I actually own the original DOS version and still have the manual and everything. One thing SimLife teaches you is that it's really hard to build up a complex ecology in a confined space. If you use the smaller maps, it's almost impossible to get carnivores to survive. There's simply not enough room for them. If you use the largest maps, I've been able to get some stable carnivore populations, but not a ton.
Fruit trees are also darn difficult to get to spread (because they require animals), whereas grasses are very easy (as they spread on the wind).
That's what I said before. This is unlikely, as the comet wasn't pristine before. It was already pocked with craters. It's extremely unlikely that a comet could survive like that, especially as its proximity to the Sun (and the existence of its tails) implies that anything under pressure would likely burst.
(b) the stuff coming out is "burning" and giving off chemical energy
No. Think about that for a moment. That would impart momentum to the ejecta, not to the comet. You'd then further have to assume that the ejecta is pushing back on the comet to reimpart some of that momentum on the comet. That's going to be tiny compared to the original impact.
No oxygen, anyway.
(c) the stuff coming out can be made to take part in a chemical reaction
See above. Won't impart momentum to the comet.
d) the stuff is volatile enough that warming it with (say) sunlight, causes it to expand sufficiently to exit the rock at speed etc. etc. etc.
See above. I guess you could make the claim that the impactor made enough of an impact to cut away to a more volatile layer that boiled off into space in sunlight, but that, again, would be a tiny, tiny fraction of the momentum imparted by the impactor. This is exceptionally unlikely, because the comet would have to have a thin layer of nonvolatile material, and then a lot of volatile material. See the "under pressure" argument.
Now there's a concept with some intresting consequences... if more than one body shares the same orbit, that too is "unstable to anything"
Nope. They probably won't collide. Consider a body starting in the L3 point of the Earth and the Sun, and perturbed slightly. If it's perturbed outwards, it will orbit slightly slower, inward, slightly faster, and so it will rotate around the Sun, toward the Earth. But in doing so, it may pass through L4 and L5, which are both stable Lagrange points, and will tend to reverse the path of the asteroid (in the rotating frame). There's a semi-large asteroid called Cruithne which is in such an orbit. You can see a drawing of its orbit in the corotating frame here. As you can see, when it approaches L4 and L5, the potential turns them around, so Cruithne is well protected against colliding with Earth.
It's a little hard to understand such an orbit, but the gist of it is this. It's important to remember that when you move inward towards the Sun, you speed up, and so end up moving counterclockwise in the corotating frame. When you move outward, you slow down, so you end up moving clockwise in the corotating frame. So if you push an object towards the Sun from L3, it'll go faster, moving counterclockwise, towards L5. As you approach L5, though, you're getting closer to the planet (Earth). It pulls you outward (since you're inward from it), which slows you down, which moves you back clockwise, and away from the planet. Repeat for L4.
L4 and L5 tend to "sweep up" all the material in the orbit between them (i.e. on the other side of the planet). There's a nice discussion on the behavior of objects near the Lagrange points here. It even mentions the timescale over which the Lagrange points are unstable. L1 and L2 are unstable on periods of ~23 days. L3 is unstable on periods of ~150 years, which means you could conceivably have a manmade body there with relatively little effort. Not much reason for anything there, though, as it is constantly out of touch with Earth, being on the opposite side of the Sun and all.
To compute the change in trajectory, you'll need to take into account the effect of all that stuff that's now spewing out of the comet which has turned into a mini rocket motor.
The only way that would be true is if the contents of the comet were under pressure to begin with, which it isn't.
There's nothing spewing out of the comet. The material that came out of the comet is merely the ejecta from the impact. Conservation of energy and momentum says that the effect of the ejecta from the impact has to be less than the effect of all of the impactor's momentum going into the comet.
Take two bodies A & B and put them in some kind of orbit about each other. Now take a third much smaller body C and put it at L1 - the Lagrange point between A & B. The positions of the three bodies should be entirely predictable for all eternity.
No. L1 is unstable. By "unstable", it doesn't mean "unstable to something hitting it", it means "unstable to anything", including alpha decay of one of the nuclei in the asteroid, or a black hole passing ten light years away. It won't stay there. A test particle would stay there if those two masses were point masses and the only masses in the known Universe. But that's the only situation.
The n-body problem is chaotic, but you won't ever get a real-life situation where you have astronomical objects in unstable equilibria.
Fortunately, people have. Give your source some credit.
Okay. My source is Google "mass tempel 1", reading the Deep Impact page regarding impactor mass and velocity, and just doing a change in momentum.
I didn't see that page before, actually. Hence the reason that everything was ballparky (save the mass of the impactor, that was from an article). Cool that I got it right. Sucks that I could've saved myself a bit of time.:)
Far from being pointless or unmeasurable
It is unmeasurable. That part was directly stated by an interviewee on NPR. Given the fact that its effective orbital shift (10 m, from the page you mentioned) is way, way below the precision that we measure its orbit, it's unmeasurable.
And actually, it's less than you think it is. Had I even looked up the orbit of Tempel 1 beforehand, I would've seen that it's in a 2:1 resonance with Jupiter. That means that we actually did nothing except induce a slight (additional) oscillation arond its current orbit that will damp with time, since resonances are stable equilibria.
I've sometimes wondered if you could trigger some kind of butterfly-effect by interfering with a (solar) system that might look anarchic, but has actually had several billion years to settle down into some kind of inscrutable relative-equilibrum... but I have to say I don't think it's very likely.
