From: mk_thisisit
Connecting Classical and Quantum Worlds
A significant area of interest in physics is understanding what connects the classical world with the quantum world, as these are fundamentally two different realms of physics [01:47:11]. The emergence of classical behavior from quantum behavior is a key aspect of this connection, considered a “grand unification” [01:55:18]. This phenomenon is considered a “really interesting thing” in physics [03:32:41].
Newton’s First Law vs. Quantum Behavior
One of the clearest distinctions can be seen when comparing Newton’s First Law in classical physics with particle behavior in quantum mechanics [04:08:49].
In classical physics, Newton’s First Law states that an object left alone without any forces acting on it will remain at rest or continue to float [03:41:16]. For instance, in space, a small object would remain in a deterministic state [04:00:09].
However, in quantum theory, the behavior is “completely different” [04:10:04]. If a particle is placed somewhere, knowing its exact location, it immediately “jumps simultaneously to every other place in the universe” [04:16:15]. This means a single particle can be simultaneously present at all points in the universe [04:30:19]. This is a “perfect demonstration of the difference between classical and quantum physics” [04:38:39]. If no force acts on it, it will “spread out” [04:47:50]. This “one particle in many places at the same time” is drastically different from a grain of sand staying put in classical physics [05:01:21].
Electron Behavior in Atoms
The behavior of an electron in a hydrogen atom provides another example of quantum phenomena [05:43:55]. If an electron is placed near a proton and released, it will “fill the space around it” [05:51:06]. The correct description of this atom states that the electron exists in multiple places simultaneously [05:59:43]. This is distinct from the classical picture, which imagines an electron as an object occupying a specific place and moving [06:16:32].
This strange behavior is fundamental to how atomic physics and chemical bonds work [06:25:01]. However, when two hydrogen atoms form a bond, electrons behave differently, and “emergent deterministic behavior” is observed, with electrons localized near protons [06:36:12].
Deterministic vs. Non-Deterministic Worlds
The universe we inhabit is considered a non-deterministic world at its fundamental quantum level [06:47:19]. The classical, deterministic world is an “emergent consequence of interactions between many quantum particles” [06:50:06].
Free Will and Quantum Physics
Regarding human free will, from the perspective of quantum physics, it is argued that quantum mechanics does not particularly contribute to this discussion [07:22:21]. It is not considered a way to introduce free will into the theory [07:35:10]. The speaker suggests that for practical purposes, we appear to have free will, even if fundamentally we might not [07:51:41].
The Holographic Principle and Gravity
The holographic principle, especially as explored by Juan Maldacena, suggests that quantum mechanics on a surface without gravity can describe physics, including the appearance of an additional dimension of space in the interior region [15:22:36]. This implies that gravity is an “emergent property of quantum mechanics” [15:43:24].
In other words, there is a fundamental connection where gravity “comes out of quantum physics” [16:08:08]. This means that gravity is not fundamental; it follows from a more fundamental statistical picture [19:06:17]. If this theory proves true with experimental evidence, it would be a major discovery in physics [19:57:48]. This understanding is consistent with the idea that the geometry of space is a consequence of “some small vibrating things” [00:35:05].
Information Paradox and Black Holes
Research on Hawking radiation relates to the information paradox concerning black holes [20:15:07]. While classical general relativity suggests that information might disappear into a black hole’s singularity, quantum mechanics states that it is impossible to completely annihilate information [21:47:38]. Recent calculations, particularly from 2019, indicate that information does not disappear, and most theorists now believe it comes out of the black hole [22:02:18]. The information paradox is an emergent phenomenon resulting from black hole evaporation [22:44:07]. Modern research addresses these issues using language familiar to those in quantum computing and quantum information [23:01:21].
The “no hair theorem” in classical black hole theory states that a black hole is completely described by only three properties: electric charge, mass, and angular momentum [23:52:43]. However, when quantum mechanics is considered in relation to black holes, this “no hair” claim is discarded [24:28:44]. Quantum mechanics suggests that black holes are “more than just their spin, mass, and angular momentum,” implying they possess additional information, akin to “hair” [24:37:37].