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	<title>Saurabh Sardesai&#039;s Blog</title>
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		<title>Soviet mind control</title>
		<link>http://saurabhsardesai.wordpress.com/2011/11/01/soviet-mind-control/</link>
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		<pubDate>Tue, 01 Nov 2011 16:28:04 +0000</pubDate>
		<dc:creator>saurabhsardesai</dc:creator>
				<category><![CDATA[Science]]></category>
		<category><![CDATA[Uncategorized]]></category>

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		<description><![CDATA[Soviet mind control<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=saurabhsardesai.wordpress.com&amp;blog=13594264&amp;post=40&amp;subd=saurabhsardesai&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>Please see my new website <a title="Saurabhsardesai.com" href="http://saurabhsardesai.com" target="_blank">www.saurabhsardesai.com</a> for all the information you need to know about Soviet mind control.</p>
<p>My only other website on this topic, <a title="www.sovietmindcontrol.com" href="http://sovietmindcontrol.com" target="_blank">www.sovietmindcontrol.com</a> is coming up in the middle of Nov.</p>
<p>There are some interesting articles about Artificial Intelligence and ETs and UFO hoaxes on these two websites.</p>
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		<title>The Uncertainty Principle</title>
		<link>http://saurabhsardesai.wordpress.com/2010/08/23/the-uncertainty-principle/</link>
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		<pubDate>Mon, 23 Aug 2010 09:01:40 +0000</pubDate>
		<dc:creator>saurabhsardesai</dc:creator>
				<category><![CDATA[Physics]]></category>
		<category><![CDATA[Quantum Mechanics]]></category>
		<category><![CDATA[Science]]></category>

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		<description><![CDATA[Quantum mechanics is generally regarded as the physical theory that is our best candidate for a fundamental and universal description of the physical world. The conceptual framework employed by this theory differs drastically from that of classical physics. Indeed, the transition from classical to quantum physics marks a genuine revolution in our understanding of the physical world. 

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			<content:encoded><![CDATA[<p>One striking aspect of the difference between classical and quantum physics is that whereas classical mechanics presupposes that exact simultaneous values can be assigned to all physical quantities, quantum mechanics denies this possibility, the prime example being the position and momentum of a particle. According to quantum mechanics, the more precisely the position (momentum) of a particle is given, the less precisely can one say what its momentum (position) is. This is (a simplistic and preliminary formulation of) the quantum mechanical uncertainty principle for position and momentum. The uncertainty principle played an important role in many discussions on the philosophical implications of quantum mechanics, in particular in discussions on the consistency of the so-called Copenhagen interpretation, the interpretation endorsed by the founding fathers Heisenberg and Bohr.</p>
<p>This should not suggest that the uncertainty principle is the only aspect of the conceptual difference between classical and quantum physics: the implications of quantum mechanics for notions as (non)-locality, entanglement and identity play no less havoc with classical intuitions.</p>
<p>Ordinary experience provides no clue of this principle. It is easy to measure both the position and the velocity of, say, an automobile, because the uncertainties implied by this principle for ordinary objects are too small to be observed. The complete rule stipulates that the product of the uncertainties in position and velocity is equal to or greater than a tiny physical quantity, or constant (about 10<sup>-34</sup> joule-second, the value of the quantity h (where h is Planck&#8217;s constant). Only for the exceedingly small masses of atoms and subatomic particles does the product of the uncertainties become significant.</p>
<p>Any attempt to measure precisely the velocity of a subatomic particle, such as an electron, will knock it about in an unpredictable way, so that a simultaneous measurement of its position has no validity. This result has nothing to do with inadequacies in the measuring instruments, the technique, or the observer; it arises out of the intimate connection in nature between particles and waves in the realm of subatomic dimensions.</p>
<p>Every particle has a wave associated with it; each particle actually exhibits wavelike behavior. The particle is most likely to be found in those places where the undulations of the wave are greatest, or most intense. The more intense the undulations of the associated wave become, however, the more ill defined becomes the wavelength, which in turn determines the momentum of the particle. So a strictly localized wave has an indeterminate wavelength; its associated particle, while having a definite position, has no certain velocity. A particle wave having a well-defined wavelength, on the other hand, is spread out; the associated particle, while having a rather precise velocity, may be almost anywhere. A quite accurate measurement of one observable involves a relatively large uncertainty in the measurement of the other.</p>
<p>The uncertainty principle is alternatively expressed in terms of a particle&#8217;s momentum and position. The momentum of a particle is equal to the product of its mass times its velocity. Thus, the product of the uncertainties in the momentum and the position of a particle equals h/(2) or more. The principle applies to other related (conjugate) pairs of observables, such as energy and time: the product of the uncertainty in an energy measurement and the uncertainty in the time interval during which the measurement is made also equals h/(2) or more. The same relation holds, for an unstable atom or nucleus, between the uncertainty in the quantity of energy radiated and the uncertainty in the lifetime of the unstable system as it makes a transition to a more stable state.</p>
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<td width="70%"><span>The uncertainty principle, developed by W. Heisenberg, is a statement of the effects of wave-particle duality on the properties of subatomic objects. Consider the concept of momentum in the wave-like microscopic world. The momentum of wave is given by its wavelength. A wave packet like a photon or electron is a composite of many waves. Therefore, it must be made of many momentums. But how can an object have many momentums?Of course, once a measurement of the particle is made, a single momentum is observed. But, like fuzzy position, momentum before the observation is intrinsically uncertain. This is what is know as the uncertainty principle, that certain quantities, such as position, energy and time, are unknown, except by probabilities. In its purest form, the uncertainty principle states that accurate knowledge of complementarity pairs is impossible. For example, you can measure the location of an electron, but not its momentum (energy) at the same time. </p>
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<p><img src="http://abyss.uoregon.edu/~js/images/position_energy_time.gif" alt="" /></p>
<p><span>A characteristic feature of quantum physics is the principle of complementarity, which &#8220;implies the impossibility of any sharp separation between the behavior of atomic objects and the interaction with the measuring instruments which serve to define the conditions under which the phenomena appear.&#8221; As a result, &#8220;evidence obtained under different experimental conditions cannot be comprehended within a single picture, but must be regarded as complementary in the sense that only the totality of the phenomena exhausts the possible information about the objects.&#8221; This interpretation of the meaning of quantum physics, which implied an altered view of the meaning of physical explanation, gradually came to be accepted by the majority of physicists during the 1930&#8242;s.</span></p>