The solar system definitely is not in equilibrium. The fact that Shoemaker-Levy 9 smashed into Jupiter should send that point home quite dramatically. If not, then Saturn's rings, the moons of Mars and (I think) Triton should also, as they're all unstable and slowly decaying.
Or you could just look at the Earth-Moon system - the Earth is slowing down its rotation, and the Moon is moving farther out.
But even if it was: when you say "equilibrium", what you really mean is "stable equilibrium". If the system's truly stable, then a small perturbation will merely cause the system to oscillate a little and return to its original state. So this wouldn't've done anything except cause a miniscule oscillation.
But, as I said before, the Solar System is definitely not in equilibrium - at least not when it comes to orbits.
In fact, though, its current situation is worse: you don't expect a 'butterfly effect' from a system in equilibrium. Systems in equilibrium just oscillate. You expect one from a chaotic system out of equilibrium, which is what we have.
In such a system, what you have to ask is "is the perturbation that we're creating on the system significant compared to the other perturbations that already exist?" and the answer to that is most definitely no. Jupiter is the largest disturber of cometary orbits, and the perturbation that Deep Impact caused is about 10 billion times weaker than its last passage near Jupiter.
But in any case, even though the system is (somewhat) chaotic, we can still determine how much we perturbed Tempel 1 with that impact. The answer is "not at all". So if Tempel 1 was previously predicted to hit Earth, it would still hit Earth. If Tempel 1 was previously predicted to miss Earth, it would still miss Earth. Hint: it's the latter.
an shy-looking astronomer was interviewed and she said something to the effect of "you know, that experiment is sort of interesting, but we regret this "american buckaroo-style" (sic) way of doing space research, as a probe that could land and latch on the comet, then drill and study things would have done a better job for not much more money."
Sorry. If that's what she honestly said (and meant), she's a loony.
1: It's not easy to land on a comet or asteroid. The gravity's quite weak, and not regular either. Especially as you don't know the composition or internal structure.
2: It's not like the comet was going to stay pristine. Comets travel through very harsh environments. It's unlikely that if we went back to Tempel I on its next orbit that we'd see the same surface features. There's no "preservation" really needed.
3: The impactor created an explosion equivalent to about 5 tons of TNT. That would've taken a lot of drilling, and it still would've only given localized information.
4: Finally, and most importantly, it's simply ludicrous to believe that this mission could've been replaced with one with a controlled, long duration landing probe for nearly equivalent money. We know very little about the surface of a comet. It's entirely possible had we tried to design a lander, we would've sent it there and then said "well, um, we found out all of its instruments are useless on comets!"
The other comment I've heard, from a friend who studies all kinds of space things, is that he hoped NASA picked their comet-target right, because they probably changed its trajectory in minute ways
Do the math. Any change in its orbit is unmeasurable. Comets are still very big - Tempel 1 is in the 10^13 kg range. The impactor was 370 kg. Relative velocity was 10 km/s. That means you're talking about a delta-V in the neighborhood of a tenth of a micron per second.
but my point was that a wall would have a higher noise temperature then space, therefore, signal-to-noise ratio would suffer.
Not if you increase the signal by more than you increase the noise.
If you put them on a wall, what are you chances that all the stations are going to line up properly to the wall planes, or are the beams wide enough that +/- 45 Degrees is acceptable?
It varies like cos(theta).
Wall plane? Why wouldn't you use the ceiling, and paint over them? Or you could literally put it in the ceiling (or in the floor) but there you might get a bit too much loss. Depends on the construction, though. A drop ceiling would make it easy.
I probably don't get 50 stations, but I get at least 20
You can only get 11 VHF stations (2-13). UHF stations are much, much shorter wavelengths. You probably only have something like 4 VHF stations, so probably only 4 antennas that are sizable.
But I don't believe doing what you say, and making it asthetically pleasing would be a trivial matter, which is why people use suboptimal antennae.
Nah. It's because people can buy rabbit ears. They can't buy tuned folded dipole antennas.
Not every game can be SuperMario with only one Jump and one Run button.
Sigh. Why do people misunderstand game design?
Almost every game has a "most commonly used" button. The ones that don't are typically Street Fighter-type games, but even those tend to have a more commonly used attack and less commonly used attacks.
Besides, honestly, if it's impossible to make Street Fighter-type games work effectively on a GC, then you just make another controller specifically for those games. But so far there hasn't been a need for it.
Nintendo games aren't simple. Hell, look at Metroid Prime, which uses all the buttons on the controller. But the point is that almost all games have a "most commonly used" button, and several secondary (less used) buttons. The games that most people here are complaining about are either poorly ported (Metal Gear Solid - that's just ridiculous) or Street Fighter type games (Soul Caliber).
Here's the point: The GC controller is ideal for probably about 90% of all games, and less than ideal for about 10%. The PS2 controller is ideal (well... somewhat - a 6-button Genesis controller is probably most ideal) for about 10% of games, and less than ideal for 90%.
Racing games, FPSs, platformers, 3D platformers, RPGs, and sports games all have 1 main action. For those games, the GC controller is ideal.
The GC controller isn't simple. It still has far more buttons and controls than any sane game would use. It just arranges them to suit the vast majority of games better.
The Gamecube controller is my favorite of the three, however the lack of buttons really is a problem and I really would like if Nintendo would stop trying to be simple as the rest and provide a consoler that actually works properly with ALL the games and not just that handfull that is released by Nintendo.
