Ok I'm back with my discusting grammar and my odd theories about time and space. Question: Say we had trains that traveled at the speed of light.(humor me) If you stepped out onto the tracks and a train "hit you"(thats the only way I can think to describe it) would it actually hit you because its going the speed of light?
Posted by Morbo (Member # 5309) on :
I'll humor you with an answer, but...a train couldn't accelerate all the way to light speed, relativity won't allow that. It would take infinite energy to do that.
So say your train is going at 0.9999 x c (c almost always equals the speed of light in physics equations.)
Well, that would circle the Earth in 1/7 of a second, it seems like overkill. But if you're on a Dyson sphere , you might need a magic train if your commute sucks.
So, you bumble onto the train tracks, and the train runs you over. Then you die, just like when a normal train does.
Although, a normal train wreck wouldn't completely vaporize you or cause a huge fireball with Gamma- and X-rays shooting out of it, visible on the other side of the solar system. So that's a plus. At least you'd finally be someone--you're name up in lights!
The collision would release collosal amounts of energy, enough to resemble a nuclear explosion. Just one reason interstellar travel is very difficult--when going at relatavistic speeds, a collision with a small pebble is a huge problem, unless you're craft is very, very tough.
Posted by vonk (Member # 9027) on :
How many cars are in the train and what is the cargo? wouldn't the train form a solid wall around the world if it were going that fast? it would be impossible to get in front of it in order to be hit. you'd just kick the side of the train and be thrown into orbit around the world. or blasted to bits in a fancy light show as Morbo said. But he used fancy words and numbers, so he's probably closer to what could be considered right in this hypothetical situation.
Posted by King of Men (Member # 6684) on :
Why would it not hit you? Photons generally don't have difficulties with this - I should know, I'm dealing with a surplus of the damn things for my thesis, at the moment.
Posted by Lupus (Member # 6516) on :
quote:Originally posted by Morbo: The collision would release collosal amounts of energy, enough to resemble a nuclear explosion. Just one reason interstellar travel is very difficult--when going at relatavistic speeds, a collision with a small pebble is a huge problem, unless you're craft is very, very tough.
Come on Morbo, everyone knows that when you go faster than light speed you have your energy sheilds turned on. Posted by Descolada Survivor (Member # 9019) on :
Ok so it kills you, thats what I'm reading? It will vaporize you instantaneously right? And the train would destroy a large chunk of the would along with it? So theres no delay between the train hitting you and you feeling it?
Posted by King of Men (Member # 6684) on :
Oh dear, you are probably thinking of time dilation. Trust me on this, you are not prepared to tackle that subject with an American high-school education.
Posted by Irregardless (Member # 8529) on :
quote:Originally posted by Descolada Survivor: So theres no delay between the train hitting you and you feeling it?
Your nerves would never have the opportunity to to convey the 'feeling' of it.
Posted by Bob_Scopatz (Member # 1227) on :
quote:Originally posted by King of Men: Oh dear, you are probably thinking of time dilation. Trust me on this, you are not prepared to tackle that subject with an American high-school education.
KOM, that may be true of the average high school kid (here and everywhere else on the planet), but there are young geniuses in our midst who may well be able to tackle this.
The problem I see with a train going near the speed of light is that you wouldn't see (and perceive) its warning lights until it'd already deconstructed you into your component atoms.
Also, judging from what high velocity dust specks do to our space craft periodically, I suspect that hitting you wouldn't do the train much good either.
Posted by Descolada Survivor (Member # 9019) on :
quote:Originally posted by King of Men: Oh dear, you are probably thinking of time dilation. Trust me on this, you are not prepared to tackle that subject with an American high-school education.
That was not very nice, but the fact is that its true. I don't understand this and probably won't comprehend this unless you explain it to me in simple terms that even I can understand.
Posted by cheiros do ender (Member # 8849) on :
Or, he could just explain it in the way that is most natural to him, and you could go and get a dictionary as you read it and work out the definitions of all the words you aren't familiar with. That's all there is to it really, when you're only being introduced to a subject. It takes a while learning things that way, but if you're memories good enough you usually end up learning all the basic vocabulary of the subject you'll need to study further from textbooks and whatnot.
Posted by clod (Member # 9084) on :
DS,
What a weird question. I don't mean that in a bad way. But why on earth would anyone attempt such a thing?
Posted by Sergeant (Member # 8749) on :
Speaking of American Battle prowess, one of my favorite quotes:
quote:The reason the American Army does so well in wartime, is that war is chaos, and the American Army practices it on a daily basis."
I've seen in attributed to various sources as well as versions that name the navy rather than the army but I would say that America in general practices chaos on a daily basis.
Sergeant
Posted by Princesska (Member # 8954) on :
KOM is about to post something stupid. Never mind it.
Posted by King of Men (Member # 6684) on :
Can you stand sit me? Or sit stand? Or even sit sit?