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		<title>Multi &#8211; universe: The many worlds interpretation</title>
		<link>http://saurabhsardesai.wordpress.com/2010/08/06/multi-universe-the-many-worlds-interpretation/</link>
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		<pubDate>Fri, 06 Aug 2010 15:03:07 +0000</pubDate>
		<dc:creator>saurabhsardesai</dc:creator>
				<category><![CDATA[Physics]]></category>
		<category><![CDATA[Science]]></category>

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		<description><![CDATA[The subject of Multiple Universes was briefly mentioned in creating reality, and alluded to in creating reality - another view.  Many of the philosophical thoughts on multiple universes are concerned with “bifurcation points”, where decisions by beings of consciousness cause a splitting of reality, and thereafter separate realities continue as it their reality was the only game in town.  This tends to decrease the value of making any decision -- although the “Catch 22” is <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=saurabhsardesai.wordpress.com&amp;blog=13594264&amp;post=32&amp;subd=saurabhsardesai&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>The subject of Multiple Universes was briefly mentioned in creating reality, and alluded to in creating reality &#8211; another view.  Many of the philosophical thoughts on multiple universes are concerned with “bifurcation points”, where decisions by beings of consciousness cause a splitting of reality, and thereafter separate realities continue as it their reality was the only game in town.  This tends to decrease the value of making any decision &#8212; although the “Catch 22” is that not making a decision is in fact making a decision about deciding or not.  Decidedly so!   </p>
<p>A slight variation on this theme is that we begin creating some aspect of our reality &#8212; be it a dream, a vision, or some goal we wish to see fulfilled.  But when it does not instantly or quickly happen, we give up on it and the remnants of our original thought forms slip away into another reality, another universe where we hung in there in our manifesting.  This is a slightly improved concept in that decisions still have value, and in fact, the really nifty ones are the ones in which we maintain a focus.  </p>
<p>It is not clear, however, what happens in an alternative universe when we manifest our visions in this one.  Is there a giant, gapping hole in the other one?  Or a duplicate of our success?  There seems to be no way to tell.  But perhaps we can make some guesses.</p>
<p>The idea of multiple universes is, after all, not purely a philosophical issue.  Science has its own vested interest as well.  If science begins to probe into the problem, will they some day catch up with philosophy and make multiple universes a scientific reality, as well as a philosophical possibility?  After all, many traditions of philosophy have long advocated the connectedness and unlimitedness of the universe we currently inhabit.  Science is only now seeing the truth of this; and in fact we can now &#8212; given the basic assumptions of <strong><span style="text-decoration:underline;"><a href="http://www.halexandria.org/dward124.htm">The Fifth Element</a></span></strong> theory &#8212; demonstrate or prove mathematically that everything in the one universe is connected energetically, and there appears no limit as to what can be attained from within our universe.  Also, research into <strong><span style="text-decoration:underline;"><a href="http://www.halexandria.org/dward413.htm">Time</a></span></strong> and <strong><span style="text-decoration:underline;"><a href="http://www.halexandria.org/dward399.htm">Mind-Matter</a></span></strong> interactions have demonstrated experimentally that we are indeed connected.  Thus if science finally begins to perceive the truth of what the ancient traditions and philosophies have been saying for millennia, why not in the context of Multiple Universes?  </p>
<p>There are also modern theories of physics under development &#8212; ranging from <strong><span style="text-decoration:underline;"><a href="http://www.halexandria.org/dward154.htm">Zero-Point Energy</a></span></strong> to <strong><span style="text-decoration:underline;"><a href="http://www.halexandria.org/dward156.htm">Superconductivity</a></span></strong>, which require the existence of multiple <em>dimensions</em>, in some cases 10 dimensions, in others 27, and in still others, an indeterminate number.  The distinction between dimensions and universes may appear clear, but there is nothing in the various theories which prohibits a dimension beyond the four dimensional space-time continuum from being a part of a full-fledged universe &#8212; the latter being composed of any number of space and/or time dimensions.   </p>
<p><strong><span style="text-decoration:underline;"><a href="http://www.halexandria.org/dward196.htm">Laurence Gardner</a></span> </strong>has written in his book, <em>Lost Secrets of the Sacred Ark</em> [HarperCollins London, 2003], that “the <strong><span style="text-decoration:underline;"><a href="http://www.halexandria.org/dward484.htm">Ark of the Covenant</a></span></strong> has its final resting at Chartres Cathedral.” [Chartres, France]  That the superconducting nature of the Ark allowed it to move into a “collapsed six dimensions, or through a portal into fully expanded dimensions”, into what Gardner refers to as “the Realm of the Orbit of Light: the <em>Plane of Shar-On</em>, the <em>Field of Mfkzt </em>that was known (even if not scientifically understood) by the Master Craftsmen of ancient times.  Considering the extraordinary characterisitics of <strong><span style="text-decoration:underline;"><a href="http://www.halexandria.org/dward156.htm">Superconductors</a></span></strong>, this scenario is well within the realm of possibility.  </p>
<p>There are also theories that suggest that Black Holes are the doorways or portals into another dimension and/or universe &#8212; else where would all those particles which fall into the Black Hole’s gravity well end up?  In a massively packed, very crowded, infinitesimally small space?  Possibly.  But wouldn’t that simply be the condition prior to a Big Bang look-alike, the latter ready to spawn a whole new universe?  And what’s to prevent that spawning happening now or in the past?  </p>
<p>In fact, the speck of dust on an astronomer’s shoulder might be a whole new universe in itself.  The idea was suggested in the popular media by the movie, <em>Men in Black</em>, in which a whole universe was contained within a ball hung around the neck of a cat.  And in the other direction, where <em>our</em> universe was nothing more than a golf ball in a much larger universe.  While the movie might not be taken seriously by scientists, the fact remains that the visualization is not that far-fetched from modern physics.  These quantum leaps of universal sizes is quite possible, but from the viewpoint of science is not something that can be readily researched (or, more importantly, receive funding for).</p>
