The multiple choice answers were 10 billion years ago, 4 billion, 500 million, and 6 million. You can strike the first and last. 500 million is the "Cambrian Explosion", so I guess life had to have begun before that time.
A lot of people have been pointing to 4 billion as the start of single-celled organisms -- just about as soon as the Earth stopped forming. The Carl Wose RNA studies that discovered the Archaea as a separate kingdom and other genetic clocks kinda suggest a 4 billion year origin. There are also fossils in Greenland that push the late 3's, but there has been a movement afoot (do a Google) to say those fossils are a crock -- they are heavily metamorphosized (sucked into the mantle and spit back out several times in the plate tectonic conveyor) that it has hard to say. I believe the earliest unambiguous stromatolite fossils are in the 2.5 billion year range along with the banded iron formations.
So the notion that "science" or a "consensus of scientists" put the origin of life at 4 billion years ago is a crock, especially in terms of the recent skepticsm about the Greenland fossils. But if I was in the "hot seat" and started arguing this point, I would have gotten some dirty looks from Regis and would have gotten the answer wrong (along with the panel of three "experts") for saying 500 million, final answer on the basis that life at 4 billion is controversial while a panoply of life at 500 million is pretty much scientific fact, I would have been out the prize money.
Michael Feldman on "Whad'ya Know?" has a solution 1) the prizes are small-value trinkets, and 2) he has this disclaimer warning the wizenheimers out there that the "official" answers are final and anyone who has a problem with that can "go get their own show."
It's not the heat, it is the humidity (honest)
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DIY HVAC
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· Score: 4, Interesting
The air conditioning load is made up of 1) sensible heat (the kind you measure with a thermometer) and 2) latent heat (the kind that makes you feel hot and sticky and mutter "it's not the heat, it's the humidity." The latent heat is the difference in enthalpy (internal energy at constant pressure) between water in the vapor and liquid states (listed in steam tables). When you cool air, you condense water, and the latent heat given off has to be carried away by the air conditioner coils.
The sensible heat load is the outside temperature seeping through the walls, but it is also the sum beating down on the roof and walls and pouring through windows. The latent heat load is largely the result of air infiltration with some contribution from showers and cooking: running a dryer contributes to latent heat because it pulls 150 CFM of inside air through the dryer vent that gets made up by air seeping in.
One of the points made was that in fall in Florida, the air conditioner runs less so the indoor humidity climbs to the sticky range. They are recommending a variable speed air handler so that a low flow setting, the air gets chilled more so more of the AC goes into humidity removal. Heat pipes have been recommended as well -- to pre-chill the air handler input and pre-warm the output to trade less cooling for more condensing.
Other approaches include not running your fan in continuous mode because that just evaporates the moisture film on the coils every time the AC cycles off to better draining cooling coil pans.
But a fundamental problem is that the latent heat load is pretty much constant across the day while the sensible load varies with the sun and contributes to the big electrical peak. One idea is to paint the roof with titanium white to cut down on the sensible heat load.
The idea I have is to try to smooth out the electrical peak load by letting the AC run more at night and run a little less during the day, and to let the sensible-heat temperature cycle up and down during the day, but to have some combined measure of heat and humidity remain constant. Instead of maintaining a constant temperature to try to maintain a constant indoor dewpoint.
This system would 1) have it cooler at night to make sleeping easier -- I can stand it warmer during the day, 2) smooth out electrical peak demand, 3) more efficiently remove humidity averaged on a 24 hour basis because humidity removal efficiency goes down if the AC duty cycle goes up during the day and you are pulling the indoor humidity below 50 percent.
Carrier makes a rather expensive ($200 plus) Humidistat product that controls the AC to both temperature and humidity targets. A cheaper solution for me is to use a setback thermometer which lets the temps go down at night and go up during the day, and to only start lowering temps at sleep time. A typical setback unit has night, wake, day, and return times -- I may go for 75 night, 74 wake, 77 day, and 78 return (the thermal pulse from the sun shining all day makes it through the house by evening, and at 78 the AC will be cycling to lower the humidity anyway). I also use an electronic humidity gauge and dial all those temps up or down a degree or two to get about 50 percent RH).
No, just been reading GoF (Johnson, Helms, Gamma, and Vlissides, Design Patterns), and it makes it seem that one's mind is under the influence of drugs.
Interface classes are great (all members declared virtual rtypr fn(argtype arg) = 0;) and it does solve the fragile header problem. And yes, you don't want very fine-grained, busy interfaces, not just for virtual functions but for the marshalling issues of distributed objects.
But even with the best of intentions, best of Law of Demeter and making objects self contained, and the separation of controls into view and model, there is always an object over here that needs a value defined over there, and I just can't see how you can design systems without designing interfaces, coding to those interfaces, seeing how it works, and extending those interfaces until you feel ready to bury those interfaces in cement to make them available to a developer public.
Didn't see pimpl in GoF, but yeah, I have found myself doing that kind of thing -- exposing a "handle" through a public interface that has meaning to those in the know. That pimpl could be a pointer, or it could be an object reference to a class you don't disclose.
Funny thing that pimpl when you see, say the Eclipse SWT exposing an HWND or an HDC through a public member function that the docs strenuously warn you is for internal use only, aw shucks, it really is a Windows HDC, but don't you all starting calling it because I warned ya and yer app is gonna be non-portable.
I am just waiting for Tablizer to jump in here and tells us that he has been warning us all along about this kind of thing, that objects don't probably divide up the world into natural classes and categories. Or perhaps we should all start using Dylan which has a funky way of binding functions to objects.
