IdentityCrisis
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Posts posted by IdentityCrisis
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accidental repost, delete please
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What do you mean by "actually exists?" Is energy a physical thing, a substance?
In a sense, that second question is what I'm asking you. It's possible that I'm inappropriately mixing philosophy and science, so let me try and clarify.
Philosophically, I'm thinking that entities (chunks of matter, gravitational fields, etc.) don't just exist, they exist in a certain state (here as opposed to there, having a temperatue of 100 Kelvin as opposed to 200 Kelvin, etc.). "Entity" and "identity," nothing new to you I'm sure. But the exact identity of entities (their location, temperature, etc.) is changing all the time. I call the transition from any one state to a differant state "action."
Passing from philosophy to physics, I understand "energy" to be a quantitative measure of action (change of state). The various types of energy (kinetic, thermal, etc.) refer to various types of changes.
But potential energy doesn't seem to fit. It doesn't measure change that's actually occuring, but only change that *could* occur under differant conditions. Now having a measure of unacheived potential is fine, but when you call it energy (a term which I associate with *actual* change-in-progress) and then use it to support the claim that energy is never created or destroyed, then I start having conceptual issues.
Does that clear it up?
What were his actual postulates?Note that these formulations are not the actual postulates which Einstein indentified when presenting, in 1905, what was eventually called special relativity.
There does not exist a valid inertial reference frame where a photon is at rest.I'd really like some explination to that.
As I understand it the motion of anything can only be measured relative to something else, and except for simplifying the math involved there is no prefered frame of referance. In other words, there's no reason I can't make a car going down the highway my point of origin and measure the rest of the world as moving relative to it.
So why can't I replace the car with a photon and see what happens?
Both of these measurements differ among observers because, in general, there is no simultaneity of events between observers in uniform relative motion to each other.I'm not sure I grasp this. Is this something that has to be treated as a basic principle (basic as in, it can't be broken down and explained in terms of anything else)?
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I'm a college student taking modern physics (or Quantum Topics, as my university calls it) and there are some things I'd like cleared up, if anyone cares to help me.
First, my classical physics question: why is potential energy held to be something that actually exists (according to the conservation of energy principle)? I can directly percieve various other forms of energy with my senses (kinetic by catching a ball, thermal by putting my hand in a fire, electric by touching an exposed live wire), but not potential.
The only justification for assuming the existence of it seems to be the conservation principle, but the conservation principle only survives because the existence of potential energy is assumed in order to make the math work (a circular arguement). I can't shake the feeling that potential energy is like the imaginary number; a useful conceptual tool, but not something that is actually found in nature.
Am I missing something?
As for modern physics...
Einstein's two postulates are that:
a) the laws of physics (Newton's laws and Maxwell's equations) must be identical in any two frames of referance which are moving at a constant velocity relative to each other and
all observers will measure the speed of light to be the same (the constant "c") regardless of their frames of referance.So, my modern physics questions are:
1) My textbook claims that b can be derived from a, but hasn't given any details yet. How? I don't see how to derive it using *only* a. What other pieces of information are involved here?
2) Suppose I declare a particular photon to be the origin of a frame of referance. Wouldn't the speed of that particular light particle be 0 rather than c in that referance frame, no matter how fast it was measured to be moving in any other frame? If so, doesn't that destroy Einstein's second claim? And if not, how on Earth could a photon still be considered to have a speed of c in a frame in which the origin travels with it?
3) I understand that time dilation has been demonstrated experimentally, and if I can accept that then I can accept the existance of length contraction as well. But has it been determined experimentally whether these phenomenon are solely the result of relative motion or matter itself being affected somehow?
A thought experiment to clarify what I mean: take a perfect sphere and set up some measuring/recording device like a camera (the "observer") next to it. Put this setup on a spaceship and have the ship accelerate along a straight line until length contraction becomes significant. Now, stop acceleration and rotate the sphere along an axis perpindicular to the direction of acceleration.