I do find 'America could obliterate your country' rather amusing as an argument. It reminds me of the kid saying 'my father can beat up yours'.
But to return to high school educations : Calculus optional. Physics optional. Mathematics taught as rote problems. (More accurately, arithmetic taught as rote problems.) The occasional bit of creationism, as evidenced by our own Ivygirl, though please let's not start that debate up again. And, of course, no special relativity.
Which is actually a rather interesting subject, in its own right, but does tend to require mathematical notation which the forum just doesn't support. However, waving my hands a bit, you will see people on board the train living in extreme slow motion, and they will see you living in extreme slow motion, since from their point of view, you're the one going at lightspeed. But since your nerves are the ones measuring the collision, that's irrelevant : You will see the impulse travelling along your nerves at their usual speed, which IIRC is around the speed of sound. That means that by the time the impulse reaches your brain, your grey matter has been splattered all over the continent - the train got there first. As ways to die go, it should be one of the more painless ones around.
Posted by Princesska (Member # 8954) on :
Actually, I agree with KoM on this one. If the train going at lightspeed isn't taking up all the mass in the universe, and if there is a way to stand in front of it and by hit by it, then who cares what speed the train is going at? A train hitting you is a train hitting you. Splat!
Still, he greatly underestimates the quality of an American high school education -- not suprising, since he's never experienced it himself.
Posted by Sergeant (Member # 8749) on :
While I admit the argument of obliteration is not the strongest argument it does bring up the point that despite our lack of a "first class" education system we have managed to become the only remaining superpower, built the largest economy in the world (if only because of our massive consumption), established the English language as the international language (don't try to convince me that the Brits did this) and even managed to be among the more innovative countries in the world.
So maybe all that math isn't really that important!
And if our education system is so broke why does the rest of the world come here to study? (Of course not in high school, I know).
Sergeant
Posted by cheiros do ender (Member # 8849) on :
Ahh, the arrogance of some Americans.
Posted by Verily the Younger (Member # 6705) on :
People, you have got to stop feeding the troll. Of course King of Men is going to say something derogatory about Americans. That's what he does. He bashes Americans, anyone with a modicum of religious faith, and, well, basically anyone who isn't him. That's what he does, and nothing we say is going to convince him to stop. When he goes into troll mode, the only thing to do is ignore it.
And by the way, when you make asinine statements like "America could obliterate your country in nothing flat," you're really not helping. First of all, the question of whom America could defeat in a major war is not relevant to the discussion at hand. It is possible to have a reasoned and intelligent discussion on whether the American public education system is up to the standards it ought to be, and whether other countries are farther ahead in this area. But when you break out the "My dad can beat up your dad" level of discourse, the only thing you contribute is to feed the flames of the arrogant trolls who delight in viewing us as subhuman.
You see, KoM already believes that we Americans are, by our very natures, a bunch of stupid, ineducable, nasty brutes. I'm not saying we have some obligation to convince him he's wrong. You'd have an easier time trying to convince Joseph McCarthy that maybe there's something to this communism business after all. But that doesn't mean we have to prove him right, either, which is all gems like "America could obliterate your country in nothing flat" could ever accomplish.
My fellow Americans, I beg you to keep the following guideline in mind: Any time you are tempted to make the argument that America could defeat some country in a war, stop and ask yourself, "Is the conversation we are already having about the relative military strengths of the nations of the world?" If the answer is no, then keep the "America could beat your country" business to yourself. It's irrelevant, it's puerile, and it gives arrogant non-Americans something to point to as proof that we are the nasty brutes they already assume we are. In other words, don't feed the trolls!
Posted by Orson Scott Card (Member # 209) on :
Hey, slighting remarks about an American high school education are always appropriate - I know, because I teach the products of that education. Generally speaking, any college student I meet who has even a rudimentary understanding of geography, history, or grammar got it on their own (or, in the case of grammar, from a foreign language class, NOT from English). Few literature teachers even teach poetry anymore; and nobody demands they learn rhetoric or logic. Stuff that I had out the wazoo before I graduated back in 68 are all alien territory to most of the college students I see; and most of the college graduates, too.
In our constant infatuation with new, unproved, and ineffective educational theories, and our insistance on turning to the very people who screwed up the system when we want someone to fix it, an American high school education is almost inevitably a joke, compared to what is POSSIBLE.
And, in case anyone wondered, piling on more homework and adding more days of school each year won't make any difference when you don't even have the vital subject matter in the curriculum ...
Posted by Orson Scott Card (Member # 209) on :
And, by the way, America could not pound any other country into the ground because it would not be politically possible. Very few Americans actually approve of into-the-ground-pounding, and an American army that indulged in it today would quickly be recalled and repudiated.
Posted by SoaPiNuReYe (Member # 9144) on :
I was literally just about to say that
Posted by Orson Scott Card (Member # 209) on :
And I figuratively knew that and delighted in preemptively pounding your observation into the ground.
