
	Where results make sense

Topic: Gedanken experiment

Related Topics

List of German expressions in English

Gesundheit

Aufbau

Ablaut

In the News (Sun 3 Jun 12)

EXECUTIVE POWER

Iran

ANALYSIS

Pakistan

Family compact

	Restoring Entanglement in Atomic Collisions: A Gedanken Experiment
		In the analysis it is shown that in such experiments, two spatially widely separated ion paths, corresponding in fact to two different charge states, would contribute coherently to the final amplitudes, describing which of the ions emerges as singly charged, i.e.
		Experiments where a single atom is prepared in an entangled state between its position and its internal state have been discussed [8], [9].
		A crossed beam experiment is schematically depicted in fig.
	web.ift.uib.no /AMOS/pub/EPJD (2647 words)

	jargon, node: gedanken (Site not responding. Last check: 2007-10-11)
		In physics, the term `gedanken experiment' is used to refer to an experiment that is impractical to carry out, but useful to consider because it can be reasoned about theoretically.
		(A classic gedanken experiment of relativity theory involves thinking about a man in an elevator accelerating through space.) Gedanken experiments are very useful in physics, but must be used with care.
		A `gedanken thesis' is usually marked by an obvious lack of intuition about what is programmable and what is not, and about what does and does not constitute a clear specification of an algorithm.
	www.jargon.net /jargonfile/g/gedanken.html (197 words)

	Thought experiment - Wikipedia, the free encyclopedia
		Thought experiment methodology is a priori, rather than empirical, in that it does not proceed by observation or physical experiment.
		The English term thought experiment was coined (as a calque) from Mach’s gedankenexperiment, and it first appeared in the 1897 English translation of one of Mach’s papers.
		In his Twin Earth thought experiment, Hilary Putnam asks us to imagine a scenario in which there is a substance with all of the observable properties of water (e.g., taste, color, boiling point), but which is chemically different from water.
	en.wikipedia.org /wiki/Gedanken_experiment (2495 words)

	Noah's Ark on the Moon :: Astrobiology Magazine ::
		Summary (Feb 27, 2006): In the second in our series of 'Gedanken,' or thought experiments, Bernard Foing suggests that the moon could act as a lifeboat in case Earth is ever struck down by a major catastrophe.
		Gedanken experiments, which have been used for hundreds of years by scientists and philosophers to ponder thorny problems, rely on the power of the imagination to project these scenarios to logical conclusions.
		Yet, as in the case of Einstein's Gedanken experiment about what it would be like to hitch a ride on a light wave, they can lead to important scientific breakthroughs.
	www.astrobio.net /news/article1880.html (1249 words)

	[No title] (Site not responding. Last check: 2007-10-11)
		More prominent is today the usage of gedanken experiments by the staunchest critic of such metaphysics, Ernst Mach; not least in virtue of their paradigmatic role for Albert Einstein whose railway embankments and freely falling elevators had an enormous influence on modern theoretical physics.
		The function of real experiments that is simulated by thought experiments is the isolation of those features of the world that are represented in a theoretical model and the approximation, as closely as possible, of the idealizations that are employed therein.
		This function of real experiments, which is to narrow the gap between theory and the world as it naturally presents itself to us, is nowadays almost exclusively guided by theory, and it indicates that thought experiments lie much closer to theory than to the world, or even its experimental refinements.
	philsci-archive.pitt.edu /archive/00000626/00/ATKINPAP3.doc (5081 words)

	Velocity Reversal and the Arrows of Time
		As will be evident later in the paper, we propose a gedanken experiment involving velocity reversal of all components of an isolated system and ask, in the context of a particular model, if the time arrow is also reversed by this operation.
		The purpose of the present paper is to propose an experiment, at the level of a gedanken experiment, which distinguishes between Model A and Model B by giving a different result depending on which model is used.
		In such an experiment the nuclei of a paramagnetic salt are initially aligned in a magnetic field and then allow to precess in an external magnetic field.
	mist.npl.washington.edu /npl/int_rep/VelRev/VelRev.html (2902 words)

