Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Why do we keep saying its impossible?

  1. Apr 22, 2003 #1
    I was wondering why we keep sayign things are impossible? If anything history has shown us that when we say something is impossible, more often than not, it isnt!

    "Everything which can be invented, has been invented" - Head of the patent office of america, 1899.

    A multitude of times in the past they said the periodic table is full, then there was somethign else to go on there! how do we know something else cant go up there ? eh eh! Lots of things were impossible (according to physisists) until the quantum theory came along, why cant the same happen again ? what if the next einstein comes along and says "well actually, look at this" then everyone goes...

    "oh right, so we can travel faster than the speed of light" but someone then goes "yeah, but it MUST be impossible to do this and that!". and it happens all the time! why does it happen!

    whether this is of interest to many i dunno, but its been bugging me for ages! :P
  2. jcsd
  3. Apr 22, 2003 #2
    I think that in some cases, restrictions restrictions that have been set by people before were "broken" while at the same time respected. For example, the speed of light is supposed to be absolute, nothing can go faster. However, we can still travel a huge distance in less time than light by using higher dimensions. Thus, relative to an absolute observer, we are going faster than the speed of light, while still not breaking any restrictions imposed by relativity. This is what I think will happen in the future. We will learn to go around the laws mostly, even though a huge deal is still waiting to be discovered if you ask me.
  4. Apr 22, 2003 #3


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Well, the "light barrier" is fundamentally different than previous "impossibilities".

    Things like "all that can be invented has been invented" is simply an extrapolation based on the wide array of things that have been invented, and the slowdown of truly innovative ideas.

    Something like "The sound barrier can't be broken" was based on the extreme physical stress placed on objects breaking the sound barrier, and the reckoning of engineers who simply had the opinion that it was too tough for any material to withstand.

    Statements like "It is impossible to travel faster than light", however, is a rigorous deduction from special relativity. Scientists say that it is impossible not because they think we've gone almost as fast as we can go, not because they think it's too difficult, but because the mathematics say it can't happen.

    If the light barrier were to be broken, that would mean Special Relativity is wrong. Of course, Special Relativity could be wrong, but scientists have no reason to think that it is.

  5. Apr 22, 2003 #4


    User Avatar

    In other words, there is no such thing as a technical impossibility. This was the flaw of previous restrictions.
  6. Apr 22, 2003 #5


    User Avatar

    Staff: Mentor

    To clarify things a bit and add to what Hurkyl said, there is a difference between a TECHNOLOGICAL barrier and a THEORETICAL barrier. A technological barrier is breakable, a theoretical one is not (unless the theory is wrong).

    The sound barrier was always known to be a technological barrier (bullets have been going supersonic for a long time). We just needed to invent the technology to break it for aircraft.

    The speed of light is a theoretical barrier in that our understanding of physics says that it isn't possible to break it regardless of our level of technology. It would be a major upheavel to physics to find that it is breakable.

    So yes, some things said to be impossible are not - but some things said to be impossible really are.
  7. Apr 23, 2003 #6
    I say that most scientist dont have a clue of anything because there minds are stuck on things of the current time and over the years things do change. They though eistien was nuts back then but we look back and say to our selfs gezz those people are smart so for the present day i would have to say scientist and science are in there infancy.
  8. Apr 23, 2003 #7


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Perhaps if you actually knew something about modern science you could make some meaningful comments.
  9. Apr 23, 2003 #8
    Well ...
    It is all about information ..
    Mainly (i believe) there is no definite way to tell if a certain info is true or not.
    Over time, we have found ways that we have agreed that everything that applies on it is true.
    Some of those include Logic, on which Mathematics are based (somehow).
    Therefore scientists believe that whatever has been derived using Mathematics will and Logic (in the right way) will be true.
    It is hard to find flaws or errors in things that have been based on Logic and/or Math, but it is not impossible, it is possible that someday someone will find something wrong in either the original data that has been used to derive a certain theoretical limit, or something wrong in the use of Math/Logic in it.