Posted by SoaPiNuReYe (Member # 9144) on :
Seriously though USA couldn't wage war on just about anybody else. Maybe and prolly could get the UN on its side (iran) but otherwise the public wouldn't like it and the US couldn't get wage war without getting past big UN countries like China.... and we all know that if it came down to china vs. usa, china would win Posted by GaalDornick (Member # 8880) on :
What OSC says about American high schools are true. I go to one. It's not even that don't teach you important things like geography, history, logic, etc. It's that they don't even bother to teach anything even they think is important. To me, it seems like school isn't about learning anymore. It's about judging the students so they can figure out where we belong in the world. And they judge us by their standards of what they think is important.
And there's nothing we can do about it.
Posted by Orson Scott Card (Member # 209) on :
GaalDornick, there's ONE thing you can do about it: You can read your brains out. Newspapers, books, magazines. You can educate yourself, and do it superbly. It's not that the information isn't available - it just isn't available IN SCHOOL.
China would likely win a war with the US fought on CHINESE soil, should anyone be stupid enough to launch one; but China does not remotely have the ability to project serious power onto US soil, short of nuclear power, which would provoke hideous retaliation and therefore would be suicidal.
But remember, when the Korean War ended in armistice and stalemate, we had, in fact, beaten back a strong Chinese invasion. But it was NOT a war on Chinese soil; and the Chinese entered it precisely when we got too close to the Chinese border. Worth considering.
There are plenty of Chinese with no love for their current government and no stomach for wars on foreign soil. But tread on soil they consider Chinese, and you may find that the Chinese don't CARE who their government is, ain't nobody going to conquer Han China. Back when the Chinese were all peasants except a very thin crust of overclass, it didn't matter who the overclass was. But those days are over. The Chinese people are now functionally middle class (the irony of Communism is that it made whole countries of peasants into bourgeouisie) and susceptible to patriotism.
Posted by GaalDornick (Member # 8880) on :
"GaalDornick, there's ONE thing you can do about it: You can read your brains out. Newspapers, books, magazines. You can educate yourself, and do it superbly. It's not that the information isn't available - it just isn't available IN SCHOOL."
Yeah, that's true, and I do my best to do that. I just get mad that I have to spend 40 hours a week learning about nothing, when, if we had a good education system, I could be spending that time learning useful things and getting good grades for it, also.
Posted by Reticulum (Member # 8776) on :
*rofl* Oh god, you guys are hilarious.
"into-the-ground-pounding"
*wipes tear from eye*
I should post more stuff like that.
You are indeed right, OSC.
Posted by Reticulum (Member # 8776) on :
Why would China win? The U.S. has enough military power to wage war on the next 17 most powerful countries. And then, it would be an equal fight.
I am quite sure that no nation would be dumb enough to launch a full scale invasion on American soil, as they would have to to deal with the most powerful nations on Earth. Us ON Cinese soil?
Our military is about... a lot stronger, and more advanced and updated. The American military is dominant in about everyaspect. Except snipers, that title goes to Britain.
I can find no reason why it wouldn't work. Even if china nuked New York say? D.C.? They would either have MAD on their hands, or inevitiably, the US would nuke eveyr major Chinese city.
Search a database. You know it too be true.
Ahhhhh, good old, ignorant, arrogant, rude, fat, stupid, and mean America. I love it...
Posted by SoaPiNuReYe (Member # 9144) on :
quote:Originally posted by Reticulum: Why would China win? The U.S. has enough military power to wage war on the next 17 most powerful countries. And then, it would be an equal fight. Iam quite sure that no nation would be dumb enough to attack a full scale invasion on American soil, as would have powerful nation on Earth. Us and Cinese soil?Our military is about... alot stronger, and more advanced and updated. I can find no reason why it wouldn't work. Even if china nuked New York say? D.C.? They would either have MAD on their hands, or inevitiably, the US would nuke eveyr major chinese city.
Search a database. You know it too be true.
Ahhhhh, good old, ignorant, arrogant, rude, fat, stupid, and mean America. I love it...
Dude China could easily win. It doesn't always come down to military power, that was one of the points in Ender's Game. It comes down to resources and how well you use them. And frankly, China has a lot of resources.
Posted by Reticulum (Member # 8776) on :
Could easily win? Do you know nothing? And what do you mean by resources? Wood, oil, other?
Easily, is a foolish comment.
Posted by SoaPiNuReYe (Member # 9144) on :
quote:Originally posted by Reticulum: Could easily win? Do you know nothing? And what do you mean by resources? Wood, oil, other?
Easily, is a foolish comment.
Resources=People LOL!!!!!
Posted by Reticulum (Member # 8776) on :
That doesn't matter!
