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B The Problem That Riddles Any Radical Thinker: WTH Is Energy

  1. Oct 14, 2015 #1
    Hello! I'm new to this forum but ok lets get this started,

    First I'll revisit the definition I know as physics; the study of nature in order to provide a reasonable(radical/rudimentary) explanation/reason. This I believe in is not quite how things are today, at school, with my teachers or at Internet. Why I'm saying this is because from the moment I learnt the concepts of energy, momentum, laws of conservation, I was never ever provided a sound reason up until now (leading me to believe it's witchcraft of science that was established at Hogwarts lol)...

    I do have some insight in this which I reached on my own. Please take a look:

    All concepts of conservation and virtues of energy and momentum probably originated from equations of motion and Newton's laws.

    Suppose for momentum: v = u + at
    multiply by a constant(mass) mv = mu + mat
    mv = mu + ft
    In by a case of a collision between two particles which has mass of m1 and m2

    We have to note that by Newt's third law the mutual force exerted during impact is of equal magnitudes
    So f=f
    time of impact is the duration of contact thereby t=t
    therefore our equation sets are m1v1 = m1u1 + ft

    m2v2 = m2u2 - ft

    for m2 (bloody subscript code gaaaah!!!)
    ft = m2u2 - m2v2

    hopefully you can do the rest by using substitution to get our conservation of momentum law (this is hard with those subscripts and I don't have all day hehe)

    It's a neat way indeed because I have carefully used logic and reason[ to some extent because I do not know how to explain why Newton's third law is being upheld and not violated( If you live in my country the stereotypical answer generated by every retard is, "It is because of newtons third law," meaning that they have some sort of a perpetual belief in Newton that he's godlike idk, hopefully none of you occults are in here)]

    Ok let us come back to energy. The concept I have is still underdeveloped because I'm not that great at converting mathematical logic into a plausible reason. Unlike the above equation which you can compensate for a non-uniform acceleration by simply tweaking out an average acceleration, this one I'm not sure ...

    We all know our equations of motion and how you get a v2=u2 + 2as

    So first thing is to multiply both sides with a 0.5m:
    0.5m(v2) = 0.5m(u2 + 2as)
    0.5mv2 = 0.5mu2 + mas
    0.5mv2 = 0.5mu2 + fs

    *note that fs is workdone
    thereby we would get a
    final K.E. = Initial K.E. + Fd( Work-done)

    And with this effective reasoning I can explain all that magic I did when solving those problems regarding objects under gravity and conservation of energy under such simple scenarios with the exceptions such as of rollercoasters as they are not under the constant force of gravity which leads to questioning of the validity of our equation because it is based by uniform acceleration.

    So I maybe able to find some sort of explanation to this query in which I'm very pessimistic about( you can understand the reason probably :frown::smile:). But albeit in such a case where non-uniform acceleration is enabled with conditions there's still the case what the world those scientists are doing with other forms of energy if it isn't based on the virtue of kinesis; bond energies, rest mass energies, electrical energies I just don't see the connection to these principles I've derived at. This is the cause for me to state all these modern-day energy principles simply the 'sorcery of science'.

    And pardon me if you spot some errors in my English. It is because most of it I learnt from my A-level textbooks and movies and tv-seies, oh don't forget the Internet :P
     
  2. jcsd
  3. Oct 14, 2015 #2
    * edit to the rollercoaster : constant force of gravity but not a constant acceleration that's caused by it's tracks reaction forces.
     
  4. Oct 14, 2015 #3

    Dale

    Staff: Mentor

    Hi hsakbo, welcome to PF!

    From a modern perspective the key reason that we have conserved quantities is because of specific symmetries of the laws of physics. So for example, we assume that the laws of physics are the same yesterday and today. That is a symmetry. Every symmetry leads to a conserved quantity. The conserved quantity corresponding to the time symmetry is called energy.

    Conservation of momentum comes from the fact that the laws of physics are the same at my house and at my neighbor's house. Conservation of angular momentum comes from the rotational symmetry of the laws of physics. Conservation of electric charge comes from the EM gauge symmetry. And so forth.

    BTW, all of the sorcery and magic references are not really in keeping with the forum.
     
  5. Oct 14, 2015 #4
    Yes I did came across this concept when I was introduced to the standard model. But sure we can dismiss all the reasoning and explanations by simply introducing another enigmatic concept. I still haven't learnt about this theorem in full details so I don't have much say in this but the abstract idea that was provided was that the universe likes to be symmetric. The point is my textbook and you didn't provide me enough reason to persuade me to believe that this is the exact cause, and what this sounds to me is as to believe and have unquestionable faith in it .. What difference would that make a from a religion huh? My aim is to understand nature without absent reason. But I do appreciate your input and I'll check into symmetry later with hopes that it would explain concisely.
     
