Ah, the touching tale of two brothers, one of which would become a famous movie star, while the other would go on to become a technophile pimp, building robots and surfing the web in his pimp outfit and purple hat. I would totally see that movie.
No, it's not. You don't buy digital scope to analyse perfect sinewaves. When you're looking at complex waveforms that might include single events and glitches, you need at least a sampling rate ten times your signal frequency. The only way you get your original signal back if it's been sampled at or near the Nyquist frequency is through interpolation. That might be ok for audio applications, but when you need to extract secondary information from the signal, there's just no way. Ten times is the bare minimum, and Tektronix advertise their scope bandwidth as 1/10th the sample rate.
You know, that's a really cool idea... just carry one or more elevators and a spool of nanotube cable with you on your spaceship. When you need to go to the surface of a planet, go into synchronous orbit, lower the cable, with some kind of robot at the end that automatically attaches it to the ground. Once the cable is anchored, attach the elevator and you can transport stuff and people up and down at will. This could be very useful for quickly strip-mining foreign planets (or invading them, if they're inhabited. Just make sure they don't notice the cable:).
Scope bandwidth - you can never have enough. If your budget is limited, you're better off with a good old analog scope. Digital bandwidth is too expensive. Calculate 10 samples per Hz of the signal that you're sampling. So, if you're looking at a 40 MHz sinewave, you need 400 MSPS. And that's just to roughly make out the shape of the waveform, 800 MSPS would be better. Just imagine what a single period of a sinewave looks like when it's divided into only 10 discrete levels. Looks like a staircase.
The other thing to consider is the input amplifier bandwidth (this applies both to analog and digital scopes). This is also known as slew rate. It describes how fast the input amp can follow a signal change. Imagine an ideal square wave with zero rise time. It has infinite bandwidth. What does this mean? If the signal has a faster riset time than your input amp, your edges will be smoothed out. If I look at the output of a 40 MHz TTL oscillator (which outputs a squarewave) with my 60 MHz scope, I see what is almost a sinewave. "60 MHz scope" means the scope can display a 60 MHz sinewave. The sinewave is the waveform with the slowest slew rate. All other 60 MHz waveforms will also look like a sinewave on this scope. If you want to analyze square waves, your scope will only show a halfway accurate depiction of the signal if it has upwards of ten times the bandwidth of the signal.
There are also problems when measuring high bandwidth signals. Above about 80 MHz, you need to use BNC jacks on both sides, properly terminated with 50 Ohms, or the stuff you see on your scope screen will have very little to do with the actual signal. Not many outputs can drive 50 Ohms. You need to build special prototypes of your stuff that are intended for scope measurements. You can't just take a scope to your CPU or stuff like that.
If I had to make a recommendation, get a 60-100 MHz analog scope in good condition. Tek 465 is a good model.
If you want to look at digital stuff, get a logic analyzer. There are some interesting DIY projects on the web.
For higher frequency or RF stuff, a spectrum analyser can't be beat. But good ones cost more than a luxury car. If you're really serious, there are DIY projects on the net for that, too.
But, an inch is defined as.0254 times one 299,792,458th of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom. I'd say that is even weirder.
Grant you the cheap joke, but... you do know that there are some insanely strong magnets right in your hard drive, right? In fact, the coercivity of today's hard disk media is so high that I'd even venture to say that any type of magnet short of a liquid nitrogen cooled superconducting coil wouldn't be strong enough to affect the data on your hard drive.
Yeah, I bet those $1600 robot dogs will be ready to defend themselves when some 13 year old kid comes along to stuff them in his backpack in order to sell them on eBay... NOT!
Old stuff indeed, the Microsoft Freestyle Pro gamepad is five years old and has a very similar feature, but instead of a gyro, it uses an acceleration sensor (ADXL202) to sense the angle of the controller relative to the earth's gravitational field. A gyro is actually not a good idea for this kind of control because it can only sense relative rotation angles (i.e. you have no zero point).