Does the sphere appear deformed (compressed along the axis it was being accelerated in) to the observer or not? If it does, that would suggest to me that time and space don't actually dilate or contract, but that the matter itself is being changed in such a way as to give that illusion. But if the sphere still appears perfect, then that would suggest that it is, in fact, relative motion that is the culprit.
Have any such experiments been done?
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I will, but I have no immediate plans. My life is just too full right now. I did do a Prodos radio show and led a two-hour IRC chat on the subject of humor and you might be able to find them on the Net somewhere.
I know about Prodos and his site, so the radio show will be easy enough to track down. But I used Google and didn't see a chat transcript. I can try looking harder later when I have more time, but first I'd like to ask if anyone here already has a copy/link.
Also feel free to ask me questions although I may not have much of a chance to answer until after my November CyberNet deadline.I'd be very interested in the rest of the "how-to" portions of your essay (the rest of the second, third and last sections). If there's anything we readers can do to speed you up, let us know... I'm sure I'm not the only one who would like to see more.
In the meantime, though, as far as questions go I'd be interested in what you have to say on sarcasm specifically.
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I know this borders on the arbitrary but I was wondering, if there is a reasoning being that can only survive by eating men, would it be moral for them to do so? If it does wouldn't it contradict our morality?
...You haven't been watching Stargate: Atlantis, have you?
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Indeed, what little there is of it.
Mrs. Speicher, you participate in these forums, right? Do you ever plan to finish? I seem to recall reading that material years ago and there seems to have been no progress in all this time. I'd be very interested in the rest of the first three sections (through to the end of "What makes humor funny or unfunny") at least.
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Hey, A Rob. Remember me?
Interesting concept. I have some points to make, though...
1) On the subject of weapons, give the guy a gun and some decent fighting skills, and let him be open about it. And I don't mean a ray-gun; give him a real iron slug-thrower. There's too much anti-gun sentiment among role-models these days; if it's rational to use force in self-defense, then "Rational Man" should embody this. Certainly the character should not be able to solve all (or even most) of his problems through force, but you can't always reason your way out of a fight either.
2) I disagree about needing a mask. First off it's an armor issue; if this guy is going to regularly be getting into the kind of trouble that requires bullet-proof clothing, why would he *not* want a bullet-proof helm? If his brain is supposed to be his most valuable asset, why is it also his least-protected one?
Second, a rational man *does* often have things to hide from his enemies. Would you publicly announce that you had evaded your taxes, or that you were an under-cover cop while you were investigating murderous criminals? It would be suicidal. The "mild-mannered professor by day" schtick will not fly if every two-bit hood that he crosses can know exactly who he is and where to find him (and his friends and family), unless he just never leaves an enemy alive (this *is* geared towards children, right?). And *then* he should have trouble with the authorities...
3) While you may not want multiple super-heroes, a good supporting cast of non-super allies (ethical businessmen, scientists, politicians, etc.) would help fill in a lot of gaps. Instead of just bringing in a corrupt politician, for example, you could contrast him against an ethical one to show how politicians are *supposed* to behave, giving kids a positive concrete example. And how is it that Rational Man can afford those cool wrist-computers? Maybe a wealthy businessman is bank-rolling him (giving you oppourtunities to show what a great thing riches can be in the right hands). And of course, it gives our hero more people to protect...
4) Have you ever heard the name "Macgyver?" It was a popular television series two or three decades ago centered around a character of the same name. He was basically an altruist who ran around helping people (the show's ethical and political stances were often horrible) and he refused to ever use a gun (stupid, considering all the trouble he got into with murderously-inclined bad guys).
None-the-less, if you want your hero to solve his problems through the application of science and technology, it's worth watching a few episodes for inspiration because the character is a scientific and mechanical genius. Without weapons or decent fighting skills he always has to overcome obstacles through the use of brains and technological improvisation. Your character could be like a Macgyver done right.
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I started a thread on the CapMag forums and was told about this
forum, so I figured I should bring this up here as well.
There was an objectivist exercise scientist and bodybuilder named
Mike Mentzer who, after a great deal of both theorization and
in-the-trenches expirementation, discovered that much of the
conventional wisdom on exercise is not only useless but harmful.
