happen as the comics strive for edginess, and language can be coarse.
So, I would read classic comics to a 3-year-old, but with modern comics I would carefully vet each issue before reading it. This could be a problem if he gets interested in a storyline and then the next comic comes out and it's horrific! The classic Stan Lee scripts from the 60's are all pretty suitable for a 3-year-old.
As someone noted, even in classic Spiderman, Peter Parker's uncle is killed... but that's really it for the death. Spiderman fights the Sandman, Doctor Octopus, the Vulture, the Green Goblin, etc. etc. without anyone being seriously hurt.
Try him on classic Doctor Strange! The original Stan Lee comics of course.
Hmm, I just checked Amazon and it seems that the search phrase to use is "Marvel Masterworks". Here's a link to the first volume of classic Spiderman:
P.S. Bless you for this project. I know this isn't a superhero comic like you asked, but may I suggest that you read this book to your son? This was the first science fiction book I ever read, and it still has an important place in my heart. It's out of print, but trust me, it's worth finding a used copy and buying it. It's probably worth it to buy a hardcover; the mass-market paperback was printed on very cheap paper that is turning brown these days. The story: a family has been living on Ganymede, but will now move to Earth. But shipping is expensive, so they plan to sell their robot and leave the robot behind. Hating to leave the robot, the boy runs away; the boy and the robot have adventures as they try to get to Earth together. It's a tale of adventure and loyalty and love, absolutely a good story for a 3-year-old. The title: The Runaway Robot by Lester Del Rey.
The team I'm in right now is coding Java for Android in NetBeans because Eclipse sucked hard.
A couple of years ago I tried out Eclipse on Ubuntu and I thought it sucked horribly.
Recently I started doing some Android development , and based on the tutorials and references and such I started using Eclipse again. I was pleased to find that the current Eclipse, "Indigo", is much better than what I tried out in the past.
So now I'm wondering what version of Eclipse you were using before. I'm also wondering if I should try out NetBeans.
steveha
Performance improvements indeed
on
Android Ported To C#
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· Score: 2, Interesting
Whoa. Those benchmarks show Java/JVM about 7 times slower than C#/DLR. (I thought "DLR" in TFA was a typo, but it's correct. DLR stands for Dynamic Language Runtime.)
I'm not entirely surprised. I remember reading the history of IronPython, where Jim Hugunin (the original author of Jython, which is Python running on the JVM) did some experiments with the CLR, intending to prove how sucky and lousy the CLR was; instead, he found that the CLR was faster than the JVM, and he went ahead and created IronPython to run on the CLR.
TFA is not worth your time. He says all sorts of outrageous stuff as if it were fact: apparently he knows exactly what Google was collectively thinking when it introduced WebM, for example.
And the ending is sort of surreal. Hooray! The patent-encrusted H.264 has defeated the challenge by the free and open software! Here are my wrists; there's still room for a couple more handcuffs, put them on! (Eh, probably not a fair summary, but about as fair as his treatment of Google.)
I don't really understand this line of thought. People use Ubuntu, dislike it, then move to (K|X)buntu or Mint... What's wrong with plain old Debian?
The Debian installer doesn't work as a live CD. I don't know where you can go to get a live CD with a standard Debian system on it and a GUI desktop that Just Works.
The Debian installer doesn't sort out all your hardware as well as the Ubuntu installer does. I have several laptops and I can boot an Ubuntu disc on any of them, and a GUI comes up with WiFi working. I am able to install Debian, but it would need to be with the laptop plugged in to a wired network, so I could manually install packages for the WiFi stuff until it works.
While I know a lot of people seem to hate PulseAudio, I want it running. With Ubuntu you just get it; with Debian you need to sort it out yourself.
Before "Unity" I could basically install Ubuntu and be productive right away. Now there is a step where I have to disable Unity and set up some other desktop, but that's still easier than installing Debian and fixing everything.
On the other hand, for servers, I run Debian Stable and I have for many years now. Rock solid reliable, and none of the above issues matter. (If I need to boot a server from a live CD, I can just use the Ubuntu one. But my servers are reliable and I basically never need to do that.)
I'm actually scared of upgrading my friend's desktop to a newer version of Ubuntu. He's computer illiterate and has been using Ubuntu more-or-less fine for several years now, but I know him and while I can tolerate even the most bone-headed of interface (I used old versions of Mentor Graphics for example) this shit is going to drive him insane and he'll stop using it.
I have been using an Ubuntu 11.10 computer with MATE installed, and I am happy with it. I have removed all the overlay-scrollbar packages and the result is a nice usable GNOME 2.x desktop.
Long-term, the future is probably Cinnamon, which is built on top of the new GNOME 3.x libraries but aims to duplicate the desktop features of GNOME 2.x.
I recently watched a Google Tech Talk about a video game that trains the exact same skills as arthroscopic surgery. The game is designed so that you can play it with Wii nunchuck controller, or with a custom controller rig that duplicates the equipment used for arthroscopic surgery.
One interesting point: they built a training facility, but the simulators were not fun, and medical students used the training facility as little as they could manage. The game is designed to be fun so people will play it willingly.