But if encapsulation is all about "need to know", in spycraft, you sometimes have to conduct transactions across public interfaces and resort to stuff like dead drops. Heck, even the CIA needs a front gate. There was this dimestore satire titled "Oh Henry", popular long ago when Henry Kissinger was in the news, that had his alter ego as a nebbish superspy. They had this deal where the road in Langley, Virginia leading up to you-know-where had this billboards saying "This is NOT the road to the CIA" and "Where did you ever get the idea that the CIA was over here?", lampooning the idea of keeping such undocumented by published interfaces private.
Given the "hot Jupiters" found orbiting nearby stars, there is nothing to say that a gas giant as to be 5 AU out -- you could have one in Earth's orbit with habitable moons all around.
But Jupiter has a strong magnetic field and an intense set of radiation belts through which its moons orbit. It would be a reasonable assumption that a gas giant would have a strong magnetic field as it probably has a core of hydrogen in some kind of superfluid, conducting state (compressed liquid hydrogen, metallic hydrogen, and other hypothesized states).
Are any of Jupiter's moons colonizable from a radiation standpoint?
Freeman Dyson had floated a proposal that I believe I had seen written up in Sky and Telescope. The idea is that you have a whole field of, say, 10 inch telescopes hooked up to photodetectors and a computer. Yes, the chances of any one telescope seeing an occultation among the stars in its field of view is small, but you use a large number of cheap telescopes.
While Dyson was more of a mathematical theory person, his claim to fame is in physics, and along the school of "when your ownly tool is a hammer, everything looks like a nail", that setup is very reminiscent of a particle detector.
A lot of the COPS car chases involve stolen vehicle checks/pursuits. But tell me: aren't a lot of these stolen vehicles Ford Escorts and early-80's vintage Buick Century's. Do the criminals ever learn to steal such stuff? Do the cops ever learn to engage in high-speed chases to recover such junk (which the suspects wreck anyway along with the sargeant's patrol car)?
I remember testing Coca Cola with pH paper in grade school science test -- don't know if it was near 0, but it shocked us how acid it is.
I had asked for a "second opinion" on some filling replacements and this dentist matter-of-factly states "don't know if it is that urgent as you don't drink soft drinks." I wondered how he knew that, but it seems that Cokes and such and do a number on your teeth, and it isn't just the sugar.
If all MS did was add extensions (like an ms.com package library) to come up with Windows-specific Java apps, SUN wouldn't have tried to go after them. Heck, SWT does the same thing.
People, it wasn't just the Visual J++ Windows API extensions. It was that MS was changing the non-Windows part of their Java enough to break things. Very sneaky.
I am trying to figure out if OO is just trying to reinvent Lisp at some level (http://www.paulgraham.com/icad.html).
My sole exposure to Lisp was half a semester at the U where it was paired with SNOBOL of all things, and this was before the M-Lisp, Common Lisp Golden Age, so I am still trying to understand what Lisp does. Graham has an example
(defun foo (n)
(lambda (i) (incf n i)))
which is a function that itself returns a function that takes an initial value n. The returned function increments that stored value of n by i whenever that new function is called, returning the updated value of n.
Graham presents this as an example of how powerful Lisp is compared to everything else, so I will take this as an example of what a Lisp advocate considers a basic operation that you would want Lisp to do.
In OO terms, function foo is a factory that poops out functions customized by the argument value n, and each function it creates has a private field variable along with a function for updating that variable and returning a result. In OO terms, that anonymous function thingy returned by foo is simply a one field variable, one function object.
Yeah, yeah, that is not really an object, an object has inheritance and polymorphism and all that. And the functional programming dudes will say that a closure (function plus state -- is that what Graham's example represents?) is not really properly represented by an object. And Graham is quick to point out that the Lisp example is also an example of generic programming because the type of n and i is not constrained.
But the core idea is like that of object instances -- you have one or more "things" with internal state that you can poke at to modify that state and return a result.
So I wonder if, after Greenspun's 10th Law, what OO is reinventing that has already been done in Lisp is creating networks of "things" with state and mutators that can interact with each other. And OO has evolved from the more Lisp-like Smalltalk to the heavy type systems of C++ and Java. Then the question is whether Lisp has a cleaner way of expressing all of this or whether Java is the way to go because it shows that a statically-typed language can express much of the same stuff as a runtime-type language but with the advantages of performance and code readability that static typing is supposed to bring. Or have the Lisp advocates been right all along only we didn't understand what they were talking about?
You always see these action heroes in movies using head butts to knock guys out. I guess movie goers think this provides comic relief to see a guy knocked out using a fighting tactic most of us don't consider using.
Then there was a film clip for real on TV news of a high-school wrestler knocking a ref out with a head butt and the stink this caused about violent anti-sportsman like conduct and what this says about values among students today.
I perhaps too innocently asked a high-school student about the physics of head butts (I was teaching a college level course mixing thermodynamics and energy policy to math and science oriented high school students). My question was why this would knock someone out without knocking yourself out.
The answer offered was that one butted with the top of one's head against the forehead of an opponent -- you took the impact eyeballs down while your opponent in the fight took the impact eyeballs in where it could inflict a counter-coups concussion injury. You are suggesting that blows to the top of the head are not a good idea.
I don't want give people ideas on how to fight dirty and inflict brain injury on other people, but I am still curious if there is some physics behind head butts.
Following the thread and the comments, it seems that the recommended GUI library is GTK#, Windows.Forms is being implemented for those people who want a "compatiblity mode", and given that Windows.Forms has so much Win32 in it (not only is it legacy-compatible in having a WinProc() hook for Windows messages, there are a lot of Win32 features not implemented in Windows.Forms that tempt developers into overriding WinProc()), the decision was made to go with WINE for that part.