Well, the whole point in doing all this is to create a system that is cheaper than today's methods of transportation. Capsules would be kinda pointless, because Hopper is unmanned. Its purpose is to transport cargo from the earth to LEO, MEO or GEO. Space plane type vehicles can also carry more cargo compared to single-shot rockets like the Ariane.
Reusable spacecraft are actually much cheaper to use, just not the way the Shuttle does it. The Hopper doesn't have any of that tile nonsense. From the third link (my translation): "Upon reentry of the compact Hopper, the reentry angle into the atmosphere is optimized in such a way that the resulting heat from friction is significantly lower than on the US Shuttle. Thus the delicate and expensive tiles can be replaced with a cheap and maintenance friendly heat protection system."
Mitsui Medical CD-Rs, for one, are specced for 100 years lifetime.
FWIW, I can't remember having a single CD-R go bad. I've had some scrathed ones which took a while to read because the reading drive slowed to a crawl, but I got the data nonetheless. I even recently found what must have been one of the first CD-Rs I've ever burned. Must have been from around '96 or '97, it had my backup copy of Duke Nukem 3D on it, among other stuff, and everything read fine (the disc was a Sony CDQ-74CN).
Say what? If you're talking console cartridges, then there's no "bit-rot", because those use factory mask-programmed ROMs, i.e. the data is etched into good ol' silicon. This is as good as it gets in terms of long-term reliability. Many arcade machines, OTOH, use EPROMs, which tend to "discharge" over the years. But real ROMs are built to last.
In fact, from what I've heard, Asimo isn't autonomous at all. Every single motion is preprogrammed, so e.g. he can climb stairs, but only a specific set of stairs that it's been programmed for, all it can do is play back preprogrammed movements. So maybe it's a nice feat of electrical/mechanical engineering, but it actually has nothing to do with what makes a 'real' robot, i.e. acting autonomously, adapting to its environment or any other AI like stuff.
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Well, maybe not.
No, it's not. You don't buy digital scope to analyse perfect sinewaves. When you're looking at complex waveforms that might include single events and glitches, you need at least a sampling rate ten times your signal frequency. The only way you get your original signal back if it's been sampled at or near the Nyquist frequency is through interpolation. That might be ok for audio applications, but when you need to extract secondary information from the signal, there's just no way. Ten times is the bare minimum, and Tektronix advertise their scope bandwidth as 1/10th the sample rate.
You know, that's a really cool idea ... just carry one or more elevators and a spool of nanotube cable with you on your spaceship. When you need to go to the surface of a planet, go into synchronous orbit, lower the cable, with some kind of robot at the end that automatically attaches it to the ground. Once the cable is anchored, attach the elevator and you can transport stuff and people up and down at will. This could be very useful for quickly strip-mining foreign planets (or invading them, if they're inhabited. Just make sure they don't notice the cable :).
The other thing to consider is the input amplifier bandwidth (this applies both to analog and digital scopes). This is also known as slew rate. It describes how fast the input amp can follow a signal change. Imagine an ideal square wave with zero rise time. It has infinite bandwidth. What does this mean? If the signal has a faster riset time than your input amp, your edges will be smoothed out. If I look at the output of a 40 MHz TTL oscillator (which outputs a squarewave) with my 60 MHz scope, I see what is almost a sinewave. "60 MHz scope" means the scope can display a 60 MHz sinewave. The sinewave is the waveform with the slowest slew rate. All other 60 MHz waveforms will also look like a sinewave on this scope. If you want to analyze square waves, your scope will only show a halfway accurate depiction of the signal if it has upwards of ten times the bandwidth of the signal.
There are also problems when measuring high bandwidth signals. Above about 80 MHz, you need to use BNC jacks on both sides, properly terminated with 50 Ohms, or the stuff you see on your scope screen will have very little to do with the actual signal. Not many outputs can drive 50 Ohms. You need to build special prototypes of your stuff that are intended for scope measurements. You can't just take a scope to your CPU or stuff like that.