Put up wind farms that generate electricity. Run electricity to dwellings. Have the dwellings run air conditioning systems that also collect condensed water.
For one thing, a purpose-built device will be much more efficient at its one intended purpose. Just how much water do you get as a side-effect of running an air conditioner? The prototype of this turbine consistently extracts 800 litres of water a day.
For another thing, in "developing" areas, it will be easier to put in a few self-contained devices than to build out a complete infrastructure. Clean water is essential to life, but air conditioning isn't, and devices like this will provide useful water as soon as they are installed. How soon does your plan start providing nontrivial amounts of drinking water?
And in "developing" areas, it is more likely possible that one of these can be installed in the middle of town, than that every home will be able to afford to have air conditioning installed. I'm not even sure if a whole town could afford to buy one of these things, but maybe an international aid organization will pay for it. But who will pay for an air conditioning unit for each home in a town?
I just installed MATE on my business laptop, and started using it. I immediately felt happier. That's not a failure... that's a success!
Now, you can argue that in the long run, it's counter-productive to try to keep the old GTK 2.x code base going. I might even agree! I have high hopes for Cinnamon.
But the GNOME 2.x code base represents man-decades of work, and Cinnamon won't reach that smooth, polished level of usability in the short run. So what can we use right now today, while we wait for Cinnamon to become mature and stable? Hmmm. Hey, I know: we can use MATE, because they picked a modest goal and accomplished it quickly. They aren't breaking any new ground with MATE; they are just keeping a good thing going a bit longer.
Ten years from now, will I still be running MATE? Not likely. Am I glad MATE is available today? You bet I am.
The only Python code I've ever seen left me shaking my head... it could have been because it was shit code, but I just can't fathom why whitespace should affect the compilers interpretation of what the code means.
It has its pluses and minuses. Overall I like it, and I just can't fathom why so many make such a big deal about it.
In C code, this is an error: if (some_test(x))
f = open_file();
write_data(f, x);
close_file(f);
The indentation makes the programmer's intent clear: those three statements are supposed to run when some_test() evaluates true. But because the programmer forgot to put the curly braces, this doesn't do what it looks like it does.
In Python, if the statements are indented the same, such that they look like they should be a block together, they actually are a block. I like that.
So, in C, just learn to not forget the curly braces and you won't have trouble! And in Python, just learn not to mix spaces and tabs, and you won't have trouble.
When I'm knocking out Python code in a hurry, I like being able to just add a second line in an if statement, without needing to fuss with curly braces.
it seems now everything has to be JavaScript-based...
I agree with you about Python; I think that for learning, Python is the best. Not JavaScript.
But if someone did want to learn to program using just web-based stuff, maybe CoffeeScript would be a good choice; I have heard very positive things about it here on Slashdot.
The reason I like Python so much is that it has the least syntactic silliness of any language I've used: Python code often reads like psuedocode, but it actually works.
To learn C, you need to start by learning what a variable is, and that means learning what the different data types are, and when you use them. In Python, there really aren't variables: you just bind values to names.
And Python has lots of great libraries, so that he can easily write a non-toy program that does something interesting. In particular, there is the library, which would allow him to write a game.
And Python is useful for doing real work. It would be a poor choice to write an operating system or a word processing program, but it is useful for all sorts of actual problems in many fields. Particularly in science, Python is becoming a top language, thanks to SciPy.
I think you are lowballing the endurance; instead of 8 hours, I think it was something like 25. Crazy good battery life! But I can easily fill 24KB of RAM, and then what? You quoted 3 pounds, but I never went anywhere without the cassette recorder, the special cable, and more batteries for the cassette recorder... more like 4 or 5 pounds.
Hardware hack: people used to get a bag of those little rubber bands used on braces, and pry off the keycaps on the keyboard; put one around the stalk of the key and put the keycap back on. The rubber bands would render the keyboard nearly silent, and better for note-taking.
If you want something with a keyboard, why not an Android device plus a Bluetooth keyboard? I've been carrying a 7" tablet and I love the size and weight (400 grams, under a pound).
My tablet is a Nook Tablet so I have a limited selection of apps and Bluetooth is not enabled; but it works great for many purposes, and I want any replacement to be about the same size and weight. As soon as the cheap Tegra 3 devices with Android 4.x and a 7" screen come out, I'm buying one... and a Bluetooth keyboard.
If you really want to go old-school, I'd suggest an AlphaSmart Dana. Lighter than the old TRS-80 slabs, and you can save your data on an SD card rather than a cassette recorder.
[Norman Spinrad has] been one of the most consistently interesting SF writers ever since, and I can't recommend his work highly enough.
He is also the author of my all-time favorite episode of Star Trek: The Doomsday Machine. That is an outstanding story, and really works as hard science fiction.
Fun trivia facts:
At the time Star Trek was made, model-building was a popular hobby, and you could buy inexpensive Enterprise models at your local hobby shop. The special effects guys went and bought an Enterprise model, and then damaged it, to be the damaged USS Constellation.
According to Norman Spinrad, the doomsday machine itself was actually a wind sock dipped in cement.