It's 1 button! Come on! Are you really telling me that you think it's so hard for a game developer to reduce the button count by one that they can't do it?
Honestly, this is stupid. The only reason you end up with stupid mappings is because certain developers are lazy with the GC port. This isn't Nintendo's problem. They provided a better controller, and developers are just screwing it up. Blame the developer, not Nintendo.
Boy, you're right, that doesn't sound arbitrary or nonintuitive at all.
Play the game before you pass judgement. Chording (using multiple keys at once) is much easier than remembering individual key locations. That's not just an opinion - that's been proven repeatedly by scientific studies. It's just hard to get people to change.
Reread the description for Turok 2 again. Instead of having 16 different button presses, they grouped them into two sets (better for memory as to the power of each one) and you don't even have to move both of your thumbs much. It's an extremely intuitive solution.
I still haven't seen an alternate keymap for Nethack, BTW.
Nethack is a Rogue derivative. Is there a Rogue derivative for consoles already? Yah, Square made one: Chocobo's Mysterious Dungeon. Lo and behold, what did it use? A menu, and a bunch of context-sensitive keys.
It should be noted that a lot of the keys in Nethack are pointless anyway, and could be replaced by context-sensitive stuff. "Go up a staircase/down a staircase", "open door/close door/kick down a door" are things that can only be done when you're near a certain object. Therefore you don't need a dedicated button - you just need one button, and proximity to the object indicates what you want to do.
At the very least, you absolutely don't need "open door" and "close door".
Plus it has a lot of redundant keys as well: "take off armor, put on armor, wield weapon" and "tell what kind of armor" "what kind of rings" etc. Those could all be easily replaced with either a menu or a button combination.
I don't fault Nethack. It used the interface it was given. But don't even try to suggest that Nethack couldn't be ported to a console with few keys. It's been done.
Community associations do have rules about what can be mounted on the outside of the house, and I know people that have had to take roof mounted antennae down. They and many people consider them eye sores, and rightly so. But anyhow, what the community association can and can't do is a question for a lawyer.
By the way, if you care, and you still know those community associations, here is the page I was talking about. Short version - you can't prevent someone from putting up a rooftop antenna. You can force them to put it in a less visible location, but only if it doesn't make the reception worse and doesn't cost any more. Note that the restriction has to be written that way - if there was a restriction that said "you can't put up TV antennas" then you can perfectly well ignore it, as it isn't a legal restriction. If they try to change it afterwards, they're probably still out of luck, as it'll cost you money and time to move it, and they can't do that, either.
But anyhow, what the community association can and can't do is a question for a lawyer.
Well, yes, but it's already been decided. It's simple enough to point the community association to the FCC's webpage and tell them to go shove it. Community associations can't say "no satellite dishes" nor "no antennas" nor anything else that allows you access to the radio spectrum. Only the FCC can say that.
Whether or not the gain of the antenna is more than the loss of the walls is less important then does the wall add to the noise temperature of the system, thereby decreasing the signal to noise ratio.
That's not what I'm saying. You're not talking about amplifying a signal - you're just talking about picking it up better. It's not like putting an amplifier in the system, because you don't amplify the noise - just the signal.
To be more specific: if you have an antenna which isn't pointed correctly, and you orient it properly, you increase the signal without increasing the noise. If you have an antenna which isn't tuned to the correct frequency, and you tune it correctly, you increase the signal and only change the noise by the difference in noise floors between the two bandwidths.
You're not talking about increasing the gain. You're talking about reducing the signal loss. The point here is: an antenna properly oriented and tuned indoors is probably better than an antenna poorly oriented and not tuned outdoors. Of course, a properly oriented and properly tuned antenna outdoors wins over all, but that's not the point.
A lot of loss just can't be followed by a lot of gain, because eventually all you will be amplifying is noise.
Tuning and orienting isn't increasing the gain of an antenna, at least, not in the sense you're thinking. It's just reducing loss.
So to get 54 different stations I need 54 different antennae?
Who the hell has 54 over the air TV stations? I've got like 6. But yah, one antenna for each station. It isn't that big a deal, considering a folded dipole is just a piece of wire.
Also, how large are these antennae and what do you estimate the beamwidth and gain of these antennae to be?
Eh, about 5' and a bit or so for the low channels, down to about 2' for the higher VHF channels. It's just about perfect to be hidden on a wall. You lose a bit more if you stick it behind a TV, due to interference, but again, if your only other option was rabbit ears on top of the TV, you're still better off.
Where are you going to mount all of these antennas? Most community associations don't even allow one to mount ONE large yagi array antennas on their rooves anymore. Even if they did, one has to rotate the array for optimal reception.
Wow. Several answers to that one.
No community association can say anything about what kind of antennas you can put up. They don't have the authority to say that - only the FCC does. The FCC has a FAQ about this somewhere. Plenty of them try to say this, but they simply can't. It's completely clear law.
Indoors. The gain you get from properly tuning an antenna and orienting each one right is probably more than the loss due to the walls.
I wasn't talking about a single conjoined array. Build a set of folded dipole antennas, each one tuned to a specific frequency, and rotated (or just build one end longer than the other to simulate a rotation) to point to the proper broadcaster.
You build them properly once, and then never have to do it again.
i'm happy to pay $40/mo not to have to adjust an antenna to only get a handful of channels.
again adjusting the antenna.
