"It is a very rare event -- it is only known to have happened five times in the last hundred years" Dr Abbott said. It has happened twice before in the UK -- the Spartina anglica was discovered in Southampton 100 years ago, and the Welsh groundsel, discovered in 1948. "
The "It" is not explicitly defined in the text, but it appears to refer to a new species occuring: one which cannot breed with it's parent species. (Or to be more precise, a new genetic mutant occuring which, by not being able to breed with its parents, yet being able to breed with like mutants, qualifies as a new species.)
So this is not the first new species (?) to have evolved recently. Apparently, there is some evidence that 4 (or 5?) other species have come into existance recently - and 3 of 5 (or 3 of 6 - sorry the article is vague on this point) have occured in England. One would assume this is because lots of people stare at plants in England, and that the flora species are well known. But imagine the potential for large numbers of species to be evolving all over the world all the time.
A simple calculation could proceede as follows: * Assume we found all new species in England. 3 per 100 years. The land area of England is 12.7x10^6 hectares.
The total land of Earth (which is productive) is about 3278x10^6 hectares (source:http://www.upstarts.net.au/site/ideas/syst em_crash/system_crash_resources.html)
Now multiply the rate (3/100 years) by the fraction of surface area of the Earth England occupies and we get: 7.7 species per year.
Two notes: (1) there are *large* numbers of species going extinct per year (estimates range from 10,000 to 100,000 per year! Source: http://www.whole-systems.org/extinctions.html) (2 ) this calculation assumes a uniform creation of new species all over the (productive) land area of Earth. One would assume areas with more speciation would experience more growth.
maybe there weren't as many comets...
on
Do Comets go Poof?
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· Score: 3, Insightful
I have lots of respect for the type of work Levison is doing. However, in order to start it you have to have pretty firm beliefs about the origin of the solar system (an event we did not see directly - nor have we seen other solar systems form; the process is slow so we won't.)
What his work is really showing is that either: (a) one (or more) of his assumptions in his simulation is wrong or (b) there were not so many comets in the early solar system. I think this is why Levison says he is trying to prove his prior work wrong (e.g. he is looking for potential errors in his assumptions.)
Here is a poster on early solar system abundance of small comets. In this example, they count craters on Europa, a moon of Jupiter, to get an indication of how many there were in the early solar system.
An example of an simple statement which, although unlikely to be true, has to worry Levison in the back of his head somewhere, would be along the lines of: at some time in the past, our solar system passed through a debris field which created many of these craters, thus the large number of craters, but it only happened once (or very, very rarely) and this is throwing off our counting.
Such projects can putter along for years but have the potential to return fabulous results. Its the kind of project graduate students are interested in, but worried they cannot get a solid thesis project out of. It is also tough to fund such projects in America these days. Thus I have respect for these people, and wish them good luck.
Then you will find that jock turned out to be: your lawyer, your judge (God forbid), your congresperson, your boss - in short America is, by and large, governed by these "jocks". I know because I went to my ten year high school reunion.
Oh and speaking of useless trivia, some of my buddies still know all 56 prepisitions in the english language we had to memorize in 5th grade (in alphabetical order). Talk about useless! At least it makes a good joke for my students.
"Before the law stands a doorkeeper, on guard" - Kafka
Although I agree with several of the replies to this, I do not think they are the main reason for the mission.
If you know what such asteroids are made of, you might be better able (1) to detect them and (2) to estimate how many of them there are. (Think: there is just so much heavy metals left over from the supernovae from which we arise. However there is lots more hydrogen from tbe big bang to combine with Oxygen which could generate lots more water based asteriods.
Further, I am sure I am too naieve on this point, but how do we really know the mass of these things? Mass cancels out in the force equations for orbits as long as the mass of the orbiter is far, far less than the mass of the object orbited.
The most cost effective means of finding out about these still seems to me to be looking from earth. $150 million would pay lots of telescope time and graduate students to analyze the data.
I am confused as to the time scale they think they are going to find this asteroid on. I it is possible that it could be found just days before striking Earth - but that does not seem very likely. It seems far more likely that it will be found at least months or years before striking. I am judging by the asteroid warnings from '97 in which asteriods were found on very near collision courses in 10-20 year time scales.
Also, those were found by amatures, not professionals. One would assume that the professionals are using better equipment (better angular resolution) and thus will catch them at even earlier stages, and thus we would have time to vote on increasing funding for, perhaps, many different anti-asteroid techniques.
Lastly, judging by radio transmissions, our galaxy is not teeming with radio broadcasting life. There might be a reason for this. That reason might be asteroids. I am glad NASA is funding this (finally) - even though that is a lot of maybes.
Perhaps the real benefit will come when some of these MMORPG's start to go out of business and someone (not me) can pick up the code cheap and make it open source. Imagine if 1000's of people could create their own server with their own mods heck they could toss killing into this game, or implement different player killing in Everquest...endless possibilities. No more monthly fee, either.
You say, "They are getting a B+ at Duke when they could easily goto a top teir national public university and earn an A".
I am sure they could easily *go* to a top teir public university, as they are cheaper and not as selective, in general. However, I would not agree that it would be easy for them to get an A there.
Grading is heavily professor dependant. I assure you that you can find "top teir public" professors who will hand out no A's at all. To anyone. At Duke, I'm pretty sure that just flat couldn't happen as people's parents who are blowing US$100k on this are going to object. However, where I went to school, UCSD and UC Riverside, you could complain until you are blue in the face. These people bring in grant money, or write books, or bring prestigue, to the University so they can pretty much do whatever they want in their classes. Sure you might get them banned from teaching Physics 101 again, but they might even *want* that, in fact that might have had that in mind when grading.