.NET is a bigger deal than Win32, but that part that uses Win32 (Windows.Forms) is not sufficiently abstracted from it, and if someone feels a hankering to use Win32 under Linux, WINE is the show that is in town.
It isn't enough to program with objects; there is a new holiness cult around using objects the divine-ordained way -- aspect-oriented programming, Law of Demeter, MVC bad, and the like.
OK, there is a text string over here which needs to be displayed in a text box over there. But putting the text string in object_a and putting the display code in object_b, and having object_b hold a reference to object_a and call object_a.getTextString(), is now morally evil.
Objects are supposed to be self contained so an object should have a method called renderThyself(). An object shouldn't expose a getTextString() method because, who knows, we might have to render the object in Hittite cuneiform, so the object should use AWT to render itself. Oh, and the A in AWT stands for abstract, so sprinkling calls throughout our program to AWT is a faith practice.
And how does one render unto AWT? Why, through a Graphics object (don't know all the Java class names, but I mean whatever Java object wraps a Windows HDC). And what is a Graphics object but yet another object? So let me get this straight. A view widget to invoke a "get" to pull a string from a model object is a sin. For a model object to poke at a Graphics object to push data into that Graphics object for display is a virtuous act. For example, pushing a string into a Graphics object by calling a "DrawTextatPos" method is OK, although I still don't know how that handles Hittite script.
What I know is that developers are going to populate their software systems with objects, and for software objects to interact there is going to have to be exchange of data across interfaces between objects, and to say that pulling the data in one form will send you to Hell while pushing data across in a different form has divine sanction seems medieval.
The KGB gets a tip that Dmitri Ivanovich has been hiding smuggled diamonds in his potato field. He gets a knock on the door at 2 AM, agents "frog march" him over to the field, and a squad of soldiers starts digging it up. They find no diamonds, give him a light beating to show their disgust, and leave.
His friend Pavel shows up the next day to see how his friend was doing. "Just a few bruises, but they took care of the potato field for me. So, next week it is my turn to inform on you?"
Java as J++ as VB wasn't the real issue
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How C# Was Made
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· Score: 1
I actually have a little bit of experience with J++. I have a set of ActiveX components I want to use with C#, but C# throws security exceptions when you use any "unmanaged code" in a C# executable launched from a network share unless you give full privileges to the network share, so I was looking into J++ as an alternative.
J++ really is.NET Version 0.9, and it is pretty slick -- it does everything Visual Basic does, but you are using Java. Never succeeded in the market: VB types weren't interested and Java types didn't want to be polluted by it.
I think the sticking point was that if Microsoft walled off its J++ Windows-specific extensions in the microsoft.com.whatever JAR files, everything would have been cool. But Microsoft was accused of monkeying with the System.lang.java stuff and some other hacks that broke Java as crossplatform -- stuff reminiscent of Windows 3.1 checking to see if it was being launched from DR-DOS and the like. Was there also some non-JNI compatible native hookup as well?
Knowing Microsoft, they were up to their old tricks, and J++ as a Visual Basic clone wasn't what the fight was about. Heck, SWT is not portable Java in the way SUN defines it, but apart from SUN's moaning and groaning about it, SWT is perfectly conformant with what you are allowed to do with Java and be square with the license agreements.
I think Microsoft got off better in the popular press (SUN wanted Microsoft to implement Java, Microsoft implemented Java and even improved it (!), and now SUN is complaining -- what is the matter with those SUN dudes?). But I believe that Microsoft was really f-ing with SUN and SUN had a leg to stand on.
Where SUN was stupid is that they told the world that Java was about breaking Microsoft dominance before they were really in a position to rule the world, and what were they thinking that they could be in partnership with Microsoft in bringing Java to Windows without Microsoft trying to ream them just like everyone else? But the ideas that SUN is a bunch of crybabies who can't decide if they want Microsoft to put Java on Windows or not is more Microsoft having better PR than the reality on the ground.
SUN is for real a "victim of a crime", and going consensually into that hotel room didn't make what happened next less of a crime, but people are saying what were they thinking when they entered that hotel room.
What I find interesting about the Face on Mars is that it sure freakin' looks like a face at low res, but at high res it breaks up into mountains and ridges and the face disappears. Come to think of it, I see the Man in the Moon everytime the full Moon is visible, but in a detail lunar map of the Near Side, I no longer see the Man in the Moon.
Sky and Telescope just did a thing about Lowell's Canals. Traditionally, planet photos are just a blur while skilled observers claim to see all kinds of stuff by waiting for glimpes of "good seeing." Look at any traditional astronomy textbook and you see these awful photos of Mars and Jupiter and Saturn. It turns out that some amateurs with CCD or WebCams can sift through tons of blury images to find the few good ones and and then use image software to stack to good images to build up contrast. Using such advanced imaging techniques, they showed some images where if you use your imagination somewhat, you can see Lowell canals.
What I want to know if there is much of any correspondence between spacecraft images of Mars and what is scene from Earth-based telescopes. The Man in the Moon is mainly three of the larger maria forming two eye sockets and a kind of Mr. Bill oooooo mouth. Stuff like Syrtis Major and the light and dark markings -- are those just wind-blown albedo features or do they correspond to some kind of continental-scale topography? How big are the Lowell Canals compared to Vallis Marinaris (I imagine Vallis Marinaris while honkin big is below what can be seen from Earth, maybe like trying to see the Grand Canyon from the Moon, but how far off is it?).