You don't have to adjust antennas to get the best reception. If you were smart, you'd build multiple antennas to the proper wavelengths and chain them together. The reason you adjust rabbit ears is because they're just about the worst design you could possibly imagine.
i'm happy to pay $40/mo not to have to adjust an antenna to only get a handful of channels. and now, i'm happy to pay $70/mo for digital cable with HDTV, because my HDTV doesn't have a tuner, and the cheapest HDTV with a tuner when i got mine was $800, when mine was $300.
I wouldn't go pushing that logic too much if I were you. Paying $30/mo to save $500 isn't a winning proposition. The latter argument is still fine, though.
Of course, you'll get the improved reception and clarity as a bonus, but if you're using a normal antenna right now... chances are you're not really too concerned about that, are you?
Dunno. Most of the OTA broadcasts in Columbus, OH are higher quality than the analog cable. Ridiculously high transmitting power tends to do that.
The six-button one wasn't the best, but you can learn that from muscle memory.
Well, I can learn a PlayStation's controller positions with muscle memory, but that doesn't stop me from hesitating a few times when a screen says "Push X" or "Push O".
Plus, for the record, the B button had a little nub on it (not unlike the j and f buttons on a qwerty keyboard) to encourage you to "touch type" on the controller.
Hey, you're right! I never noticed that before (... and that's sad, really). Not quite as intelligent as the SNES convex/concave, but still pretty good. Better than the crap PlayStation controllers, at least.
and a decent shape that fits into your hands.
Well, the DC controller is a little too big. It's not stupid Xbox big, but it was a little unwieldy.
But the right thumbstick I've never really liked, and, gasp, its short a button.
I don't understand the "short a button" argument. Games that actually use 8 buttons are poorly designed. Plain and simple. It's far easier to add an extra button than to figure out a way to simplify gameplay. That's why the GC's controller is nice, because it encourages developers to simplify gameplay and to reduce the button usage. But saying 7 buttons is worse than 8 is just silly, especially when the shoulder buttons on a PS2 controller are awkward, and the black and white buttons are awkward as well.
Just sayin', guys, that he's wrong on some counts and right on others. Doesn't mean he can't present his opinion.
He's not consistent. That's the problem. He starts off by saying that the Genesis controller's 3 button layout is better than the SNES's 4 button layout, and then later criticizes Nintendo for not using the standard 4 button layout.
In general, he never actually really addresses the entire topic - ergonomics of the controller.
I've seen conflicting answers on that, actually. I can't find the actual original Nintendo patent (the first one I can find was from 1990). I've also seen places that describe that the Dreamcast's D-pad is sufficiently different that it didn't violate Nintendo's patent.
That would be why Master System, Genesis, GameGear, Turbosomethingorother, Nomad, Saturn, DreamCast, XBox, almost all 3rd party PS1/2 controllers, and almost all controllers made since Game and Watch was released make use of a cross controller?
Go and look at the controllers of all of those systems.
None of them have a cross controller, save the Dreamcast. They have a 4-way D-pad, but it's not a cross - it's a disk with a cross raised on it. The Dreamcast gets around it because the internal mechanism is sufficiently different (and worse, in my opinion).
Maybe he misnamed the article. Maybe he wanted it to be "controller aesthetics" rather than "controller ergonomics".
You're dead on, though. The GC controller is extremely well designed. It fits in your hand, after all. My big problem with the GC controller is it takes just a little bit too much effort to click the shoulder buttons, but to be honest, I don't really notice them all that much.
Plus, I don't know how anyone could call the N64 controller a disaster. It was excellent for the console it was made for - a transition between a 4-way D-pad and analog sticks. Honestly, I have no idea why Sony still has a D-pad on the PS3 controller - it's fairly anachronistic by now. If they were smart, they would've made the controller modular - able to switch in and out a D-pad or an analog stick with a little module.
Man. Nice attempt, but it's too bad they're really, really wrong when it comes to their scores.
Take a look at the Genesis controller versus the SNES Controller. The Genesis controller had a better D-pad? What? The whole problem with semi-8 way D-pads is that they aren't actually as precise as the pure 4-way ones. In some games this is okay, but in others you prefer actually knowing which direction you're pushing. Sega didn't use it as an improvement. It was because Nintendo had a patent on a 4-way cross D-pad.
And deriding the SNES controller for its buttons? What? The Genesis 3-button and 6-button controllers had identical buttons. You had no idea which ones you were pushing without looking down (or knowing from position). The three-button design was bad, not good - you can locate two buttons, because whatever button your thumb is on, the second button is the other one. With three, that's not the case. The SNES controller, on the other hand, had two concave and two convex buttons. You could tell which button you were pressing by touch, and you could locate at least 2 of the other 3 buttons purely by touch, and because they were lined up in the way they were, you could locate the last one as well. Much, much smarter, and the touch-location is sorely missing from most modern controllers.
My favorite is this comment, regarding the GameCube controller:
This encouraged simple, single-button play without sacrificing versatility. It also made multi-console games a lot harder to play and made ports from other consoles worse.
I see. So Nintendo makes the most intelligent controller of all of them, and they lose points because it's harder to play games that were poorly ported and designed for worse controllers. Good call.
And, also...
And, in a cruelly ironic twist, everything else changed but the d-pad is still split... because Nintendo has a patent on a 4-way cross controller.