Star Trek had limited budget, and they had a policy of trying to alternate between "planet episodes" and "ship episodes". A "planet episode" would involve going to some interesting place (a planet or space station or whatever) and might involve location shots or new sets; a "ship episode" would be shot mostly or entirely on the existing Enterprise ship sets. "The Doomsday Machine" was conceived as a ship episode, and it was one of the most effective ones: they redressed one of the Enterprise sets to be the "auxiliary control room" of the Constellation, and didn't need any additional sets or location shots.
I love the idea of using Bluetooth for the sensors. Does Bluetooth pose extra problems though? Licensing, certification, RF interference?
Rather than delivering the data as HTML, I would suggest JSON. JSON is very widely supported, and it is so simple that it doesn't have compatibility problems. You could do a REST interface, but web servers are not really suited to continuous streams of data. I think it would be better to just have a device use the web interface to request a socket and then stream the data to the socket continuously.
Most of the comments posted so far have been jokes. But I think this is great.
I would have very much loved to have one of these when I was taking science classes in high school. Heck, I'd love to have one now.
The biggest flaw is that this is an expensive piece of custom equipment. No criticism of Dr. Jansen intended; he made the gadget he wanted to have. But I would like to see a design that is less expensive and mass-produced, that has just the sensors in a sort of cradle; you would put a smart phone into the cradle and plug in by USB. The cradle might need to contain a battery (I'm not sure how much current a smartphone micro-USB port can source).
It would be more elegant if it used something like the iPhone's docking connector, but Apple charges money to use that thing, and on Android there is no similar standard. Just using USB would seem to offer the widest compatibility.
Since the CPU needs are low, you should be able to use phones from 2+ years ago. When people upgrade to new phones they often have a surplus older phone, and maybe they will donate the older phone to the high school science program. Or if you just want one for yourself, you could buy something from eBay or Craigs List.
This makes me think back to when the Palm PDA was new. The Palm had a serial port on the bottom, and there were sensor packages you could get to plug in to it. I read about a high school science teacher taking his class on a field trip, and they used pH and temperature sensors to measure a wetlands.
Back when I carried around a Handspring Visor, I always wanted a Springboard module with a Volt/Ohm meter and probes; and another one with thermometer and such. There really was one with a magnetic compass, and I think there was at least one with a GPS receiver in it.
If the K.P. goes through, as planned, and has a B.P. style incident? There goes the country's capability to feed ourselves.
There is an important difference between the BP well and a pipeline: a pipeline can be shut down. Pipelines have multiple pumping stations to keep pushing the oil along, and those pumping stations can be shut down; pipelines have leak detectors. Not only do the oil companies not want to waste valuable oil and incur financial penalties for pollution, but additionally governmental regulations require them to have leak detectors and safety shutdowns.
Wikipedia says the Keystone XL pipeline has a planned maximum capacity of 510000 barrels of oil per day. If I am not mistaken, that's about 354 barrels of oil per minute. Wikipedia says that one state (Washington) imposes a requirement to be able to detect and pinpoint the location of leakage of 8% of maximum flow within 15 minutes. Using this standard, if we assume the Keystone XL leaks 8% for 15 minutes and is then shut down, that would seem to work out to about 23 barrels of oil leaked before shutdown. I'm not an engineer, but I should think it would be easier to detect more significant flows and shut down.
On the other hand, what if we assume some catastrophic event completely breaks the pipeline at some point? Wikipedia says that industry practice is to place "block valve stations":
These are the first line of protection for pipelines. With these valves the operator can isolate any segment of the line for maintenance work or isolate a rupture or leak. Block valve stations are usually located every 20 to 30 miles (48 km), depending on the type of pipeline
If we assume that a catastophe completely breaks the pipeline and all the crude oil in an entire 48 km segment drains out, and use the Wikipedia pipe diameter of 910mm, then if I have done my sums correctly that would be a spill on the order of 25000 tonnes of oil. Checking the Wikpedia List of oil spills page, we find that the Deepwater Horizon leak in the Gulf was at least 492000 tonnes. If we assume that most segments of the pipeline are not completely flat, then it seems likely that less than the maximum oil will leak out.
Also, according to press releases from TransCanada, there is at least one route available that takes the pipeline completely around the aquifers, and other routes were studied that shortened the pipe runs by putting some sections in aquifer areas. One possible solution is to insist that the pipeline simply not go through the aquifer areas. I'm not an expert on pipeline risk assessment so I won't take a position on the tradeoffs involved.
Also, I wonder just how much crude oil will soak through the ground and into an aquifer, and what the consequences would be; whether crude oil ever naturally leaks into aquifers, and if so how serious it is when it happens. I haven't found a sober assessment of the situation; I have mostly found breathless and fact-free assertions that the pipeline would instantly destroy "the heartbeat of America" and such.
While pipeline disasters suck, the level of disaster that worries you should not be possible.
steveha
Re:C6X support is surprising
on
Linux 3.3 Released
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· Score: 4, Informative
The TI C6X line of chips are not only VLIW, they are "DSP" chips, optimized for signal processing operations. Also, this chip has no MMU. Nobody is going to build a tablet computer or any other general-purpose device based on one of these.
I think for the near term at least, anyone using a TI C6X will be using the TI C compiler. TI has a whole IDE, called Code Composer Studio.