Part of the Yucca Mountain fiasco has to do with President Carter's decision not to reprocess spent nuclear fuel rods -- the idea was to do a once-through fuel cycle, leaving the spent fuel rods chock full of radioactive, yes, but potentially valuable chemicals and radioactive elements. Heck, there is still a lot of usable uranium (not all U-235 in the partially-enriched fuel is "burnt up") in those rods not to mention plutonium, radioactive strontium that could be used for an atomic heat source (the Russians did that kind of thing that feeds into "dirty bomb" scares).
Now President Carter has had his share of critics, but his worry about reprocessing is opening up more avenues for diversion of atomic materials and making the Bomb available to more people. Yeah, yeah, the plutonium that is cooked in a LWR is the wrong isotope for the Bomb compared to the plutonium cooked for shorter times under different conditions up at the old Hanford reactor. I guess there is some controversy as to whether with enough technical smarts you could make a bomb from LWR plutonium.
I say we forget about Yucca Mountain and just store the spent fuel rods "on site" and build more storage, whether it is more "swimming pools" or perhaps "dry cask storage."
OK wait, would everyone here agree that compact fluorescent lamps (CFL's) are a Good Thing -- saving on coal and nuclear power and saving the Earth and everything? Is there any Amory Lovins disciple out there with anything bad to say about CFL's? Guess what, they have mercury in them, and no, they don't last forever -- I have had enough of them long enough to see them burn out. For years, the City of Madison wouldn't take them in the garbage, telling us to pile them up in our basements. Oh, and I have dropped more than one of those things, so I suppose I am brain damaged from the mercury by now.
The City of Madison now collects CFL's and fluorescent tubes if you wrap them and separate them from other garbage -- have no idea what happens to them. I say lets just stockpile spent fuel rods until some future markets develop for what is in them.
I thought mankind was descended from the B-Ark colonists -- you know, the hair dressers and telephone sanitizer salesmen. Where do apes come in to the picture?
"Drink from a fire hose" is a term used to describe freshman year at places like MIT and Caltech -- you have research-oriented faculty given the liberty to teach introductory courses at whatever level they chose, and a lot of the material goes over the heads of even very well motivated and intellectually capable students. The students figure they can benefit even if they only retain a tiny fraction of this stream of knowledge pouring by.
I suppose in taking to the Grammer Police, anything I write can and will be used as testimony against me, but I argue that the fire hose is a metaphor here -- "Her breasts are like twin gazelles" from the Song of Solomon in the Bible is more simile.
When I said "literally taking a drink from a fire hose", I was using a phrase familiar to many Slashdot readers, but taking it out of the realm of metaphor, past simile, and into accurate physical description. The scramjet is like the drink from the fire hose in that 1) the scramjet encounters a highly energetic fluid flow, and 2) the fluid flow is so energetic that it cannot trap, entrain, deccelerate, or otherwise control that flow; it can only hope to interact with that flow weakly in the hope that it obtains the desired outcome (i.e., slacken thirst from the fire hose or obtain useful thrust by burning fuel in a barely-deccelerated hypersonic air stream.
When I used "literally", I was aiming midway between "is exactly" and "is very much like." No, the scramjet is not the fire hose drinker, but the comparison is stronger than simile. We talk of a literal translation -- a word for word mapping between two languages. I am arguing that there is an equally strong correspondence between the scramjet and the fire hose drinker -- highly energetic fluid flow, requirement to weakly interact with the flow because strong interaction would have catastrophic consequences, challenging technical requirement to have weak interaction with flow and still accomplish objective.
The other set of code names that are a puzzle are the names given to 707's. Looking Glass is the old SAC airborne command post (relays Presidential order to drop the Bomb if Omaha has been turned to glass), Rivet Joint is the electronic spy, while Cobra Ball uses a telescope to observe Russian reentry vehicle tests to make inferences as to their missile accuracy. Or at least that is what is known through Aviation Week and has otherwise been leaked for public consumption.
I think these names are cool, but these names for the electronic warriors are very different from the more macho names for the gun and bomb warriors.
There is a great attraction to airbreathing propulsion. Using LH2 and LO2 as fuel and oxidizer, it takes about 85-90 percent of the vehicle mass as fuel to reach orbit on one stage, or a comparable number of stages to fake that mass ratio. This is a consequence of the rocket equation and that the exhaust velocity of a hydrogen-oxygen rocket is small compared to orbital velocity.
So, why carry the oxygen, why not get oxygen from the air? For LH2-LO2, that eliminates most of the mass and solves the mass fraction problem right away. The 1960's Aerospaceplane project originally considered liquifying the O2 from the air -- careful tweaking can be enriched on LO2 over LN2 on account of boiling point differences. You used (boiled off) some of your LH2 to get the coolant.
The trouble with LACE (liquid air cycle engine) is that you have to slow down the air rushing into the inlet (or speed it up to your rushing vehicle). If you are going fast enough relative to orbital velocity, slowing the O2 down in the inlet will heat it so much that you cannot burn it with H2 and get any energy -- the stagnation temperature of the shock front gets higher than your flame temperature. Hey, if this were not the case, orbital velocity would be low compared to rocket exhaust velocity and mass fraction would not be a problem.
Ah, the scramjet, and scramjet was also considered for Aerospaceplane. It is literally the taking a drink from a fire hose. You only slow down the inlet air stream a little bit so you get some compression, and burn H2 in that hypersonic air blast and 1) hope that the flame doesn't blow out and 2) hope that you get any positive net thrust out of the works.