If I had to make a recommendation, get a 60-100 MHz analog scope in good condition. Tek 465 is a good model.
If you want to look at digital stuff, get a logic analyzer. There are some interesting DIY projects on the web.
For higher frequency or RF stuff, a spectrum analyser can't be beat. But good ones cost more than a luxury car. If you're really serious, there are DIY projects on the net for that, too.
Well, in any case, you might want to get an Immortality Device before you board one of these things.
You think it's funny, but that's how you actually program in a stack-based language (Forth, Postscript, ...).
It couldn't be easier. Just make sure you use dselect when prompted. It's Debian's phenomenal menu-oriented package selection tool.
Powerline internet?
So they're like the U.S. of the IT world. Which country would SCO be then ... I leave that to your imagination.
No kidding. Ring voltage is around 90Vac at some non-trivial current. That would have been some deep-fryed tongue.
Whoa, dude! That's, like, totally deep and stuff.
Yeah, if "countless" is by your definition "less than 24".
Uhhh ... ever heard of Nero Drive Speed? It allows you to set the speed of your CD/DVD drives. It's free, BTW.
Psshhh, forget John Jones, have a look at this guy here!
But, an inch is defined as .0254 times one 299,792,458th of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom. I'd say that is even weirder.
Grant you the cheap joke, but ... you do know that there are some insanely strong magnets right in your hard drive, right? In fact, the coercivity of today's hard disk media is so high that I'd even venture to say that any type of magnet short of a liquid nitrogen cooled superconducting coil wouldn't be strong enough to affect the data on your hard drive.
Don't worry, even the NASA has problems with this sort of thing.
Yeah, I bet those $1600 robot dogs will be ready to defend themselves when some 13 year old kid comes along to stuff them in his backpack in order to sell them on eBay ... NOT!
Old stuff indeed, the Microsoft Freestyle Pro gamepad is five years old and has a very similar feature, but instead of a gyro, it uses an acceleration sensor (ADXL202) to sense the angle of the controller relative to the earth's gravitational field. A gyro is actually not a good idea for this kind of control because it can only sense relative rotation angles (i.e. you have no zero point).
Download it here. Still great fun today, and even runs in XP.
Reusable spacecraft are actually much cheaper to use, just not the way the Shuttle does it. The Hopper doesn't have any of that tile nonsense. From the third link (my translation): "Upon reentry of the compact Hopper, the reentry angle into the atmosphere is optimized in such a way that the resulting heat from friction is significantly lower than on the US Shuttle. Thus the delicate and expensive tiles can be replaced with a cheap and maintenance friendly heat protection system."
FWIW, I can't remember having a single CD-R go bad. I've had some scrathed ones which took a while to read because the reading drive slowed to a crawl, but I got the data nonetheless. I even recently found what must have been one of the first CD-Rs I've ever burned. Must have been from around '96 or '97, it had my backup copy of Duke Nukem 3D on it, among other stuff, and everything read fine (the disc was a Sony CDQ-74CN).
Say what? If you're talking console cartridges, then there's no "bit-rot", because those use factory mask-programmed ROMs, i.e. the data is etched into good ol' silicon. This is as good as it gets in terms of long-term reliability. Many arcade machines, OTOH, use EPROMs, which tend to "discharge" over the years. But real ROMs are built to last.
In fact, from what I've heard, Asimo isn't autonomous at all. Every single motion is preprogrammed, so e.g. he can climb stairs, but only a specific set of stairs that it's been programmed for, all it can do is play back preprogrammed movements. So maybe it's a nice feat of electrical/mechanical engineering, but it actually has nothing to do with what makes a 'real' robot, i.e. acting autonomously, adapting to its environment or any other AI like stuff.
Real geeks don't draw, they program in PostScript.