<p>Theorists, in fact, have suggested that yes, it might be very likely that other universes do exist.  The idea is not something that can currently be proven, but the implication is very seriously considered.  Quantum mechanics, for example, as a mathematical description of how the universe works on the smallest scales, claims (among other things) that matter and/or energy can appear spontaneously out of the vacuum of space, via something known as a quantum fluctuation, something equivalent to a hiccup in the energy field.  One hiccup resulted in what is referred to as the Big Bang, an explosion of all matter in our universe when it was initially in an incredibly small dimension.  The Big Bang continues now as an expanding universe, the particles of the explosion for the most part racing away from each other, but intermingling along the way, forming galaxies, suns, planets, golf balls, etc.  It’s as if there was an absolute nothingness, and then&#8230; hiccup&#8230; and a few billion years later there is a vast, expanding universe full of stars and other celebrities.  </p>
<p>The source of the hiccup is of particular interest.  If one lived in only 2-dimensions (aka as “Flatland”), then something in the third dimension passing through our plane would appear suddenly, and just as quickly disappear.  From the three dimensional point of view, not much has happened, but from the two dimensional point of view, it’s a real eye opener.  Thus why not an object normally residing in four or five dimensions casually wandering through our three dimensions, and thus the “hiccup”.  Or perhaps an ever grander event, the kind that gives rise to new religions?  </p>
<p>Also, if there was one Big Bang, then another quantum fluctuation could give rise to another universe &#8212; separate from ours.  According to a so-called anthropic principle, there are perhaps an infinite number of universes, each with its own set of physical laws.  The fact that one of them happens to be ours is not that big of a deal.  It’s much easier to believe, say the anthropic advocates, than a single universe “fine-tuned” for our existence.  </p>
<p>Unfortunately, this argument assumes only one form of life &#8212; what works in our universe.  It doesn’t take too much imagination to conceive of other universes with other natural laws, and life of a whole new variety.  Even life in <em>this</em> universe may be quite diverse!  </p>
<p>One can also make the argument that if there is no fundamental reason that something cannot exist, then it is not only possible for that thing to exist, but it’s likely that it does.  Of course, there might not be a way of detecting another universe, but this does not negate its possible existence.  After all, there is no way to detect the means by which a magnet does its magnetic thing, even when we see or can detect the results.  </p>
<p>Andreas Albrecht, a cosmologist at the University of California at Davis, says the question isn’t open for debate for the simple reason that you can’t argue with quantum mechanics.  “As far as we can tell,” Albrecht says, “that’s the fundamental language that Nature speaks. Nature doesn’t answer questions for certain; it answers questions by giving probabilities.”  And in quantum mechanics, “There’s a possibility that <em>almost anything happens</em>.&#8221; Including other universes.  If cosmologists are queasy about that, they don&#8217;t have a choice.  “It comes out of the mathematics,” Albrecht explains. “It”s forced down our throats.”  </p>
<p>The latter does, admittedly, assume that one accepts Quantum Mechanics as reality.  If not then there’s very little forcing.  It’s just that the current data on the subject of reality is that the mathematics of modern Quantum Physics implies multiple universes.  What the math does not address is:  “Why?”</p>
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		<title>Quantum teleportation</title>
		<link>http://saurabhsardesai.wordpress.com/2010/07/30/quantum-teleportation/</link>
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		<pubDate>Fri, 30 Jul 2010 09:44:30 +0000</pubDate>
		<dc:creator>saurabhsardesai</dc:creator>
				<category><![CDATA[Physics]]></category>
		<category><![CDATA[Quantum Mechanics]]></category>
		<category><![CDATA[Science]]></category>

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		<description><![CDATA[Teleportation is the name given by science fiction writers to the feat of making an object or person disintegrate in one place while a perfect replica appears somewhere else. How this is accomplished is usually not explained in detail, but the general idea seems to be that the original object is scanned in such a way as to extract all the information from it, then this information is transmitted to the receiving location and used to construct the replica, not necessarily from the actual material of the original, but perhaps from atoms of the same kinds, arranged in exactly the same pattern as <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=saurabhsardesai.wordpress.com&amp;blog=13594264&amp;post=28&amp;subd=saurabhsardesai&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>Teleportation is the name given by science fiction writers to the feat of making an object or person disintegrate in one place while a perfect replica appears somewhere else. How this is accomplished is usually not explained in detail, but the general idea seems to be that the original object is scanned in such a way as to extract all the information from it, then this information is transmitted to the receiving location and used to construct the replica, not necessarily from the actual material of the original, but perhaps from atoms of the same kinds, arranged in exactly the same pattern as the original. A teleportation machine would be like a fax machine, except that it would work on 3-dimensional objects as well as documents, it would produce an exact copy rather than an approximate facsimile, and it would destroy the original in the process of scanning it. A few science fiction writers consider teleporters that preserve the original, and the plot gets complicated when the original and teleported versions of the same person meet; but the more common kind of teleporter destroys the original, functioning as a super transportation device, not as a perfect replicator of souls and bodies.</p>
<p>In 1993 an international group of six scientists, including IBM Fellow Charles H. Bennett, confirmed the intuitions of the majority of science fiction writers by showing that perfect teleportation is indeed possible in principle, but only if the original is destroyed. In subsequent years, other scientists have demonstrated teleportation experimentally in a variety of systems, including single photons, coherent light fields, nuclear spins, and trapped ions.  Teleportation promises to be quite useful as an information processing primitive, facilitating long range quantum communication (perhaps unltimately leading to a &#8220;quantum internet&#8221;), and making it much easier to build a working quantum computer.   But science fiction fans will be disappointed to learn that no one expects to be able to teleport people or other macroscopic objects in the foreseeable future, for a variety of engineering reasons, even though it would not violate any fundamental law to do so. </p>