If you could get any single-stage-to-orbit vehicle built that had reasonable engineering margins, you could fly it like an airplane, and even if it had a very small payload, you could fly it often enough to make a profit. NASA blew a wad in the late 80's, early 90's with National Aero Space Plane (NASP) and pulled the plug. But forget the scramjet -- if you could build a rocket out of composite materials, you could get the mass fraction. NASA blew a wad in the late 90's on the X-33 and then pulled the plug.
Jerry Pournelle states that the Strategic Defense Office (which needed a way to loft Star Wars into orbit) could have done the job -- the DC-X demonstrated the control of vertical-takeoff vertical-landing (lands tail first on rocket flames just like in Buck Rogers -- maybe not so wasteful of fuel because reentry is mainly aerobraking and landing is to last applying the brakes on a mainly empty vehicle), and he talks about a program called Have Region (don't know the source of Air Force code names, although NASA these days seems to have projects code named Have Boner) that proved that the mass fraction target was achievable and one didn't need scramjets.
Your point was that a software product can have a niche market and be mainstream at the same time -- that Matlab is mainstream in its target market because it dominates that market.
Linux is far from mainstream in its target market if the target market is desktop computing beyond hobbyists and people in science and engineering computing with prior Unix experience. I thought it somewhat ironic, however, comparing Matlab and Linux. Matlab is user friendly in a way that C and Shell are far from friendly. Part of why Linux is not mainstream on the desktop is that it is pointedly not like Matlab. Unless Linux changes or evolves, my opinion is that Linux will never hit mainstream in desktop computing (or even in a significant subsegment of desktop computing) the way Matlab is mainstream in science and engineering calculations.
Apart from Matlab being far from Open Source and coming from a single source (far be it for me to criticize MathWorks), what does Matlab and Linux have in common (apart from running Matlab under *nix OS's)?
Matlab is very user friendly, very engineer-proof in its treatment of error conditions. It is not anything like C or even anything like any of the popular Unix command-prompt shells. It even has a GUI based on figure windows in which you can do drag-and-drop layouts. If anything, it is to engineers and scientists what Visual Basic is to accounting.
Yes, Windows at the API level is even more arcane and opaque than anything in Unix land. But Visual Basic (much maligned in these quarters) makes Windows development accessible to all to persons expert in their respective applications. Is there anything remotely like Visual Basic for Linux/Unix? Yup, Matlab, but Matlab is more cross-platform than a particular goody that you have to run Linux for. Oh, and Matlab is increasingly migrating in the direction of Java for their cross-platform (Matlab is not - yet - a Java app, but Math Works says that their IDE is written in Java and I heard they are JITing their interpreted loops to get some speed).
So Linux can have its Open office and browsers and e-mail programs and stuff. When is it going to get its RAD development tools (and don't say Kylix -- it was a port of a Windows tool that didn't catch on)?
Slashdot Mirror
A lot of people have been pointing to 4 billion as the start of single-celled organisms -- just about as soon as the Earth stopped forming. The Carl Wose RNA studies that discovered the Archaea as a separate kingdom and other genetic clocks kinda suggest a 4 billion year origin. There are also fossils in Greenland that push the late 3's, but there has been a movement afoot (do a Google) to say those fossils are a crock -- they are heavily metamorphosized (sucked into the mantle and spit back out several times in the plate tectonic conveyor) that it has hard to say. I believe the earliest unambiguous stromatolite fossils are in the 2.5 billion year range along with the banded iron formations.
So the notion that "science" or a "consensus of scientists" put the origin of life at 4 billion years ago is a crock, especially in terms of the recent skepticsm about the Greenland fossils. But if I was in the "hot seat" and started arguing this point, I would have gotten some dirty looks from Regis and would have gotten the answer wrong (along with the panel of three "experts") for saying 500 million, final answer on the basis that life at 4 billion is controversial while a panoply of life at 500 million is pretty much scientific fact, I would have been out the prize money.
Michael Feldman on "Whad'ya Know?" has a solution 1) the prizes are small-value trinkets, and 2) he has this disclaimer warning the wizenheimers out there that the "official" answers are final and anyone who has a problem with that can "go get their own show."
The sensible heat load is the outside temperature seeping through the walls, but it is also the sum beating down on the roof and walls and pouring through windows. The latent heat load is largely the result of air infiltration with some contribution from showers and cooking: running a dryer contributes to latent heat because it pulls 150 CFM of inside air through the dryer vent that gets made up by air seeping in.
One of the points made was that in fall in Florida, the air conditioner runs less so the indoor humidity climbs to the sticky range. They are recommending a variable speed air handler so that a low flow setting, the air gets chilled more so more of the AC goes into humidity removal. Heat pipes have been recommended as well -- to pre-chill the air handler input and pre-warm the output to trade less cooling for more condensing.
Other approaches include not running your fan in continuous mode because that just evaporates the moisture film on the coils every time the AC cycles off to better draining cooling coil pans.
But a fundamental problem is that the latent heat load is pretty much constant across the day while the sensible load varies with the sun and contributes to the big electrical peak. One idea is to paint the roof with titanium white to cut down on the sensible heat load.
The idea I have is to try to smooth out the electrical peak load by letting the AC run more at night and run a little less during the day, and to let the sensible-heat temperature cycle up and down during the day, but to have some combined measure of heat and humidity remain constant. Instead of maintaining a constant temperature to try to maintain a constant indoor dewpoint.
This system would 1) have it cooler at night to make sleeping easier -- I can stand it warmer during the day, 2) smooth out electrical peak demand, 3) more efficiently remove humidity averaged on a 24 hour basis because humidity removal efficiency goes down if the AC duty cycle goes up during the day and you are pulling the indoor humidity below 50 percent.