But now we have the possibility of running Linux on the chip.
The one time I worked with a TI DSP chip, I didn't really have an operating system. Just a bootstrap loader, and then my code ran on the bare metal, along with some TI-supplied library code. Now I'm working with an Analog Devices DSP chip and it's the same situation. For my current purposes I'm not using any OS at all. But Linux support could potentially be great; for example, if you were using a platform with an Ethernet interface, you could use the Linux networking code; if you were using a platform with USB, you could use Linux USB code and file system code and so on.
I should be stone deaf but still my "low-pass" kicks in at no less than 21kHz.
For your sake, I'm glad. I would rather you have good hearing than bad, even if it makes you the exception that proves the rule.
I know that the ear takes certain measures to protect itself in the presence of loud sounds. Perhaps your ear is better at this than most.
But seriously, no one (and I include you) should put your hearing at risk. If you ever do tear any inner hair cells, you will have a notch in your hearing that cannot be fixed with current medical technology. Why risk it?
Hearing recovers just fine, given time. The ear is much better at healing than had been thought at one time.
This is a bold claim, and I would like a citation to back it up, please.
I will counter with my own bold claim: if you listen to noise that is energetic enough to rip hair cells, you permanently lose the hearing from those hair cells. It won't come back.
Here's a citation. This citation talks about the hope of overcoming the above, someday. Mouse hair cells were damaged, and some hair cells sort of partially regrew but the hearing never came back. They hope to find a way to encourage this process to restore some hearing, but that is a hope and not present reality.
For the sake of your hearing, don't expose yourself to any sounds with sufficient energy to tear your hair cells. Maybe in 20 years doctors will have a way to fix this. Why risk it?
I read a posting here on Slashdot. A guy said he used to be able to hear very high-pitched sounds that other people couldn't hear; he must have been hearing over 20 kHz or so. He went to a Motorhead performance and was deaf for two days. His hearing came back but he had lost his unusual ability to hear high frequencies. Reading this story, I was sad.
When I am at a loud music performance or in a loud movie, I stuff some tissue paper in my ears. Not enough that I can't hear; just enough that it isn't deafening.
Yes, I believe I've heard of Google MapReduce once or twice.
Why is he complaining that his Python job will take a week to run then? Can't he throw some extra cores, extra cluster nodes, or perhaps extra data centers at it?
Have I missed something... is his problem actually not embarrassingly parallel? Or is he already running it in parallel and it will take a week anyway? I don't run jobs that big and I don't know how to estimate how long it should take.
I have a Python program running right now which will run for over a week, parsing the street address of every business in the US into a standard format.
If you have a big machine with lots of cores, the Python multiprocessing module could speed that up quite a bit. (At work, we have one computer with two 12-core Opterons, and if you can get all 24 cores working together, it can really crunch some data. It's fun to run make -j 25! Sadly, it doesn't see much use.)
But here are two ways you might be able to split the work up across multiple computers, possibly on the Amazon E2 cluster or some other rented cluster. The first one uses Hadoop, which should already be available on a rented cluster. The second one I've never heard of before, but likely you could install it on your own cluster if you have one. Interestingly, they wrote the map/reduce system in Erlang, but user jobs are submitted in Python.
I used to work for JJ Johnston. He took a popular music track (I won't say which one) and ripped a.wav file from the CD, and then ran a simple Matlab script that tallied how many samples there were of each value. CDs use 16-bit samples, so there were 64K bins in this histogram. You would expect a pretty much Bell-curve shape to the histogram. With this particular song, over half of all samples were either +1 or -1 (i.e., 16-bit sample values of either +32767 or -32768).
That music is so horribly overcompressed that most of the wave forms are sawed-off into square waves. Square waves, in turn, add unpleasant harmonics, which make the music harder to enjoy, and make it louder (in the psychoacoustic meaning of "louder").
I'm hoping that "audiophile" versions of songs become available, not because I think I need all my music in 24-bit 192KHz but because I'm hoping the mix engineers will be allowed to do the mix properly, instead of mixing it far too hot.
I'm sort of afraid to buy remastered versions of old classic rock albums, because I'm worried they will actually sound worse than the originals!
Slashdot Mirror
I suggest you dig up reprint volumes of classic Silver Age comics. The original Spiderman stories, the original Iron Man stories, etc.
In those days, the comics were striving to not violate the "comics code" and they contained very little death, no actual swear words, and generally had a lighter tone than modern comics.
These days, comics are marketed toward teen males; horrible things happen as the comics strive for edginess, and language can be coarse.
So, I would read classic comics to a 3-year-old, but with modern comics I would carefully vet each issue before reading it. This could be a problem if he gets interested in a storyline and then the next comic comes out and it's horrific! The classic Stan Lee scripts from the 60's are all pretty suitable for a 3-year-old.
As someone noted, even in classic Spiderman, Peter Parker's uncle is killed... but that's really it for the death. Spiderman fights the Sandman, Doctor Octopus, the Vulture, the Green Goblin, etc. etc. without anyone being seriously hurt.
Try him on classic Doctor Strange! The original Stan Lee comics of course.