A whole lot of opinion, but absolutely no concept of ergonomics.
Slashdot Mirror
SimLife is a better analogy.
I actually own the original DOS version and still have the manual and everything. One thing SimLife teaches you is that it's really hard to build up a complex ecology in a confined space. If you use the smaller maps, it's almost impossible to get carnivores to survive. There's simply not enough room for them. If you use the largest maps, I've been able to get some stable carnivore populations, but not a ton.
Fruit trees are also darn difficult to get to spread (because they require animals), whereas grasses are very easy (as they spread on the wind).
(a) the stuff coming out is under pressure
That's what I said before. This is unlikely, as the comet wasn't pristine before. It was already pocked with craters. It's extremely unlikely that a comet could survive like that, especially as its proximity to the Sun (and the existence of its tails) implies that anything under pressure would likely burst.
(b) the stuff coming out is "burning" and giving off chemical energy
No. Think about that for a moment. That would impart momentum to the ejecta, not to the comet. You'd then further have to assume that the ejecta is pushing back on the comet to reimpart some of that momentum on the comet. That's going to be tiny compared to the original impact.
No oxygen, anyway.
(c) the stuff coming out can be made to take part in a chemical reaction
See above. Won't impart momentum to the comet.
d) the stuff is volatile enough that warming it with (say) sunlight, causes it to expand sufficiently to exit the rock at speed etc. etc. etc.
See above. I guess you could make the claim that the impactor made enough of an impact to cut away to a more volatile layer that boiled off into space in sunlight, but that, again, would be a tiny, tiny fraction of the momentum imparted by the impactor. This is exceptionally unlikely, because the comet would have to have a thin layer of nonvolatile material, and then a lot of volatile material. See the "under pressure" argument.
Now there's a concept with some intresting consequences... if more than one body shares the same orbit, that too is "unstable to anything"
Nope. They probably won't collide. Consider a body starting in the L3 point of the Earth and the Sun, and perturbed slightly. If it's perturbed outwards, it will orbit slightly slower, inward, slightly faster, and so it will rotate around the Sun, toward the Earth. But in doing so, it may pass through L4 and L5, which are both stable Lagrange points, and will tend to reverse the path of the asteroid (in the rotating frame). There's a semi-large asteroid called Cruithne which is in such an orbit. You can see a drawing of its orbit in the corotating frame here. As you can see, when it approaches L4 and L5, the potential turns them around, so Cruithne is well protected against colliding with Earth.
It's a little hard to understand such an orbit, but the gist of it is this. It's important to remember that when you move inward towards the Sun, you speed up, and so end up moving counterclockwise in the corotating frame. When you move outward, you slow down, so you end up moving clockwise in the corotating frame. So if you push an object towards the Sun from L3, it'll go faster, moving counterclockwise, towards L5. As you approach L5, though, you're getting closer to the planet (Earth). It pulls you outward (since you're inward from it), which slows you down, which moves you back clockwise, and away from the planet. Repeat for L4.
L4 and L5 tend to "sweep up" all the material in the orbit between them (i.e. on the other side of the planet). There's a nice discussion on the behavior of objects near the Lagrange points here. It even mentions the timescale over which the Lagrange points are unstable. L1 and L2 are unstable on periods of ~23 days. L3 is unstable on periods of ~150 years, which means you could conceivably have a manmade body there with relatively little effort. Not much reason for anything there, though, as it is constantly out of touch with Earth, being on the opposite side of the Sun and all.
To compute the change in trajectory, you'll need to take into account the effect of all that stuff that's now spewing out of the comet which has turned into a mini rocket motor.
The only way that would be true is if the contents of the comet were under pressure to begin with, which it isn't.
There's nothing spewing out of the comet. The material that came out of the comet is merely the ejecta from the impact. Conservation of energy and momentum says that the effect of the ejecta from the impact has to be less than the effect of all of the impactor's momentum going into the comet.
Take two bodies A & B and put them in some kind of orbit about each other. Now take a third much smaller body C and put it at L1 - the Lagrange point between A & B. The positions of the three bodies should be entirely predictable for all eternity.
No. L1 is unstable. By "unstable", it doesn't mean "unstable to something hitting it", it means "unstable to anything", including alpha decay of one of the nuclei in the asteroid, or a black hole passing ten light years away. It won't stay there. A test particle would stay there if those two masses were point masses and the only masses in the known Universe. But that's the only situation.
The n-body problem is chaotic, but you won't ever get a real-life situation where you have astronomical objects in unstable equilibria.
Fortunately, people have. Give your source some credit.
:)
Okay. My source is Google "mass tempel 1", reading the Deep Impact page regarding impactor mass and velocity, and just doing a change in momentum.
I didn't see that page before, actually. Hence the reason that everything was ballparky (save the mass of the impactor, that was from an article). Cool that I got it right. Sucks that I could've saved myself a bit of time.
Far from being pointless or unmeasurable
It is unmeasurable. That part was directly stated by an interviewee on NPR. Given the fact that its effective orbital shift (10 m, from the page you mentioned) is way, way below the precision that we measure its orbit, it's unmeasurable.
And actually, it's less than you think it is. Had I even looked up the orbit of Tempel 1 beforehand, I would've seen that it's in a 2:1 resonance with Jupiter. That means that we actually did nothing except induce a slight (additional) oscillation arond its current orbit that will damp with time, since resonances are stable equilibria.