I tried his program instead, and got wonderful results. But the thing is
that I never would have heard of this guy if someone in the
CapMag forums hadn't made an announcement about him when he died
a few years back.
I also discovered a guy named Thomas Hodges who took a similair
scientific approach to studying dating and romance (from the
man's perspective) and *also* found out the hard way that the
conventional wisdom on the subject was dead wrong. And I never
would have heard of or benefitted from his work either if he
hadn't made an Ayn Rand reference in one of his online articles
(I got a hit on a web search).
This bothers me. Many of us want to improve, but in the same way
that a well-meaning activist can do more harm than good if he
doesn't know what causes to fight for, so we can end up damaging
instead of improving ourselves if we don't know what changes to
make (and how to go about it). It's great that there are people
like Mentzer and Hodges who challenge commonly accepted beliefs
and do the dirty-work of figuring this stuff out for us, but it seems
that most people (like me) just don't ever hear about them (to our
loss).
For myself, having improved both my physical and social prowess
thanks to these guys I'd like to turn now to mental prowess.
Perhaps some of you know about people who have done similair work
in such areas as speed-reading, increasing one's ability to focus or
gaining improved (or even photographic) memory?
Hence this thread, and another just like it by the same name over
in the CapMag forums. I think it would be very useful for many
of us to have a central repository of links, book titles, etc.
concerning such people and their work. That way when one of us
wants to do some self-improvement, we know exactly where to look
for information on how to do it *right.* So if you know of any
others like Mentzer and Hodges who have learned the hard way what
works and what doesn't in some area of self-improvement
(especially if you've had personal success using their techniques
and can vouch for them), post some basic info here and add your
knowledge to the pool.
I'll start things off: anyone interested in what's probably the
best bodybuilding program out there should head to
www.mikementzer.com and those men looking for help in the romance
department should go to www.doclove.com or go to the "dating and
love" section of www.askmen.com and check out the repository of
free online "Doc Love" articles.
Modern And Classical Physics Questions
in Physics and Mathematics
Posted
Argh. I caught that mistake shortly after I posted and changed it to say "gravitational fields" instead, but you must have grabbed a copy to work with offline too quickly. That's also why I made the accidental double-post; I hit the wrong button the first time I tried to change it. Sorry about all of that.
To answer your questions, no. Entities are independent substances, energy is a quantitative measure of change in entities and as such by definition can't exist independently of them. Not in my book, anyway.
Examples are gravitational fields, magnetic fields, etc. I'll just call them "fields" instead of "energy fields," as using the word "energy" in two differant ways will be confusing. I classify fields as entities, not actions; they can cause changes and be changed, but they are not themselves a process of change.
Good point. That would definitely go in the same file as potential energy. I'm thinking more and more that my concept of energy does not match the definition of modern science.Yes, that is differant from what I thought. And it removes the objection I was going to give to your claim that you can't use a photon as a point of origin. Not that I'm conceding the point just yet (I'm still thinking it through), but my first counter-arguement doesn't hold.
It's called "Quantum Topics" here (Loyola University of New Orleans), though I'm told that most other universities just call it "Modern Physics." It's a second-year course. As for the text...
Title: Modern Physics (for scientists and engineers), second edition
Authors: Stephen T. Thornton & Andrew Rex
ISBN: 0-03-006049-4
On a tangent, I was thinking about what you said earlier about how we can't measure length contraction with modern instrumentation. But there's another way; if you can get a rocket going fast enough for length contraction to become pronounced, you can just launch that sucker past some measuring instruments.
I realize we can't do that on Earth, but with the success of SpaceShipOne and all we may soon have the infrastructure to build rockets in space that don't have to worry about escaping atmosphere or overcoming air drag. Give one a big enough fuel tank, fire it towards the sun for bonus acceleration from gravity and you're there. Of course I'm sure the price tag would make even Bill Gates blink twice, but for something as big as experimental verification of length contraction I'm sure you could get enough people to contribute.
What do you think? Could we actually see this happen in a couple of decades?