Hmm, I just checked Amazon and it seems that the search phrase to use is "Marvel Masterworks". Here's a link to the first volume of classic Spiderman:
http://www.amazon.com/Amazing-Spider-Man-Vol-Marvel-Masterworks/dp/0785136932
P.S. Bless you for this project. I know this isn't a superhero comic like you asked, but may I suggest that you read this book to your son? This was the first science fiction book I ever read, and it still has an important place in my heart. It's out of print, but trust me, it's worth finding a used copy and buying it. It's probably worth it to buy a hardcover; the mass-market paperback was printed on very cheap paper that is turning brown these days. The story: a family has been living on Ganymede, but will now move to Earth. But shipping is expensive, so they plan to sell their robot and leave the robot behind. Hating to leave the robot, the boy runs away; the boy and the robot have adventures as they try to get to Earth together. It's a tale of adventure and loyalty and love, absolutely a good story for a 3-year-old. The title: The Runaway Robot by Lester Del Rey.
http://www.amazon.com/The-Runaway-Robot-Lester-Del/dp/B000DZDQD0
steveha
That's Dalvik, NOT the JVM.
Whoops, you are correct. Sorry about that.
I wish I could go back and edit the post. Oh well.
steveha
The team I'm in right now is coding Java for Android in NetBeans because Eclipse sucked hard.
A couple of years ago I tried out Eclipse on Ubuntu and I thought it sucked horribly.
Recently I started doing some Android development , and based on the tutorials and references and such I started using Eclipse again. I was pleased to find that the current Eclipse, "Indigo", is much better than what I tried out in the past.
So now I'm wondering what version of Eclipse you were using before. I'm also wondering if I should try out NetBeans.
steveha
The chart from TFA:
http://tirania.org/s/71de890b.png
Whoa. Those benchmarks show Java/JVM about 7 times slower than C#/DLR. (I thought "DLR" in TFA was a typo, but it's correct. DLR stands for Dynamic Language Runtime.)
I'm not entirely surprised. I remember reading the history of IronPython, where Jim Hugunin (the original author of Jython, which is Python running on the JVM) did some experiments with the CLR, intending to prove how sucky and lousy the CLR was; instead, he found that the CLR was faster than the JVM, and he went ahead and created IronPython to run on the CLR.
steveha
TFA is not worth your time. He says all sorts of outrageous stuff as if it were fact: apparently he knows exactly what Google was collectively thinking when it introduced WebM, for example.
And the ending is sort of surreal. Hooray! The patent-encrusted H.264 has defeated the challenge by the free and open software! Here are my wrists; there's still room for a couple more handcuffs, put them on! (Eh, probably not a fair summary, but about as fair as his treatment of Google.)
steveha
I don't really understand this line of thought. People use Ubuntu, dislike it, then move to (K|X)buntu or Mint... What's wrong with plain old Debian?
The Debian installer doesn't work as a live CD. I don't know where you can go to get a live CD with a standard Debian system on it and a GUI desktop that Just Works.
The Debian installer doesn't sort out all your hardware as well as the Ubuntu installer does. I have several laptops and I can boot an Ubuntu disc on any of them, and a GUI comes up with WiFi working. I am able to install Debian, but it would need to be with the laptop plugged in to a wired network, so I could manually install packages for the WiFi stuff until it works.
While I know a lot of people seem to hate PulseAudio, I want it running. With Ubuntu you just get it; with Debian you need to sort it out yourself.
Before "Unity" I could basically install Ubuntu and be productive right away. Now there is a step where I have to disable Unity and set up some other desktop, but that's still easier than installing Debian and fixing everything.
On the other hand, for servers, I run Debian Stable and I have for many years now. Rock solid reliable, and none of the above issues matter. (If I need to boot a server from a live CD, I can just use the Ubuntu one. But my servers are reliable and I basically never need to do that.)
steveha
I'm actually scared of upgrading my friend's desktop to a newer version of Ubuntu. He's computer illiterate and has been using Ubuntu more-or-less fine for several years now, but I know him and while I can tolerate even the most bone-headed of interface (I used old versions of Mentor Graphics for example) this shit is going to drive him insane and he'll stop using it.
I have been using an Ubuntu 11.10 computer with MATE installed, and I am happy with it. I have removed all the overlay-scrollbar packages and the result is a nice usable GNOME 2.x desktop.
http://mate-desktop.org/
Long-term, the future is probably Cinnamon, which is built on top of the new GNOME 3.x libraries but aims to duplicate the desktop features of GNOME 2.x.
http://cinnamon.linuxmint.com/
steveha
I recently watched a Google Tech Talk about a video game that trains the exact same skills as arthroscopic surgery. The game is designed so that you can play it with Wii nunchuck controller, or with a custom controller rig that duplicates the equipment used for arthroscopic surgery.
One interesting point: they built a training facility, but the simulators were not fun, and medical students used the training facility as little as they could manage. The game is designed to be fun so people will play it willingly.
http://www.youtube.com/watch?v=rpSvDvYvJGk
steveha
Put up wind farms that generate electricity.
Run electricity to dwellings. Have the dwellings run air conditioning systems that also collect condensed water.
