From: mk_thisisit
Classical vs. Quantum Worlds
The world we commonly experience consists of large objects [00:00:53]. However, matter is ultimately made of atoms [00:01:10], which are incredibly small [00:01:34]. Atoms do not behave like everyday objects such as trams or ping-pong balls; they exist and operate in a fundamentally different world [00:01:58]. This quantum world is alien to our direct experience [00:02:16].
Quantum Mechanics and Observation
Quantum mechanics is described as a theory of our observations of the microworld [00:02:50]. While observing macroscopic objects generally has negligible effect on them [00:03:15], observing quantum objects completely changes our knowledge about them, and often their state [00:03:30]. For instance, the photons used to observe quantum phenomena can disrupt what is being observed [00:03:47]. This contrasts with observing the moon, where the light used for observation has a negligible effect on its physical properties [00:04:50]. The act of observation in the microscopic stage is active and changes our information about the object, which is a key to understanding quantum mechanics [00:05:31].
Teleportation
Teleportation, as it relates to quantum physics, is an artificial process that does not occur naturally [00:07:05]. It is crucial to understand that teleportation does not involve the transfer of matter [00:08:12]. Instead, as quoted by Den Greenberger, only the “soul” (or rather, the quantum state/information) is transferred [00:08:15].
For teleportation to occur, an object whose state will be transformed must already be waiting at the target location [00:08:27]. The process typically involves maximally entangled particles that form a “teleportation channel,” often referred to as the Einstein-Podolsky-Rosen channel [00:09:00].
The Bell Measurement in Teleportation
A key step in quantum teleportation is performing a Bell measurement on the particle whose state is to be teleported, along with an auxiliary particle from the entangled pair [00:09:43]. This measurement completely erases the information about the state of these particles [00:10:04] and yields one of four possible results for a single photon [00:10:13]. For instance, in the case of photon polarization, there are only two possible outcomes [00:10:39].
Limitations of Teleporting Large Objects
While elementary particles can be teleported [00:07:15], teleporting a human being or even a more complicated object like a glass is currently considered impossible [00:07:42]. The process for such objects would require resources beyond the technical possibilities of the universe [00:07:50]. For a glass, for example, the number of possible Bell states that would need to be controlled is astronomically large (e.g., 10^25 or 10^26 atoms) [00:11:13].
Even teleporting an atom in an arbitrary state is considered impossible because of the infinite number of possible energy states for electrons in an atom, such as a hydrogen atom [00:31:30]. This would necessitate a Bell measurement with infinitely many outcomes, which is not feasible [00:31:54]. So, the thesis that one can never “teleport an object” but rather its state remains true, meaning the receiving object must already be present [00:35:16].
Pioneering Research and the Nobel Prize
Research on quantum mechanics has advanced significantly, particularly concerning fundamental concepts like Bell’s theorem. The speaker collaborated with Anton Zeilinger, a 2022 Nobel Prize winner, whose work built upon these foundations [00:13:22].
Collaboration with Anton Zeilinger
The speaker’s collaborative work with Anton Zeilinger began in 1991 when Zeilinger invited him to be a visiting professor [00:40:40]. During this time, they focused on the interference of independent single photons [00:20:57]. Initially, they thought such interference was impossible, but they discovered a hidden assumption related to time resolution, which, when broken, allowed independent photons to interfere [00:22:33]. This understanding led to a paper showing the possibility of entanglement exchange [00:23:14].
Zeilinger’s Nobel Prize was awarded for studies on entangled photons, showing the violation of the Bell inequality, and for pioneering experiments on quantum information [00:21:26]. This included work on teleportation [00:21:55].
Bell’s Theorem and Paradoxical Situations
Bell’s theorem highlights the gap between phenomena explainable by classical mechanics and relativity, and those that are purely quantum mechanical [00:41:43]. The speaker’s own research in this area faced strong opposition from colleagues initially [00:40:07], who felt the topic was settled [00:42:36]. However, the speaker persisted due to the intellectual shock caused by these concepts [00:42:46]. Bell’s theorem reveals “absolutely paradoxical” situations in the quantum world compared to the macroscopic world [00:15:04].
The Nature of Entanglement
Entanglement occurs everywhere, even in the basic state of a hydrogen atom [00:44:02]. The phenomenon of parametric conversion is particularly beautiful and important for creating entangled photons [00:53:51]. In this process, a crystal generates pairs of photons, where the appearance of one photon in a certain position implies its “brother” will appear symmetrically [00:54:47]. These photons can be polarized, and their polarization can be entangled in a way that, if one photon’s polarization is unknown, its entangled partner’s polarization is also unknown until a measurement is made [00:55:36]. This specific property of parametric conversion was discovered by a large group of people [00:55:47] and was used in teleportation experiments [00:56:11].
Ethical Considerations in Physics
The discussion touches upon the ethical implications of massive spending on projects like a second Large Hadron Collider. While the collisions created in such accelerators are natural processes (unlike teleportation, which is artificial) [00:16:25], the question arises whether creating “unnatural states” justifies the enormous cost [00:15:37]. Such projects lead to technical achievements and a deeper understanding of matter states, bringing us closer to understanding the early universe [00:18:12]. However, it also raises concerns about diverting funds from other research [00:18:50].
Polish Scientists and the Nobel Prize
It is believed that there is a pool of Polish scientists who are very close to receiving the Nobel Prize [00:49:35]. However, Poland’s spending on science (around 3% of GDP) is significantly lower than leading countries [00:50:42], and the country experiences a “brain drain” [00:51:50]. Despite this, some individuals, like Wojtek Żurek, are recognized as being very close to receiving the prize [00:52:01]. The Nobel Committee’s preference for experimental verification of theories, as seen with Trautman’s work, is also a factor [00:52:28].