Have you ever needed a holistic detective agency? And do you know what a holistic detective agency is? If you do not know, don't panic: I am going to say what it is this strange agency.
The term ‘holistic’ refers to my [detective's] conviction that what we are concerned with here is the fundamental interconnectedness of all things. I do not concern myself with such petty things as fingerprint powder, telltale pieces of pocket fluff and inane footprints. I see the solution to each problem as being detectable in the pattern and web of the whole. The connections between causes and effects are often much more subtle and complex than we with our rough and ready understanding of the physical world might naturally suppose.
And what are its secret origins?
Well, some researchers were once conducting such an experiment [Schroedinger's cat], but when they opened up the box, the cat was neither alive nor dead but was in fact completely missing, and they called me in to investigate. I was able to deduce that nothing very dramatic had happened. The cat had merely got fed up with being repeatedly locked up in a box and occasionally gassed and had taken the first opportunity to hoof it through the window. It was for me the work of a moment to set a saucer of milk by the window and call “Bernice” in an enticing voice -- the cat’s name was Bernice, you understand -- and the cat was soon restored. A simple enough matter, but it seemed to create quite an impression in certain circles, and soon one thing led to another as they do and it all culminated in the thriving career you see before you.
The Schroedinger's cat is a thought experiment proposed by Erwin Schroedinger in 1935 in order to proof the limits of quantum mechanics and Copenaghen interpretation. One of the most known consequence of the paradox is the many worlds interpretation, but also artist was inspired by the paradox. For example Chavdar Yordanov created a beautiful and funny animation with the music created by Sian Smith (via Open Culture).
The Infinite Improbability Drive is a faster-than-light drive. The most prominent usage of the drive is in the starship Heart of Gold. It is based on a particular perception of quantum theory: a subatomic particle is most likely to be in a particular place, such as near the nucleus of an atom, but there is also an infinitesimally small probability of it being found very far from its point of origin (for example close to a distant star). Thus, a body could travel from place to place without passing through the intervening space (or hyperspace, for that matter), if you had sufficient control of probability. According to the Guide, the drive "passes through every conceivable point in every conceivable universe almost simultaneously," meaning that you are "never sure where you'll end up or even what species you'll be when they get there" and "it's therefore important to dress accordingly".
The Guide's entry on the drive also states that it was invented "following research into finite improbability, which was often used to break the ice at parties by making all the molecules in the hostess' undergarments leap one foot simultaneously to the left, in accordance with the theory of indeterminacy". It further explains that many respectable physicists wouldn't stand for that sort of thing, "partly because it was a debasement of science, but mostly because they didn't get invited to those sort of parties."
The first application of the concept behind the infinite improbability drive comes from an old experiment from the 20th century:
Well, some researchers were once conducting such an experiment, but when they opened up the box, the cat was neither alive nor dead but was in fact completely missing, and they called me in to investigate. I was able to deduce that nothing very dramatic had happened. The cat had merely got fed up with being repeatedly locked up in a box and occasionally gassed and had taken the first opportunity to hoof it through the window. It was for me the work of a moment to set a saucer of milk by the window and call "Bernice" in an enticing voice -- the cat's name was Bernice, you understand -- and the cat was soon restored.
(from Dirk Gently's Holistic Detective Agency by Douglas Adams)
Following Uri Geller (via Peter Woit), today it could be open a portal to another universe!
Geller support his original idea with a mix of string theory and numerology. At the other hand, this mixture of science and superstition is perfect for a fiction, for example The Invisibles, the cult comics written by Grant Morrison in the past century.
The comic book series, behind the entertainment pourposes, hides a political purpose, to tell the world and the use of mass media in order to control people. But I don't write about this subject, but about the scientific background, in particular I would start from the many worlds hypothesis(1).
In The Invisibles there is, indeed, a war against alien from another universe. The scientific basis of the comics is the string theory: for example the simbols of early cristians is interpreted like a part of the infinity symbol, that it also represents the connection between the two universes, like two universal strings or two membranes (or branes). But the story of the scientific multiversity began woth the famous Schroedinger's cat:
The thought experiment was proposed by Schroedinger in 1935 in order to proof the limits of quantum mechanics and Copenaghen interpretation, but Erwind could not know that his paradox would be generate a lot of intriguing theoretical science. One consequence is the many worlds interpretation, but another research line is the construction of a real Schroedinger's cat!
A first right attempt was made by Jonathan Friedman and collegues(2) (read physicsworld). The team realized a superconducting quantum interference device (SQUID):
The simplest SQUID is a superconducting loop of inductance $L$ broken by a Josephson tunnel junction with capacitance $C$ and critical current $I_c$. In equilibrium, a dissipationless supercurrent can flow around this loop, driven by the difference between the flux that threads the loops and the external flux $\phi_x$ applied to the loop.
They used two junctions in their experimental setup, and so they realized a superposition between two different states:
Such a superposition would manifest itself in an anticrossing, where the energy-level diagram of two levels of different fluxoid states (labelled $| 0 >$ and $| 1 >$) is shown in the neighbourhood in which they would become degenerate without coherent interaction (dashed lines). Coherent tunnelling lifts the degeneracy (solid lines) so that at the degeneracy point the energy eigenstates are
\[\frac{1}{2} \left ( | 0 > + | 1 > \right )\]
and
\[\frac{1}{2} \left ( | 0 > - | 1 > \right ) \, ,\]
the symmetric and anti-symmetric superpositions. The energy difference $E$ between the two states is given approximately by $E = \epsilon^2 + \Delta^2$, where $\Delta$ is known as the tunnel splitting.
In order to proof the existence of the splitting, a necessary condition is that:
(...) the experimental linewidth of the states be smaller than $\Delta$(3). The SQUID is extremely sensitive to external noise and dissipation (including that due to the measurement of ), both of which broaden the linewidth. Thus, the experimental challenges to observing coherent tunnelling are severe. The measurement apparatus must be weakly coupled to the system to preserve coherence, while the signal strength must be sufficiently large to resolve the closely spaced levels. In addition, the system must be well shielded from external noise. These challenges have frustrated previous attempts5, 6 to observe coherence in SQUIDs.
But the observation presents some difficulties, like the SQUID's sensibility to the noise, which must be shielded, and to the dissipation; the device must also preserve the coherence,
(...) while the signal strength must be sufficiently large to resolve the closely spaced levels.
All of these problems influenced previous attempts(4, 5), but they found an answer thanks Friedman's team:
In the plot it is showed the probability to realize a transition like function of the flux $\phi_x$. The curves, plotted for different potentials, are shifted upwards in order to clarify the shapes. The quantum behaviour of the macroscopic system is argued by the existence of two peaks, that decreasing potential separate one from each other and reach the same amplitude. The two peaks correspond to two distinct macroscopic fluxes and we can conclude that they realize a macroscopic Schroedinger's cat.
A most recent attempt has made this year (via tumblr) by a team of China's researchers leaded by Xing-Can Yao(6). The team, using the following experimental setup:
