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GENERAL DISCUSSIONS
Things I learned in physics class
Tuesday, July 19, 2005 7:35 PM
SIGMANUNKI
Tuesday, July 19, 2005 7:57 PM
SIMONSAYS
Quote:Originally posted by thatweirdgirl: Quote:Originally posted by SimonSays: God I love thatweirdgirl I bet Physics conflicted with Cheerleading Practice Are you really Cordelia Chase? Or perhaps Harmony? Cheerleader? Maybe band or AP French...It was a while ago. Um, no. Never ever been a cheerleader. Geek. Nerd. Dork. Or perhaps weirdo would better explain it. I have A Brief History of Time on my clie...I read it whenever I'm bored. I admit, I struggled through the third chapter. Bet it gets easier as you go. www.thatweirdgirl.com --- "...turn right at the corner then skip two blocks...no, SKIP, the hopping-like thing kids do...Why? Why not?"
Quote:Originally posted by SimonSays: God I love thatweirdgirl I bet Physics conflicted with Cheerleading Practice Are you really Cordelia Chase? Or perhaps Harmony?
Tuesday, July 19, 2005 9:13 PM
ZOID
Wednesday, July 20, 2005 12:20 PM
THATWEIRDGIRL
Wednesday, July 20, 2005 12:41 PM
Quote:Originally posted by SimonSays: AP French , Geek , Nerd , Dork ....thatweirdgirl will you marry me and have my children?
Thursday, July 21, 2005 5:44 AM
Thursday, July 21, 2005 6:19 AM
FOURSKYS
Thursday, July 21, 2005 7:01 AM
QBEAM
Quote:Jayne gets hit and goes flying back a few metres. Looking at it from a conservation of momentum point of view, the guy who fired it should have flown back about the same distance to conserve momentum. Basically, when the alliance guy fired the weapon, it should have pushed him back with the same force that hit Jayne. Imagine the sonic gun as being like a cannon. You remember what happens to cannons that arent tied down? hehe... Something like this was on mythbusters a few weeks ago.
Thursday, July 21, 2005 7:28 AM
Quote:I like your idea about constant 1g acceleration, though I'd have to sit down and do the math (after remembering) to figure out how long it would take you to get to any significant speed. As far as your thought of a brief period of freefall: You could simply have your ship make a wide turn using some sort of RCS - without cutting the main drive - until it pointed in the opposite direction. That would eliminate any weightlessness. If you stretched that manouver out over a long enough period of time, the passengers/crew would barely notice the change in direction.
Thursday, July 21, 2005 7:30 AM
SKYDANCE
Quote:Originally posted by TheGreyJedi: The guns the alliance uses, to me at least, seem to be sonic based. Sound, no matter how focused, isn't going to do a whole lot to a heavy metal door with a solid lock. Not for a while at least. A human, however, with it's squishy fleshy bits is likely to catch the sonic wave like a sail and go flying back like a plastic bag in the breeze.
Thursday, July 21, 2005 7:43 AM
Quote:One of the best realistic SF solutions to both those problems is to have a ship accelerating at a constant 1G for half the trip, and then decellerate at 1G for the other half, giving the entire spaceship an Earthlike gravity, with Down being the direction the engines are pointed, (although they have a brief period of zero G and readjustment as up becomes down for the rest of the trip). This requires a lot of fuel, however.
Thursday, July 21, 2005 7:58 AM
GROUNDED
Quote:Originally posted by QBeam: If you approximate 1g as 10m/s, and c as 4*10^8m/s
Thursday, July 21, 2005 8:05 AM
Quote:Originally posted by zoid: Would I also be correct in stating that since everything is relative, as one approaches infinite mass while accelerating to c, every other bit of matter one might encounter (even massive particles) could be seen as acquiring infinite mass instead, from the viewpoint of a traveler who felt stationary on the ship?
Quote:Again from Zoid: I'm also not keen on the names 'Shiva' and 'Nova' for an earth-based reactor...
Thursday, July 21, 2005 8:20 AM
Thursday, July 21, 2005 8:39 AM
Quote:Originally posted by zoid: ... ventured to comment that the differing viewpoints -- many of which have been duly pointed out by each author I have read -- as well as the fantastic basis of QM, reminded me of religion: 'Believing' in something totally unrelated to everyday experience, and which you have very little hope of ever actually observing (i.e, like 'God'), and then settling into 'interpretation groups' regarding the best guess of what is really going on at the most basic level (i.e., like differing sects of the Protestant faith).
Thursday, July 21, 2005 9:12 AM
Thursday, July 21, 2005 10:16 AM
DAIKATH
Thursday, July 21, 2005 10:18 AM
Quote:Originally posted by zoid: Next up: How politics are like team sports...
Thursday, July 21, 2005 11:01 AM
Quote:Originally posted by zoid: P.P.S. Someone else want to tackle the reason why individual electrons fired through a two-slit screen build up a QM-predicted interference pattern? I've said enough crazy things before lunch today (obscure reference intended). For the readers: It has to do with Feynman's sum-over-histories. You're gonna love this.
Thursday, July 21, 2005 4:03 PM
Quote:Why would you approximate c to that? It's 3x10^8 m/s...
Thursday, July 21, 2005 4:33 PM
Quote:While QM doesn't tell you where each specific electron is going to strike a phosphor (in the classic two-slit example), the results of firing thousands of individual electrons results in a distribution that exactly matches the mathematical prediction. (Or am I misunderstanding or otherwise over/understating this point?) This predictive power makes QM the most successful theory ever devised by Man. (Everybody agrees on this point, so I'm not even going to make that a question.) ... As you said, the math is undeniably descriptive of a level of reality that is incredibly bizarre when compared to the 'macro' world of our existence (which corresponds more closely with Relativity), and I wouldn't be typing this on a computer were the predictive powers of QM 'untrue'.
Quote:Thanks for understanding and -- I'm begging you -- please correct anything I've said that is either incorrect or misleading, not only for myself but for others who might be following this with some interest (like TiPpY). You can even call me an idiotic poser if you'd like, so long as you enumerate specifically where I've gotten it wrong. I'm seeking deeper understanding and a greater depth of perspective, which can only be gotten from honest and unafraid discussion with others ...
Thursday, July 21, 2005 6:52 PM
Thursday, July 21, 2005 8:10 PM
Thursday, July 21, 2005 11:51 PM
Quote:Originally posted by zoid: Very aesthetically pleasing and the fact that it may be summed up so simply (i.e., E=mc², or as originally written, "m = L/c²") adds to its beauty..
Friday, July 22, 2005 4:31 AM
Quote:Your 'P.P.S' only makes this question more beguiling, since you reported QM effects may -- under the right circumstances -- be writ large enough to be viewed with the naked eye. And you actually observed the superposition(?) of the detector yourself?! Could you take me to work with you someday? I'd give a lot to see that.
Quote:Adding your observation to the 'changeover point' question, has anybody begun thinking about what mechanism caused the quantum effect to be extended to a human scale? Is it simply because the detector was so precisely measured in one of two corresponding attributes, that the other (position, in this case) necessarily became more uncertain? What would happen if human observers were thus measured; would using conscious observers as the subjects of the precision measurement change the results in any way, and I wonder what they would see, should they begin to become 'fuzzy' in position like the detector? I hereby request more data...
Friday, July 22, 2005 5:35 AM
Friday, July 22, 2005 6:46 AM
Quote:Originally posted by QBeam: So let me pull all this together in a thesis. I think Zoid has made a valid point, by identifying different factions of scientists. The nature of science appears to be such that we always have more questions than answers. And the idea that science is all about deductive reasoning is a fiction that results from focusing only on the part of science that gets published in the finished papers. The truth is, the most important part of what happens in science is what happens before the experiment ever gets run. Because there's never enough time or money to test every hypothesis, those scarce resources get allocated according to what the scientists collectively believe will be most fruitful--in other words, based on unscientific guesses. Finally, for reasons that are obvious, I expect, when scientists talk to each other, or to non-scientists about their community, they're usually talking about those non-scientific guesses, because they are emotionally invested in their particular favority guesses. After all, people don't waste time talking about things they don't care about.
Friday, July 22, 2005 6:52 AM
Quote:Originally posted by QBeam: Rather, I suggesting thinking of it as another example like the wave/particle duality of light. When you run certain kinds of tests, light acts like it's made up of particles. When you run other kinds of tests, it acts like it's waves. The truth is, neither is entirely correct--they're just both different aspects of light's true nature.
Friday, July 22, 2005 10:09 AM
Quote:But, it's, in my opinion, "what happens before the experiments get run" is certainly not the most important part. What gets decided upon for future research projects really isn't based on "non-scientific guesses". Just the opposite. There's so much fighting over funding, you really can only get money to look at something that you're absolutely assured of seeing. In fact, most people end up doing a good deal of the work before they put in the grant and experiment proposals, just so they can show good cause that it's worth the investor's money. Additionally, while the actual money is handed out by people who know nothing about science, there are many many committees whose sole job it is to look at the scientific validity of their propositions. If they were based on "non-scientific guesses", they wouldn't be funded. (Insert quip/argument for/against string theory here).
Friday, July 22, 2005 10:27 AM
Quote:It's not just 'like' the wave/particle duality of light, it IS wave/particle duality. Particles like electrons have associated wavelengths, just as photons have associated momenta. The 'changeover' (if you want to call it that) occurs when the particle in question is so massive that its associated wavelength is too small for us to perceive its wave-like properties.
Friday, July 22, 2005 10:35 AM
Quote:Originally posted by QBeam: How old were you the first time the wave/particle duality was explained to you?
Friday, July 22, 2005 10:50 AM
Quote:Quote: -------------------------------------------------------------------------------- Originally posted by QBeam: How old were you the first time the wave/particle duality was explained to you? -------------------------------------------------------------------------------- 17 if I remember correctly. I was damn excited too, although I suspect I didn't quite grasp it at the time.
Friday, July 22, 2005 10:52 AM
Quote:Originally posted by QBeam: So there it is: funding decisions being made on purely unscientific guesswork.
Friday, July 22, 2005 12:29 PM
Friday, July 22, 2005 1:25 PM
Quote:Originally posted by QBeam: Quote:Quote: -------------------------------------------------------------------------------- Originally posted by QBeam: How old were you the first time the wave/particle duality was explained to you? -------------------------------------------------------------------------------- 17 if I remember correctly. I was damn excited too, although I suspect I didn't quite grasp it at the time. Really? That old? I think I first learned it in 4th grade. It's such an important part of what drove our 20th Century history, I thought they taught it to everyone around then, any more. Well, maybe my thesis is flawed...
Friday, July 22, 2005 3:37 PM
Quote:...Well I don't know what 4th grade equates to (I'm in Scotland) but our physics program (I had physics right through school for 6 years) advanced steadily through 'conventional' topics until the final two years when we started looking at duality and more interesting stuff. Personally I would have loved to have had that stuff earlier on, but the fact is that it's relevant only to the tiny number of students who will go on to study in more detail.
Saturday, July 23, 2005 12:32 AM
Quote:Originally posted by zoid: Born in the Summer of 1958, I was in the 4th grade at the age of nine. They were still using balloons and fruit to illustrate math problems. Then, in the following year, we learned the long division. If they'd tried to teach us wave/particle duality at that point, I'd've sh*t myself... QBeam's school must've been one of those in which they gather the cream of the scholastic crop and accelerate their learning. Kinda like The Academy, in Firefly. Can't stop the signal... v/r, -zed
Saturday, July 23, 2005 8:31 AM
Saturday, July 23, 2005 10:25 AM
Saturday, July 23, 2005 3:16 PM
BATMARLOWE
Saturday, July 23, 2005 5:02 PM
Saturday, July 23, 2005 7:38 PM
Quote:...Anne Francis played "Honey West", not "Kitty West"...
Saturday, July 23, 2005 9:31 PM
Saturday, July 23, 2005 11:19 PM
Sunday, July 24, 2005 7:45 AM
Monday, July 25, 2005 4:33 AM
Quote:Originally posted by SigmaNunki: \begin{wife and I} .... \end{wife and I}
Monday, July 25, 2005 5:27 AM
Quote:QBeam's school must've been one of those in which they gather the cream of the scholastic crop and accelerate their learning. Kinda like The Academy, in Firefly.
Monday, July 25, 2005 5:39 AM
Quote:I'm still astounded that anyone would be taught this sort of stuff at age nine. In primary school (7 years of school before high school - I guess this would equate to junior high?) we did almost no physics that I can recall. I don't see how you can even touch on wpd without already having a solid basis in the subject.
Monday, July 25, 2005 5:46 AM
Quote:You state that the direction of science is based on unscientific guesses. This couldn't be more false. The scientific guesses are based on previous science and what direction that they seem to point us in. Of course there is some human factor in there, and people will investigate what they like. You cannot say that science is based on unscientific principles based on what funding committees decisions are based on. If you would give an example of actual science that'd be helpful.
Quote:I'm going to summerize what I think QBeams and FourSkys positions are: 1) QBeam: that science is based on unscientific principles and that unscientific principle can get funding. 2) FourSkys: that science is based on scientific principles and that most (all) funding goes to scientificly based work.
Quote:Now QBeam gets back with non-understanding why FourSkys says that people can't get funding with research based on non-scientific guesses and further remarks that "scientist often formulate their opinions based on unscientific guesses." (NOTE: This is different to what QBeam said prior which is quoted above. ie diff between often and all) Then gives an example of funding decisions based on "purely unscientific guesswork." and FourSkys gets back with two examples of well planned and justified funding projects.
Quote:I must say that QBeam and FourSkys are both right depending on what area they are talking about. If I remember correctly FourSkys is in Physics (Masters, right?) and QBeam has stated undergrade Physics and then goes onto use examples from medical related feilds, which leads me to think that he's in a medically related feild.
Monday, July 25, 2005 5:58 AM
Quote:Originally posted by QBeam: All I'm saying is that, by definition, before we know something via the scientific method, we have to form opinions about it using our other faculties.
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