For one thing, a purpose-built device will be much more efficient at its one intended purpose. Just how much water do you get as a side-effect of running an air conditioner? The prototype of this turbine consistently extracts 800 litres of water a day.
For another thing, in "developing" areas, it will be easier to put in a few self-contained devices than to build out a complete infrastructure. Clean water is essential to life, but air conditioning isn't, and devices like this will provide useful water as soon as they are installed. How soon does your plan start providing nontrivial amounts of drinking water?
And in "developing" areas, it is more likely possible that one of these can be installed in the middle of town, than that every home will be able to afford to have air conditioning installed. I'm not even sure if a whole town could afford to buy one of these things, but maybe an international aid organization will pay for it. But who will pay for an air conditioning unit for each home in a town?
steveha
If I am spending my own money, I'd be tempted to just get this one:
http://thewirecutter.com/reviews/best-led-lightbulb-philips-ambientled/
I wonder what the differences are? Maybe the $25 one is assembled in China?
steveha
This approach is doomed to failure.
I just installed MATE on my business laptop, and started using it. I immediately felt happier. That's not a failure... that's a success!
Now, you can argue that in the long run, it's counter-productive to try to keep the old GTK 2.x code base going. I might even agree! I have high hopes for Cinnamon.
But the GNOME 2.x code base represents man-decades of work, and Cinnamon won't reach that smooth, polished level of usability in the short run. So what can we use right now today, while we wait for Cinnamon to become mature and stable? Hmmm. Hey, I know: we can use MATE, because they picked a modest goal and accomplished it quickly. They aren't breaking any new ground with MATE; they are just keeping a good thing going a bit longer.
Ten years from now, will I still be running MATE? Not likely. Am I glad MATE is available today? You bet I am.
steveha
The only Python code I've ever seen left me shaking my head ... it could have been because it was shit code, but I just can't fathom why whitespace should affect the compilers interpretation of what the code means.
It has its pluses and minuses. Overall I like it, and I just can't fathom why so many make such a big deal about it.
In C code, this is an error:
if (some_test(x))
f = open_file();
write_data(f, x);
close_file(f);
The indentation makes the programmer's intent clear: those three statements are supposed to run when some_test() evaluates true. But because the programmer forgot to put the curly braces, this doesn't do what it looks like it does.
In Python, if the statements are indented the same, such that they look like they should be a block together, they actually are a block. I like that.
So, in C, just learn to not forget the curly braces and you won't have trouble! And in Python, just learn not to mix spaces and tabs, and you won't have trouble.
When I'm knocking out Python code in a hurry, I like being able to just add a second line in an if statement, without needing to fuss with curly braces.
But some people really hate this, I guess.
steveha
it seems now everything has to be JavaScript-based...
I agree with you about Python; I think that for learning, Python is the best. Not JavaScript.
But if someone did want to learn to program using just web-based stuff, maybe CoffeeScript would be a good choice; I have heard very positive things about it here on Slashdot.
http://coffeescript.org/
steveha
I strongly recommend Python.
The reason I like Python so much is that it has the least syntactic silliness of any language I've used: Python code often reads like psuedocode, but it actually works.
To learn C, you need to start by learning what a variable is, and that means learning what the different data types are, and when you use them. In Python, there really aren't variables: you just bind values to names.
And Python has lots of great libraries, so that he can easily write a non-toy program that does something interesting. In particular, there is the library, which would allow him to write a game.
And Python is useful for doing real work. It would be a poor choice to write an operating system or a word processing program, but it is useful for all sorts of actual problems in many fields. Particularly in science, Python is becoming a top language, thanks to SciPy.
Python is also the language used for SAGE, which he might enjoy using to plot graphs.
P.S. If he loves Python and wants to learn a second language, I would suggest C. Not C++, C.
steveha
I used to have a TRS-80 Model 100. I've moved on.
I think you are lowballing the endurance; instead of 8 hours, I think it was something like 25. Crazy good battery life! But I can easily fill 24KB of RAM, and then what? You quoted 3 pounds, but I never went anywhere without the cassette recorder, the special cable, and more batteries for the cassette recorder... more like 4 or 5 pounds.
Hardware hack: people used to get a bag of those little rubber bands used on braces, and pry off the keycaps on the keyboard; put one around the stalk of the key and put the keycap back on. The rubber bands would render the keyboard nearly silent, and better for note-taking.
If you want something with a keyboard, why not an Android device plus a Bluetooth keyboard? I've been carrying a 7" tablet and I love the size and weight (400 grams, under a pound).
My tablet is a Nook Tablet so I have a limited selection of apps and Bluetooth is not enabled; but it works great for many purposes, and I want any replacement to be about the same size and weight. As soon as the cheap Tegra 3 devices with Android 4.x and a 7" screen come out, I'm buying one... and a Bluetooth keyboard.
If you really want to go old-school, I'd suggest an AlphaSmart Dana. Lighter than the old TRS-80 slabs, and you can save your data on an SD card rather than a cassette recorder.
http://www.amazon.com/AlphaSmart-Dana-Handheld-Palm-4-1/dp/B00007FV2Z
steveha
[Norman Spinrad has] been one of the most consistently interesting SF writers ever since, and I can't recommend his work highly enough.
