Friday, May 11, 2001
Oops, where did the time go?
Yea, I know—lack of updates.
So sue me.
Random Meal #5
It's gotten to the point where I no longer expect to actually get the food I order from Burger King. I expect to get something, but not necessarily what I order.
Ocasionally, I end up in the drive through of Burger King on my way to work. It's one of the few places still left open and more importantly, on the way to work. And each time I go, I order the same thing.
Bzzzzz crackle “—ry a n<bzzzzzzzz>ombo mea—” snap click.
“Um, yea,” I say, assuming this now signifies my chance to order. “I'll take a Whopper™ with cheese, onion rings and a medium Coke™.”
Bzzzzzzzz snap “—ng els—” snap click.
“No, that's it.”
Snap crackle pop “—ive. Dri<bzzzzzzz>ough—” bzzzzzzz click.
I drive up to the window, pay whatever amount they say I owe, which is always different, but is between $4.50 and $5.50 and get my food, which is almost, but not entirely like what I ordered. Sometimes it's French fries instead of onion rings. Or maybe it's a Whopper™ instead of a Whopper™ with cheese. Or even a Whopper Jr.™, fries and a Diet Coke™
I figure the first fast food chain to offer a Random Value Meal for $5.00 is going to make a killing! (for the record tonight I got two Whoppers™ without cheese, no fries, no onion rings and no Coke™)
Whopper™ is a registered trademark of Burger King.
Whopper Jr™ is a registered trademark of Burger King.
Coke™ is a registered trademark of the Coca-Cola Corporation.
Diet Coke™ is a registered trademark of the Coca-Cola Corporation.
Tuesday, May 15, 2001
Richard Feynman is a Notorious Spacetime Crackpot
Why is motion in spacetime impossible? It has to do with the definitions of space and time and the equation of velocity
v = dx/dt.What the equation is saying is that, if an object moves over any distance x, there is an elapsed time t. Since time is defined in physics as a parameter for denoting change (evolution), changing position from one point in a time dimension (time axis) to another is self-referential. Why? Because the equation for velocity along the time axis would have to bev = dt/dtwhich is meaningless, of course. It is logically impossible for thetcoordinate of an object to change in spacetime. Et voil´! It's that simple. No time travel, no motion in spacetime, no spacetime and no time dimension.
I've always been unconfortable with the notion of time being considered the fourth dimension. You just don't have the freedom of motion as with the other three spatial dimentions and that wierd things start happening if you reverse time or otherwise can affect the past. The fourth dimention as another spatial dimention I can live with.
But I'm not about to go calling Richard Feynman a crackpot though!
Gravity arrested for speeding
The most amazing thing I was taught as a graduate student of celestial mechanics at Yale in the 1960s was that all gravitational interactions between bodies in all dynamical systems had to be taken as instantaneous. This seemed unacceptable on two counts. In the first place, it seemed to be a form of "action at a distance". Perhaps no one has so elegantly expressed the objection to such a concept better than Sir Isaac Newton: "That one body may act upon another at a distance through a vacuum, without the mediation of any thing else, by and through which their action and force may be conveyed from one to the other, is to me so great an absurdity, that I believe no man who has in philosophical matters a competent faculty of thinking, can ever fall into it." (See Hoffman, 1983.) But mediation requires propagation, and finite bodies should be incapable of propagate at infinite speeds since that would require infinite energy. So instantaneous gravity seemed to have an element of magic to it.
The second objection was that we had all been taught that Einstein's special relativity (SR), an experimentally well established theory, proved that nothing could propagate in forward time at a speed greater than that of light in a vacuum. Indeed, as astronomers we were taught to calculate orbits using instantaneous forces; then extract the position of some body along its orbit at a time of interest, and calculate where that position would appear as seen from Earth by allowing for the finite propagation speed of light from there to here. It seemed incongruous to allow for the finite speed of light from the body to the Earth, but to take the effect of Earth's gravity on that same body as propagating from here to there instantaneously. Yet that was the required procedure to get the correct answers.
The Speed of Gravity - What the Experiments Say
You know, I've always wondered about this, and I was also under the impression that if the sun were to suddenly snuff out of existance, we wouldn't know for another eight minutes or so. But this seems to say that gravity, while not instantaneous, is certainly faster than the speed of light so a savy scientist might be able to make a sucker bet with the janitor (“Say Bob, I bet my house that the sun will snuff out in five minutes.”), not that it will do the scientist much good.
There is abundant literature on SR dealing with the seeming inconsistencies which Van Flandern brings up in his “paper”, and then mentions in passing as being "non-trivial". They are forbiddingly described as non-trivial, perhaps, because he is ultimately advocating a common-sense approach to cosmology, requiring no special knowledge of mathematics nor original experimentation to generate grand, sweeping hypotheses on how the universe works. His message seems to be that mainstream cosmological researchers are pointy-headed acolytes who either purposely or through accidental oversight have made things out to be far more complex than they really are, and that the “truth” of the matter is readily discernible by Everyman, if only he had all the facts laid out for him in plain English. No mathematics required.
Discussion about said paper on Jerry Pournelle's site.
