Is there a truly random experiment ?

Question

i don't think there are any random experiments... they jus happen randomly cause the experiments are not repeated under the "same" conditions...

Answer 1

Random adj. Having no specific pattern, purpose, or objective.

I think I'll do an experiment where I toss a couple of dice. No pattern, purpose or objective, just tossing dice.

==> Random experiment

Answer 2

Random means in effect without cause. That is, if there were a one on one cause-effect relationship, the effects, e.g., events or outcomes, would not be random. They would be deterministic. One way to specify deterministic outcomes is to say that the probability of such outcome given a cause is exactly 1.00.

Further, random implies an event or outcome has some probability (less than one) of ocurring as a result of a test or trial. That is, there is some uncertainty about what the outcome will be for a given test or trial. Finally, an experiment is a defined set of tests or trials designed to resolve some hypothesis or WAG.

Experiments are neither random nor deterministic. They are simply the performance of tests or trials, and recording and analyzing the results based on predefined protocols and procedures. For example, to test a pair of dice for fairness, we could design an experiment (e.g., tossing the dice N times, and recording and analyzing the results) to examine the null hypothesis that the dice were indeed fair.

So, to answer your question...no, there is no such thing as a random experiment. But I don't think that's what you meant to ask. What I think you meant is "is there a truly random outcome"? And that is a more interesting question.

I believe random outcomes are simply cause-effect, deterministic outcomes that cannot be measured by today's current state of technology and mathematics. For example, the point made by a roll of dice is considered random. We can guesstimate the chances of rolling a 7 for instance. That's P(7) = n(7)/36 = 6/36 = 1/6; where n(7) = 6 the number of ways a seven can be rolled and 36 is the total number of possible outcomes when rolling a pair of dice. And, for the most part, using probability to determine the chances of rolling that seven suffices (for a game of craps for example).

But if we had the tools and technology, we could actually observe and measure the momenta, energies, and such of each die as it is rolled and show why the point that comes up came up. That is, if we had the means, that probabilistic outcome could be shown to be deterministic in that it resulted from a series of cause-effect events. But the time, effort, and money expended to do a cause-effect analysis would be way too costly when compared to simply invoking probabilities.

Quantum mechanics, for example, is based on empirically derived probability densities. So the jitter, probability clouds, and such associated with QM give the answers and results we most often look for (e.g., momentum, location) in quanta. And the experiments we design are designed to give distributions of randomly derived results. Because of their size and quantity, there is no way we can do a deterministic analysis like the pair of dice. So we are relegated to experiments that invoke random outcomes and probability distributions of those outcomes.

To your last point...experiments are designed in today's labs with great precision. That is, there is very little variation in replication and certainly no measurable variation that is significant. When validating results, the precise replication of previous experiments is essential; without it, there will always be skeptics of the outcomes attained. Physicists are reknowned skeptics of other people's work.

Answer 3

This falls into a large category of questions concerning determinism. Suppose you have a system set up, you press start and let it run and record the paths of all the moving objects. Then suppose you bring them all back to the start and set it up exactly as before except with one miniscule change (eg a tiny change of starting position of one of the components). Let it run again and record the paths. If the paths become increasingly different to the first recording then we say that the system is chaotic, or for all intensive purposes, random. Examples are the three body problem and picking bingo balls. These systems follow the simple rules of physics that we understand but we cannot calculate the end result unless we know the exact initial positions and velocities of the components. But Heisenberg's uncertainty relation tells us that it is impossible to know these with complete accuracy. This uncertainty is not noticeable for some cases, especially on large scales such as the position of the planets in our solar system, so we can calculate their location many years into the future with good accuracy. With a powerful computer and, say, five bingo balls, we might be able to calculate which ball would be removed after the drum was turned for a short period of time. It becomes difficult on smaller scales and with more components, such as a metal full of electrons. Now the uncertainty in position and momentum is comparable to the measurements we are trying to establish, so we cannot predict where they are going to go. What is more astounding is that not only do we not know where the electron is (and its velocity) but the electron itself does not know where it is, it genuinely does not have an exact location or velocity and can behave as though it is in many places at once. This behaviour is only relevant at these very small scales. This behaviour is truly random and would not repeat itself even if you set up the experiment exactly as before. You can buy quantum mechanical random number generators for your computer (they look like a computer mouse) if you are writing programs that require random input. This would also be of use to online gambling and so on.

Answer 4

Random is a misleading word. By random we mean
to test that the hypothesis is universally applicable to the
observation contingency. In other words, we have identified
some combination of qualities and quantities and we
conduct experiments with proportion to verify the
projected deductive conclusion by using induction.
Therefore, by random we usually mean utilizing different
proportions and measuring for consistency. In other
words, test the experiment on proportions even
if we might tend to think they are inconvenient;
the goal is to eliminate observer/experimenter bias.

Answer 5

Sounds like you answered your own question there.