<p>In the past, the idea of teleportation was not taken very seriously by scientists, because it was thought to violate the uncertainty principle of quantum mechanics, which forbids any measuring or scanning process from extracting all the information in an atom or other object. According to the uncertainty principle, the more accurately an object is scanned, the more it is disturbed by the scanning process, until one reaches a point where the object&#8217;s original state has been completely disrupted, still without having extracted enough information to make a perfect replica. This sounds like a solid argument against teleportation: if one cannot extract enough information from an object to make a perfect copy, it would seem that a perfect copy cannot be made. But the six scientists found a way to make an end run around this logic, using a celebrated and paradoxical feature of quantum mechanics known as the Einstein-Podolsky-Rosen effect. In brief, they found a way to scan out part of the information from an object A, which one wishes to teleport, while causing the remaining, unscanned, part of the information to pass, via the Einstein-Podolsky-Rosen effect, into another object C which has<img src="http://www.research.ibm.com/quantuminfo/teleportation/figureB.gif" alt="figure" hspace="10" width="480" height="403" align="left" /> never been in contact with A. Later, by applying to C a treatment depending on the scanned-out information, it is possible to maneuver C into exactly the same state as A was in before it was scanned. A itself is no longer in that state, having been thoroughly disrupted by the scanning, so what has been achieved is teleportation, not replication.</p>
<p>As the figure to the left suggests, the unscanned part of the information is conveyed from A to C by an intermediary object B, which interacts first with C and then with A. What? Can it really be correct to say &#8220;first with C and then with A&#8221;? Surely, in order to convey something from A to C, the delivery vehicle must visit A before C, not the other way around. But there is a subtle, unscannable kind of information that, unlike any material cargo, and even unlike ordinary information, can indeed be delivered in such a backward fashion. This subtle kind of information, also called &#8220;Einstein-Podolsky-Rosen (EPR) correlation&#8221; or &#8220;entanglement&#8221;, has been at least partly understood since the 1930s when it was discussed in a famous paper by Albert Einstein, Boris Podolsky, and Nathan Rosen. In the 1960s John Bell showed that a pair of entangled particles, which were once in contact but later move too far apart to interact directly, can exhibit individually random behavior that is too strongly correlated to be explained by classical statistics. Experiments on photons and other particles have repeatedly confirmed these correlations, thereby providing strong evidence for the validity of quantum mechanics, which neatly explains them. Another well-known fact about EPR correlations is that they cannot by themselves deliver a meaningful and controllable message. It was thought that their only usefulness was in proving the validity of quantum mechanics. But now it is known that, through the phenomenon of quantum teleportation, they can deliver exactly that part of the information in an object which is too delicate to be scanned out and delivered by conventional methods.</p>
<p>Further reading: <a href="http://www.research.ibm.com/quantuminfo/teleportation/teleportation.html">http://www.research.ibm.com/quantuminfo/teleportation/teleportation.html</a></p>
<p><a href="http://news.bbc.co.uk/2/hi/science/nature/3777589.stm">http://news.bbc.co.uk/2/hi/science/nature/3777589.stm</a></p>
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		<title>The Wonderful Quantum World &#8211; Breakdown of Classical Mechanics</title>
		<link>http://saurabhsardesai.wordpress.com/2010/07/06/the-wonderful-quantum-world-breakdown-of-classical-mechanics/</link>
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		<pubDate>Tue, 06 Jul 2010 08:58:12 +0000</pubDate>
		<dc:creator>saurabhsardesai</dc:creator>
				<category><![CDATA[Physics]]></category>
		<category><![CDATA[Quantum Mechanics]]></category>
		<category><![CDATA[Science]]></category>

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		<description><![CDATA[Dartmouth researchers have discovered a potentially important piece of the quantum/classical puzzle -- learning how the rules of physics in the quantum world (think smaller than microscopic) change when applied to the classical world (think every day items, like cars and trees).
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			<content:encoded><![CDATA[<p>Dartmouth researchers have discovered a potentially important piece of the quantum/classical puzzle &#8212; learning how the rules of physics in the quantum world (think smaller than microscopic) change when applied to the classical world (think every day items, like cars and trees).</p>
<p>In a study published in the July 1 issue of the journal <em>Nature</em>, Associate Professor of Physics and Astronomy Alex Rimberg and his colleagues describe one example of the microscopic quantum world influencing, even dominating they say, the behavior of something in the macroscopic classical world. They used tiny semiconducting crystals that contain two separate reservoirs of electrons to explore the different influences of both classical and quantum physics.</p>
<p>&#8220;We found that the motion of the crystals is not dominated by something classical like thermal motion, but instead by random quantum fluctuations in the number of electrons tunneling through the barrier; the fluctuations were the size of about 10,000 electrons,&#8221; says Rimberg. &#8220;But the macroscopic world in this study also influences the quantum world, in that the vibrations of the crystal caused the electrons to tunnel in big bunches, more or less in sync with the vibrations of the crystal.&#8221;</p>
<p>One major question in quantum physics deals with the connection between the microscopic and macroscopic worlds. Rimberg explains that scientists know that microscopic objects such as electrons obey the laws of quantum mechanics, while macroscopic objects obey Newton&#8217;s laws. Researchers are still learning exactly how classical behavior emerges from quantum behavior as systems become larger and larger.</p>
<p>Rimberg says that the difference in size between the classical and quantum parts of thesystem described in this paper is really extreme. &#8220;To give a sense of perspective, we could imagine that the 10,000 electrons correspond to something small like a flea. To complete the analogy, the crystal would have to be the size of Mt. Everest. If we imagine the flea jumping on Mt. Everest to make it move, then the resulting vibrations would be on the order of meters.&#8221;</p>
<p>Rimberg&#8217;s future work will use nonlinear superconducting systems, different from using the semiconducting crystals in this experiment, to make very strongly quantum mechanical systems. Nonlinear classical systems can show unpredictable, chaotic behavior; the behavior of the corresponding quantum systems is not well understood. This effort will be a prelude to studying the quantum properties of mechanical resonators that are smaller than the crystals in this experiment, but definitely not microscopic either; they are the things in the murky borderland between quantum and classical regimes.</p>
<p>Rimberg was worked on this study with colleagues at Dartmouth, Miles Blencowe, Joel Stettenheim, Feng Pan, Mustafa Bal, and Weiwei Zue. They were joined by Madhu Thalakulam and Zhonquig Ji from Rice University; and Loren Pfeiffer and K.W. West from Bell Laboratories.</p>
<p>The research was funded by the U.S. Army Research Office and the National Science Foundation.</p>
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		<title>IS TIME TRAVEL POSSIBLE?</title>
		<link>http://saurabhsardesai.wordpress.com/2010/06/14/is-time-travel-possible/</link>
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		<pubDate>Mon, 14 Jun 2010 08:34:42 +0000</pubDate>
		<dc:creator>saurabhsardesai</dc:creator>
				<category><![CDATA[Physics]]></category>
		<category><![CDATA[Science]]></category>

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		<description><![CDATA[In H.G. Wells’ novel, THE TIME MACHINE, our protagonist jumped into a special chair with blinking lights, spun a few dials, and found himself catapulted several hundred thousand years into the future, where England has long disappeared and is now inhabited by two groups of strange creatures, the Morlocks and the Eloi.