I've sometimes wondered if you could trigger some kind of butterfly-effect by interfering with a (solar) system that might look anarchic, but has actually had several billion years to settle down into some kind of inscrutable relative-equilibrum... but I have to say I don't think it's very likely.
The solar system definitely is not in equilibrium. The fact that Shoemaker-Levy 9 smashed into Jupiter should send that point home quite dramatically. If not, then Saturn's rings, the moons of Mars and (I think) Triton should also, as they're all unstable and slowly decaying.
Or you could just look at the Earth-Moon system - the Earth is slowing down its rotation, and the Moon is moving farther out.
But even if it was: when you say "equilibrium", what you really mean is "stable equilibrium". If the system's truly stable, then a small perturbation will merely cause the system to oscillate a little and return to its original state. So this wouldn't've done anything except cause a miniscule oscillation.
But, as I said before, the Solar System is definitely not in equilibrium - at least not when it comes to orbits.
In fact, though, its current situation is worse: you don't expect a 'butterfly effect' from a system in equilibrium. Systems in equilibrium just oscillate. You expect one from a chaotic system out of equilibrium, which is what we have.
In such a system, what you have to ask is "is the perturbation that we're creating on the system significant compared to the other perturbations that already exist?" and the answer to that is most definitely no. Jupiter is the largest disturber of cometary orbits, and the perturbation that Deep Impact caused is about 10 billion times weaker than its last passage near Jupiter.
But in any case, even though the system is (somewhat) chaotic, we can still determine how much we perturbed Tempel 1 with that impact. The answer is "not at all". So if Tempel 1 was previously predicted to hit Earth, it would still hit Earth. If Tempel 1 was previously predicted to miss Earth, it would still miss Earth. Hint: it's the latter.
an shy-looking astronomer was interviewed and she said something to the effect of "you know, that experiment is sort of interesting, but we regret this "american buckaroo-style" (sic) way of doing space research, as a probe that could land and latch on the comet, then drill and study things would have done a better job for not much more money."
Sorry. If that's what she honestly said (and meant), she's a loony.
1: It's not easy to land on a comet or asteroid. The gravity's quite weak, and not regular either. Especially as you don't know the composition or internal structure.
2: It's not like the comet was going to stay pristine. Comets travel through very harsh environments. It's unlikely that if we went back to Tempel I on its next orbit that we'd see the same surface features. There's no "preservation" really needed.
3: The impactor created an explosion equivalent to about 5 tons of TNT. That would've taken a lot of drilling, and it still would've only given localized information.
4: Finally, and most importantly, it's simply ludicrous to believe that this mission could've been replaced with one with a controlled, long duration landing probe for nearly equivalent money. We know very little about the surface of a comet. It's entirely possible had we tried to design a lander, we would've sent it there and then said "well, um, we found out all of its instruments are useless on comets!"
The other comment I've heard, from a friend who studies all kinds of space things, is that he hoped NASA picked their comet-target right, because they probably changed its trajectory in minute ways
Do the math. Any change in its orbit is unmeasurable. Comets are still very big - Tempel 1 is in the 10^13 kg range. The impactor was 370 kg. Relative velocity was 10 km/s. That means you're talking about a delta-V in the neighborhood of a tenth of a micron per second.
It's just completely and totally pointless.
but my point was that a wall would have a higher noise temperature then space, therefore, signal-to-noise ratio would suffer.
Not if you increase the signal by more than you increase the noise.
If you put them on a wall, what are you chances that all the stations are going to line up properly to the wall planes, or are the beams wide enough that +/- 45 Degrees is acceptable?
It varies like cos(theta).
Wall plane? Why wouldn't you use the ceiling, and paint over them? Or you could literally put it in the ceiling (or in the floor) but there you might get a bit too much loss. Depends on the construction, though. A drop ceiling would make it easy.
I probably don't get 50 stations, but I get at least 20
You can only get 11 VHF stations (2-13). UHF stations are much, much shorter wavelengths. You probably only have something like 4 VHF stations, so probably only 4 antennas that are sizable.
But I don't believe doing what you say, and making it asthetically pleasing would be a trivial matter, which is why people use suboptimal antennae.
Nah. It's because people can buy rabbit ears. They can't buy tuned folded dipole antennas.
Not every game can be SuperMario with only one Jump and one Run button.
Sigh. Why do people misunderstand game design?
Almost every game has a "most commonly used" button. The ones that don't are typically Street Fighter-type games, but even those tend to have a more commonly used attack and less commonly used attacks.
Besides, honestly, if it's impossible to make Street Fighter-type games work effectively on a GC, then you just make another controller specifically for those games. But so far there hasn't been a need for it.
Nintendo games aren't simple. Hell, look at Metroid Prime, which uses all the buttons on the controller. But the point is that almost all games have a "most commonly used" button, and several secondary (less used) buttons. The games that most people here are complaining about are either poorly ported (Metal Gear Solid - that's just ridiculous) or Street Fighter type games (Soul Caliber).
Here's the point: The GC controller is ideal for probably about 90% of all games, and less than ideal for about 10%. The PS2 controller is ideal (well... somewhat - a 6-button Genesis controller is probably most ideal) for about 10% of games, and less than ideal for 90%.
Racing games, FPSs, platformers, 3D platformers, RPGs, and sports games all have 1 main action. For those games, the GC controller is ideal.