	TIQM: 4.0 Examples of Application of the Transactional Interpretation
		This is a gedanken experiment focusing on the collapse of the SV produced by the absence of an interaction of the system measured (a photon) with measurement apparatus.
		This gedanken experiment demonstrates that the physical interaction of the photon with the slit system has not collapsed the SV, which must remain uncollapsed at least until the experimenter decides which experiment to do.
		Wigner (1962) further heightened the weirdness implicit in the CI description by replacing the cat with a "friend", i.e., an intelligent observer and at the same time replacing the prussic acid mechanism with a less lethal piece of apparatus, e.g., a light bulb which is switched on when a count is recorded.
	mist.npl.washington.edu /npl/int_rep/tiqm/TI_40.html (3819 words)

	A "thought" experiment on venous return and central venous pressure
		Experiments like Levy's and Shoukas’s cited in the present revision reveal the cardiac output - Pra relationship via adjustment of pump output and no Starling resistor.
		I present this as a “gedanken” experiment, not one that I expect would be practical to perform, but one whose outcome we can confidently predict from what we know.
		I hope the referees agree that this “gedanken” experiment would, in principle, yield the same venous return curves obtained by Guyton et al.
	faculty.washington.edu /brengelm/Gedanken.htm (1847 words)

	Ekklesia discussion: A Gedanken Experiment
		A Gedanken experiment is a "thought" experiment common in the physics community, to help explain some observed characteristics and to defend a theory.
		A Gedanken experiment is useful to question a physical observation in a case where one might not be able to make a physical observation or measurement, and yet, draw a valid conclusion.
		The above Gedanken experiment was constructed to show that the age of the universe is not derivable from the observations.
	www.ekklesia.co.uk /discus/messages/11/2249.html?1156401256 (3340 words)

	The double-slit experiment (September 2002) - Physics World - PhysicsWeb
		Young carried out his original double-slit experiment with light some time in the first decade of the 1800s, showing that the waves of light from the two slits interfered to produce a characteristic fringe pattern on a screen.
		Moreover, the Bologna experiment was performed under very difficult experimental conditions: the intrinsic coherence of the thermionic electron source used by the Bologna group was considerably lower than that of the field-emission source used in the Hitachi experiment.
		We believe that we carried out the first experiment in which the build-up process of an interference pattern from single-electron events could be seen in real time as in Feynman's famous double-slit Gedanken experiment under the condition, we emphasize, that there was no chance of finding two or more electrons in the apparatus.
	physicsweb.org /articles/world/15/9/1 (3316 words)

	Quantum Mechanics and its Paradox
		A gedanken experiment has been described by Mermin in order to prove that no classical description is compatible with the observed results.
		Furthermore, in actual experiments, as in Aspect's experiment, there is a random background and therefore other unpaired (non correlated) photons that would certainly render independent synchronization impossible.
		In the case of an imperfect quantum efficiency of the detectors, when one of the detectors has not detected the particle, it is not possible for the operator to choose a new switch setting, since he does not know whether or not an event took place.
	www.newtonphysics.on.ca /Uncertainty/Uncertainty.html (2810 words)

	Critique of Hooper-Monstein Experiment.
		The experiment is then discussed in more detail and used as an example of how our established EM theory has been interpreted incorrectly in regard to field cancellation and photon annihalation.
		By simple reasoning of results from similar (gedanken) experiments it is argued that the electrically neutral aether must be a dense quantum sea of EM particles who’s overall macroscopic effect averages out to zero.
		In the Hooper-Monstein experiment most of the induction does take place in the section between the magnets, where the magnetic field is zero, and it is this fact that people find amazing.
	jnaudin.free.fr /html/hpmoncrt.htm (1913 words)

	Bell's Theorem (Site not responding. Last check: 2007-10-11)
		Random Trials - The data of Table 1 is the summary of the average run of 72 purely random trials of a Bell gedanken experiment.
		They are exactly the same for each experiment, that is, there is a 1/2 probabilitiy that the light will flash green or red and a 1/3 probability that the switches will have the same setting.
		Note: David Mermin in his aticle (for simplicity) preferred to say for his gedanken experiment that the lights flashed the same color when the switches had the same setttng.
	www.svcc.edu /~duncanb/Bell.html (657 words)