Posted by SoaPiNuReYe (Member # 9144) on :
Of course it does. More people means more numbers on the battlefied. It means more chances of finding better generals to lead those men. It means that while the USA is initiating the drafting of young men to join their army, China still has enough men to counter the USA's army w.o denting their workforce. It doesn't really matter though because China and USA won't be going to war anytime soon. Hopefully...
Posted by Reticulum (Member # 8776) on :
Okay then. That is the most illogical thing I have ever heard. The U.S. army is marginally LARGER then China's, or marginally smaller. It all depends on what database you look.
Numbers in today's military, mean almost nothing. And without denting their workforce? Do you think America would continue to trade with a country it is at war with? NO.
We would try to destroy them in everyway possible, and if that would mean, not buying, we would go somewhere else.
The Chinese economy would plummet, and they would lose MANY of their trading allies, for they would pull out along with the U.S.
You realise, if the U.S. fell, tens of nations would go with it?
I am not being arrogant here, I am simply telling what has a likely chance of happening.
Posted by King of Men (Member # 6684) on :
Before going off all half-cocked, let's define our terms, shall we? 'To win a war' can mean any of several things :
To put young men with rifles in the cities of the opposing nation, and impose your own administration for your own purposes - whether to build a stable ally, or suck the wealth out of the region.
To force the opposing government to make concessions, whether of tribute, trading rights, ceasing to support regimes you dislike, or stopping a particular artist from making music.
To reduce the enemy country to a radioactive wasteland haunted by cancerous ghosts, while your own remains a viable industrial nation.
The United States has, I believe, the power to 'win' in the third sense; whether it has the will to apply its power is not clear. It probably has the power to win in the second sense; the US navy is good enough to impose a blockade of the Chinese coast, which would cripple their economy - they are even more dependent on imported oil than the US is. (This might not be a good idea, though. The last time the US imposed a strategic-material embargo on an Asian nation with an authoritarian government, it got Pearl Harbour. Doing that to a nation with nukes might not be terribly bright, even if the US would 'win' the exchange.)
Finally, the US certainly does not have the power to win in the first sense. (Neither does China, of course.) Certainly, the US army can defeat any number of Chinese divisions; but they cannot control anything but the ground they stand on, and that tenuously. China is just too large, as the Japanese found out in their time.
Posted by SoaPiNuReYe (Member # 9144) on :
Dude lets look at it like this. You're saying that USA has better military equipment than China. I won't argue there. However, all you have to do is look at the war going on now to see how the US handles their military. They simply dont have the MacArthurs anymore do they?? I believe KoM was right about USA successfully blockading the China seaborder. But look at it this way if it was just China vs. USA i believe China would win because: China has a ton of people. Even if they draft or w.e it is they do over there, they still are gonna be able to produce enough money, steel, and ammunition required by the war. China is quite capable of fending for itself. Otherwise how would it have lasted this long? I mean sure they might run low. But the Chinese Navy isnt that bad. They proved that with their war on Russia. So they could just win those resources back. It all comes down to who has the better people up top.
Posted by Reticulum (Member # 8776) on :
Okay, their economy would not allow for them do all of this. You claim that having more men, would guarentee vicotory. Producing steel, and ammunition, and other goods for war. Their economy is SMALL compared to the US's. They could not afford this.
So, when the U.S. destroys their trade are they going to be able to produce all of this? They would plow themslelves into the ground. The U.S., however, has the largest economy in the world, and COULD afford this. The U.S. would plow China into the ground, their economy along with it. Having a huge population means nothing. The U.S. has the 3rd highest population.
But, I do have to agree with KoM, on this. Niether could win on each other's soils.
Posted by Reticulum (Member # 8776) on :
Well, actually, China is the fourth largest country, and The U.S. is thrid.
Posted by King of Men (Member # 6684) on :
Hang on a moment. When did the Chinese fight the Russians?
Posted by Reticulum (Member # 8776) on :
Never.
Posted by King of Men (Member # 6684) on :
Well, apart from the constant border skirmishing that's been going on since the Russian colonisers reached Siberia, anyway. But we were speaking of navies. Perhaps comrade Soap is thinking of the Russo-Japanese war?
Posted by Reticulum (Member # 8776) on :
Probably. Interestingly, a peace treaty was never divised, so they technically, still at war.
Posted by King of Men (Member # 6684) on :
As for winning a war in the traditional sense of occupying and such, we do not have the political will or stomach for the atrocities that it would take to really assimilate any country let alone one of China's size. I do think that we could bomb, invade and leave, knocking their economy back a couple of decades. But once again, there would have to be some sort of aggression from China's side for us to get involved. Simply the do not really have anything we want besides cheap goods which we evidently want way too bad.
Back to the high school question, I think there are some aspects of an American high school education that are superior to those of other countries. (of course I only experienced an American high school) My high school education was lacking everything that KoM and OSC mentioned. As a matter of fact the I learned very little academically (sp) from high school because I was an avid reader. But aside from this I was afforded the opportunity to participate in 2 sports (could have done 3 but I didn't like basketball or wrestling), sing in the choir, play in the band, participate in Future Business Leaders of America, Academic decatholon as well as several other activites. Of course my school was very small so you were almost forced to participate in at least 3 activities in order to have enough people for them all to function. I think the extracurriculars taught me more than class did.
