Chris Thornton Introduction When looking at mechanisms with cognitive functionality and artificial intelligence in general it is useful to begin with the simplest cases. And yet we know very well that there is nothing in these vehicles that we have not put in ourselves. The speed of the motor rectangular box at the tail end is controlled by a sensor half circle on a stalk, at the front end.
Perhaps the key experiment in the history of modern science is Galileo 's demonstration that falling objects must fall at the same rate regardless of their masses. This is widely thought  to have been a straightforward physical demonstration, involving climbing up the Leaning Tower of Pisa and dropping two heavy weights off it, whereas in fact, it was a logical demonstration, using the 'thought experiment' technique.
The 'experiment' is described by Galileo in Discorsi e dimostrazioni matematiche literally, 'Discourses and Mathematical Demonstrations' thus: If then we take two bodies whose natural speeds are different, it is clear that on uniting the two, the more rapid one will be partly retarded by the slower, and the slower will be somewhat hastened by the swifter.
Do you not agree with me in this opinion? You are unquestionably right. But if this is true, and if a large stone moves with a speed of, say, eight while a smaller moves with a speed of four, then when they are united, the system will move with a speed less than eight; but the two stones when tied together make a stone larger than that which before moved with a speed of eight.
Hence the heavier body moves with less speed than the lighter; an effect which is contrary to your supposition. Thus you see how, from your assumption that the heavier body moves more rapidly than the lighter one, I infer that the heavier body moves more slowly. Strange then, as Cohen says, that philosophers and scientists alike refuse to acknowledge either Galileo in particular, or the thought experiment technique in general for its pivotal role in both science and philosophy.
Variety[ edit ] Thought experiments have been used in a variety of fields, including philosophylawphysicsand mathematics. In philosophy, they have been used at least since classical antiquitysome pre-dating Socrates.
In law, they were well-known to Roman lawyers quoted in the Digest. Much later, Ernst Mach used the term Gedankenexperiment in a different way, to denote exclusively the imaginary conduct of a real experiment that would be subsequently performed as a real physical experiment by his students.
Mach asked his students to provide him with explanations whenever the results from their subsequent, real, physical experiment differed from those of their prior, imaginary experiment. However, people had no way of categorizing it or speaking about it.
This helps to explain the extremely wide and diverse range of the application of the term "thought experiment" once it had been introduced into English. Uses[ edit ] Thought experiments, which are well-structured, well-defined hypothetical questions that employ subjunctive reasoning irrealis moods — "What might happen or, what might have happened if.
In thought experiments we gain new information by rearranging or reorganizing already known empirical data in a new way and drawing new a priori inferences from them or by looking at these data from a different and unusual perspective.
In law, the synonym "hypothetical" is frequently used for such experiments. Regardless of their intended goal, all thought experiments display a patterned way of thinking that is designed to allow us to explain, predict and control events in a better and more productive way.
Theoretical consequences[ edit ] In terms of their theoretical consequences, thought experiments generally: However, they may make those theories themselves irrelevant, and could possibly create new problems that are just as difficult, or possibly more difficult to resolve.
In terms of their practical application, thought experiments are generally created to: In these cases, the result of the "proxy" experiment will often be so clear that there will be no need to conduct a physical experiment at all.
Scientists also use thought experiments when particular physical experiments are impossible to conduct Carl Gustav Hempel labeled these sorts of experiment "theoretical experiments-in-imagination"such as Einstein's thought experiment of chasing a light beam, leading to special relativity.
This is a unique use of a scientific thought experiment, in that it was never carried out, but led to a successful theory, proven by other empirical means.
Relation to real experiments[ edit ] The relation to real experiments can be quite complex, as can be seen again from an example going back to Albert Einstein. In this paper, starting from certain philosophical assumptions,  on the basis of a rigorous analysis of a certain, complicated, but in the meantime assertedly realizable model, he came to the conclusion that quantum mechanics should be described as "incomplete".
Niels Bohr asserted a refutation of Einstein's analysis immediately, and his view prevailed. These experiments tested the Bell inequalities published in in a purely theoretical paper. The above-mentioned EPR philosophical starting assumptions were considered to be falsified by empirical fact e.
Thus thought experiments belong to a theoretical discipline, usually to theoretical physicsbut often to theoretical philosophy. In any case, it must be distinguished from a real experiment, which belongs naturally to the experimental discipline and has "the final decision on true or not true", at least in physics.
Causal reasoning[ edit ] The first characteristic pattern that thought experiments display is their orientation in time. Seven types[ edit ] Temporal representation of a prefactual thought experiment.
Sanna in  — speculate on possible future outcomes, given the present, and ask "What will be the outcome if event E occurs? Semifactual speculations are an important part of clinical medicine.Introduction When looking at mechanisms with cognitive functionality (and artificial intelligence in general) it is useful to begin with the simplest cases.
Braitenberg `vehicles' are very simple mobile machines that use basic sensory-motor connections to produce seemingly cognitive behaviors. Braitenberg's vehicles consist of the simplest sort of wheeled robots in which sensors that are sensitive to different stimuli are wired directly to motors that drive the wheels.
In these models, we assume that the sensor generates a signal that is proportional to the stimulus. Why Vehicle? In , Italian neuroscientist and cyberneticist Valentino Braitenberg described a series of hypothetical vehicles with simple internal structures in his book Vehicles: Experiments in Synthetic timberdesignmag.comnberg argues that his extraordinarily simple mechanical vehicles manifest behaviors such as fear, aggression, love, foresight, and optimism.
A thought experiment (German: Gedankenexperiment, Gedanken-Experiment, or Gedankenerfahrung,) considers some hypothesis, theory, or principle for the purpose of thinking through its consequences.
Given the structure of the experiment, it may not be possible to perform it, and even if it could be performed, there need not be an intention to perform it..
The common goal of a thought experiment. The behavior of passive robots depend upon the choice of its designer and it can hardly be said to be autonomous.
In contrast, evolutionary robotics largely rely on self organization and many of the evolved robots exploit active interaction with the environment. May 05, · This video introduces the Vehicle type in Quelea for Grasshopper and explains a demo where the Braitenberg Vehicles traverse a solar radiance map of a roof surface.