The GC controller isn't simple. It still has far more buttons and controls than any sane game would use. It just arranges them to suit the vast majority of games better.
Sure about that? I count 4 more on the PS2 Pad.
and only 1 more on the Xbox pad. If you're talking about cross platform capabilities, then you need to consider what's common between the other two.
It's 1 if you ignore "select" (only the second shoulder button is missing).
The Gamecube controller is my favorite of the three, however the lack of buttons really is a problem and I really would like if Nintendo would stop trying to be simple as the rest and provide a consoler that actually works properly with ALL the games and not just that handfull that is released by Nintendo.
It's 1 button! Come on! Are you really telling me that you think it's so hard for a game developer to reduce the button count by one that they can't do it?
Honestly, this is stupid. The only reason you end up with stupid mappings is because certain developers are lazy with the GC port. This isn't Nintendo's problem. They provided a better controller, and developers are just screwing it up. Blame the developer, not Nintendo.
Boy, you're right, that doesn't sound arbitrary or nonintuitive at all.
Play the game before you pass judgement. Chording (using multiple keys at once) is much easier than remembering individual key locations. That's not just an opinion - that's been proven repeatedly by scientific studies. It's just hard to get people to change.
Reread the description for Turok 2 again. Instead of having 16 different button presses, they grouped them into two sets (better for memory as to the power of each one) and you don't even have to move both of your thumbs much. It's an extremely intuitive solution.
I still haven't seen an alternate keymap for Nethack, BTW.
Nethack is a Rogue derivative. Is there a Rogue derivative for consoles already? Yah, Square made one: Chocobo's Mysterious Dungeon. Lo and behold, what did it use? A menu, and a bunch of context-sensitive keys.
It should be noted that a lot of the keys in Nethack are pointless anyway, and could be replaced by context-sensitive stuff. "Go up a staircase/down a staircase", "open door/close door/kick down a door" are things that can only be done when you're near a certain object. Therefore you don't need a dedicated button - you just need one button, and proximity to the object indicates what you want to do.
At the very least, you absolutely don't need "open door" and "close door".
Plus it has a lot of redundant keys as well: "take off armor, put on armor, wield weapon" and "tell what kind of armor" "what kind of rings" etc. Those could all be easily replaced with either a menu or a button combination.
I don't fault Nethack. It used the interface it was given. But don't even try to suggest that Nethack couldn't be ported to a console with few keys. It's been done.
Community associations do have rules about what can be mounted on the outside of the house, and I know people that have had to take roof mounted antennae down. They and many people consider them eye sores, and rightly so. But anyhow, what the community association can and can't do is a question for a lawyer.
By the way, if you care, and you still know those community associations, here is the page I was talking about. Short version - you can't prevent someone from putting up a rooftop antenna. You can force them to put it in a less visible location, but only if it doesn't make the reception worse and doesn't cost any more. Note that the restriction has to be written that way - if there was a restriction that said "you can't put up TV antennas" then you can perfectly well ignore it, as it isn't a legal restriction. If they try to change it afterwards, they're probably still out of luck, as it'll cost you money and time to move it, and they can't do that, either.
But anyhow, what the community association can and can't do is a question for a lawyer.
Well, yes, but it's already been decided. It's simple enough to point the community association to the FCC's webpage and tell them to go shove it. Community associations can't say "no satellite dishes" nor "no antennas" nor anything else that allows you access to the radio spectrum. Only the FCC can say that.
Whether or not the gain of the antenna is more than the loss of the walls is less important then does the wall add to the noise temperature of the system, thereby decreasing the signal to noise ratio.
That's not what I'm saying. You're not talking about amplifying a signal - you're just talking about picking it up better. It's not like putting an amplifier in the system, because you don't amplify the noise - just the signal.
To be more specific: if you have an antenna which isn't pointed correctly, and you orient it properly, you increase the signal without increasing the noise. If you have an antenna which isn't tuned to the correct frequency, and you tune it correctly, you increase the signal and only change the noise by the difference in noise floors between the two bandwidths.
You're not talking about increasing the gain. You're talking about reducing the signal loss. The point here is: an antenna properly oriented and tuned indoors is probably better than an antenna poorly oriented and not tuned outdoors. Of course, a properly oriented and properly tuned antenna outdoors wins over all, but that's not the point.
A lot of loss just can't be followed by a lot of gain, because eventually all you will be amplifying is noise.
Tuning and orienting isn't increasing the gain of an antenna, at least, not in the sense you're thinking. It's just reducing loss.
So to get 54 different stations I need 54 different antennae?
Who the hell has 54 over the air TV stations? I've got like 6. But yah, one antenna for each station. It isn't that big a deal, considering a folded dipole is just a piece of wire.
Also, how large are these antennae and what do you estimate the beamwidth and gain of these antennae to be?
Eh, about 5' and a bit or so for the low channels, down to about 2' for the higher VHF channels. It's just about perfect to be hidden on a wall. You lose a bit more if you stick it behind a TV, due to interference, but again, if your only other option was rabbit ears on top of the TV, you're still better off.
Wow. Several answers to that one.
You build them properly once, and then never have to do it again.
i'm happy to pay $40/mo not to have to adjust an antenna to only get a handful of channels.
again adjusting the antenna.