Of course, with education funding as it is, these are the programs that get cut and schools are so large now that most kids probably don't have an opportunity to do any extracurricular. But as my mom told me as a kid, you get the kind of education that you take.
Sergeant
(sorry for the lack of parrallel structures in my lists.)
Posted by cheiros do ender (Member # 8849) on :
Now can we please drop the "my dad could beat your dad" thing? If you want to discuss China v America, or really any countries at war, make a new thread.
I have little to say in regard to formal schooling. It's horrible and I hate it. Of course I'm talking about Australia. I have no opinion on the American formal schooling system, obviously.
[ February 06, 2006, 04:31 AM: Message edited by: cheiros do ender ]
Posted by mr_porteiro_head (Member # 4644) on :
quote:If you want to discuss China v America, or really any countries at war, make a new thread.
The harder you try to keep a thread from derailing, the more it will be derailed.
Posted by cheiros do ender (Member # 8849) on :
If I was to make a China v America thread, the hardest I'm willing to try to stop this thread derailing, I think you'd be pleasantly surprised.
Posted by Reticulum (Member # 8776) on :
I cana agree sergeant, that America does not really have the stomach for it a war like that. As for the cheap goods, that's true, but I think another thing that America would go to war for is probably that we want to stop China from becoming a superpower.
Posted by cheiros do ender (Member # 8849) on :
Oh, so it's alright for you to be a superpower, but you have the right to attack China because they don't deserve to be one. Why?
Wait, no, I'm creating a forum for it on the other side. Posted by MateoMcD (Member # 1452) on :
I teach in an American High School (math and physics, as it happens), and I cannot for the life of me figure out what they're teaching in Elementary and Middle Schools...
It's true, however, that American High School education is being horribly twisted away from anything that is actually worth learning. In my opinion, the push for Standardized Testing as the ultimate measure of student and teacher accomplishment is one of the biggest factors behind this.
Don't get me wrong, I think that we need to have standards, because we need a way to measure that getting credit for "Geometry" at High School A means that the student has gained mastery over the same concepts and to the same level as a student who got credit for "Geometry" from High School B. Obviously, some means of measuring this is necessary. If every student in the state or nation is to be given the same test at the same time and the results assessed in a timely and cost-efficient manner, a computer-scorable, multiple choice test on a representative sample of problems makes sense... of a sort.
Unfortunately, this solution raises as many problems as it solves. As they currently exist, standardized tests are designed more to show the comparative achievement of students and schools rather than an absolute scale. Another way of saying that is that the test results tell you how many students you did better than, but not how well you did overall. If the test focused only on the basics of each discipline that all schools teach well, you would get everyone scoring pretty much the same and the results wouldn't be very helpful in sorting out the "good" schools from the "bad" schools. As a result, test questions have been shifting away from the basic principles that are actually worth knowing and useful (at least in math and science) and toward more esoteric, abstract concepts that are not foundational to the discipline. Schools are pressured to focus on the "fringe" of a given discipline, which concepts cannot be fully understood in context without a solid grounding in the basics, which are being rushed through. The only way to teach these concepts is rote memorization that involves knowledge of algorithms and mnemonics removed from any meaningful context.
Although my experience is in math and science, my colleagues assure me that the same pressure is at play in the humanities as well. What kind of meaningful learning in the humanities is measurable by multiple choice tests? What level of literature can be read, analyzed, and understood in the context of a 45 minute test covering five reading selections from different genres?
There are a lot of problems with the American educational system. Fatal problems that are killing education and our kids. Something does need to be done, but the current mania for more and more testing isn't part of the solution, it's just making the problem worse.
Posted by IB_wench (Member # 9081) on :
On a somewhat related note...
I live in Ontario, and the government has just decided to drop Calculus from the high school curriculum. Starting next year, students will NOT be able to take calculus (not even as an option!) until they reach university.
What is your opinion on this? (especially you, Mateo, as a high school math teacher?) What sort of long-term concequences will we see?
Personally, as an avid calculus student, I think we just shot ourselves in the foot.
Posted by Hamson (Member # 7808) on :
That's terrible Wench. We thankfully have a lot of options at our school, but with having so many options comes the fact that you don't have time to take most of those options.
The school curriculum is seriously messed up. Did you know that the only MI state requirements for high school are 1 semester of Civics, and 1 semester of Econ (And starting for freshmen next year, either 1 or 2 semesters of World History). That is ALL that is required by state. No English, Math, Science, or Language or anything- Of course, individual districts set more rigorous requirements. I just find that whole idea sort of weird though.
