Do random experiments actually exist?












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I am studying probability and in most of the books that i have read they mention that for an experiment to be random-- (1)there should be more than 1 possible outcome--(2)even when the experiment is repeated under similar conditions the outcomes must not be predictable.The second point really confuses me...if we take a coin toss for example and we repeat the experiment under totally similar conditions of gravity,air resistance,apply the same force,etc won't we be able to predict the exact outcome every time and as long as the conditions remain same my intuition tells me that i will get the same outcome every time....so do random experiments exist?and if they do what can be considered as a random experiment?










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  • $begingroup$
    I don't know why you're confused by the second point. You correctly deduced that a coin toss is not random. Also, talking about "random" in the real world is not rigorous. Maybe you should post this question on some physics or engineering page
    $endgroup$
    – mathworker21
    Dec 12 '18 at 19:23






  • 1




    $begingroup$
    Whatever a "random experiment" is, it is supposed to include things like rolling a die and shooting a free throw. You are right that if the same exact experiment were performed we would get the same result every time (except perhaps in quantum mechanics). The axiomatic approach to probability sidesteps this issue. Mathematical modelers are then free to use the axioms of probability to predict what will happen if you roll a die a large number of times, etc. By the way, an alternative viewpoint is that probabilities represent degrees of belief.
    $endgroup$
    – littleO
    Dec 12 '18 at 19:35


















2












$begingroup$


I am studying probability and in most of the books that i have read they mention that for an experiment to be random-- (1)there should be more than 1 possible outcome--(2)even when the experiment is repeated under similar conditions the outcomes must not be predictable.The second point really confuses me...if we take a coin toss for example and we repeat the experiment under totally similar conditions of gravity,air resistance,apply the same force,etc won't we be able to predict the exact outcome every time and as long as the conditions remain same my intuition tells me that i will get the same outcome every time....so do random experiments exist?and if they do what can be considered as a random experiment?










share|cite|improve this question









$endgroup$












  • $begingroup$
    I don't know why you're confused by the second point. You correctly deduced that a coin toss is not random. Also, talking about "random" in the real world is not rigorous. Maybe you should post this question on some physics or engineering page
    $endgroup$
    – mathworker21
    Dec 12 '18 at 19:23






  • 1




    $begingroup$
    Whatever a "random experiment" is, it is supposed to include things like rolling a die and shooting a free throw. You are right that if the same exact experiment were performed we would get the same result every time (except perhaps in quantum mechanics). The axiomatic approach to probability sidesteps this issue. Mathematical modelers are then free to use the axioms of probability to predict what will happen if you roll a die a large number of times, etc. By the way, an alternative viewpoint is that probabilities represent degrees of belief.
    $endgroup$
    – littleO
    Dec 12 '18 at 19:35
















2












2








2


1



$begingroup$


I am studying probability and in most of the books that i have read they mention that for an experiment to be random-- (1)there should be more than 1 possible outcome--(2)even when the experiment is repeated under similar conditions the outcomes must not be predictable.The second point really confuses me...if we take a coin toss for example and we repeat the experiment under totally similar conditions of gravity,air resistance,apply the same force,etc won't we be able to predict the exact outcome every time and as long as the conditions remain same my intuition tells me that i will get the same outcome every time....so do random experiments exist?and if they do what can be considered as a random experiment?










share|cite|improve this question









$endgroup$




I am studying probability and in most of the books that i have read they mention that for an experiment to be random-- (1)there should be more than 1 possible outcome--(2)even when the experiment is repeated under similar conditions the outcomes must not be predictable.The second point really confuses me...if we take a coin toss for example and we repeat the experiment under totally similar conditions of gravity,air resistance,apply the same force,etc won't we be able to predict the exact outcome every time and as long as the conditions remain same my intuition tells me that i will get the same outcome every time....so do random experiments exist?and if they do what can be considered as a random experiment?







probability probability-theory






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asked Dec 12 '18 at 19:18









Suzie WatersSuzie Waters

553




553












  • $begingroup$
    I don't know why you're confused by the second point. You correctly deduced that a coin toss is not random. Also, talking about "random" in the real world is not rigorous. Maybe you should post this question on some physics or engineering page
    $endgroup$
    – mathworker21
    Dec 12 '18 at 19:23