	The Experiment of Fizeau (Site not responding. Last check: 2007-10-11)
		Special relativity (SRT) was born on the basis of a gedanken experiment involving the relative simultaneity of distant events as perceived by observers with different inertial velocities.
		The experiment was repeated by Michelson in 1886 with much more rigor, and quantitative results were obtained [5].
		Clearly, whatever analysis one uses to derive the formulas for the observed fringe shift, one must take into account the fact that the wavelength of the light in the moving medium is different from that of the source due to the motion induced Doppler effect of (8).
	renshaw.teleinc.com /papers/fizeau4b/fizeau4b.stm (1464 words)

	[No title]
		The main difference is that the M-M experiment relied on careful observation whereas the gedanken experiment was proven based on mathematics alone.
		The main difference is that the gedanken and M-M experiments approached the idea of the ether from different points of view.
		The main difference is that a gedanken experiment isn’t an experiment.
	newton.uor.edu /FacultyFolder/tyler_nordgren/Proudian/HW10.doc (439 words)

	Incompatibility between Einstein's General Relativity and the Principle of Equivalence
		Unfortunately, this gedanken experiment is not easily transformed into a practical experimental test which has never been done.
		We see that the experiment described on figure 1A can be used as a test of the principle of equivalence using light deflection by a gravitational field.
		Let us now consider this experiment in detail and show that the sum of a large number of the same experiment, with different and continuously changing values of the gravitational field, corresponds to the one in which light is deflected by the solar gravitational field.
	www.newtonphysics.on.ca /Equivalence/Equivalence.html (2073 words)

	SPACE.com -- Quantum Astronomy: Knowability and Unknowability in the Universe
		In the previous two articles we discussed the basic double-slit experiment that demonstrates the dual nature of light -- wave and particle -- and then the Heisenberg Uncertainty Principle which demonstrates the complimentary (mutual exclusion) of what one can measure at the same time.
		Several Bell-type experiments have successfully shown that this would seem to be the simplest interpretation of the situation.
		In this Gedanken experiment gravitational lenses, which can bend light from distance quasars or galaxies, are used as sort-of giant slits to create two paths for photons from a quasar or distance galaxy.
	www.space.com /searchforlife/quantum_astronomy_041216.html (1902 words)

	[No title]
		Invalidation of the light clock gedanken The following is one of the observations that we have made during our research into special relativity.
		The atomic clock experiment has been conducted whilst the light clock gedanken is nothing more than a diagrammatical interpretation of a mathematical proposition that - according to Einstein, does not refer to reality.
		If, as we suggest, the gedanken is nullified as indicated by the results of the Hafele-Keating experiment it follows that special theories concept of time dilation will not take place as claimed.
	www.amasci.com /lghtclok.txt (564 words)

	Optics and Interferometry with Atoms and Molecules - B. Coherence Loss due to Scattering a Single Photon -- Discussion
		In a more recent gedanken experiment suggested by Feynman, a Heisenberg light microscope is used to provide Welcher Weg information in a Young's two-slit experiment with electrons (Feynman et al.
		The effects of such entanglement is an important issue in contemporary quantum mechanics, particularly with regards to EPR type correlations and for understanding the measurement process and the loss of coherence in the passage from quantum to classical mechanics.
		In this section we discuss experiments we performed to measure the loss of atomic coherence due to scattering single photons from the atoms inside our three grating Mach-Zehnder interferometer (see Fig.
	www.rle.mit.edu /ifm/pubs/AAMOP/AAMOP-B-6.html (517 words)

	SPACE.com -- Quantum Astronomy: A Cosmic-Scale Double-Slit Experiment
		Each article is a piece of a mosaic, so every one is needed to understand the final explanation of the quantum astronomy experiment we propose, possibly using the Allen Telescope Array and the narrow-band radio-wave detectors being build by the SETI Institute and the University of California, Berkeley.
		In the preceding three essays we discussed Young’s double-slit experiment where light was shown to behave as a wave.
		What we have outlined here is just one experiment in many possible experiments that could be performed in what may be one of the most interesting new fields of the 21st Century, quantum astronomy.
	www.space.com /searchforlife/quantum_astronomy_050113.html (1610 words)