Also Sergeant mentioned earlier that he was an avid reader in high school, and I was just thinking, I don't really have time to read AT ALL anymore. Throughout middle and elementary school, reading was stressed up the wazoo and I would do it willingly, I love reading. But now I'm in high school, I realize I don't have time to read and that just really GETS to me. Because I know that one of the reasons I do so well in school is from a long history of avid reading, and I can't fit that in anymore. Actually, it's not even that I can't really fit it in, I have the free time for it, it is just that my free time is limited enough so that I always feel like I should be doing something else besides reading that I never have time to do, like hang out with friends, or play a video game or something. I'm always in the mood to read at night, and I do, but I normally end up reading a page or two before drifting to sleep. And whenever I DO try to read during the day, I also end up falling asleep very fast because I'm worn out from school and my lack of sleep from the night before.
I started reading The Dispossessed about 2 months ago, and I'm barely 80 pages in. More time needs to be allotted to take part in cool activities like reading.
Posted by Irregardless (Member # 8529) on :
quote:Originally posted by King of Men: Which is actually a rather interesting subject, in its own right, but does tend to require mathematical notation which the forum just doesn't support. However, waving my hands a bit, you will see people on board the train living in extreme slow motion, and they will see you living in extreme slow motion, since from their point of view, you're the one going at lightspeed.
KoM, changing the subject slightly, this comment made me think of a question. It's my perception that relativity holds that there is no absolute inertial reference frame, i.e., it is just as legitimate to say that the train is still and that the universe is sweeping around it at 0.99c (or whatever hefty fraction of c we want to use). The question of which is moving and which is stationary is a relative one, dependent on the observer, right? This seems consistent with what you said above.
Yet, even though each group (those on the train and those outside it) perceives the other as living in extreme slow motion, 'time dilation' as I understand it says that one party will experience little passage of time while the other grows old and dies (e.g., Ender is still around when 3,000 years have passed back on Earth). So, in the absence of any absolute inertial reference frame, what determines which group gets old and which one stays young? Why doesn't Ender, having been left behind in his arbitrarily 'stationary' position on the spaceship, grow old and die while Peter lives on, speeding away (with the rest of the solar system) at nearly the speed of light?
Obviously I have too simplistic an understanding of one part or another, I just don't know which.
Posted by clod (Member # 9084) on :
personal confession: I can't use chopsticks properly. Dunno where that tangential thought came from, and it won't do much to contribute to this thread. But, here I thought I was pretty adept with the sticks in moving food from my plate to my gullet, only to learn that it wasn't necessarily so. Alas! While my technique is efficient and would put most American's to shame, I came to learn that I'm quite crude and inelegant. For shame, for shame.
Even if I could move my chopsticks at lightspeed (far surpassing any fly-catching antics), I'd still be behind, relativistically speaking.
Posted by King of Men (Member # 6684) on :
Indeed, this is a classic question, referred to as the Twin Paradox. (It is a common misconception that this just refers to one twin being biologically younger than the other; that would be an interesting effect, but hardly a paradox. The paradox is that both twins should be younger than the other, for precisely the reasons you give : They both see the other as moving at near lightspeed.)
Let me reformulate the question in the classical way : We have two twins, Traveller and Stay-at-home. Traveller uses a spaceship to travel to Alpha Centauri and back at something very close to the speed of light. Stay-at-home, meanwhile, does exactly what his name suggests. When Traveller gets back, he is essentially the same age as when he lefts; Stay-at-home is eight years older. "No fair!" cries Stay-at-home. "I was going at lightspeed too!"
The answer is that Traveller has not, in fact, been sitting in an inertial frame of reference. At some point, his spaceship accelerated. That takes us right away into the domain of general, not special, relativity. While accelerating, all bets are off; the spaceship loses any claim to be an inertial reference frame.
You might ask, then, why we could not just as well consider the spaceship to be at rest, and the Earth to be accelerating. But here we can distinguish between the two frames : If you drop an object in a spaceship that is accelerating at, say, 600G, it will fall to the floor at 5880 meters per second per second. That won't happen on Earth. It is not unreasonable to say that all the differential aging is taking place in those few seconds of acceleration.
Now, of course, if you drop something on Earth, it will fall to the floor at 9.8 meters per second per second. So the Earth is also an accelerated reference frame, and in consequence, time goes slightly more slowly for us than it would in free space. (This indistinguishability of gravity and other acceleration, incidentally, is the major postulate of general relativity.) It is this effect that is being measured when people send atomic clocks into orbit; it needs to be taken into account when doing the math for GPS satellites. This is one of the major tests for general relativity, in fact.
You'll note that the Twin Paradox only arises if the twins meet up later and can compare life histories. Since they start out in different reference frames, presumably moving quite fast relative to one another, this means that one or both must accelerate. If they remain in their state of relative motion, then it is indeed perfectly valid to consider either one as being the old one - but the question never arises, because they cannot meet up and compare notes.