I would agree that, on average, it may be easier at less expensive and/or selective universities because you always have people who don't really belong there to make you look better, but to be honest, in physics we use the same books and cover the same chapters. I get exams from fellow professors at other Universities so I know the exams are similar. Thus I am sure you will agree that it saddens me greatly to think my A students should be judged less than A students from other, more prestigious Universities. What you have said is very close to that.
I have never heard the term "boffin" before and I have hung out at physics departments for over 12 years where many people have ties to military research. But mostly in Southern California.
So my question is, to those of you who have heard this term, or use it, where are you? Anyone here on the west cost? Do I just live a sheltered life? (Hey, I *like* shelter).
Here is the point which you probably don't care about. The equation can be written: E=hv (where v is the greek letter nu) or E=h_bar w (where w is omega, and h_bar is h-bar an h with a cross on it, like you would cross a t).
v is the frequency, in Hertz, which is cycles per second. w is the angular frequency, in radians per second. Since there are 2 pi radians in a circle, you multiply v by 2 pi to get w. (E.g. you will go through more radians per second than you will cycles).
Anything measured in Hertz (Hz) should be a frequency (v), not an angular frequency (w). Sadly, this is not always the case. This is kind of an infamous problem in physics. The conversation goes something like this: Person 1) Hey look my data looks just like yours, but there is some offset. Person 2) Oh ya? Is it a factor of 10? Person 1) Nope but about 2/3 of that... Person 2) Oh you aren't using an HP 228a are you? Person 1) Um, ya sure am. Person 2) Oh well then w is really v. Person 1) Doh. Best to check if you need to know the answer to within a factor of 6.3 or so.
I always think of artificial intelligence when I hear data mining, and I kind of assumed that was what would be clairified (at least) by this article. However I was wrong.
The most concerete evidence of success that is presented is that Victoria's Secret realized it sold tons of size X bras in New York and 10x as many white as black items in Miami. Um, I really hope they didn't have to hire a firm to tell them that. Don't they have spreadsheets? Does anyone look around the store and notice what sells?
Which moves me on to another point. Companies seem to have very little faith in their employees and ask very little of them these days. (Gets out his pipe and rocking chair.) I remember when my sister got her first job at an ice skating rink. They sold ice skating outfits to (mostly) Mothers of young girls taking private ice skating lessons. My sister could tell you at a glance what outfits would sell first. (As I recall it was the most garish ones - she used to specifically ask for "ugly" or "anything that it looks designed by the color blind").
Now a days, when I have to ask for help finding something in a store and I suggest a different location for it (real life example: Why don't you stock the phone connectors with your phones?) I get blank stares and comments along the lines of "ya, like my manager would listen".
Thank god! Finally! Someone mentions other people. For me, this is the only answer. Just think: what is the one thing which you could not live without? (Beyond what is biologically necessary such as nutrients, air, water, etc.) It is other people.
I have everything I need, all the computers, cars, living space, and money I need. So do you, probably, if you think about it. Why do most people keep grabbing for more? Other people. If there were no one there to see your car, would you drive a Lexus? If you had no one to share it with, would you buy a great big house? If there were no one to see it? To envy it?
At some point almost everyone in the US is financially independent and has all that they need to survive. (Many, many other people around the world - and some in the US - do not achieve that. That saddens me. That is another topic.) And virtually *all* of those people go on collecting more trinkets. Some say it is for personal security. Some say it is for their children. Some (many on slashdot I have found!) make no bones about it - they collect trinkets for their own personal enjoyment.
Thus we are constantly answering the question posed by the author. He asks who are we? We are materialistic people - but we do not have to be.
What is the alternative? We can be good parents, good friends, good sons or daughters, good employees or good citizens. Basically, you already know how. I cannot tell you any more here than you already know.
But is it rewarding? For me it is. If it is not so for you, that is fine. I will admire you BMW if you like, but I would never buy one. Sharing a meal with friends is more important to me. My time is more important to me.
The only answer to the author's question, What should I do with my life? is to love. If you love your car, bully for you. My love is only for people, well and pets I suppose, and for some ideas, but just a little bit. Most all of my love is for my wife and family and friends. Some for humans with all their great and terrible potential.
I teach. I enjoy and love what I do. I do it well because I love and enjoy it. I'm sure it is possible to love and enjoy other forms of work. Find them.
First, Laughlin does not mention military research. This is by and large closed. (Not all of it is closed! I know many great glassy-systems people from the Naval Warfare in DC). Far more money is spent on military research than University research in the US. Many talented people in physics go to work for the military because there are not enough University positions. This is a shame because what frightens me more than what some of you have already brought up, "What if Einstein did not get funded?" rather, what if Einstein did get funded, but by the military and all his ideas became clasified, locked away never to be seen and shared among the academic community.
My second point is that there are many, many more people in Physics now than there were 50 years ago. It used to be that a Physics Ph.D. was a gateway to numerous good job opportunities for the bright and hardworking. Now a Ph.D. is not. For the American citizen, this is a good thing. You get young smart people working hard to achieve one of the few tenured professorships opening up and those 95% or more who do not make it are tossed out on the scrap heap just as they turn old enough to stop spinning out new ideas. Oh, and you don't have to pay them much and by and large they don't get health care or any kind of job security. They are called post-docs. They are hired for a prescribed number of years, typically 1-3 and they are ubiquitus in physics today. It is estimated there are 30,000 of them in the US alone. On the order of 300 jobs open up for tenure track professorships at research universities per year in physics. About 1600 Ph.D's are granted in physics per year. (See www.aip.org when their site is back up).