Carrier makes a rather expensive ($200 plus) Humidistat product that controls the AC to both temperature and humidity targets. A cheaper solution for me is to use a setback thermometer which lets the temps go down at night and go up during the day, and to only start lowering temps at sleep time. A typical setback unit has night, wake, day, and return times -- I may go for 75 night, 74 wake, 77 day, and 78 return (the thermal pulse from the sun shining all day makes it through the house by evening, and at 78 the AC will be cycling to lower the humidity anyway). I also use an electronic humidity gauge and dial all those temps up or down a degree or two to get about 50 percent RH).
No, just been reading GoF (Johnson, Helms, Gamma, and Vlissides, Design Patterns), and it makes it seem that one's mind is under the influence of drugs.
But even with the best of intentions, best of Law of Demeter and making objects self contained, and the separation of controls into view and model, there is always an object over here that needs a value defined over there, and I just can't see how you can design systems without designing interfaces, coding to those interfaces, seeing how it works, and extending those interfaces until you feel ready to bury those interfaces in cement to make them available to a developer public.
Funny thing that pimpl when you see, say the Eclipse SWT exposing an HWND or an HDC through a public member function that the docs strenuously warn you is for internal use only, aw shucks, it really is a Windows HDC, but don't you all starting calling it because I warned ya and yer app is gonna be non-portable.
I am just waiting for Tablizer to jump in here and tells us that he has been warning us all along about this kind of thing, that objects don't probably divide up the world into natural classes and categories. Or perhaps we should all start using Dylan which has a funky way of binding functions to objects.
But if encapsulation is all about "need to know", in spycraft, you sometimes have to conduct transactions across public interfaces and resort to stuff like dead drops. Heck, even the CIA needs a front gate. There was this dimestore satire titled "Oh Henry", popular long ago when Henry Kissinger was in the news, that had his alter ego as a nebbish superspy. They had this deal where the road in Langley, Virginia leading up to you-know-where had this billboards saying "This is NOT the road to the CIA" and "Where did you ever get the idea that the CIA was over here?", lampooning the idea of keeping such undocumented by published interfaces private.
But Jupiter has a strong magnetic field and an intense set of radiation belts through which its moons orbit. It would be a reasonable assumption that a gas giant would have a strong magnetic field as it probably has a core of hydrogen in some kind of superfluid, conducting state (compressed liquid hydrogen, metallic hydrogen, and other hypothesized states).
Are any of Jupiter's moons colonizable from a radiation standpoint?
While Dyson was more of a mathematical theory person, his claim to fame is in physics, and along the school of "when your ownly tool is a hammer, everything looks like a nail", that setup is very reminiscent of a particle detector.
A lot of the COPS car chases involve stolen vehicle checks/pursuits. But tell me: aren't a lot of these stolen vehicles Ford Escorts and early-80's vintage Buick Century's. Do the criminals ever learn to steal such stuff? Do the cops ever learn to engage in high-speed chases to recover such junk (which the suspects wreck anyway along with the sargeant's patrol car)?
I had asked for a "second opinion" on some filling replacements and this dentist matter-of-factly states "don't know if it is that urgent as you don't drink soft drinks." I wondered how he knew that, but it seems that Cokes and such and do a number on your teeth, and it isn't just the sugar.
Given the monster Van Allen belts and the radiation environment, could humans even contemplate getting near Europa without getting fried?
People, it wasn't just the Visual J++ Windows API extensions. It was that MS was changing the non-Windows part of their Java enough to break things. Very sneaky.
My sole exposure to Lisp was half a semester at the U where it was paired with SNOBOL of all things, and this was before the M-Lisp, Common Lisp Golden Age, so I am still trying to understand what Lisp does. Graham has an example
(defun foo (n) (lambda (i) (incf n i)))
which is a function that itself returns a function that takes an initial value n. The returned function increments that stored value of n by i whenever that new function is called, returning the updated value of n.
Graham presents this as an example of how powerful Lisp is compared to everything else, so I will take this as an example of what a Lisp advocate considers a basic operation that you would want Lisp to do.
In OO terms, function foo is a factory that poops out functions customized by the argument value n, and each function it creates has a private field variable along with a function for updating that variable and returning a result. In OO terms, that anonymous function thingy returned by foo is simply a one field variable, one function object.
Yeah, yeah, that is not really an object, an object has inheritance and polymorphism and all that. And the functional programming dudes will say that a closure (function plus state -- is that what Graham's example represents?) is not really properly represented by an object. And Graham is quick to point out that the Lisp example is also an example of generic programming because the type of n and i is not constrained. But the core idea is like that of object instances -- you have one or more "things" with internal state that you can poke at to modify that state and return a result.
So I wonder if, after Greenspun's 10th Law, what OO is reinventing that has already been done in Lisp is creating networks of "things" with state and mutators that can interact with each other. And OO has evolved from the more Lisp-like Smalltalk to the heavy type systems of C++ and Java. Then the question is whether Lisp has a cleaner way of expressing all of this or whether Java is the way to go because it shows that a statically-typed language can express much of the same stuff as a runtime-type language but with the advantages of performance and code readability that static typing is supposed to bring. Or have the Lisp advocates been right all along only we didn't understand what they were talking about?
I perhaps too innocently asked a high-school student about the physics of head butts (I was teaching a college level course mixing thermodynamics and energy policy to math and science oriented high school students). My question was why this would knock someone out without knocking yourself out.
The answer offered was that one butted with the top of one's head against the forehead of an opponent -- you took the impact eyeballs down while your opponent in the fight took the impact eyeballs in where it could inflict a counter-coups concussion injury. You are suggesting that blows to the top of the head are not a good idea.