	A possible experiment with apes (Site not responding. Last check: 2007-10-11)
		Here's a gedanken experiment aimed at determining whether apes (or other animals) have free will in the sense of this article.
		Let there be a sequence of (say) six baffles that are put in a randomly selected configuration by the experimenter or his program at each trial.
		If a training set of (say) 32 combinations permits the ape to do the remaining 32 without further trial and error, it would be reasonable to conclude that the ape can predict the effects of the successive bounces.
	www-formal.stanford.edu /jmc/freewill2/node7.html (490 words)

	The Space Review: Levity and gravity: behind the story of Gravity Probe-B
		He proposed that in principle, a gyroscope could prove in a new way the General Theory of Relativity, which posits that space and time are distorted around a massive gravity source, a phenomenon known as “frame dragging.” It would require a gyro drift rate of less than one degree per million years.
		The problem was that in 1959 all of the instruments needed for conducting the experiment were almost impossible to build.
		This is how the Gravity Probe-B experiment was born—with three nude men dangling their feet in a swimming pool pondering Einsteinian physics and spacecraft.
	www.thespacereview.com /article/132/1 (899 words)

	GEDANKEN (THOUGHT) EXPERIMENT ZUR GEZIELTEN KERNFUSION by WFH (Site not responding. Last check: 2007-10-11)
		The purpose of this thought experiment is to find better answers for fundamental nuclear and elementary particle interactions.
		The goal is to apply these new basic principles in the search for more efficient fusion of hydrogen isotopes into helium, releasing huge amounts of energy.
		The complexities of the quark and string models are neither necessary nor justifiable.
	www.energiewirbel.com (558 words)

	Bell's Gedanken Experiment
		I have organized the data of this experiment in chart form and I believe your viewers would be interested in seeing this chart so I posted it at the following website Bell's Gedanken Experiment.
		Indeed, the concern that the device might exploit such hidden connections can be simply disposed of by arranging for the switches not to be set until after the particles have left the source, but before they have arrived at the detectors.
		If the experiment is thus refined, the character of the data does not change at all.
	www.physicsforums.com /showthread.php?t=135098 (2289 words)

	Paul Jakma's Weblog : Weblog
		Google have their "Zeitgeist", blogs talk of the "gestalt" and even IEEE papers talk about their "Gedanken" experiment.
		Likely most english authors using this word simply are clueless and just use the word cause it seems cool, ignoring the fact their writing and readers would be better served with plain english.
		The most pointless use of a german word in the English language goes to "Gedanken", as in "Gedanken Experiment".
	blogs.sun.com /paulj/entry/politics_and_the_english_language (567 words)

	Burgy's Quantum Mechanics Source Page
		In this last experiment, a single particle is shown clearly to have both a particle and a wave characteristic, starting as a particle, changing to a wave, then back to a particle as it makes its way through the apparatus:
		The Aspect experiment, in France, in the early 1980s, showed clearly that single photons demonstrated both wave and particle properties.
		But the experiment HAS been done (not with cats) and the results were exactly as I've described them.
	www.burgy.50megs.com /qm.htm (1093 words)

	Mailing List complex-science@necsi.org Message 3505
		experiment is a thought experiment, nothing more or less.
		Einstein was particularly prone to using gedanken experiments.
		gedanken experiments as arguments "set up only to be easily confuted."
	necsi.org:8100 /Lists/complex-science/Message/3505.html (486 words)

	Uncertainty principle Gedanken experiment
		Various philosophical statements are bandied about as a consequence of the uncertainty principle but many are incorrect as is illustrated by a simple Gedanken experiment.
		In that case the computer starts out with a list of accurate positions and momenta for the whole sequence of bounces that are yet to occur.
		I don't want to bore you with the details of how the reversible computer eats up the data before the measurements are made during the reversed experiment, but nevertheless, this Gedanken experiment seems to poke holes in various English language stories that people tell each other as to how uncertainty works.
	www.lns.cornell.edu /spr/2002-10/msg0044826.html (393 words)

Try your search on: Qwika (all wikis)