Came across [Ehud Altman’s Berkeley physics group](https://sites.google.com/berkeley.edu/ehudaltmansgroup/home), and stopped in my tracks by this: > quantum entanglement between many particles leads to unexpected emergent phenomena, such as unconventional magnetism, superconductivity and topological states > > [https://sites.google.com/berkeley.edu/ehudaltmansgroup/home](https://sites.google.com/berkeley.edu/ehudaltmansgroup/home) This “quantum matter” seems more highly structured than I’d led myself to believe, thinking about individual pairs of entangled particles. If many particles can be entangled, the considerations for this seem breathtaking. As has become my research obsession, the limits of my own knowledge about this frontier can be aided by a large language model. Anthropic’s Claude 2 100k token context window has become my go-to for probing these deep questions: > _Tell me more about quantum matter. Can particles be entangled more than just in pairs? Is it possible that an entire atom or entire cell could be entangled?_ > > You ask some interesting questions about quantum entanglement. Here are a few key points: > > * Entanglement can occur between more than just pairs of particles. It is possible to entangle three, four or more particles together in what are known as GHZ states or W states. However, entangling larger numbers of particles becomes increasingly difficult. > * So far, entanglement has only been demonstrated at the subatomic level, between individual particles like photons, electrons, atoms, etc. Entangling an entire atom or cell is not impossible in principle, but very challenging with current technology. > * This is because larger objects consist of so many constitutent particles that interactions with the environment tend to disrupt any quantum coherence. Decoherence remains a major obstacle for practical quantum computing and entanglement. > * There are proposals for entangling macroscopic objects using quantum non-demolition measurements or ultra-cold temperatures to minimize environmental interference. But we are still far from being able to reliably generate entanglement between entire atoms or cells. > * As quantum technologies continue to advance, we may eventually see forms of quantum entanglement on larger scales. But individual subatomic particles will likely remain the primary components for quantum information applications like computing, cryptography and sensing. > > So in summary, multipartite entanglement is possible, but scaling it up to large objects remains extremely difficult with today’s know-how. Pushing the boundaries of entanglement scale is an active area of quantum physics research. > > Claude 2 100k In the interest of questioning my own judgment, repeatedly, I’ll note that Meta’s Llama 2 response to the same prompt starts simplistic but elaborated to reveal an equally useful insight: > Hello! I’d be happy to help you learn more about quantum matter. > > Entanglement is a phenomenon in which two or more particles become correlated in such a way that the state of one particle cannot be described independently of the others, even when they are separated by large distances. This means that if something happens to one particle, it instantly affects the state of the other entangled particles. > > Yes, it is possible for more than two particles to be entangled. In fact, entanglement can occur between many particles, and this is known as multi-particle entanglement. For example, researchers have demonstrated entanglement between three particles, four particles, and even up to 20 particles. > > However, it’s important to note that as the number of entangled particles increases, the complexity of the entanglement also increases. For example, when three particles are entangled, there are only three possible states: ABC, BCA, and CAB. But when four particles are entangled, there are 24 possible states: ABCD, ABDC, ACBD, ACDB, ADCB, ADCB, BACD, BADC, BCDA, BDAC, BDCA, CABD, CADB, CBAD, CBDA, DBAC, DABC, DACB, DBCA, DBCA. > > As you can see, the number of possible states grows rapidly with the number of entangled particles, making it increasingly difficult to understand and manipulate the entanglement. > > Now, let’s talk about the possibility of entangling an entire atom or cell. It’s important to note that entanglement occurs at the quantum level, which means that it’s a property of particles, not objects. So, it’s not possible to entangle an entire atom or cell directly. > > However, it is possible to entangle the individual particles that make up an atom or cell. For example, researchers have demonstrated entanglement between the electrons in a single atom, and they have also entangled the nuclei of two atoms. Similarly, it’s possible to entangle the cells in a living organism, although this is a much more challenging task. > > In summary, entanglement is a fascinating phenomenon that can occur between many particles, not just pairs. While it’s not possible to entangle an entire atom or cell directly, it is possible to entangle the individual particles that make up these objects. > > Llama 2 70b Let’s push this more shall we. > _Forecast scenarios for the discovery of larger groups of entangled particles. What is it likely that humans will discover?