  • 1




    $begingroup$
    Whatever a "random experiment" is, it is supposed to include things like rolling a die and shooting a free throw. You are right that if the same exact experiment were performed we would get the same result every time (except perhaps in quantum mechanics). The axiomatic approach to probability sidesteps this issue. Mathematical modelers are then free to use the axioms of probability to predict what will happen if you roll a die a large number of times, etc. By the way, an alternative viewpoint is that probabilities represent degrees of belief.
    $endgroup$
    – littleO
    Dec 12 '18 at 19:35




















  • $begingroup$
    I don't know why you're confused by the second point. You correctly deduced that a coin toss is not random. Also, talking about "random" in the real world is not rigorous. Maybe you should post this question on some physics or engineering page
    $endgroup$
    – mathworker21
    Dec 12 '18 at 19:23






  • 1




    $begingroup$
    Whatever a "random experiment" is, it is supposed to include things like rolling a die and shooting a free throw. You are right that if the same exact experiment were performed we would get the same result every time (except perhaps in quantum mechanics). The axiomatic approach to probability sidesteps this issue. Mathematical modelers are then free to use the axioms of probability to predict what will happen if you roll a die a large number of times, etc. By the way, an alternative viewpoint is that probabilities represent degrees of belief.
    $endgroup$
    – littleO
    Dec 12 '18 at 19:35


















$begingroup$
I don't know why you're confused by the second point. You correctly deduced that a coin toss is not random. Also, talking about "random" in the real world is not rigorous. Maybe you should post this question on some physics or engineering page
$endgroup$
– mathworker21
Dec 12 '18 at 19:23




$begingroup$
I don't know why you're confused by the second point. You correctly deduced that a coin toss is not random. Also, talking about "random" in the real world is not rigorous. Maybe you should post this question on some physics or engineering page
$endgroup$
– mathworker21
Dec 12 '18 at 19:23




1




1




$begingroup$
Whatever a "random experiment" is, it is supposed to include things like rolling a die and shooting a free throw. You are right that if the same exact experiment were performed we would get the same result every time (except perhaps in quantum mechanics). The axiomatic approach to probability sidesteps this issue. Mathematical modelers are then free to use the axioms of probability to predict what will happen if you roll a die a large number of times, etc. By the way, an alternative viewpoint is that probabilities represent degrees of belief.
$endgroup$
– littleO
Dec 12 '18 at 19:35






$begingroup$
Whatever a "random experiment" is, it is supposed to include things like rolling a die and shooting a free throw. You are right that if the same exact experiment were performed we would get the same result every time (except perhaps in quantum mechanics). The axiomatic approach to probability sidesteps this issue. Mathematical modelers are then free to use the axioms of probability to predict what will happen if you roll a die a large number of times, etc. By the way, an alternative viewpoint is that probabilities represent degrees of belief.
$endgroup$
– littleO
Dec 12 '18 at 19:35












3 Answers
3






active

oldest

votes


















1












$begingroup$

There is a long standing question of whether true randomness actually exists. Sometimes these discussions delve closer to theology than math or physics. Computers have long been criticized for the low quality of their random number generators.



Radioactive decay, and quantum properties are considered to be random. They are definitely unknowable.



Chaos theory says that many systems have a high degree of sensitivity to initial conditions. And so, as we move away from these initial conditions, the future state of the system becomes increasingly difficult to predict. This means that no matter how good our data is, we will never be able to generate good long-range weather forecasts. It also suggests that coin flipping, dice rolling and bingo hoppers tend to be good random number generators.



So, while we probably can build a coin flipping machine that flips head every time, it is safe to say that a human who has not practiced his coin flipping will only flip heads 50% of the time.






share|cite|improve this answer









$endgroup$





















    1












    $begingroup$

    In classical physics it is true that if you were able to reproduce the initial conditions exactly, the result would be the same. However, in quantum mechanics it is not. If you measure an observable in a state that is not an eigenstate of that observable, the results you get are not determined. Such a measurement does constitute a "random experiment" in the sense of probability theory.



    This is not just theory: you can buy a device that conducts such experiments to produce random numbers






    share|cite|improve this answer











    $endgroup$





















      1












      $begingroup$

      This has nothing to to with mathematics but with physics.