The people I know getting tenure have done this, moving all over the world every year or two, for about 10 years before getting a tenure track position.
But by treating people so poorly, many smart young people are turned away. And this is the worst possibility of all. If Einstein did turn up today but decided to go get a job as a computer programmer because the field of physics was already so croweded, and the people treated so poorly, that he says to himself, "I don't need that kind of grief. Let one of those poor bastards figure out relativity."
Of course, Einstein would have done physics anyways. It was in his personality. But how many great minds become discoraged and leave a dysfunctional system?
Galileo was a devout Christian. His daughters were both sent to covenents. All his books were reviewed by the inquisition before they were published. Later in life, under a new pope, some of his works were re-examined and trouble started. I think Galileo was not trying to:
"shape physics as a keeper of absolute truth, as a religion which would replace or surpass the religious doctrines of the time".
Certainly, physics should be about truth - as close to absolute as we can find. If you want real certainty, try math. Galileo never imagined his work would replace religion. I believe he would have found the thought repugnant. See, for example, _Galileo's_Daughter_, or similar texts. These are not secrets.
Laughlin writes against the trend towards commercializing physics and keeping results secret. I would imagine you agree with him at least on the secrets part.
I agree, and Laughlin would agree (I think) that Physics will be something very different in the future. He simply wants it to remain a science and not become an appendage of business. Would you not agree currently physics professors are more like Galileo with his telescope in the town square than, say, Microsoft is with their source code?
The real danger is not patents. Those are public knowledge. The serious danger is trade secrets: science which is invented, then re-invented, ad infinitum, because all those with the money to fund the research and get the results choose to hide them.
Hi I tried to find a study that would help you but failed. Perhaps there are no studies in this area. (I fail to see how moderators can mod up posts which don't actually refer to studies, as that is what was asked for...). Perhaps you could study your residents (if this is legal, the governing body doesn't mind, etc, etc.)
I can see two benefits to games in the shelter. One it keeps the residents in the program. From my limited experience with the unhoused, this would seem a tremendous benefit to most (most needing some kind of help). The second is their emotional growth, which you described. This latter point would be tough to measure. Perhaps a psychology or sociology graduate student could help. They should be eager for a thesis topic. If interested, the best people to call are department secrataries. They usually can tell you which professor would be most helpful.
The first kind of help the residents get may be easier to measure - you just count them and see if the ones who play games stay longer (on average). I assume there is some kind of "graduation" from the program. You could see if that event became more likely with those residents who played the games. Perhaps you could also see if the rate of rule breaking is reduced in those who play games. I'm sure you will know which (if any) of these make sense for your situation.
I hate reducing things as complicated, beautiful and powerful as people or emotions to numbers, but if you can measure a benefit, you can write about it in a more concrete way and perhaps spread the benefit to other, similar, shelters. Journal papers could be written. Grants could be written - if for nothing else than for further study. (Since this forum has a libritarian tinge to it I will add: money is allocated for studies and programs like this right now. The gatekeepers of this money assumedly choose from a field of valid proposals thus will choose to follow this only if it is better than the alternatives.)
You may say: I am not an academic I cannot (1) write a study about this or (2) analyize the number to quantify the study. On the first point, I would recommend you try to talk to academics in related fields. But the fields are complicated and the experts may not know as much as you.
On the second point, I will compute any statistical quantities about your data that you (or they) want. I am a physicist so I can probably compute any quantity in the socail sciences. I will spend the time to do this to the best of my ability as it sounds important to me. I cannot guarentee the statistics will be great (hey, I have 10^20 manganese atoms in my sample, you probably have around 20 to 100 people...) but I will compute whatever is needed for this kind of study. Honest.
The discover of Jupitor-like planets is, in part, so exciting because Jupitor-like plantes are necessary to suck up all the cosmic junk floating through the solar system. (Disclaimer: being a physicist, I have heard this first hand from real astrophysicists I trust - obviously they could have miscalculated).
The origional did so well in part because it was rated PG-13 and there was virtually nothing out which had a similar rating. It's success spurred the production of movies aimed at the young teen audience.
I've seen both films and neither is very origional. There are origional movies coming out all the time in my neighborhood but people do not go see them. Alas.
I saw the movie. I enjoyed it. One observation: if The Rock's motto is "live free, die well" why does he become a king at the end of the movie? Why doesn't he just yell to his people "you are free now, no kings anymore"? I understand that they have to set this movie up so that he is the evil king of the next movie...but given his motto, he should try to free these poor people from absolute monarchy if he believes in freedom...or maybe only freedom for guys with huge muscles. (Excluding most/.ers I suppose).
Also, why is everyone bashing Katz on this thread? I suspect if the Taco misspells Akkadian the posts to correct it would be very different.
Yes, this is what the webpage I quoted says. However, I think they are wrong. In the absence of any other force to cause rotation, coriolis will dominate. Inertia refers to the mass, and is not a force. However, you can buy a special bowl where water will drain the opposite direction because water is encouraged to circulate in one direction via the shape of the bottom of the bowl. You can think, for example, of a fan. The shape of the fan causes the air to blow past the fan in one direction.
I would agree that the coriolis force will not overcome very slight water currents. Fill up your sink. See which way it drains. Fill it up again and induce a small water current in the opposite direciton. You will likely see the water drain in this new direction because the "interia" of the water overcame the coriolis force. (Baring, of course, specially shaped bottoms of the basin).
The sum of all forces on an object of mass m traveling in a circlular path of radius r must be mv^2/r (directed radially inward) to continue circular motion at constant speed. The problem many of my students have is that they feel there must be a force exactly equal to mv^2/r, which is untrue. Further, the sum of the tangential speeds must be zero to have constant speed.