  6. Oct 14, 2015 #5

    Dale

    Staff: Mentor

    Oh, I should mention. The proof of the relationship between symmetries and conserved quantities is called "Noether's theorem". It is probably one of the single most important proofs in all of physics.
     
  7. Oct 14, 2015 #6
    And btw is there a no further in my proof about conservation of energies using just simple maths because I'm still a student awaiting enrollment?
     
  8. Oct 14, 2015 #7

    Dale

    Staff: Mentor

    Using simple maths there is the "work energy theorem". However, it is not as general as Noether's theorem and it assumes Newton's laws. I understood from your first post that you did not want to assume Newton's laws, so all I know for that is Noether's theorem.
     
  9. Oct 14, 2015 #8

    ogg

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    IF I understand you correctly, you are claiming that Physics' "purpose" is to explain WHY (the natural world is as it is, and behaves as it behaves). No, that is wrong, I think. The "purpose" of Physics is to explain HOW. (this can be reduced/transformed to "the purpose of Physics is to enable us to predict...")
    It has turned out that much of our world (observable Universe) can be framed, using Physics, so that many, many "WHY" questions are answered, but philosophically, we (should) have no expectation of reaching the point where all of our WHY questions are answered, even in principle/theory. Attempting to construct a 100% logical structure, which is provably self-consistent and complete and which describes the observable Universe is (probably) not possible. That is, from what we know now, there is no reason (note! no REASON) to believe such a thing is possible, and many reasons to believe it is NOT possible. Philosophy is depreciated on this website for good reason, but if you want to research the conceptual problems in looking for the ultimate answer to WHY (any "WHY" question subordinate to the ultimate one can (arguably) be transformed into a HOW question) then search the literature for Hilbert's 6th Problem. Of course, until you understand modern Physics, especially the mathematical structures and constraints involved, the difference between WHY and HOW is hard to perceive, when it even exists; this can be discouraging for beginners.
     
  10. Oct 14, 2015 #9

    ZapperZ

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    The problem here is that you have such a naive view of the physics! It is incomplete and can't describe everything that we know already.

    The Noether theorem provides a clear and fundamental connection between conservation laws and the symmetries that we observe in the universe. This is well-tested in numerous situations! We just didn't accept it because it was written in some sacred text! This more general idea trumps the narrow confines of your "theory" by miles!

    But what is more troubling is your refusal to actually learn what you've been told. It appears that you either just heard of this principal, or was not aware of it till recently. Yet, instead of trying to figure out what it is and learn from it (especially on why it is such a general principle), you're dismissing it in favor of what you are proposing. Is this rational?

    Zz.
     
  11. Oct 14, 2015 #10
    @ogg My hardcore ardent fervor to find the answer to everything won't be ever discouraged even if Newton and Einstein and the whole physics community said that it's impossible, because I believe in cause and effect. Everything has their own reason to be that way, and yes how or why (is still maybe potato potato) is the key. If I can't challenge physics with reason then there is no point for me to learn the modern physics because what I seek is an ultimate explanation for to everything.

    @ZapperZ I wouldn't call myself a rational thinker if I'd be ignorant and refused information would I? As I've said earlier all these Noether and hilbert (which I'll be looking into in near future) stuff isn't quite what I've heard from our curriculum. Nor did know if there was more to this(they didn't gave a definition of energy either). So you see from my perspective, what you people do is complete alien. I will wholeheartedly challenge my current view of fundamentals of nature if I was provided with a sound theorem. And in by case If it didn't provide a proper reason, which at my scope I can only imagine it being limited to what I've posted earlier, the only options are to dismiss or put it onto my bucket of scrutinize later. So why not state why It is not possible to see the future of my proof instead of sounding like a condescending person huh or is just not possible for you without the help of hiding behind big names??
     
  12. Oct 14, 2015 #11

    sophiecentaur

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    I fail to see how quoting someone, who has proved themselves and is acknowledged to be an authority in a subject is "hiding behind them". Why should ZZ go to the trouble of producing his own personal version of what has already been published and approved? PF has a policy of avoiding personal theories without at least some evidence to back them up and using references is a very acceptable justification for any ideas that are written on these forums. We don't fly kites - or when we do, PF points it out.
    When you have read and can understand Noether's Theorem, you may change your view. Meanwhile, don't get offended when your lack of knowledge is pointed out. Don't get mad - get even, with loads of study. (I am pretty ancient, I am sure, by your standards and I try to learn something new every day. (Long way to go still.)
     