He is also the author of my all-time favorite episode of Star Trek: The Doomsday Machine. That is an outstanding story, and really works as hard science fiction.
Fun trivia facts:
At the time Star Trek was made, model-building was a popular hobby, and you could buy inexpensive Enterprise models at your local hobby shop. The special effects guys went and bought an Enterprise model, and then damaged it, to be the damaged USS Constellation.
According to Norman Spinrad, the doomsday machine itself was actually a wind sock dipped in cement.
Star Trek had limited budget, and they had a policy of trying to alternate between "planet episodes" and "ship episodes". A "planet episode" would involve going to some interesting place (a planet or space station or whatever) and might involve location shots or new sets; a "ship episode" would be shot mostly or entirely on the existing Enterprise ship sets. "The Doomsday Machine" was conceived as a ship episode, and it was one of the most effective ones: they redressed one of the Enterprise sets to be the "auxiliary control room" of the Constellation, and didn't need any additional sets or location shots.
steveha
I love the idea of using Bluetooth for the sensors. Does Bluetooth pose extra problems though? Licensing, certification, RF interference?
Rather than delivering the data as HTML, I would suggest JSON. JSON is very widely supported, and it is so simple that it doesn't have compatibility problems. You could do a REST interface, but web servers are not really suited to continuous streams of data. I think it would be better to just have a device use the web interface to request a socket and then stream the data to the socket continuously.
steveha
Most of the comments posted so far have been jokes. But I think this is great.
I would have very much loved to have one of these when I was taking science classes in high school. Heck, I'd love to have one now.
The biggest flaw is that this is an expensive piece of custom equipment. No criticism of Dr. Jansen intended; he made the gadget he wanted to have. But I would like to see a design that is less expensive and mass-produced, that has just the sensors in a sort of cradle; you would put a smart phone into the cradle and plug in by USB. The cradle might need to contain a battery (I'm not sure how much current a smartphone micro-USB port can source).
It would be more elegant if it used something like the iPhone's docking connector, but Apple charges money to use that thing, and on Android there is no similar standard. Just using USB would seem to offer the widest compatibility.
Since the CPU needs are low, you should be able to use phones from 2+ years ago. When people upgrade to new phones they often have a surplus older phone, and maybe they will donate the older phone to the high school science program. Or if you just want one for yourself, you could buy something from eBay or Craigs List.
This makes me think back to when the Palm PDA was new. The Palm had a serial port on the bottom, and there were sensor packages you could get to plug in to it. I read about a high school science teacher taking his class on a field trip, and they used pH and temperature sensors to measure a wetlands.
Back when I carried around a Handspring Visor, I always wanted a Springboard module with a Volt/Ohm meter and probes; and another one with thermometer and such. There really was one with a magnetic compass, and I think there was at least one with a GPS receiver in it.
steveha
If the K.P. goes through, as planned, and has a B.P. style incident? There goes the country's capability to feed ourselves.
There is an important difference between the BP well and a pipeline: a pipeline can be shut down. Pipelines have multiple pumping stations to keep pushing the oil along, and those pumping stations can be shut down; pipelines have leak detectors. Not only do the oil companies not want to waste valuable oil and incur financial penalties for pollution, but additionally governmental regulations require them to have leak detectors and safety shutdowns.
http://en.wikipedia.org/wiki/Pipeline_transport#Leak_detection_systems
Wikipedia says the Keystone XL pipeline has a planned maximum capacity of 510000 barrels of oil per day. If I am not mistaken, that's about 354 barrels of oil per minute. Wikipedia says that one state (Washington) imposes a requirement to be able to detect and pinpoint the location of leakage of 8% of maximum flow within 15 minutes. Using this standard, if we assume the Keystone XL leaks 8% for 15 minutes and is then shut down, that would seem to work out to about 23 barrels of oil leaked before shutdown. I'm not an engineer, but I should think it would be easier to detect more significant flows and shut down.
On the other hand, what if we assume some catastrophic event completely breaks the pipeline at some point? Wikipedia says that industry practice is to place "block valve stations":
If we assume that a catastophe completely breaks the pipeline and all the crude oil in an entire 48 km segment drains out, and use the Wikipedia pipe diameter of 910mm, then if I have done my sums correctly that would be a spill on the order of 25000 tonnes of oil. Checking the Wikpedia List of oil spills page, we find that the Deepwater Horizon leak in the Gulf was at least 492000 tonnes. If we assume that most segments of the pipeline are not completely flat, then it seems likely that less than the maximum oil will leak out.
Also, according to press releases from TransCanada, there is at least one route available that takes the pipeline completely around the aquifers, and other routes were studied that shortened the pipe runs by putting some sections in aquifer areas. One possible solution is to insist that the pipeline simply not go through the aquifer areas. I'm not an expert on pipeline risk assessment so I won't take a position on the tradeoffs involved.
Also, I wonder just how much crude oil will soak through the ground and into an aquifer, and what the consequences would be; whether crude oil ever naturally leaks into aquifers, and if so how serious it is when it happens. I haven't found a sober assessment of the situation; I have mostly found breathless and fact-free assertions that the pipeline would instantly destroy "the heartbeat of America" and such.