As for what you feel, there is no difference between experiencing the gravitational force near the surface of earth and actually being in a space ship accelerating at 9.8 meters per second per second (far from any large masses...). This is according to general relativity, which I am not an expert in, so I cannot prove it, but I have heard it from people I trust. Alas, if only I had a year to learn all that differential geometry...but grading papers cannot wait.
As for people not grasping this, I am sorry to say most people never take a physics class. That is not aweful, but I feel first it is important that everyone can do simple math. One could say that is what calculators are for, but to understand anything about the world I think there are many, many things everyone should know. Like what a logarithm is, and what semi-log graph paper is and how to use it. Sound like I ask too much? Look at any stock quotes. All that I have seen are on semi-log scales. If you don't know where zero is on the semi-log graph, you don't really understand what that graph means. (Hint: you are not going to see the zero plotted...)
I think all people should be given the opportunity to learn lots of math, and at least one science very well. Sadly, many are chasing green pieces of paper.
I teach Physics 100A. The best way to think about Centripital "force" is: it is whatever force holds the object in circular motion. (Thus it must be directed towards the center of the circular motion). For example, the earth is held in a (nearly) circular orbit around the sun by gravity. Your car can go around a curve, and locally travel in "circular" motion and it is held in the turn by friction (unless the turn is "banked" - you know, like highway turns, then gravity assists you, also).
What is called "centrifugal" force does not exist. What is most commonly cited as a "centrifugal" force is a force which pushes things out from the center of circular motion. In fact, there is no magical force pushing things away from the center of circular motion. What you feel is called inertia: the tendancy for objects to go in a straight line unless acted on by an outside force. This is not a force, it is Newton's first law.
The expression which is *not* a force is mass times speed squared divided by radius. It is a mass times acceleration, which belongs on the "right" hand side of Newton's second law, which says: the sum of all forces equals mass times acceleration. There is an expression for centripital acceleration because by stating the object is traveling in circular motion, you are saying something about what acceleration it is experiencing: namely that the acceleration is directed inward and has magnitude equal to speed squared divided by radius. (What is called "uniform" circular motion adds an additional requirement: that the speed does not change. (The velocity is a vector, so it sure does change in circular motion!) In the case of uniform circular motion, the only acceleration is centripital (center seeking), whereas in general you can also have tangential acceleration as well which changes the speed). There are magnetic, electric, and frictional forces. There are no equations for magnetic, electric, and frictional accelerations. The live on the left hand side of Newton's second law. Each can cause circular motion, and thus can be what is refered to as a "centripital" force. In general, there may be many forces acting to hold an object in circular motion.
By the way, floW is actually right about Newton's laws not holding in accelerating frames of reference. However, we don't invoke centrifugal forces to deal with this "problem". Perhaps the author was refering to the coriolis force, which *is* a fictional force.
We use the coriolis force because the effect is rather small on Earth and it is more intuitive to view Earth as a non-accelerating system, rather than one which is rotating. You may have hear about the coriolis force in physics 101 but you likely did not compute it. To do so you need the vector product (or cross product) which generally is not used in into physics books like Giancoli, Serway or Haladay and Resnik. The coriolis force effects: storm systems, water swirling down a drain, the Foucault pendulum (in fact any pendulum, but the giant pendulums in museums which knock over dominoes or trace out lines in sand are designed with coriolis in mind and called "Foucalut's" - it has to do with velocity that the pendulum achieves), and actually is used in firing Naval guns. See, for example: some physics stuff
There is quite a bit of confusion as to what the force is that is holding the disc in circular motion. Most forces cited are actually what will cause the disc to either speed up, or slow down. The force holding the disc in circular motion is actually the atomic forces. This is why the disc does not fly apart (each part traveling in a staight line).
By the way, I actually searched for a few minuets trying to find a decent explanation of all this on the web, but most have mistakes. I am sorry to say the only way to really learn this seems to be to get a published book like Giancoli, Serway or Haladay's books (all titled Physics or something like that).
This is actually a rather delicate issue which I don't think most physics 100 students *ever* grasp. In fact, even after careful re-reading, I may have made mistakes. Heck, I get paid to explain this stuff to people, (which is a great joy) so I hope someone gets something out of this, even if it is inexact.
That is an awesome rule. Bravo to Fred Brooks. I should re-read The Mythical Man Month. I think it is fairly clear why people want to go to management, and that is for power. It is not necessairly the desire to control other people, but often the desire to fund their own projects. This is exactly what Einstein did not have to do. He was a theoretical physicist. No one needed to allocate him any resources for him to get his job done. If you look into the lives of experimental physicists (which would be far, far closer to programmers) like Compton or Faraday you will see they struggled greatly to get the support they needed for their projects - and that they were project managers at some level themselves. A far better title to the book would have been "Managing Edisons", but of course you know Edison was both a manager and an experimentalist. Indeed, as I recall from the History channel, Edison lost the person who went on to make the first widly available commerical motion picture projector *because* he was not an ideal manager.
No management is the best management for creative environments. Look at how your local physics department is run. The only purely management people are the secretaries.
Slashdot Mirror
How many people saw this little gem:
t em_crash/system_crash_resources.html)
2 ) this calculation assumes a uniform creation of new species all over the (productive) land area of Earth. One would assume areas with more speciation would experience more growth.
"It is a very rare event -- it is only known to have happened five times in the last hundred years" Dr Abbott said. It has happened twice before in the UK -- the Spartina anglica was discovered in Southampton 100 years ago, and the Welsh groundsel, discovered in 1948. "
The "It" is not explicitly defined in the text, but it appears to refer to a new species occuring: one which cannot breed with it's parent species. (Or to be more precise, a new genetic mutant occuring which, by not being able to breed with its parents, yet being able to breed with like mutants, qualifies as a new species.)