   
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<td width="262"><strong><span style="font-size:xx-small;font-family:Times New Roman,Times,Times NewRoman;">I</span></strong><span style="font-family:Times New Roman,Times,Times NewRoman;">n H.G. Wells’ novel, THE TIME MACHINE, our protagonist jumped into a special chair with blinking lights, spun a few dials, and found himself catapulted several hundred thousand years into the future, where England has long disappeared and is now inhabited by two groups of strange creatures, the Morlocks and the Eloi.</span></td>
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<td colspan="3" width="264"><span style="font-family:Times New Roman,Times,Times NewRoman;">       That may have made great fiction, but physicists have always scoffed at the idea of time travel, considering it to be the realm of cranks, mystics, and charlatans, and with good reason. However, rather remarkable advances in quantum gravity are reviving the theory; time travel has now become fair game for theoretical physicists writing in the pages of PHYSICAL REVIEW  magazine.<br />
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<td width="423"><span style="font-family:Times New Roman,Times,Times NewRoman;">       One stubborn problem with time travel is that it is riddled with several types of paradoxes. For example, there is the paradox of the man with no parents: What happens when you go back in time and kill your parents before you are born? If your parents died before you were born, then how could you have been born to kill them in the first place?</span></p>
<p><span style="font-family:Times New Roman,Times,Times NewRoman;">     There is also the paradox of the man with no past. For example, let’s say that a young inventor is trying futilely to build a time machine in his garage. Suddenly, an elderly man appears from nowhere and gives the youth the secret of building a time machine. The young man then becomes enormously rich playing the stock market, race tracks, and sporting events because he knows the future. Then, as an old man, he decides to make his final trip back to the past and give the secret of time travel to his youthful self. Where did the idea of the time machine come from?  <br />
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<td width="427"><strong><span style="font-size:xx-small;font-family:Times New Roman,Times,Times NewRoman;">T</span></strong><span style="font-family:Times New Roman,Times,Times NewRoman;">here is also the paradox of the man who is his own mother. (My apologies to science fiction writer Robert Heinlein.) “Jane” is left at an orphanage as a foundling. When “Jane” is a teenager, she falls in love with a drifter, who abandons her but leaves her pregnant. Then disaster strikes. She almost dies giving birth to a baby girl, who is then mysteriously kidnapped. The doctors find that Jane is bleeding badly, but, oddly enough, has both sex organs. So, to save her life, the doctors convert “Jane” to “Jim.”</span></p>
<p><span style="font-family:Times New Roman,Times,Times NewRoman;">    “Jim” subsequently becomes a roaring drunk, until he meets a friendly bartender (actually a time traveler in disguise) who wisks “Jim” way back into the past. “Jim” meets a beautiful teenage girl, then accidentally gets her pregnant with a baby girl. Out of guilt, he kidnaps the baby girl and drops her off at the orphanage. Later, “Jim” joins the time travelers corps, leads a distinguished life, and has one last dream: to disguise himself as a bartender to meet a certain drunk named “Jim” in the past. So,  who is “Jane’s” mother, father, brother, sister, grandfather, grandmother, and grandchild?</span></td>
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<td width="133"><img src="http://www.pbs.org/wnet/hawking/mysteries/assets/auto_generated_images/img_2dbbc002.gif" border="0" alt="Learn more about:" width="133" height="19" /></td>
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<a href="http://www.pbs.org/hawking/cosmostar/html/eins.html"><span style="font-family:Arial,Helvetica;">Albert Einstein</span></a></p>
<p><a href="http://www.pbs.org/hawking/cosmostar/html/newt.html"><span style="font-family:Arial,Helvetica;">Isaac Newton</span></a></td>
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<td width="276"><span style="font-family:Times New Roman,Times,Times NewRoman;">     Not surprisingly, time travel has always been considered impossible. After all, Newton believed that time was like an arrow; once fired, it soared in a straight, undeviating line. One second on the earth was one second on Mars. Clocks scattered throughout the universe beat at the same rate.</span></td>
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<td width="426"><span style="color:#000000;">     </span><span style="color:#000000;font-family:Times New Roman,Times,Times NewRoman;">Einstein gave us a much more radical picture. According to Einstein, time was more like a river, which meandered around stars and galaxies, speeding up and slowing down as it passed around massive bodies. One second on the earth was NOT one second on Mars. Clocks scattered throughout the universe beat to their own drummer.</span></p>
<p><span style="color:#000000;font-family:Times New Roman,Times,Times NewRoman;">     However, before Einstein died, he was faced with an embarrassing problem. Einstein’s neighbor at Princeton, Kurt Gödel, perhaps the greatest mathematical logician of the past 500 years, found a new solution to Einstein’s own equations which allowed for time travel!</span></p>
<p><span style="color:#000000;font-family:Times New Roman,Times,Times NewRoman;">     The “river of time” now had whirlpools in which time could wrap itself into a circle. Gödel’s solution was quite ingenious: It postulated a universe filled with time that flowed like a rotating fluid. Anyone walking along the direction of rotation would find oneself back at the starting point, but backwards in time!<br />
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<td width="427"><strong><span style="font-size:xx-small;font-family:Times New Roman,Times,Times NewRoman;">I</span></strong><span style="font-family:Times New Roman,Times,Times NewRoman;">n his memoirs, Einstein wrote that he was disturbed that his equations contained solutions that allowed for time travel. But he finally concluded that the universe does not rotate, it expands (as in the Big Bang theory) and hence G</span><span style="color:#000000;font-family:Times New Roman,Times,Times NewRoman;">ö</span><span style="font-family:Times New Roman,Times,Times NewRoman;">del’s solution could be thrown out for “physical reasons.” (Apparently, if the Big Bang was rotating, then time travel would be possible throughout the universe!)</span></td>
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<td width="271"><span style="font-family:Times New Roman,Times,Times NewRoman;">     Then in 1963, Roy Kerr, a New Zealand mathematician, found a solution of Einstein’s equations for a rotating black hole, which had bizarre properties. The black hole would not collapse to a point (as previously thought) but into a spinning ring (of neutrons). The ring would be circulating so rapidly that centrifugal force would keep the ring from collapsing under gravity.</span></td>