  13. Oct 14, 2015 #12

    russ_watters

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    Dale provided an excellent description of the logical foundation of these principles, but you seem to be more interested in proof (evidence). That's fine: the evidence is that these concepts are continuously tested both by scientists and by everyone, every second of their lives, even if they aren't realizing it. So that's pretty much the exact opposite of faith/religion, which is belief without evidence. These concepts have so much evidence that there isn't enough paper in the world to write it all down! With so much evidence, it is far past the point where scientists have to put conscious thought into these issues, but don't mistake the fact that you haven't gotten there yet (that you don't recognize the evidence yet) with faith.

    I know for some students, the "trust me" style of teaching can be unsatisfying, but there is a reason for it: there is a lot of information to cover and getting bogged down in unnecessary details wastes valuable time. So you really do need to trust people (us, your teachers) who know, when they give that knowledge to you a bite at a time.
    That's a bad road to go down, for several reasons:
    1. You know those names because those guys were rock star/hall of famers. Odds are that you are not(so you should listen to/trust them), but even if you are:
    2. The road you are going down is way too long and twisty for it to be possible for it to take you anywhere useful. You'd spend your whole life researching and never catch up. More likely, you'd try to take shortcuts, festering in wasting your life on thoroughly debunked crackpottery.
     
    Last edited: Oct 14, 2015
  14. Oct 14, 2015 #13
    Am I misunderstanding the purpose of a forum? Or just this specific one??? I thought they were there to help us out or start a debate... Anyways please don't misunderstand me because I really am deeply grateful for the input I've received about symmetries etc.. I'll be googling them later

    @russ_watters I'm sorry I can't help being overly curious and that I got plenty of time to waste hehe
     
  15. Oct 14, 2015 #14

    russ_watters

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    It would appear so: the purpose of this forum - like school - is to learn/teach, not debate. These issues are far beyond the need/value of debate.
    I added on to my last post something that addresses that. Short answer: no, you dont. And even if you did, odds are you would not get anywhere useful that way.
     
  16. Oct 14, 2015 #15
    That sucks because you'd learn better with debates and arguments( Don't need to mention why Greeks still have a living legacy even after thousands of years later...). Nevertheless I understood.

    That sounds more like an invitation :))
     
  17. Oct 14, 2015 #16

    russ_watters

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    It might be thorough, but it is time consuming. Sorry, but even if you aren't concerned about the effective use of your time, we are concerned about ours.
     
  18. Oct 14, 2015 #17

    sophiecentaur

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    Unfortunately for them, the Greeks weren't big on experimental evidence. Many of their theories were based on misinterpretation of what they observed. By the time of the Enlightenment, there was a gear change and their Science has been rather left behind. Strangely, their Philosophy is still featured a lot in modern Non-Sciences. That always makes me wonder about Philosophers.
     
  19. Oct 14, 2015 #18

    Bandersnatch

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    @hsakbo, perhaps it's worth clarifying, that the results obtained in the OP are perfectly valid (apart from one mistake). It's good that you've managed to come up with them yourself, and it shows promise. It's just that they're trivial, and not anything deep or radical. One should not give oneself airs of superiority because of them.

    Your first result, once you correct the mistake (forces are equal but opposite, so ##F_1≠F_2## but ##F_1=-F_2##) is nothing else than restating Newton's first law in terms of momentum: ##F=\frac{\Delta p}{\Delta t}##, and using it to show that it's conserved.
    Open any college-level introductory physics textbook and you'll find it there, or here:
    https://en.wikipedia.org/wiki/Momentum#Conservation

    The second result is the work-energy theorem, to be found here:
    https://en.wikipedia.org/wiki/Work_...n_for_a_particle_moving_along_a_straight_line

    It's a shame your textbook and classes omit those, but then again, it's par for the course for a pre-university education to be rudimentary. You should grab yourself an undergrad textbook with proper physics, and get cracking. I'm sure you'll find it stimulating, and perhaps also a bit humbling.
     
  20. Oct 14, 2015 #19
    Mate, you clearly have a long way ... Greeks basically came up with numerous solutions to what puzzled them. Be it may be a hypotenuse of a triangle, or buoyancy, geometry well what not, out of nothing, thin air. And yes with no maths( from what I know they went on to create it) to help em, but what they had was simply eyes to observe and a brain to contemplate about. That alone I believe is philosophy( go ahead and correct me)

    @Bandersnatch I thought about that but it was too trivial to state that because I've already stated Newt's third law which implies the opposite directions. What I wanted was for the reader to focus that those forces have equal magnitudes (better yet I never even defined the two vectors (I wrote f=f, not F1 = F2))
     
  21. Oct 14, 2015 #20
    And dammit!! Have you people read the title(that title tag says high school). I'm here simply to understand whether my energy equation was right or not... NOT here to deba.. be elucidated about greeks or basics of physics or stuff thats out of my league ... :mad::mad::mad::mad:
     
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