So this is not the first new species (?) to have evolved recently. Apparently, there is some evidence that 4 (or 5?) other species have come into existance recently - and 3 of 5 (or 3 of 6 - sorry the article is vague on this point) have occured in England. One would assume this is because lots of people stare at plants in England, and that the flora species are well known. But imagine the potential for large numbers of species to be evolving all over the world all the time.
A simple calculation could proceede as follows:
* Assume we found all new species in England. 3 per 100 years. The land area of England is 12.7x10^6 hectares.
The total land of Earth (which is productive) is about 3278x10^6 hectares (source:http://www.upstarts.net.au/site/ideas/sys
Now multiply the rate (3/100 years) by the fraction of surface area of the Earth England occupies and we get: 7.7 species per year.
Two notes:
(1) there are *large* numbers of species going extinct per year (estimates range from 10,000 to 100,000 per year! Source: http://www.whole-systems.org/extinctions.html)
(
I have lots of respect for the type of work Levison is doing. However, in order to start it you have to have pretty firm beliefs about the origin of the solar system (an event we did not see directly - nor have we seen other solar systems form; the process is slow so we won't.)
What his work is really showing is that either: (a) one (or more) of his assumptions in his simulation is wrong or (b) there were not so many comets in the early solar system. I think this is why Levison says he is trying to prove his prior work wrong (e.g. he is looking for potential errors in his assumptions.)
Here is a poster on early solar system abundance of small comets. In this example, they count craters on Europa, a moon of Jupiter, to get an indication of how many there were in the early solar system.
An example of an simple statement which, although unlikely to be true, has to worry Levison in the back of his head somewhere, would be along the lines of: at some time in the past, our solar system passed through a debris field which created many of these craters, thus the large number of craters, but it only happened once (or very, very rarely) and this is throwing off our counting.
Such projects can putter along for years but have the potential to return fabulous results. Its the kind of project graduate students are interested in, but worried they cannot get a solid thesis project out of. It is also tough to fund such projects in America these days. Thus I have respect for these people, and wish them good luck.
Then you will find that jock turned out to be: your lawyer, your judge (God forbid), your congresperson, your boss - in short America is, by and large, governed by these "jocks". I know because I went to my ten year high school reunion.
Oh and speaking of useless trivia, some of my buddies still know all 56 prepisitions in the english language we had to memorize in 5th grade (in alphabetical order). Talk about useless! At least it makes a good joke for my students.
"Before the law stands a doorkeeper, on guard" - Kafka
Although I agree with several of the replies to this, I do not think they are the main reason for the mission.
If you know what such asteroids are made of, you might be better able (1) to detect them and (2) to estimate how many of them there are. (Think: there is just so much heavy metals left over from the supernovae from which we arise. However there is lots more hydrogen from tbe big bang to combine with Oxygen which could generate lots more water based asteriods.
Further, I am sure I am too naieve on this point, but how do we really know the mass of these things? Mass cancels out in the force equations for orbits as long as the mass of the orbiter is far, far less than the mass of the object orbited.
The most cost effective means of finding out about these still seems to me to be looking from earth. $150 million would pay lots of telescope time and graduate students to analyze the data.
I am confused as to the time scale they think they are going to find this asteroid on. I it is possible that it could be found just days before striking Earth - but that does not seem very likely. It seems far more likely that it will be found at least months or years before striking. I am judging by the asteroid warnings from '97 in which asteriods were found on very near collision courses in 10-20 year time scales.
Also, those were found by amatures, not professionals. One would assume that the professionals are using better equipment (better angular resolution) and thus will catch them at even earlier stages, and thus we would have time to vote on increasing funding for, perhaps, many different anti-asteroid techniques.
Lastly, judging by radio transmissions, our galaxy is not teeming with radio broadcasting life. There might be a reason for this. That reason might be asteroids. I am glad NASA is funding this (finally) - even though that is a lot of maybes.
Some people might want to be warned for religous reasons. Perhaps they want to purify themselves or pray or meditate.
NASA is from a country which is, ostensively, a democracy so shouldn't the people have a say?
Perhaps the real benefit will come when some of these MMORPG's start to go out of business and someone (not me) can pick up the code cheap and make it open source. Imagine if 1000's of people could create their own server with their own mods heck they could toss killing into this game, or implement different player killing in Everquest...endless possibilities. No more monthly fee, either.
Yes. Rumor is Feynman had to leave Princeton for Caltech after an trist with a colleague's wife.
You say, "They are getting a B+ at Duke when they could easily goto a top teir national public university and earn an A".
I am sure they could easily *go* to a top teir public university, as they are cheaper and not as selective, in general. However, I would not agree that it would be easy for them to get an A there.
Grading is heavily professor dependant. I assure you that you can find "top teir public" professors who will hand out no A's at all. To anyone. At Duke, I'm pretty sure that just flat couldn't happen as people's parents who are blowing US$100k on this are going to object. However, where I went to school, UCSD and UC Riverside, you could complain until you are blue in the face. These people bring in grant money, or write books, or bring prestigue, to the University so they can pretty much do whatever they want in their classes. Sure you might get them banned from teaching Physics 101 again, but they might even *want* that, in fact that might have had that in mind when grading.
I would agree that, on average, it may be easier at less expensive and/or selective universities because you always have people who don't really belong there to make you look better, but to be honest, in physics we use the same books and cover the same chapters. I get exams from fellow professors at other Universities so I know the exams are similar. Thus I am sure you will agree that it saddens me greatly to think my A students should be judged less than A students from other, more prestigious Universities. What you have said is very close to that.