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<a href="http://www.pbs.org/hawking/cosmostar/html/eins.html"><span style="font-family:Arial,Helvetica;">Albert Einstein</span></a></p>
<p><a href="http://www.pbs.org/hawking/strange/html/bigbang.html"><span style="font-family:Arial,Helvetica;">The Big Bang</span></a></p>
<p><a href="http://www.pbs.org/hawking/strange/html/blackh.html"><span style="font-family:Arial,Helvetica;">Black Holes</span></a></p>
<p><a href="http://www.pbs.org/hawking/strange/html/wormhole.html"><span style="font-family:Arial,Helvetica;">Wormholes</span></a></p>
<p><a href="http://www.pbs.org/hawking/strange/html/schrod.html"><span style="font-family:Arial,Helvetica;">Schrödinger’s Cat</span></a><span style="font-family:Arial,Helvetica;"><br />
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<td colspan="2" width="146"><span style="font-family:Times New Roman,Times,Times NewRoman;">The ring, in turn, acts like Alice’s Looking Glass. Anyone walking through the ring would not die, but could pass through the ring into an alternate universe. Since then, hundreds of other “wormhole” solutions have been found to Einstein’s equations. These wormholes connect not only two regions of space (hence the name) but also two regions of time as well. In principle, they can be used as time machines.</span></td>
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<td width="426"><span style="font-family:Times New Roman,Times,Times NewRoman;">      Recently, attempts to add the quantum theory to gravity (and hence create a “theory of everything”) have given us some insight into the paradox problem.</p>
<p>      In the quantum theory, we can have multiple states of any object. For example, an electron can exist simultaneously in different orbits (a fact which is responsible for giving us the laws of chemistry). Similarly, Schrödinger’s famous cat can exist simultaneously in two possible states: dead and alive. So by going back in time and altering the past, we merely create a parallel universe. So we are changing someone ELSE’s past by saving, for example, Abraham Lincoln from being assassinated at the Ford Theater, but our Lincoln is still dead. In this way, the river of time forks into two separate rivers.<br />
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<td width="422"><span style="font-size:xx-small;font-family:Times New Roman,Times,Times NewRoman;"><strong>B</strong></span><span style="font-family:Times New Roman,Times,Times NewRoman;">ut does this mean that we will be able to jump into H.G. Wells’ machine, spin a dial, and soar several hundred thousand years into a future of some England?</span></p>
<p><span style="font-family:Times New Roman,Times,Times NewRoman;">       No, or at least, not right now. There are a number of difficult hurdles to overcome. First, the main problem is one of energy. In the same way that a car needs gasoline, a time machine needs to have fabulous amounts of energy. One either has to harness the power of a star, or to find something called “exotic” matter (which falls up, rather than down) or find a source of negative energy. (Physicists once thought that negative energy was impossible. But tiny amounts of negative energy have been experimentally verified for something called the Casimir effect, i.e. the energy created by two parallel plates.) All of these are exceedingly difficult to obtain in large quantities, at least for several more centuries!<br />
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<a href="http://www.pbs.org/hawking/strange/html/blackh.html"><span style="font-family:Arial,Helvetica;">Black Holes</span></a></p>
<p><a href="http://www.pbs.org/hawking/strange/html/wormhole.html"><span style="font-family:Arial,Helvetica;">Wormholes</span></a></p>
<p><a href="http://www.pbs.org/hawking/cosmostar/html/hawking.html"><span style="font-family:Arial,Helvetica;">Stephen Hawking</span></a></p>
<p><a href="http://www.pbs.org/hawking/strange/html/strings.html"><span style="font-family:Arial,Helvetica;">Superstrings</span></a></td>
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<td width="272"><span style="font-family:Times New Roman,Times,Times NewRoman;">       Then there is the problem of stability. Kerr’s rotating black hole, for example, may be unstable if one falls through it. Similarly, quantum effects may build up and destroy the wormhole before you enter it. Unfortunately, our mathematics is not powerful enough to answer the question of stability because you need a “theory of everything” which combines both quantum forces and gravity. At present, superstring theory is the leading candidate for such a theory. (Actually, it is the ONLY candidate; it really has no rivals at all.) But superstring theory, which happens to be my specialty, is still too difficult to solve completely. The theory is well-defined, but no one on earth is smart enough to solve it.</span><span style="color:#000000;">  </span></td>
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<td width="426"><span style="color:#000000;font-family:Times New Roman,Times,Times NewRoman;">      </span><span style="color:#000000;font-family:Times New Roman,Times,Times NewRoman;">Interestingly enough, Stephen Hawking once opposed the idea of time travel. He even claimed he had “empirical” evidence against it. If time travel existed, he said, then we would have been visited by tourists from the future. Yet we see no tourists from the future. Ergo: time travel is not possible.</span></p>
<p><span style="color:#000000;font-family:Times New Roman,Times,Times NewRoman;">      Because of the enormous amount of work done by theoretical physicists within the last five years or so, Hawking has since changed his mind, and now believes that time travel is possible (although not necessarily practical). Furthermore, perhaps we are simply not very interesting to these tourists from the future. Anyone who can harness the power of a star would consider us to be very primitive. Imagine your friends coming across an ant hill. Would they bend down to the ants and give them trinkets, books, medicine, and power? Or would some of your friends have the strange urge to step on a few of them?</span></p>
<p><span style="color:#000000;font-family:Times New Roman,Times,Times NewRoman;">     In conclusion, don’t turn someone away who knocks at your door one day and claims to be your future great-great-great-granddaughter. She may be right.<br />
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		<title>What is quantum mechanics? The Double Slit experiment</title>
		<link>http://saurabhsardesai.wordpress.com/2010/05/10/what-is-quantum-mechanics/</link>
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		<pubDate>Mon, 10 May 2010 10:45:20 +0000</pubDate>
		<dc:creator>saurabhsardesai</dc:creator>
				<category><![CDATA[Physics]]></category>
		<category><![CDATA[Quantum Mechanics]]></category>