Posted by clod (Member # 9084) on :
huh?
that's curious. I say potatoe and you say potatoe, But, like, we're not saying it at the same time... whoa!
hello Doppler?!
Posted by MateoMcD (Member # 1452) on :
Sorry for not responding earlier, IB_wench, I hope the intervening posts haven't irretrievably lost us the thread of your question (though as a physics teacher I thoroughly enjoy the diversion!).
No calculus at all? Hmmmm. Off the top of my head, I'd say that while requiring all students to take calculus is wildly inappropriate, it seems similarly inappropriate to deny the option to anyone. Of course, the option is still there, it just isn't available until University-level studies.
I think that there are obviously students who are ready to study calculus at a level beyond memorizing tricks and algorithms to allow them to pass the AP (Advanced Placement) test. In some ways, calculus is one of the most useful branches of mathematics, as it provides a way to understand and predict natural phenomena as well as give us the tools to venture where we haven't been able to go before.
I think that most calculus taught in the US (I don't know about Canada) is designed to allow a student to do well on the AP exam and get college credit. I think that the number of high school students who are prepared by an American public school education to actually study calculus from a conceptual viewpoint and not just know how to solve problems but understand what they're doing is pretty low. I also think that learning calculus any other way is in many ways a waste of time...
I guess my answer would be that if you're going to teach calculus in high school and make it a course that's worth taking, you need to teach math differently for the previous 10 years to train students to expect math to make sense and be useful.
What do you think?
Posted by Will B (Member # 7931) on :
...and if a train moved at the speed of light, it would have infinite mass. Reducing its speed would release infinite energy, which would destroy not only you, but the universe.
This is why we have speed limits.
Posted by IB_wench (Member # 9081) on :
Thanks for responding, Mateo! As one of the calculus students who loves to go beyond memorization tricks and algorithms, I definitely agree with you. Not only is calculus the branch of mathematics with the most real-world application, but the logic and the types of thinking required are useful - even necessary - for many other disciplines as well! Unfortunately, while we don't have AP exams in most high schools, thorough understanding continues to be bypassed in favour of an "easier" curriculum.
Part of the problem stems from the decision to eliminate grade 13, thus compacting 5 years worth of curriculum into 4 years of high school. Many students couldn't handle the more intense workload, and as a result the curriculum continues to be watered down further and further.
Of course, the obvious solution would be to move some of the curriculum down to a younger grade level, distributing it more equally and lessening the burden on the students once they reach high school. (As it is, grade 9 Canadian students are about 2 years behind grade 9 students from elsewhere in the world.) But instead of bringing the students up to the level where they can meet the standard, we simply lower the standard. Aaargh, frustrating!
I'm really lucky in that I take IB math (which covers many concepts that are not included in regular Calculus, including trig functions and antiderivatives) and I have an enthusiastic teacher who loves to show us HOW and WHY the math works rather than just listing formuae. But it's too bad so many other students won't get the same chance to find out how interesting calculus really is...
Posted by Oliver Dale (Member # 8398) on :
quote:Originally posted by Will B: ...and if a train moved at the speed of light, it would have infinite mass. Reducing its speed would release infinite energy, which would destroy not only you, but the universe.
This is why we have speed limits.
This isn't strictly possible either as it would take an infinite amount of energy to slow it down.
Posted by Descolada Survivor (Member # 9019) on :
So if what Dale says is true then your body would be instantly vaporixed and you'd be nothing more than a splatter on the side of the train. Please note that the train would not be traveling continuously it would make super fast trips from place to place.
Posted by forensicgeek (Member # 8430) on :
As a recent graduate of the American High School educational system, I can honestly say I got what I wanted to get out of my classes. And that I probably got more than most people. Most classes were taught with obvious contempt to the way the government is currently being run. And our textbooks were some of the most biased material I've read.
But I did, in my opinion, gain enough of an education that I was somewhat prepared to entire college life.
I learned several years ago, not to bother with what I would be tested on, because that's what is stressed so much. I came to the conclusion anything I wanted to learn I would have to get on my own. So instead of asking questions in class that had relevance to the current topic. I asked questions that fulfilled my curiosity.
As I learn of what my younger siblings are being taught, I come to realize why schools are starting to fail so miserably. When I was younger we were taught things at a pace which accomodated students who did not understand the material as quickly as others. Nowdays it seems as though those students are just out of luck. They rush through basics to get to the 'important'- high level- information. But since students do not get a full understanding of the basics it becomes difficult for them to grasp anything else.
Posted by genius00345 (Member # 8206) on :
I'm an American high school student, and I have to say that I'm extremely disappointed in the way that our curriculum is headed.
I'm very academically accelerated, and grasp concepts much more quickly than other students. Our school does not offer "AP" classes, but because we are very small (300 students total, grades 9-12), if you wish you just take a higher level course. For example, as a sophomore, I'm in Algebra II, Chemistry, and Short Story/Novel, all three of which are typically junior level courses.