Just something to think about.
Sorry here is a proper link:
Master of Orion III Preview
phew.
Preview can be found here:e ws/0,10 869,2902095,00.html
http://gamespot.com/gamespot/stories/previ
Enjoy
I have never heard the term "boffin" before and I have hung out at physics departments for over 12 years where many people have ties to military research. But mostly in Southern California.
So my question is, to those of you who have heard this term, or use it, where are you? Anyone here on the west cost? Do I just live a sheltered life? (Hey, I *like* shelter).
Cheers,
Greg
Here is the point which you probably don't care about. The equation can be written:
E=hv (where v is the greek letter nu)
or
E=h_bar w (where w is omega, and h_bar is h-bar an h with a cross on it, like you would cross a t).
v is the frequency, in Hertz, which is cycles per second. w is the angular frequency, in radians per second. Since there are 2 pi radians in a circle, you multiply v by 2 pi to get w. (E.g. you will go through more radians per second than you will cycles).
Anything measured in Hertz (Hz) should be a frequency (v), not an angular frequency (w). Sadly, this is not always the case. This is kind of an infamous problem in physics. The conversation goes something like this:
Person 1) Hey look my data looks just like yours, but there is some offset.
Person 2) Oh ya? Is it a factor of 10?
Person 1) Nope but about 2/3 of that...
Person 2) Oh you aren't using an HP 228a are you?
Person 1) Um, ya sure am.
Person 2) Oh well then w is really v.
Person 1) Doh.
Best to check if you need to know the answer to within a factor of 6.3 or so.
Cheers,
Greg Wood
I always think of artificial intelligence when I hear data mining, and I kind of assumed that was what would be clairified (at least) by this article. However I was wrong.
The most concerete evidence of success that is presented is that Victoria's Secret realized it sold tons of size X bras in New York and 10x as many white as black items in Miami. Um, I really hope they didn't have to hire a firm to tell them that. Don't they have spreadsheets? Does anyone look around the store and notice what sells?
Which moves me on to another point. Companies seem to have very little faith in their employees and ask very little of them these days. (Gets out his pipe and rocking chair.) I remember when my sister got her first job at an ice skating rink. They sold ice skating outfits to (mostly) Mothers of young girls taking private ice skating lessons. My sister could tell you at a glance what outfits would sell first. (As I recall it was the most garish ones - she used to specifically ask for "ugly" or "anything that it looks designed by the color blind").
Now a days, when I have to ask for help finding something in a store and I suggest a different location for it (real life example: Why don't you stock the phone connectors with your phones?) I get blank stares and comments along the lines of "ya, like my manager would listen".
Thank god! Finally! Someone mentions other people. For me, this is the only answer. Just think: what is the one thing which you could not live without? (Beyond what is biologically necessary such as nutrients, air, water, etc.) It is other people.
I have everything I need, all the computers, cars, living space, and money I need. So do you, probably, if you think about it. Why do most people keep grabbing for more? Other people. If there were no one there to see your car, would you drive a Lexus? If you had no one to share it with, would you buy a great big house? If there were no one to see it? To envy it?
At some point almost everyone in the US is financially independent and has all that they need to survive. (Many, many other people around the world - and some in the US - do not achieve that. That saddens me. That is another topic.) And virtually *all* of those people go on collecting more trinkets. Some say it is for personal security. Some say it is for their children. Some (many on slashdot I have found!) make no bones about it - they collect trinkets for their own personal enjoyment.
Thus we are constantly answering the question posed by the author. He asks who are we? We are materialistic people - but we do not have to be.
What is the alternative? We can be good parents, good friends, good sons or daughters, good employees or good citizens. Basically, you already know how. I cannot tell you any more here than you already know.
But is it rewarding? For me it is. If it is not so for you, that is fine. I will admire you BMW if you like, but I would never buy one. Sharing a meal with friends is more important to me. My time is more important to me.
The only answer to the author's question, What should I do with my life? is to love. If you love your car, bully for you. My love is only for people, well and pets I suppose, and for some ideas, but just a little bit. Most all of my love is for my wife and family and friends. Some for humans with all their great and terrible potential.
I teach. I enjoy and love what I do. I do it well because I love and enjoy it. I'm sure it is possible to love and enjoy other forms of work. Find them.
Cheers,
Greg G. Wood
First, Laughlin does not mention military research. This is by and large closed. (Not all of it is closed! I know many great glassy-systems people from the Naval Warfare in DC). Far more money is spent on military research than University research in the US. Many talented people in physics go to work for the military because there are not enough University positions. This is a shame because what frightens me more than what some of you have already brought up, "What if Einstein did not get funded?" rather, what if Einstein did get funded, but by the military and all his ideas became clasified, locked away never to be seen and shared among the academic community.
My second point is that there are many, many more people in Physics now than there were 50 years ago. It used to be that a Physics Ph.D. was a gateway to numerous good job opportunities for the bright and hardworking. Now a Ph.D. is not. For the American citizen, this is a good thing. You get young smart people working hard to achieve one of the few tenured professorships opening up and those 95% or more who do not make it are tossed out on the scrap heap just as they turn old enough to stop spinning out new ideas. Oh, and you don't have to pay them much and by and large they don't get health care or any kind of job security. They are called post-docs. They are hired for a prescribed number of years, typically 1-3 and they are ubiquitus in physics today. It is estimated there are 30,000 of them in the US alone. On the order of 300 jobs open up for tenure track professorships at research universities per year in physics. About 1600 Ph.D's are granted in physics per year. (See www.aip.org when their site is back up).