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		<category><![CDATA[quantum theory]]></category>
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		<description><![CDATA[Quantum theory is bizarre. In order to try and understand it we need to forget everything we know about cause and effect, reality, certainty, and much else besides. This is a different world, it has its own rules, rules of probability that make no sense in our everyday world. Richard Feynman, the greatest physicist of his generation, said of quantum theory

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			<content:encoded><![CDATA[<p>Quantum theory is bizarre. In order to try and understand it we need to forget everything we know about cause and effect, reality, certainty, and much else besides. This is a different world, it has its own rules, rules of probability that make no sense in our everyday world. Richard Feynman, the greatest physicist of his generation, said of quantum theory</p>
<p>&#8216;<em>It is impossible, absolutely impossible to explain it in any classical way&#8217;. </em></p>
<p>Quantum theory is much more than just bizarre, it is also without doubt the most amazing theory in existence. If after reading this section you are not totally amazed by it, then the fault will be mine, for I will have failed to reveal to you its deep underlying significance. This theory is not just about experiments and equations, it reveals something extraordinary about our very understanding of what constitutes reality.</p>
<p>This is a very complex theory, and in order to fully do it justice it would require at least a fair sized book. However, in order to grasp the basic principles involved it will suffice to study just three key experiments. The three experiments are generally known as: the &#8216;Double Slit Experiment&#8217;, Schrödinger&#8217;s &#8216;Cat-in-the-Box Experiment&#8217; and the &#8216;EPR Paradox&#8217;.</p>
<p>We will start with the famous double slit experiment as it demonstrates beautifully the central mystery of quantum theory. Quantum theory however, needs some introduction before we get too involved in the experiment.</p>
<p>The standard explanation of what takes place at the quantum level is known as the Copenhagen Interpretation. This is because much of the pioneering work was carried out by the Danish physicist Niels Bohr, who worked in Copenhagen. Quantum theory attempts to describe the behaviour of very small objects, generally speaking the size of atoms or smaller, in much the same way as relativity describes the laws of larger everyday objects. We find it necessary to have two sets of rules because particles do not behave in the same way as larger everyday objects, such as billiard balls. We can, for example, say precisely where a billiard ball is, what it is doing, and what it is about to do. The same cannot be said for particles. They are, quite literally, a law unto themselves, and why this should be so is a source of much debate. The classic experiment to illustrate this is the famous double slit experiment, originally devised to determine if light travels as waves or particles. Feynman said of it:</p>
<p>&#8216;Any other situation in quantum mechanics, it turns out, can always be explained by saying, <em>&#8220;You remember the case of the experiment with the two holes? It&#8217;s the same thing.&#8221;&#8216;</em></p>
<p><strong><span style="color:#ff0000;">The double slit experiment.</span></strong></p>
<p>If light travels as particles we can imagine particles of light (photons) as bullets fired from a rifle. Imagine a brick wall with two holes in it, each the same size and large enough to fire bullets through, with a second wall behind where the bullets will strike. After firing a few rounds you would expect to see on the second wall two clusters of hits in line with the two holes. This is of course precisely what you get with bullets, so if we get the same result with photons we can say they are particles.</p>
<p>Now imagine that instead of particles, that light travels as a wave, we can replicate that with a water tank. As the wave spreads out from its source it would reach both holes at the same time and each hole would then act as a new source. Waves would then spread out again from each of the holes, exactly in step, or in phase, and as the waves moved forward, spreading as they go, they would eventually interfere with one another. Where both waves are lifting the water surface upward, we get a more pronounced crest; where one wave is trying to create a crest and the other is trying to create a trough the two cancel out and the water level is undisturbed. The effects are called constructive and destructive interference.</p>
<p>If we carried out this procedure with light instead of water, and if light travels as waves, then the pattern on the second wall would appear as an interference pattern of alternate dark and light bands across the wall. Particles, on the other hand, would produce two separate areas of light (where the bullets would hit). This experiment has in fact been carried out many, many times, with the same results every time, and the results are nothing less than amazing.</p>
<p><img src="http://www.thekeyboard.org.uk/Waves" alt="" width="300" height="178" align="bottom" /></p>
<p>When the experiment is set up as shown in the above diagram, with both slits open, the resulting interference pattern clearly shows that light behaves as a wave. Now if that was all there was to it we could all fold up our tents and go home happy in the knowledge that light travels as a wave; but there is much more to it than that. This is where the word &#8216;weird&#8217; can become over-used.</p>
<p>If the experiment is set up to fire <em>individua</em>l photons, so that only one photon at a time goes through the set up, we would not expect the same interference pattern to build up; we would surely expect that a single photon would only go through one hole or another, it cannot go through both at the same time and create an interference pattern. So what happens?</p>
<p>If we wait until enough individual photons have passed through to build up a pattern &#8211; and this takes millions of photons &#8211; we do not get two clusters opposite the two holes, we get the same interference pattern! It is as if each individual photon &#8216;knows&#8217; that both holes are open and gives that result. Each individual photon, passing through the set up will place itself on the wall in such a position that when enough have passed through they have collectively built up an interference pattern, when there cannot possibly be any interference!</p>
<p>If we repeat the experiment, this time with only one hole open, the individual photons behave themselves and all cluster round a point on the detector screen behind the open hole, just as you would expect. However, as soon as the second hole is opened they again immediately start to form an interference pattern. An individual photon passing through one of the holes is not only aware of the other hole, but also aware of whether or not it is open!</p>