I don't want give people ideas on how to fight dirty and inflict brain injury on other people, but I am still curious if there is some physics behind head butts.
OK, there is a text string over here which needs to be displayed in a text box over there. But putting the text string in object_a and putting the display code in object_b, and having object_b hold a reference to object_a and call object_a.getTextString(), is now morally evil.
Objects are supposed to be self contained so an object should have a method called renderThyself(). An object shouldn't expose a getTextString() method because, who knows, we might have to render the object in Hittite cuneiform, so the object should use AWT to render itself. Oh, and the A in AWT stands for abstract, so sprinkling calls throughout our program to AWT is a faith practice.
And how does one render unto AWT? Why, through a Graphics object (don't know all the Java class names, but I mean whatever Java object wraps a Windows HDC). And what is a Graphics object but yet another object? So let me get this straight. A view widget to invoke a "get" to pull a string from a model object is a sin. For a model object to poke at a Graphics object to push data into that Graphics object for display is a virtuous act. For example, pushing a string into a Graphics object by calling a "DrawTextatPos" method is OK, although I still don't know how that handles Hittite script.
What I know is that developers are going to populate their software systems with objects, and for software objects to interact there is going to have to be exchange of data across interfaces between objects, and to say that pulling the data in one form will send you to Hell while pushing data across in a different form has divine sanction seems medieval.
His friend Pavel shows up the next day to see how his friend was doing. "Just a few bruises, but they took care of the potato field for me. So, next week it is my turn to inform on you?"
J++ really is .NET Version 0.9, and it is pretty slick -- it does everything Visual Basic does, but you are using Java. Never succeeded in the market: VB types weren't interested and Java types didn't want to be polluted by it.
I think the sticking point was that if Microsoft walled off its J++ Windows-specific extensions in the microsoft.com.whatever JAR files, everything would have been cool. But Microsoft was accused of monkeying with the System.lang.java stuff and some other hacks that broke Java as crossplatform -- stuff reminiscent of Windows 3.1 checking to see if it was being launched from DR-DOS and the like. Was there also some non-JNI compatible native hookup as well?
Knowing Microsoft, they were up to their old tricks, and J++ as a Visual Basic clone wasn't what the fight was about. Heck, SWT is not portable Java in the way SUN defines it, but apart from SUN's moaning and groaning about it, SWT is perfectly conformant with what you are allowed to do with Java and be square with the license agreements.
I think Microsoft got off better in the popular press (SUN wanted Microsoft to implement Java, Microsoft implemented Java and even improved it (!), and now SUN is complaining -- what is the matter with those SUN dudes?). But I believe that Microsoft was really f-ing with SUN and SUN had a leg to stand on.
Where SUN was stupid is that they told the world that Java was about breaking Microsoft dominance before they were really in a position to rule the world, and what were they thinking that they could be in partnership with Microsoft in bringing Java to Windows without Microsoft trying to ream them just like everyone else? But the ideas that SUN is a bunch of crybabies who can't decide if they want Microsoft to put Java on Windows or not is more Microsoft having better PR than the reality on the ground.
SUN is for real a "victim of a crime", and going consensually into that hotel room didn't make what happened next less of a crime, but people are saying what were they thinking when they entered that hotel room.
Sky and Telescope just did a thing about Lowell's Canals. Traditionally, planet photos are just a blur while skilled observers claim to see all kinds of stuff by waiting for glimpes of "good seeing." Look at any traditional astronomy textbook and you see these awful photos of Mars and Jupiter and Saturn. It turns out that some amateurs with CCD or WebCams can sift through tons of blury images to find the few good ones and and then use image software to stack to good images to build up contrast. Using such advanced imaging techniques, they showed some images where if you use your imagination somewhat, you can see Lowell canals.
What I want to know if there is much of any correspondence between spacecraft images of Mars and what is scene from Earth-based telescopes. The Man in the Moon is mainly three of the larger maria forming two eye sockets and a kind of Mr. Bill oooooo mouth. Stuff like Syrtis Major and the light and dark markings -- are those just wind-blown albedo features or do they correspond to some kind of continental-scale topography? How big are the Lowell Canals compared to Vallis Marinaris (I imagine Vallis Marinaris while honkin big is below what can be seen from Earth, maybe like trying to see the Grand Canyon from the Moon, but how far off is it?).
Now President Carter has had his share of critics, but his worry about reprocessing is opening up more avenues for diversion of atomic materials and making the Bomb available to more people. Yeah, yeah, the plutonium that is cooked in a LWR is the wrong isotope for the Bomb compared to the plutonium cooked for shorter times under different conditions up at the old Hanford reactor. I guess there is some controversy as to whether with enough technical smarts you could make a bomb from LWR plutonium.
I say we forget about Yucca Mountain and just store the spent fuel rods "on site" and build more storage, whether it is more "swimming pools" or perhaps "dry cask storage."
OK wait, would everyone here agree that compact fluorescent lamps (CFL's) are a Good Thing -- saving on coal and nuclear power and saving the Earth and everything? Is there any Amory Lovins disciple out there with anything bad to say about CFL's? Guess what, they have mercury in them, and no, they don't last forever -- I have had enough of them long enough to see them burn out. For years, the City of Madison wouldn't take them in the garbage, telling us to pile them up in our basements. Oh, and I have dropped more than one of those things, so I suppose I am brain damaged from the mercury by now.