    Otherwise, every other impossibility is just people that are too lazy to work to make something possible.
  10. Apr 23, 2003 #9
    Hmm, that makes sense! I never thought of it as 2 categories, technical and theoretical. I understand a little better now :) thanks for all the replys :)
  11. Apr 23, 2003 #10


    User Avatar

    Hi Bunting

    re - " was wondering why we keep sayign things are impossible?"

    Excellant point. I would guess that people become very convinced of something to the point that they get tired of saying "This has never happened and it seems that it never will."

    and simply say "This is impossible."

    But it's incorrect to say that since what has always happened in the past might not happen always happen in the future. For example: Maybe the laws of nature will all of s sudden change one day. We have no reason to believe they will. Yet we are basing the future on the past and I see no reason that is the way it must be. I just see that is the way it "seems" to be at the moment.

    However consider a definition, from Webster's Dictionar for example.

    Impossible: felt to be incapable of being done, attained, or fulfilled : insuperably difficult

  12. Apr 23, 2003 #11
    hmmmm, i dont agree with that definition :-/ impossible IS when you cant do something, not when you just feel you cant do it :-/
  13. Apr 23, 2003 #12
    Hi P. Bunting,
    Quantum Theory was created as an augmentation of Newton-Einstein classical mechanics rather than a replacement for it. I argue that the physicists you mentioned in your quote were short sighted in failing to realize that the neutral charge of the neutron and the energetics and leptonic items expelled (at the time of decay to a proton) were unarguably proof that a neutral orbital coupling of the expelled electron and the retained positron charge of the proton existed, when in the neutron, in the same volume occupied by the ultimate positive charge of the proton. It follows that the neutron, per se, contains an oppositely charged (neutral) quantum orbital structure. Such an orbital called singlet positronium was discovered in the 1930's.
    I'm no Einstein but I am a learned logician and I predict that a new breed of physicists will ultimately despair of the QED Gell-Mann Standard model of the proton and look to augment classical physics with Nature's real pair of positronium quanta.
    Proof that a second e+e- triplet quantum is present in the neutron as a building block of its SR mass enhanced heavy shell is evidenced by its presence in the atom-smasher debris of a crushed proton (remember that the singlet e+e- no longer exists in the proton).
    PS: The pi meson has a larger cross-section for e+e- decay than that for charged mu meson production; in natural cosmic ray destruction, the expelled neutral e+e- and its auto-annihilation are both undetectable. Thanks for you audience, Jim
  14. Apr 23, 2003 #13
    I don't totally agree with what some of you said about if derived from logic and math then it should in most cases be true. I base myself to say that on geometry. Not so long ago, people were almost always using euclidean geometry. Nowadays, we know that euclidean geomtry cannot always be used especially if not on a plane. Although euclidean geometry is totally true and no one has any doubts about the sum of angles inside a triangle on a plane, it is quite logical that thius doesn't apply on a sphere. Euclid used logic to fimnd his theorems upon which many other math theorems have been built. Thus, what we really discover is limitations to limitations. Thus, this is not false, but no absolute neither, as we learn more about the space surrounding us. Thus, something might be impossible at one time, using logic and math, but logic is not failproof, and math is often based on math. Thus, there may be ways to go around the limitations that we found to exist. I believe, as i said earlier, that instead of remodelling laws, we more often find the little possibility in which it doesn't apply and exploity it to come to our goals. Also what used to be impossible changes as the society and the people are changing i think, but i would leave that to sociologists and people who know what they are talking about in that field. I'm only interested in the physics/math part.
  15. Apr 23, 2003 #14
    How about optimistic law of human brain: human neurons can't possibly fire in direction that is absolutely, finally impossible in this universe? (its dictated by fine structure of the universe :wink: )

    The only impossible thing is that which hasn't (yet) occured to us as a goal. All else is just matter of money...

    GR is not much better nor worse than newton's. GR has probs, QM has probs, there is that miss-universe of TOE's going on over the years, and we've yet to see the winner.