The people I know getting tenure have done this, moving all over the world every year or two, for about 10 years before getting a tenure track position.
But by treating people so poorly, many smart young people are turned away. And this is the worst possibility of all. If Einstein did turn up today but decided to go get a job as a computer programmer because the field of physics was already so croweded, and the people treated so poorly, that he says to himself, "I don't need that kind of grief. Let one of those poor bastards figure out relativity."
Of course, Einstein would have done physics anyways. It was in his personality. But how many great minds become discoraged and leave a dysfunctional system?
Galileo was a devout Christian. His daughters were both sent to covenents. All his books were reviewed by the inquisition before they were published. Later in life, under a new pope, some of his works were re-examined and trouble started. I think Galileo was not trying to:
1 40 280553/qid=1039813359/sr=8-1/ref=sr_8_1/102-486054 4-8813720?v=glance&s=books&n=507846
"shape physics as a keeper of absolute truth, as a religion which would replace or surpass the religious doctrines of the time".
Certainly, physics should be about truth - as close to absolute as we can find. If you want real certainty, try math. Galileo never imagined his work would replace religion. I believe he would have found the thought repugnant. See, for example, _Galileo's_Daughter_, or similar texts. These are not secrets.
http://www.amazon.com/exec/obidos/tg/detail/-/0
Laughlin writes against the trend towards commercializing physics and keeping results secret. I would imagine you agree with him at least on the secrets part.
I agree, and Laughlin would agree (I think) that Physics will be something very different in the future. He simply wants it to remain a science and not become an appendage of business. Would you not agree currently physics professors are more like Galileo with his telescope in the town square than, say, Microsoft is with their source code?
The real danger is not patents. Those are public knowledge. The serious danger is trade secrets: science which is invented, then re-invented, ad infinitum, because all those with the money to fund the research and get the results choose to hide them.
Honest.
-Gregory Wood
Hi I tried to find a study that would help you but failed. Perhaps there are no studies in this area. (I fail to see how moderators can mod up posts which don't actually refer to studies, as that is what was asked for...). Perhaps you could study your residents (if this is legal, the governing body doesn't mind, etc, etc.)
I can see two benefits to games in the shelter. One it keeps the residents in the program. From my limited experience with the unhoused, this would seem a tremendous benefit to most (most needing some kind of help). The second is their emotional growth, which you described. This latter point would be tough to measure. Perhaps a psychology or sociology graduate student could help. They should be eager for a thesis topic. If interested, the best people to call are department secrataries. They usually can tell you which professor would be most helpful.
The first kind of help the residents get may be easier to measure - you just count them and see if the ones who play games stay longer (on average). I assume there is some kind of "graduation" from the program. You could see if that event became more likely with those residents who played the games. Perhaps you could also see if the rate of rule breaking is reduced in those who play games. I'm sure you will know which (if any) of these make sense for your situation.
I hate reducing things as complicated, beautiful and powerful as people or emotions to numbers, but if you can measure a benefit, you can write about it in a more concrete way and perhaps spread the benefit to other, similar, shelters. Journal papers could be written. Grants could be written - if for nothing else than for further study. (Since this forum has a libritarian tinge to it I will add: money is allocated for studies and programs like this right now. The gatekeepers of this money assumedly choose from a field of valid proposals thus will choose to follow this only if it is better than the alternatives.)
You may say: I am not an academic I cannot (1) write a study about this or (2) analyize the number to quantify the study. On the first point, I would recommend you try to talk to academics in related fields. But the fields are complicated and the experts may not know as much as you.
On the second point, I will compute any statistical quantities about your data that you (or they) want. I am a physicist so I can probably compute any quantity in the socail sciences. I will spend the time to do this to the best of my ability as it sounds important to me. I cannot guarentee the statistics will be great (hey, I have 10^20 manganese atoms in my sample, you probably have around 20 to 100 people...) but I will compute whatever is needed for this kind of study.
Honest.
Cheers,
Greg G. Wood
gregory.wood@csun.edu
The discover of Jupitor-like planets is, in part, so exciting because Jupitor-like plantes are necessary to suck up all the cosmic junk floating through the solar system. (Disclaimer: being a physicist, I have heard this first hand from real astrophysicists I trust - obviously they could have miscalculated).
Cheers,
G. G. Wood
The origional did so well in part because it was
rated PG-13 and there was virtually nothing out which
had a similar rating. It's success spurred the production
of movies aimed at the young teen audience.
I've seen both films and neither is very origional. There
are origional movies coming out all the time in my neighborhood
but people do not go see them. Alas.
-G. G. Wood
I saw the movie. I enjoyed it. One observation: if The Rock's motto is "live free, die well" why does he become a king at the end of the movie? Why doesn't he just yell to his people "you are free now, no kings anymore"? I understand that they have to set this movie up so that he is the evil king of the next movie...but given his motto, he should try to free these poor people from absolute monarchy if he believes in freedom...or maybe only freedom for guys with huge muscles. (Excluding most /.ers I suppose).
Also, why is everyone bashing Katz on this thread? I suspect if the Taco misspells Akkadian the posts to correct it would be very different.
Yes, this is what the webpage I quoted says. However, I think they are wrong. In the absence of any other force to cause rotation, coriolis will dominate. Inertia refers to the mass, and is not a force. However, you can buy a special bowl where water will drain the opposite direction because water is encouraged to circulate in one direction via the shape of the bottom of the bowl. You can think, for example, of a fan. The shape of the fan causes the air to blow past the fan in one direction.