The City of Madison now collects CFL's and fluorescent tubes if you wrap them and separate them from other garbage -- have no idea what happens to them. I say lets just stockpile spent fuel rods until some future markets develop for what is in them.
I thought mankind was descended from the B-Ark colonists -- you know, the hair dressers and telephone sanitizer salesmen. Where do apes come in to the picture?
"Drink from a fire hose" is a term used to describe freshman year at places like MIT and Caltech -- you have research-oriented faculty given the liberty to teach introductory courses at whatever level they chose, and a lot of the material goes over the heads of even very well motivated and intellectually capable students. The students figure they can benefit even if they only retain a tiny fraction of this stream of knowledge pouring by.
I suppose in taking to the Grammer Police, anything I write can and will be used as testimony against me, but I argue that the fire hose is a metaphor here -- "Her breasts are like twin gazelles" from the Song of Solomon in the Bible is more simile.
When I said "literally taking a drink from a fire hose", I was using a phrase familiar to many Slashdot readers, but taking it out of the realm of metaphor, past simile, and into accurate physical description. The scramjet is like the drink from the fire hose in that 1) the scramjet encounters a highly energetic fluid flow, and 2) the fluid flow is so energetic that it cannot trap, entrain, deccelerate, or otherwise control that flow; it can only hope to interact with that flow weakly in the hope that it obtains the desired outcome (i.e., slacken thirst from the fire hose or obtain useful thrust by burning fuel in a barely-deccelerated hypersonic air stream.
When I used "literally", I was aiming midway between "is exactly" and "is very much like." No, the scramjet is not the fire hose drinker, but the comparison is stronger than simile. We talk of a literal translation -- a word for word mapping between two languages. I am arguing that there is an equally strong correspondence between the scramjet and the fire hose drinker -- highly energetic fluid flow, requirement to weakly interact with the flow because strong interaction would have catastrophic consequences, challenging technical requirement to have weak interaction with flow and still accomplish objective.
I think these names are cool, but these names for the electronic warriors are very different from the more macho names for the gun and bomb warriors.
So, why carry the oxygen, why not get oxygen from the air? For LH2-LO2, that eliminates most of the mass and solves the mass fraction problem right away. The 1960's Aerospaceplane project originally considered liquifying the O2 from the air -- careful tweaking can be enriched on LO2 over LN2 on account of boiling point differences. You used (boiled off) some of your LH2 to get the coolant.
The trouble with LACE (liquid air cycle engine) is that you have to slow down the air rushing into the inlet (or speed it up to your rushing vehicle). If you are going fast enough relative to orbital velocity, slowing the O2 down in the inlet will heat it so much that you cannot burn it with H2 and get any energy -- the stagnation temperature of the shock front gets higher than your flame temperature. Hey, if this were not the case, orbital velocity would be low compared to rocket exhaust velocity and mass fraction would not be a problem.
Ah, the scramjet, and scramjet was also considered for Aerospaceplane. It is literally the taking a drink from a fire hose. You only slow down the inlet air stream a little bit so you get some compression, and burn H2 in that hypersonic air blast and 1) hope that the flame doesn't blow out and 2) hope that you get any positive net thrust out of the works.
If you could get any single-stage-to-orbit vehicle built that had reasonable engineering margins, you could fly it like an airplane, and even if it had a very small payload, you could fly it often enough to make a profit. NASA blew a wad in the late 80's, early 90's with National Aero Space Plane (NASP) and pulled the plug. But forget the scramjet -- if you could build a rocket out of composite materials, you could get the mass fraction. NASA blew a wad in the late 90's on the X-33 and then pulled the plug.
Jerry Pournelle states that the Strategic Defense Office (which needed a way to loft Star Wars into orbit) could have done the job -- the DC-X demonstrated the control of vertical-takeoff vertical-landing (lands tail first on rocket flames just like in Buck Rogers -- maybe not so wasteful of fuel because reentry is mainly aerobraking and landing is to last applying the brakes on a mainly empty vehicle), and he talks about a program called Have Region (don't know the source of Air Force code names, although NASA these days seems to have projects code named Have Boner) that proved that the mass fraction target was achievable and one didn't need scramjets.
Linux is far from mainstream in its target market if the target market is desktop computing beyond hobbyists and people in science and engineering computing with prior Unix experience. I thought it somewhat ironic, however, comparing Matlab and Linux. Matlab is user friendly in a way that C and Shell are far from friendly. Part of why Linux is not mainstream on the desktop is that it is pointedly not like Matlab. Unless Linux changes or evolves, my opinion is that Linux will never hit mainstream in desktop computing (or even in a significant subsegment of desktop computing) the way Matlab is mainstream in science and engineering calculations.
Matlab is very user friendly, very engineer-proof in its treatment of error conditions. It is not anything like C or even anything like any of the popular Unix command-prompt shells. It even has a GUI based on figure windows in which you can do drag-and-drop layouts. If anything, it is to engineers and scientists what Visual Basic is to accounting.
Yes, Windows at the API level is even more arcane and opaque than anything in Unix land. But Visual Basic (much maligned in these quarters) makes Windows development accessible to all to persons expert in their respective applications. Is there anything remotely like Visual Basic for Linux/Unix? Yup, Matlab, but Matlab is more cross-platform than a particular goody that you have to run Linux for. Oh, and Matlab is increasingly migrating in the direction of Java for their cross-platform (Matlab is not - yet - a Java app, but Math Works says that their IDE is written in Java and I heard they are JITing their interpreted loops to get some speed).
So Linux can have its Open office and browsers and e-mail programs and stuff. When is it going to get its RAD development tools (and don't say Kylix -- it was a port of a Windows tool that didn't catch on)?