    Claiming that lightspeed is final barrier now is not much better than soundbarrier back then, only selfconfidence is higher. Noone has actually tried to brake it, right? Besides, GR doesn't forbid FTL, its just our deduction that by ordinary means its impossible. What remains, is obviously unconventional means...
  16. Apr 23, 2003 #15


    User Avatar

    We have. If you accelerate an electron with a potential difference, the work done is equal to e * V. So, you can increase the kinetic energy of the electron by jacking up the voltage. However, you will find that though you can approach c for the velocity of the electron, you can never reach it. The momentum increases, but the velocity doesn't get there.
  17. Apr 23, 2003 #16
    ahhh right, should have done a bit more reserch into that really :P but my case stands, physists do say things arent possible.

    no matter how much quantum mechanics is imilar to class relativity, it still dispelled some reasonings that some things are impossible!

    as for what NEOclassic says, im not even gonna pretend to understand it :) in lamens terms ?? ;)
  18. Apr 23, 2003 #17


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Indeed it is commonly understood that it is theoretically impossible to accelerate massive bodies to the speed of light. The point you naysayers seem to missing is that it has NOT been blindly accepted. From the first time Einstein dervived the result it has been challgenged experimentally. Einstein's results have been verified and are a standard factor in ALL HIGH ENERGY partical physics experiments.

    Now if you say "well that is in the world subatomic particals, how do we know that it applies to bigger things, perhaps this limit only exists in the quantum world." To that I say, since you are nothing but an assembly of subatomic particals, at what point does the laws of physics change? This phenomnea has observed with single electrons, single protons and ionized atoms. Do you suppose that the laws of physics change when 10 or 10 million atoms gather together?

    My message to you is if you do not believe it, fine. Learn some physics, get your PhD then design and execute an experiment which substainicates your belief.

    IF you are not willing, or unable to, achive the above then you are at the mercy of those who have done, or at least have studied the results of the experiments that have been done.

    IF you choose not to persue higher knowlege of Physics then you must learn to accept the results of those who have. Physics is not an armchair science, it is experimental science. You are playing the part of the armchair scientists, if you do not like a result it cannot be correct, simply because you do not wish it to be. Sorry, the universe cares nothing for what we want. The goal of physicists is to understand the universe as it is, not as we wish it to be.

    I tend to be somewhat short with armchair physicists whose entire education comes from coffee table physics books. Your naysaying is essentially calling 3 generations of the best minds of mankind idiots. I don't buy it.
  19. Apr 23, 2003 #18
    I'm sorry if i offended someone, i just think that stuff such as going pass the speed of light can be countered by say hyperdimensions. The thing which i considered to be the problem people think is impossible to solve is to travel large distances in a humanlifetime that even light would be too slow do. I never doubted that one can't go faster than the speed of light, just that the possibility of shorcuts would mean we don't need to try to do so.
    I never thought any of those scientists were idiots, on the contrary, i'd like to be able to do 1/100 of what they did for the world and i would still be happy. And once again, if i offended you in any way, please know that i am very sorry i did so.
  20. Apr 24, 2003 #19
    Right. Integral, please don't feel offended. Most people very highly respect current science and believe all that is generally accepted, including impossible FTL. The hope remains that this is not the end, new developments will reveal other new ways to do it.
    Reminds me doors with "Pull" sign on them - if you attack them head on, you might get hurt..
  21. Apr 24, 2003 #20


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Not to worry, I am not offended, I simply would like to see more effort to understand the lessons modern Physics has to offer, and fewer dreams of what is essentially science fiction.

    It seems that the universe has construted inpenatrable barriers, at least according to our current understanding. This does not mean that physicts simply accept this and make no further efforts.

    What does the future hold? While it is impossible to say for sure, I'll bet that the speed of light barrier is real. Mankind will continue to extend his understanding of the universe, what we now know will not change, prehaps it will be extended, as Einstein did Newtons laws, but not thrown out.

    For me, the biggest lesson we must learn it that the earth and nearby planets is what we have to work with, we must not squander it.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Similar Discussions: Why do we keep saying its impossible?
  1. Why do we feel this? (Replies: 2)