Pass the popcorn, physics just got interesting again …
The GPS has revolutionized the transportion industry, as well as offering unprecedented position and chronometer accuracy to field researchers involved in biology, botany, ecology, geology, and petroleum exploration, among others. While the system was not designed as a test of gtr, it turns out that in addition to numerous extremely complex Newtonian physical issues which must be taken account of, there are also about a dozen distinct str and gtr effects which must be taken into account in the design and operation of the system. This takes quite a bit of explaining, since the actual system is quite complex, and I certainly won't attempt to explain all the engineering details here (although I'll provide links to sites where you can obtain more detailed information).
Some Scientifically Inaccurate Claims Concerning Cosmology and Relativity
Wednesday, May 23, 2001
Freedonian Feminists and Knitting Society Web Ring
For more than two years, a sizable group of internet users were caught up in the story of Kaycee Nicole. She was an attractive High School/College student dying from leukemia and she kept users updated via her online diary. Eventually her mom also started a companion diary to express the feelings associated with caring for a child with cancer. Many people became close friends with Kaycee Nicole through email, chatroom, and even phone conversations. When Kaycee finally succumbed, her online friends grieved like they had lost members of their own families. Well, there is one problem. Kaycee Nicole never existed.
Via The Gus, the Kaycee Nicole (Swenson) FAQ
This is an interesting case here. Fictional journals and diaries are nothing new to literature (for instance, Bram Stoker's Dracula or even to the web. But books (such as Dracula) are sold as fiction, and those that exist on the web (such as The Gus' Bobby the Eight-Year-Old Spanking Victim) can be determined to be fake (or works of satire) if you care to look closely enough and usually they're fairly static works, meaning that the author rarely interacts with the audience. But in this case, “Kaycee” did indeed interact with several people via email and over the phone so the author did go to a somewhat extreme measure in the fictional account of a 19 year old cancer victim.
The web is an interesting medium to work in, and one that I still feel hasn't been fully exploited yet (to its full artistic measure, not economically) and we probably won't see it coming unto its own for another ten to twenty years yet. For instance, movies and television.
At first, both movies and television were nothing more than recording (or broadcasting) of theater and it took awhile for artists to view the medium as something other than a play or vaudvillian show. Movies were the first to break away (in the “time from first use imitating an existing medium to standing on its own as a new medium” sense) to its own conventions since the filmmakers didn't immediately need an audience. Television took longer since most of the early television broadcasts were done in front of a live studio audience and all the televesion was used for was broadcasting the entertainment to a larger audience than could normally be held in a theater or sports arena.
It's odd that even though both mediums started from the same premise (theater) and still use the same basics (to a degree) the two mediums are now percieved to be different. Movies are more remote, more expressive (if you've never seen Blade Runner on a movie screen, you're missing a lot!) than television. Television is more intimate, warmer than movies are (due to the amount of space available to show an image), immediate (it's easier to record and edit on videotape than on film since there's no develop stage, or cutting and splicing in the physical sense), and until recently, a lesser medium than movies (it used to be that actors who started out in television and went to movies were moving up, while going from movies to television was a sign of a spiralling career). Movies are as distinct from television as it is from theater.
We're still working out the new means of expressions and asthetics that are available on the web. Is Kaycee pointing us toward a direction where taking on a new identity or persona can be an artistic expression? (Much like Andy Kaufman did with Tony Clifton). Can we expect to see several interacting journals for a whole community of non-existant people? (Freedonian Feminists and Knitting Society anyone?)
Is anyone still reading this at all?
Duck Soup
In case you are wondering about the Freedonian Feminists and Knitting Society, you might want to read up on Duck Soup. And here's more information on the making of Duck Soup.
They never learn …
According to SlashDot, there's a new OS called, appropriately enough, NewOS. Okay, I have an interest in these things, and, unlike some others, this one seems to actually be in a working state.
I download the code and peruse it.
Not five minutes and already I find a horrible bug:
void aquire_spinlock(int *lock)
{
if(smp_num_cpus > 1) {
while(1) {
while(*lock != 0)
;
if(test_and_set(lock, 1) == 0)
break;
}
}
}
void release_spinlock(int *lock)
{
*lock = 0;
}
newos/kernel/smp.c:48
It works if you have more than one CPU, but on your typical single-CPU system, this
fails to do The Right Thing and you end up with very hard to track down
bugs. Also, the code for test_and_set() is needlessly complicated:
test_and_set:
movl 4(%esp),%edx /* load address of variable into edx */
_test_and_set1:
movl 8(%esp),%ecx /* load the value to set the lock to */
movl (%edx),%eax /* load the value of variable into eax */
cmpl $0, %eax /* see if someone else got it */
jnz _test_and_set2 /* if so, bail out */
lock
cmpxchg %ecx,(%edx)
jnz _test_and_set1 /* if zf = 0, cmpxchng failed so redo it */
_test_and_set2:
ret
newos/kernel/arch/i386/arch_i386.S:61
Sigh. It's not hard or complicated.
Hold quotas
Nice. I just got an automated call from a computerized telemarketer. It made its pitch then put me on hold. I have trouble wrapping my brain around the concept. What? The company is below its quota of customers on hold? It has to call up random people and put them on hold? There's money to be made in putting people on hold?
My God, what are we devolving to?