      A few years ago I had a discussion with some person who claimed that something is impossible because some process is "random"; this is why I was searching the internet for an answer to your question:



      According to the website I found it was not possible to find out if there really are processes that are what you call "random". I think that this still is not possible.



      However that website said that there are different "levels" of randomness:



      One "level" is: Although the outcome of the experiment is predetermined, it is not possible to predict the outcome. Such experiments definitely exist.






      share|cite|improve this answer









      $endgroup$













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        3 Answers
        3






        active

        oldest

        votes








        3 Answers
        3






        active

        oldest

        votes









        active

        oldest

        votes






        active

        oldest

        votes









        1












        $begingroup$

        There is a long standing question of whether true randomness actually exists. Sometimes these discussions delve closer to theology than math or physics. Computers have long been criticized for the low quality of their random number generators.



        Radioactive decay, and quantum properties are considered to be random. They are definitely unknowable.



        Chaos theory says that many systems have a high degree of sensitivity to initial conditions. And so, as we move away from these initial conditions, the future state of the system becomes increasingly difficult to predict. This means that no matter how good our data is, we will never be able to generate good long-range weather forecasts. It also suggests that coin flipping, dice rolling and bingo hoppers tend to be good random number generators.



        So, while we probably can build a coin flipping machine that flips head every time, it is safe to say that a human who has not practiced his coin flipping will only flip heads 50% of the time.






        share|cite|improve this answer









        $endgroup$


















          1












          $begingroup$

          There is a long standing question of whether true randomness actually exists. Sometimes these discussions delve closer to theology than math or physics. Computers have long been criticized for the low quality of their random number generators.



          Radioactive decay, and quantum properties are considered to be random. They are definitely unknowable.



          Chaos theory says that many systems have a high degree of sensitivity to initial conditions. And so, as we move away from these initial conditions, the future state of the system becomes increasingly difficult to predict. This means that no matter how good our data is, we will never be able to generate good long-range weather forecasts. It also suggests that coin flipping, dice rolling and bingo hoppers tend to be good random number generators.



          So, while we probably can build a coin flipping machine that flips head every time, it is safe to say that a human who has not practiced his coin flipping will only flip heads 50% of the time.






          share|cite|improve this answer









          $endgroup$
















            1












            1








            1





            $begingroup$

            There is a long standing question of whether true randomness actually exists. Sometimes these discussions delve closer to theology than math or physics. Computers have long been criticized for the low quality of their random number generators.



            Radioactive decay, and quantum properties are considered to be random. They are definitely unknowable.



            Chaos theory says that many systems have a high degree of sensitivity to initial conditions. And so, as we move away from these initial conditions, the future state of the system becomes increasingly difficult to predict. This means that no matter how good our data is, we will never be able to generate good long-range weather forecasts. It also suggests that coin flipping, dice rolling and bingo hoppers tend to be good random number generators.



            So, while we probably can build a coin flipping machine that flips head every time, it is safe to say that a human who has not practiced his coin flipping will only flip heads 50% of the time.






            share|cite|improve this answer









            $endgroup$



            There is a long standing question of whether true randomness actually exists. Sometimes these discussions delve closer to theology than math or physics. Computers have long been criticized for the low quality of their random number generators.



            Radioactive decay, and quantum properties are considered to be random. They are definitely unknowable.



            Chaos theory says that many systems have a high degree of sensitivity to initial conditions. And so, as we move away from these initial conditions, the future state of the system becomes increasingly difficult to predict. This means that no matter how good our data is, we will never be able to generate good long-range weather forecasts. It also suggests that coin flipping, dice rolling and bingo hoppers tend to be good random number generators.



            So, while we probably can build a coin flipping machine that flips head every time, it is safe to say that a human who has not practiced his coin flipping will only flip heads 50% of the time.







            share|cite|improve this answer












            share|cite|improve this answer



            share|cite|improve this answer










            answered Dec 12 '18 at 19:48









            Doug MDoug M

            45.3k31954




            45.3k31954























                1












                $begingroup$

                In classical physics it is true that if you were able to reproduce the initial conditions exactly, the result would be the same. However, in quantum mechanics it is not. If you measure an observable in a state that is not an eigenstate of that observable, the results you get are not determined. Such a measurement does constitute a "random experiment" in the sense of probability theory.