You don't have to adjust antennas to get the best reception. If you were smart, you'd build multiple antennas to the proper wavelengths and chain them together. The reason you adjust rabbit ears is because they're just about the worst design you could possibly imagine.
i'm happy to pay $40/mo not to have to adjust an antenna to only get a handful of channels. and now, i'm happy to pay $70/mo for digital cable with HDTV, because my HDTV doesn't have a tuner, and the cheapest HDTV with a tuner when i got mine was $800, when mine was $300.
I wouldn't go pushing that logic too much if I were you. Paying $30/mo to save $500 isn't a winning proposition. The latter argument is still fine, though.
Of course, you'll get the improved reception and clarity as a bonus, but if you're using a normal antenna right now... chances are you're not really too concerned about that, are you?
Dunno. Most of the OTA broadcasts in Columbus, OH are higher quality than the analog cable. Ridiculously high transmitting power tends to do that.
The six-button one wasn't the best, but you can learn that from muscle memory.
Well, I can learn a PlayStation's controller positions with muscle memory, but that doesn't stop me from hesitating a few times when a screen says "Push X" or "Push O".
Plus, for the record, the B button had a little nub on it (not unlike the j and f buttons on a qwerty keyboard) to encourage you to "touch type" on the controller.
Hey, you're right! I never noticed that before (... and that's sad, really). Not quite as intelligent as the SNES convex/concave, but still pretty good. Better than the crap PlayStation controllers, at least.
and a decent shape that fits into your hands.
Well, the DC controller is a little too big. It's not stupid Xbox big, but it was a little unwieldy.
But the right thumbstick I've never really liked, and, gasp, its short a button.
I don't understand the "short a button" argument. Games that actually use 8 buttons are poorly designed. Plain and simple. It's far easier to add an extra button than to figure out a way to simplify gameplay. That's why the GC's controller is nice, because it encourages developers to simplify gameplay and to reduce the button usage. But saying 7 buttons is worse than 8 is just silly, especially when the shoulder buttons on a PS2 controller are awkward, and the black and white buttons are awkward as well.
Just sayin', guys, that he's wrong on some counts and right on others. Doesn't mean he can't present his opinion.
He's not consistent. That's the problem. He starts off by saying that the Genesis controller's 3 button layout is better than the SNES's 4 button layout, and then later criticizes Nintendo for not using the standard 4 button layout.
In general, he never actually really addresses the entire topic - ergonomics of the controller.
This means that if I want to play a Gamecube game, I have to pluck the system out of the cabinet and put it in the middle of the floor.
Uh...
This seems like a simpler solution.
I've seen conflicting answers on that, actually. I can't find the actual original Nintendo patent (the first one I can find was from 1990). I've also seen places that describe that the Dreamcast's D-pad is sufficiently different that it didn't violate Nintendo's patent.
That would be why Master System, Genesis, GameGear, Turbosomethingorother, Nomad, Saturn, DreamCast, XBox, almost all 3rd party PS1/2 controllers, and almost all controllers made since Game and Watch was released make use of a cross controller?
Go and look at the controllers of all of those systems.
None of them have a cross controller, save the Dreamcast. They have a 4-way D-pad, but it's not a cross - it's a disk with a cross raised on it. The Dreamcast gets around it because the internal mechanism is sufficiently different (and worse, in my opinion).
He's basing it on what they look like.
Maybe he misnamed the article. Maybe he wanted it to be "controller aesthetics" rather than "controller ergonomics".
You're dead on, though. The GC controller is extremely well designed. It fits in your hand, after all. My big problem with the GC controller is it takes just a little bit too much effort to click the shoulder buttons, but to be honest, I don't really notice them all that much.
Plus, I don't know how anyone could call the N64 controller a disaster. It was excellent for the console it was made for - a transition between a 4-way D-pad and analog sticks. Honestly, I have no idea why Sony still has a D-pad on the PS3 controller - it's fairly anachronistic by now. If they were smart, they would've made the controller modular - able to switch in and out a D-pad or an analog stick with a little module.
Man. Nice attempt, but it's too bad they're really, really wrong when it comes to their scores.
... because Nintendo has a patent on a 4-way cross controller.
Take a look at the Genesis controller versus the SNES Controller. The Genesis controller had a better D-pad? What? The whole problem with semi-8 way D-pads is that they aren't actually as precise as the pure 4-way ones. In some games this is okay, but in others you prefer actually knowing which direction you're pushing. Sega didn't use it as an improvement. It was because Nintendo had a patent on a 4-way cross D-pad.
And deriding the SNES controller for its buttons? What? The Genesis 3-button and 6-button controllers had identical buttons. You had no idea which ones you were pushing without looking down (or knowing from position). The three-button design was bad, not good - you can locate two buttons, because whatever button your thumb is on, the second button is the other one. With three, that's not the case. The SNES controller, on the other hand, had two concave and two convex buttons. You could tell which button you were pressing by touch, and you could locate at least 2 of the other 3 buttons purely by touch, and because they were lined up in the way they were, you could locate the last one as well. Much, much smarter, and the touch-location is sorely missing from most modern controllers.
My favorite is this comment, regarding the GameCube controller:
This encouraged simple, single-button play without sacrificing versatility. It also made multi-console games a lot harder to play and made ports from other consoles worse.
I see. So Nintendo makes the most intelligent controller of all of them, and they lose points because it's harder to play games that were poorly ported and designed for worse controllers. Good call.
And, also...
And, in a cruelly ironic twist, everything else changed but the d-pad is still split
A whole lot of opinion, but absolutely no concept of ergonomics.