I would agree that the coriolis force will not overcome very slight water currents. Fill up your sink. See which way it drains. Fill it up again and induce a small water current in the opposite direciton. You will likely see the water drain in this new direction because the "interia" of the water overcame the coriolis force. (Baring, of course, specially shaped bottoms of the basin).
Physics: not for the faint of heart.
Gregory G. Wood
The sum of all forces on an object of mass m traveling in a circlular path of radius r must be mv^2/r (directed radially inward) to continue circular motion at constant speed. The problem many of my students have is that they feel there must be a force exactly equal to mv^2/r, which is untrue. Further, the sum of the tangential speeds must be zero to have constant speed.
As for what you feel, there is no difference between experiencing the gravitational force near the surface of earth and actually being in a space ship accelerating at 9.8 meters per second per second (far from any large masses...). This is according to general relativity, which I am not an expert in, so I cannot prove it, but I have heard it from people I trust. Alas, if only I had a year to learn all that differential geometry...but grading papers cannot wait.
As for people not grasping this, I am sorry to say most people never take a physics class. That is not aweful, but I feel first it is important that everyone can do simple math. One could say that is what calculators are for, but to understand anything about the world I think there are many, many things everyone should know. Like what a logarithm is, and what semi-log graph paper is and how to use it. Sound like I ask too much? Look at any stock quotes. All that I have seen are on semi-log scales. If you don't know where zero is on the semi-log graph, you don't really understand what that graph means. (Hint: you are not going to see the zero plotted...)
I think all people should be given the opportunity to learn lots of math, and at least one science very well. Sadly, many are chasing green pieces of paper.
I teach Physics 100A. The best way to think about Centripital "force" is: it is whatever force holds the object in circular motion. (Thus it must be directed towards the center of the circular motion). For example, the earth is held in a (nearly) circular orbit around the sun by gravity. Your car can go around a curve, and locally travel in "circular" motion and it is held in the turn by friction (unless the turn is "banked" - you know, like highway turns, then gravity assists you, also).
What is called "centrifugal" force does not exist. What is most commonly cited as a "centrifugal" force is a force which pushes things out from the center of circular motion. In fact, there is no magical force pushing things away from the center of circular motion. What you feel is called inertia: the tendancy for objects to go in a straight line unless acted on by an outside force. This is not a force, it is Newton's first law.
The expression which is *not* a force is mass times speed squared divided by radius. It is a mass times acceleration, which belongs on the "right" hand side of Newton's second law, which says: the sum of all forces equals mass times acceleration. There is an expression for centripital acceleration because by stating the object is traveling in circular motion, you are saying something about what acceleration it is experiencing: namely that the acceleration is directed inward and has magnitude equal to speed squared divided by radius. (What is called "uniform" circular motion adds an additional requirement: that the speed does not change. (The velocity is a vector, so it sure does change in circular motion!) In the case of uniform circular motion, the only acceleration is centripital (center seeking), whereas in general you can also have tangential acceleration as well which changes the speed). There are magnetic, electric, and frictional forces. There are no equations for magnetic, electric, and frictional accelerations. The live on the left hand side of Newton's second law. Each can cause circular motion, and thus can be what is refered to as a "centripital" force. In general, there may be many forces acting to hold an object in circular motion.
By the way, floW is actually right about Newton's laws not holding in accelerating frames of reference. However, we don't invoke centrifugal forces to deal with this "problem". Perhaps the author was refering to the coriolis force, which *is* a fictional force.
We use the coriolis force because the effect is rather small on Earth and it is more intuitive to view Earth as a non-accelerating system, rather than one which is rotating. You may have hear about the coriolis force in physics 101 but you likely did not compute it. To do so you need the vector product (or cross product) which generally is not used in into physics books like Giancoli, Serway or Haladay and Resnik. The coriolis force effects: storm systems, water swirling down a drain, the Foucault pendulum (in fact any pendulum, but the giant pendulums in museums which knock over dominoes or trace out lines in sand are designed with coriolis in mind and called "Foucalut's" - it has to do with velocity that the pendulum achieves), and actually is used in firing Naval guns. See, for example:
some physics stuff
There is quite a bit of confusion as to what the force is that is holding the disc in circular motion. Most forces cited are actually what will cause the disc to either speed up, or slow down. The force holding the disc in circular motion is actually the atomic forces. This is why the disc does not fly apart (each part traveling in a staight line).
By the way, I actually searched for a few minuets trying to find a decent explanation of all this on the web, but most have mistakes. I am sorry to say the only way to really learn this seems to be to get a published book like Giancoli, Serway or Haladay's books (all titled Physics or something like that).
This is actually a rather delicate issue which I don't think most physics 100 students *ever* grasp. In fact, even after careful re-reading, I may have made mistakes. Heck, I get paid to explain this stuff to people, (which is a great joy) so I hope someone gets something out of this, even if it is inexact.
Gregory G. Wood
That is an awesome rule. Bravo to Fred Brooks. I should re-read The Mythical Man Month. I think it is fairly clear why people want to go to management, and that is for power. It is not necessairly the desire to control other people, but often the desire to fund their own projects. This is exactly what Einstein did not have to do. He was a theoretical physicist. No one needed to allocate him any resources for him to get his job done. If you look into the lives of experimental physicists (which would be far, far closer to programmers) like Compton or Faraday you will see they struggled greatly to get the support they needed for their projects - and that they were project managers at some level themselves. A far better title to the book would have been "Managing Edisons", but of course you know Edison was both a manager and an experimentalist. Indeed, as I recall from the History channel, Edison lost the person who went on to make the first widly available commerical motion picture projector *because* he was not an ideal manager.
No management is the best management for creative environments. Look at how your local physics department is run. The only purely management people are the secretaries.
Cheers,
Greg