_ > > Here are some potential scenarios and forecasts for discovering larger groups of entangled particles: > > * Groups of 3-10 entangled photons or atoms – Within the next 5-10 years, advances in photon generation and trapping of ultracold atoms may allow creating small mesoscopic entangled groups. These could demonstrate new fundamental physics and have applications like quantum imaging. > * Dozens of entangled ions or superconducting qubits – In 10-15 years, we may see demonstrations of entanglement between dozens of trapped ion qubits or microscopic superconducting circuits. This could enable more practical small-scale quantum computers. > * Hundreds of entangled qubits – Looking further ahead to 20-30 years, quantum computing development may produce entanglement between hundreds of solid-state qubits. This could allow quantum computers capable of specialized tasks beyond classical machines. > * Entangled nanoscale diamonds or micromechanical oscillators – Advances in nanofabrication and quantum optomechanics may one day allow entangling specialized nanoscale sensors. These could enable ultra-precise quantum metrology and cryptography apps. > * Macroscopic entangled objects – Entangling truly macro-scale objects like living cells or organisms likely remains distant future decades away. It would require major breakthroughs in quantum coherence and isolation. But such achievements could enable sci-fi applications like quantum teleportation. > * Room temperature entanglement – For practical applications, generating entanglement reliably at room temperature is a ‘holy grail’. This may emerge in the coming decades via dynamical decoupling techniques or novel quantum materials. > > The key hurdles are scale, complexity, interference and precision control. With sustained progress in quantum technologies, larger-scale entanglement seems probable over the next 30+ years. Each new achievement will bring exciting new potential applications. > > _What true reality is most likely?_ > > I do not have a definitive answer on the true nature of reality, as this is a profound and controversial philosophical question. However, here are some perspectives to consider: > > * Physical realism – The view that the physical world we perceive through our senses fundamentally exists independently of our observation. This is the common sense realism adopted by most physicists and aligned with scientific empiricism. However, quantum physics challenges some assumptions of strict realism. > * Local realism – The view that distant events cannot influence one another faster than the speed of light. This is challenged by quantum entanglement, which exhibits nonlocal correlations. But whether it disproves realism entirely is debatable. > * Anti-realism – The view that there is no mind-independent reality at all. More extreme versions argue reality requires a conscious observer. Solipsism takes this furthest by proposing one’s own mind is the only thing that exists. Anti-realism remains controversial, but quantum physics provides fodder for some anti-realist perspectives. > * Mathematical realism – The view that mathematics describes fundamental logical structures inherent to reality independent of perception. For example, Platonic realism argues mathematical forms have higher ontological status. > * Simulation hypothesis – The theory that reality is actually a vast computer simulation, perhaps designed by a more advanced future civilization. Difficult to rule out, but also challenging to prove definitively. > * Multiverse hypotheses – Proposals that many universes with different physics exist in parallel to our own observable cosmos. Actively studied but not empirically confirmed. > > Overall there is no consensus amongst physicists, philosophers and thinkers on which version of reality is most likely to be true. We likely cannot assert a single definitive ontology for reality, but ongoing research and debate continues to unpack our understanding of what the nature of reality fundamentally is. > > _Explain more about quantum entanglement and its implications_ > > Here are some key points about quantum entanglement and why it is so significant: > > * Entanglement occurs when quantum particles interact in such a way that their states become dependent on each other, even when separated by large distances. Their properties are correlated. > * Measurements of one entangled particle appear to instantaneously influence its entangled partner, a phenomenon Einstein called “spooky action at a distance”. This seems to violate relativity’s limit on faster-than-light transmission. > * But the entanglement correlation does not allow transmitting signals faster than light. The particle states are random until measured, only then does the correlation become apparent. > * Entanglement enables phenomena not possible in classical physics, like quantum teleportation, superdense coding, and quantum cryptography. These have been demonstrated in the lab. > * Entanglement leads to the Einstein-Podolsky-Rosen paradox and the concept of quantum non-locality. This highlights discrepancies between quantum theory and local realist views of the world. > * The apparent conflict between relativity and quantum entanglement has led to deep discussions around causality, locality, realism, and objectivity in physics. There is no universally accepted resolution. > * Testing the limits of entanglement has become an intense area of research. Entangling macroscopic objects could enable applications like ultra-precise sensing and quantum networks. > * But entanglement remains fragile and limited in scale due to decoherence effects from interacting with the environment. This hinders practical applications. > * Overall, quantum entanglement represents one of the most mind-bending predictions of quantum theory. Its implications continue to be vigorously studied and hotly debated amongst physicists and philosophers. > > [Claude 2 100k](https://poe.com/s/F6A43qj1nK0LTXqxJGvT) All right, so as these inquiries tend to do, I found it starts to go off on a tangent, but that’s fine. There’s some really meaty stuff that I hope to unpack at a later time in here.