While pipeline disasters suck, the level of disaster that worries you should not be possible.
steveha
The TI C6X line of chips are not only VLIW, they are "DSP" chips, optimized for signal processing operations. Also, this chip has no MMU. Nobody is going to build a tablet computer or any other general-purpose device based on one of these.
I think for the near term at least, anyone using a TI C6X will be using the TI C compiler. TI has a whole IDE, called Code Composer Studio.
But now we have the possibility of running Linux on the chip.
The one time I worked with a TI DSP chip, I didn't really have an operating system. Just a bootstrap loader, and then my code ran on the bare metal, along with some TI-supplied library code. Now I'm working with an Analog Devices DSP chip and it's the same situation. For my current purposes I'm not using any OS at all. But Linux support could potentially be great; for example, if you were using a platform with an Ethernet interface, you could use the Linux networking code; if you were using a platform with USB, you could use Linux USB code and file system code and so on.
steveha
I should be stone deaf but still my "low-pass" kicks in at no less than 21kHz.
For your sake, I'm glad. I would rather you have good hearing than bad, even if it makes you the exception that proves the rule.
I know that the ear takes certain measures to protect itself in the presence of loud sounds. Perhaps your ear is better at this than most.
But seriously, no one (and I include you) should put your hearing at risk. If you ever do tear any inner hair cells, you will have a notch in your hearing that cannot be fixed with current medical technology. Why risk it?
steveha
Hearing recovers just fine, given time. The ear is much better at healing than had been thought at one time.
This is a bold claim, and I would like a citation to back it up, please.
I will counter with my own bold claim: if you listen to noise that is energetic enough to rip hair cells, you permanently lose the hearing from those hair cells. It won't come back.
Here's a citation. This citation talks about the hope of overcoming the above, someday. Mouse hair cells were damaged, and some hair cells sort of partially regrew but the hearing never came back. They hope to find a way to encourage this process to restore some hearing, but that is a hope and not present reality.
http://report.nih.gov/NIHfactsheets/ViewFactSheet.aspx?csid=94
Wikipedia confirms it: in mammals, destroyed inner hair cells structures do not regenerate.
http://en.wikipedia.org/wiki/Stereocilia_(inner_ear)#Destruction_of_stereocilia
For the sake of your hearing, don't expose yourself to any sounds with sufficient energy to tear your hair cells. Maybe in 20 years doctors will have a way to fix this. Why risk it?
I read a posting here on Slashdot. A guy said he used to be able to hear very high-pitched sounds that other people couldn't hear; he must have been hearing over 20 kHz or so. He went to a Motorhead performance and was deaf for two days. His hearing came back but he had lost his unusual ability to hear high frequencies. Reading this story, I was sad.
When I am at a loud music performance or in a loud movie, I stuff some tissue paper in my ears. Not enough that I can't hear; just enough that it isn't deafening.
steveha
Yes, I believe I've heard of Google MapReduce once or twice.
Why is he complaining that his Python job will take a week to run then? Can't he throw some extra cores, extra cluster nodes, or perhaps extra data centers at it?
Have I missed something... is his problem actually not embarrassingly parallel? Or is he already running it in parallel and it will take a week anyway? I don't run jobs that big and I don't know how to estimate how long it should take.
steveha
I have a Python program running right now which will run for over a week, parsing the street address of every business in the US into a standard format.
If you have a big machine with lots of cores, the Python multiprocessing module could speed that up quite a bit. (At work, we have one computer with two 12-core Opterons, and if you can get all 24 cores working together, it can really crunch some data. It's fun to run make -j 25! Sadly, it doesn't see much use.)
But here are two ways you might be able to split the work up across multiple computers, possibly on the Amazon E2 cluster or some other rented cluster. The first one uses Hadoop, which should already be available on a rented cluster. The second one I've never heard of before, but likely you could install it on your own cluster if you have one. Interestingly, they wrote the map/reduce system in Erlang, but user jobs are submitted in Python.
http://www.michael-noll.com/tutorials/writing-an-hadoop-mapreduce-program-in-python/
http://discoproject.org/
steveha
Wikipedia's article on the "loudness war" does a good job of explaining the problem.
http://en.wikipedia.org/wiki/Loudness_war
I used to work for JJ Johnston. He took a popular music track (I won't say which one) and ripped a .wav file from the CD, and then ran a simple Matlab script that tallied how many samples there were of each value. CDs use 16-bit samples, so there were 64K bins in this histogram. You would expect a pretty much Bell-curve shape to the histogram. With this particular song, over half of all samples were either +1 or -1 (i.e., 16-bit sample values of either +32767 or -32768).
That music is so horribly overcompressed that most of the wave forms are sawed-off into square waves. Square waves, in turn, add unpleasant harmonics, which make the music harder to enjoy, and make it louder (in the psychoacoustic meaning of "louder").
I'm hoping that "audiophile" versions of songs become available, not because I think I need all my music in 24-bit 192KHz but because I'm hoping the mix engineers will be allowed to do the mix properly, instead of mixing it far too hot.
I'm sort of afraid to buy remastered versions of old classic rock albums, because I'm worried they will actually sound worse than the originals!
steveha