<p>We could try peeking, to see which hole the photon goes through, and to see if it goes through both holes at once, or if half a photon goes through each hole. When the experiment is carried out, and detectors are placed at the holes to record the passage of electrons through each of the holes, the result is even more bizarre. Imagine an arrangement that records which hole a photon goes through but lets it pass on its way to the detector screen. Now the photons behave like normal, self respecting everyday particles. We always see a photon at one hole or the other, never both at once, and now the pattern that builds up on the detector screen is exactly equivalent to the pattern for bullets, with no trace of interference. As if that was not bad enough, it gets even worse! We do not need place detectors at both holes, we can get the same result by watching just one hole. If a photon passes through a hole that does not have a detector, it not only knows if the other hole is open or not, it knows if the other hole is being observed! If there is no detector at the other hole as well as the one it is passing through, it will produce an interference pattern, otherwise it will act as a particle. When we are watching the holes we can&#8217;t catch out the photon going through both at once, it will only go through one. When we are not watching it will go through both at the same time! There is no clearer example of the interaction of the observer with the experiment. When we try to look at the spread-out photon wave, it collapses into a definite particle, but when we are not looking it keeps its options open.</p>
<p>What the double slit experiment demonstrates is this: Each photon starts out as a single photon &#8211; a particle &#8211; and arrives at the detector as a particle, but appears to have gone through both holes at once, interfered with itself, and worked out just where to place itself on the detector to make its own small contribution to the overall interference pattern. This behaviour raises a number of significant problems! Does the photon go through both holes at the same time? How does a photon go through both holes at the same time? How does it know where to place itself on the detector to form part of the overall pattern? Why don&#8217;t all the photons follow the same path and end up in the same place?</p>
<p>As a possible explanation it could perhaps be said that this is just one more example of the extraordinary nature of light, after all it does have some very unusual properties. Photons have no rest mass for example, a very odd property! Light is also unique in that it always travels at the same speed. However you move, and however the light source moves, when you measure the speed of light you always come up with the same answer. By way of comparison, two cars approaching each other and each having a speed of 30 mph will be approaching each other at a speed of 60 mph. Two light beams, both travelling of course at the speed of light, will be approaching each other at the speed of light, not twice the speed of light. Perhaps the weird behaviour of photons in the experiment is due to the weird nature of light. Unfortunately further experiments have demonstrated that this is not the case. Electrons have been used instead of photons, and they not only have mass, they have an electric charge, and furthermore they move at different speeds depending on circumstances, like normal everyday objects. The double slit experiments still gives the same result using electrons as it does using photons; electrons also alter their behaviour depending on whether or not they are being observed. The experiment has even been performed using atoms, again with the same result, and atoms are large enough to be individually photographed, they are very real solid objects. This odd behaviour of particles is a very <em>real</em> phenomenon.</p>
<p>The double slit experiment is not simply an oddball theory that has no application in the real world. This strange behaviour of particles lies at the very heart of our understanding of the physical properties of the world. Quantum theory is used in many applications, including television and computers, and even explains the nuclear processes taking place inside stars.</p>
<p>One possible explanation for quantum weirdness is a theory concerning the nature of the wave that is passing through the experiment. The key concept of the theory, which forms a central part of the Copenhagen Interpretation, is known as the &#8216;collapse of the wave function&#8217;. The theory seeks to explain how an entity such as a photon or an electron, could &#8216;travel as a wave but arrive as a particle&#8217;. According to the theory, what is passing through the experiment is not a material wave at all, but is a &#8216;probability wave&#8217;. In other words, the particle does not have a definite location, but has a probability of being here or there, or somewhere else entirely. Some locations will be more probable than others, such as the light areas in the interference pattern for example, and some will be less probable, such as in the dark areas. In this theory, an electron that is not being observed does not exist as a particle at all, but has a wave-like property covering the areas of probability where it could be found. Once the electron is observed, the wave function collapses and the electron becomes a particle. This theory rather neatly explains the behaviour of the particles in the double slit experiment. When we are not looking at the particle, the probability wave, of even a single particle, is spread out and will pass through both slits at the same time and arrive at the detector as a wave showing an interference pattern. When we observe the electron by placing detectors at the slits, it is forced into revealing its location which causes the probability wave to collapse into a particle. If the theory is correct, its implications are staggering. What it suggests is that nothing is real until it has been observed!</p>
<p><em>Nothing is real until it has been observed! </em>This clearly needs thinking about. Are we really saying that in the &#8216;real&#8217; world &#8211; outside of the laboratory &#8211; that until a thing has been observed it doesn&#8217;t exist? This is precisely what the Copenhagen Interpretation is telling us about reality. This has caused some very well respected cosmologists (Stephen Hawking for one) to worry that this implies that there must actually be something &#8216;outside&#8217; the universe to look at the universe as a whole and collapse its overall wave function. John Wheeler puts forward an argument that it is only the presence of conscious observers, in the form of ourselves, that has collapsed the wave function and made the universe exist. If we take this to be true, then the universe only exists because <em>we</em> are looking at it.</p>
<p>See Wikipedia for more on this <a href="http://en.wikipedia.org/wiki/Double-slit_experiment">http://en.wikipedia.org/wiki/Double-slit_experiment</a></p>
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