                This is not just theory: you can buy a device that conducts such experiments to produce random numbers






                share|cite|improve this answer











                $endgroup$


















                  1












                  $begingroup$

                  In classical physics it is true that if you were able to reproduce the initial conditions exactly, the result would be the same. However, in quantum mechanics it is not. If you measure an observable in a state that is not an eigenstate of that observable, the results you get are not determined. Such a measurement does constitute a "random experiment" in the sense of probability theory.



                  This is not just theory: you can buy a device that conducts such experiments to produce random numbers






                  share|cite|improve this answer











                  $endgroup$
















                    1












                    1








                    1





                    $begingroup$

                    In classical physics it is true that if you were able to reproduce the initial conditions exactly, the result would be the same. However, in quantum mechanics it is not. If you measure an observable in a state that is not an eigenstate of that observable, the results you get are not determined. Such a measurement does constitute a "random experiment" in the sense of probability theory.



                    This is not just theory: you can buy a device that conducts such experiments to produce random numbers






                    share|cite|improve this answer











                    $endgroup$



                    In classical physics it is true that if you were able to reproduce the initial conditions exactly, the result would be the same. However, in quantum mechanics it is not. If you measure an observable in a state that is not an eigenstate of that observable, the results you get are not determined. Such a measurement does constitute a "random experiment" in the sense of probability theory.



                    This is not just theory: you can buy a device that conducts such experiments to produce random numbers







                    share|cite|improve this answer














                    share|cite|improve this answer



                    share|cite|improve this answer








                    edited Dec 12 '18 at 19:30

























                    answered Dec 12 '18 at 19:25









                    Robert IsraelRobert Israel

                    325k23214468




                    325k23214468























                        1












                        $begingroup$

                        This has nothing to to with mathematics but with physics.



                        A few years ago I had a discussion with some person who claimed that something is impossible because some process is "random"; this is why I was searching the internet for an answer to your question:



                        According to the website I found it was not possible to find out if there really are processes that are what you call "random". I think that this still is not possible.



                        However that website said that there are different "levels" of randomness:



                        One "level" is: Although the outcome of the experiment is predetermined, it is not possible to predict the outcome. Such experiments definitely exist.






                        share|cite|improve this answer









                        $endgroup$


















                          1












                          $begingroup$

                          This has nothing to to with mathematics but with physics.



                          A few years ago I had a discussion with some person who claimed that something is impossible because some process is "random"; this is why I was searching the internet for an answer to your question:



                          According to the website I found it was not possible to find out if there really are processes that are what you call "random". I think that this still is not possible.



                          However that website said that there are different "levels" of randomness:



                          One "level" is: Although the outcome of the experiment is predetermined, it is not possible to predict the outcome. Such experiments definitely exist.






                          share|cite|improve this answer









                          $endgroup$
















                            1












                            1








                            1





                            $begingroup$

                            This has nothing to to with mathematics but with physics.



                            A few years ago I had a discussion with some person who claimed that something is impossible because some process is "random"; this is why I was searching the internet for an answer to your question:



                            According to the website I found it was not possible to find out if there really are processes that are what you call "random". I think that this still is not possible.



                            However that website said that there are different "levels" of randomness:



                            One "level" is: Although the outcome of the experiment is predetermined, it is not possible to predict the outcome. Such experiments definitely exist.






                            share|cite|improve this answer









                            $endgroup$



                            This has nothing to to with mathematics but with physics.



                            A few years ago I had a discussion with some person who claimed that something is impossible because some process is "random"; this is why I was searching the internet for an answer to your question:



                            According to the website I found it was not possible to find out if there really are processes that are what you call "random". I think that this still is not possible.



                            However that website said that there are different "levels" of randomness:



                            One "level" is: Although the outcome of the experiment is predetermined, it is not possible to predict the outcome. Such experiments definitely exist.







                            share|cite|improve this answer












                            share|cite|improve this answer



                            share|cite|improve this answer










                            answered Dec 12 '18 at 19:39









                            Martin RosenauMartin Rosenau

                            1,1661410




                            1,1661410






























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