In Chemistry one day, we were doing electron configurations of elements in the F-orbitals (lanthanides & actinides). I noticed that the teacher had forgotten something, so as he gave us a break to work on our homework for the chapter, I told him that he had forgotten to include the electron from the d orbital. He told me that he skipped that part because people would get more confused and not understand it. I was astounded! How could he 'make up' material just because everyone else can't understand the reality? (We've since worked this out, by the way.)
I would be nowhere near the level I'm at today if I had not studied on my own over the years. I probably have more textbooks in my room than some of the teachers do! (In the online world, Wikipedia is my savior when it comes to research. So many students resort to frantic Google searching that they get everything mixed up.)
Standardized testing is the (if I may twist the idiom) straw that will break the camel's back eventually. Instead of teaching until everyone grasps the concept, we teach what will be on the test, and must fit everything in before the test. Even in math class, where I see this problem the least, it is evident that lessons are rushed through. If teachers in areas like math weren't afraid to (pardon the pun) go off on a tangent once in a while and explain the history of something, or tie into another subject, maybe students could generalize their learning, and begin to see connections. This is the only way I can stand to learn things in school.
I'm especially concerned with extracurricular downfalls, because I'm involved in so many activities. I've found that I'm running out of time to take classes I want to take (like Band and Yearbook) because of the classes I'm required to take (like PE and foreign langauge). I was excited earlier today when I read in the newspaper about the possible integration of a government-sponsored online "public school". In essence, students would be able to take online classes for high school credit. The article wasn't clear if you could be dually enrolled in an actual school or not, but did mention the possibility of participating in the activities (band, etc) in your local school district. The installation of this program could be my lifesaver, because I desperately need the time for 'required' classes. (On a related note, I wish PE credit was given for sports...it has been in the past but is no longer done, at least at my school...it makes sense!)
Posted by ketchupqueen (Member # 6877) on :
quote:I'm especially concerned with extracurricular downfalls, because I'm involved in so many activities. I've found that I'm running out of time to take classes I want to take (like Band and Yearbook) because of the classes I'm required to take (like PE and foreign langauge). I was excited earlier today when I read in the newspaper about the possible integration of a government-sponsored online "public school". In essence, students would be able to take online classes for high school credit. The article wasn't clear if you could be dually enrolled in an actual school or not, but did mention the possibility of participating in the activities (band, etc) in your local school district. The installation of this program could be my lifesaver, because I desperately need the time for 'required' classes. (On a related note, I wish PE credit was given for sports...it has been in the past but is no longer done, at least at my school...it makes sense!)
Can you not take 0 and 7th period classes, and get required courses like history, math, P.E. out of the way during the summer? That's what everyone in my HS did.
Posted by genius00345 (Member # 8206) on :
My school offers 7 classes per day, required. There are no classes offered before 1st period or after 7th.
I have explored the option of taking summer school classes for some credit, however not many higher-level courses are offered (assuming that the students coming to summer school are not the ones needing high-level courses, I guess). Also, I only receive half a credit for a six-week course, which would only be good in PE for me, really. I'd me much more willing to attend 'night classes' or correspondence courses for credit.
Which is why I'm kind of excited about this new online prospect, although I'm nervous that I can't be dually enrolled.
Posted by dantesparadigm (Member # 8756) on :
I'm taking a VHS (virtual High School) class in which a group of students from around the country takes the same class and everything is done online. It's not the same as a regular class education wise, in that you're only going to learn if you want to. however it's a nice alternative if your school doesn't offer many classes or they are full.
Posted by Nikisknight (Member # 8918) on :
I recently taught high school chemistry in an urban school. (I'm now looking for an alternate career track, to put it mildly.) As bad as many teachers may be, I have to have some admiration for their ability to take the abuse students can dish out, though much more so for those that can abely correct and improve behavior.
Standard test were certainly a problem, although I don't know if they would have been if I'd had 30 students like foresicgeek and genius. Basically, I was repeating the most basic concepts of a chapter for a month, then giving a test that everyone flunked, then moving on despite the fact that no one had the foundation needed, because we had to learn x y & z before the test that was stupidly six weeks before the end of the year, and if our test results didn't improve, blah blah blah.
(That was when I wasn't breaking up fights or begging kids to take out a pencil, or sending them out for refusing to mess up their hair with goggles, or taking away electronic devices, or trying to make sure every student had a textbook before we were auditied, or trying to find chairs for the extra 20 students that would only be their until classes were 'balanced' in late october, etc.)
It was my first year full-time teaching, but I wasn't the only one, the other teachers who had non-AP/IB students told me the same stories. I would have quit sooner, rather than the end of the year, but the other teacher who did had a long succession of short-lived subs fill in, and that would have served the students slightly less than my frustrated attempts.
I'm not sure what can or should be done about it all, I just think, "God, I don't want to send kids of mine into that mess."
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