Quantum consciousness: Penrose and Hameroff’s Orch-OR, fairly examined

Author: Raymond Hackland · Last reviewed: 18 October 2026 · Reading time: about 7 minutes

In short

• What this is: Orch-OR (“orchestrated objective reduction”) is a hypothesis by the physicist Roger Penrose and the anaesthesiologist Stuart Hameroff. It proposes that consciousness arises from quantum processes in tiny protein tubes inside nerve cells, called microtubules.
• What the evidence says: Some recent lab findings are intriguing, but none shows quantum coherence in living brains linked to consciousness. Physicists have raised strong objections, and one key ingredient has been narrowed down by experiment. The hypothesis remains speculative.
• What it means for your practice: Orch-OR is an open question about how the brain works. It doesn’t support any health claim, and our practice makes no quantum claims.

The hypothesis, fairly stated

Label for this section: Speculative (this describes the hypothesis, not established science).

In the mid-1990s, Penrose and Hameroff proposed that consciousness depends on “orchestrated”, coherent quantum processes in collections of microtubules inside neurons. Microtubules are part of the cell’s skeleton, built from a protein called tubulin. According to the hypothesis, these quantum processes interact with ordinary nerve activity, and each one ends in an “objective reduction”: a collapse of the quantum state caused by gravity, following a scheme proposed by Lajos Diósi and Penrose. Each such event, they suggest, is a moment of conscious experience [1].

In their 2014 review, the two authors answered earlier criticisms, linked the idea to developments in quantum biology, and proposed that “beat frequencies” of fast microtubule vibrations might help explain the brain rhythms seen in EEG recordings. They concluded that consciousness plays an intrinsic role in the universe [1]. That is a bold claim, and they present it openly as a scientific hypothesis that can be tested.

What tests and critiques show

Label for this section: Speculative overall; individual results are described for what they show.

The decoherence objection. In 2000, Max Tegmark calculated how long quantum superpositions could survive in the brain. For microtubules he estimated about 10⁻¹³ seconds, far shorter than the 0.001 to 0.1 seconds on which neurons work, and concluded that the brain is best treated as a classical system [2]. Hameroff and colleagues replied in 2002 that Tegmark had modelled a different system from theirs; after their corrections, they estimated 10⁻⁵ to 10⁻⁴ seconds and argued that biology could shield or sustain coherence [3]. Whether such protection really happens in living tissue has not been shown.

A physical ingredient tested. In 2009, a group of chemists and physicists analysed a kind of collective vibration, called Fröhlich condensation, that some quantum-mind models relied on. They concluded that the coherent form, in which the energy sits in a single quantum state, would be extremely fragile and inaccessible in a biological environment, and that models needing it as an essential element were untenable [4]. Proponents have responded to criticisms of this kind in their later review [1].

Testing gravity-related collapse. Orch-OR needs the Diósi–Penrose collapse to be real. In 2021, a team ran a sensitive experiment deep underground at the Gran Sasso laboratory in Italy. If such collapse occurred in its simplest form, it would make charged particles emit faint radiation. They found too little radiation, ruling out the natural, parameter-free version of the Diósi–Penrose model [5]. Versions with adjustable parameters remain possible, so this narrows the idea rather than ending it.

Microtubules and anaesthesia. Anaesthetics switch off consciousness, so they are a natural test. In 2024, rats given a drug that stabilises microtubules took on average 69 seconds longer to lose their righting reflex under the anaesthetic isoflurane [6]. A 2026 study found a smaller delay of 29 seconds in mice, and notes that a different mouse study with daily dosing of a similar drug found the opposite, greater sensitivity [7]. These results suggest that microtubules may be one of the many targets of anaesthetics. On their own, they don’t show that a quantum process is involved.

Light and energy in microtubules. In 2023, a team including Hameroff and Penrose found that excitation energy can spread about 6.6 nanometres along microtubules in the lab, further than conventional theory predicted, and that two anaesthetics reduced this spread [8]. A 2024 study reported “superradiance”, a collective quantum effect in networks of the amino acid tryptophan in microtubule structures [9]. A 2017 computer-modelling study suggested that anaesthetic gases alter vibrations in tubulin in step with their potency [10]. These are genuine findings about isolated proteins, purified samples and computer models. None of them measured quantum coherence in a living brain, or linked it to conscious experience.

Where this leaves Orch-OR. It has produced testable predictions, which is to its credit. But its central claim, that consciousness depends on orchestrated quantum collapse in microtubules, has not been confirmed, and the main physical objections have not been resolved. Mainstream neuroscience studies consciousness without assuming quantum effects. That’s why we label it Speculative.

Where popular claims go beyond the evidence

Label for this section: Speculative.

Even supporters of Orch-OR do not claim most of what is said in its name:

• “Science has shown consciousness is quantum.” It hasn’t. Orch-OR is one hypothesis among many and is unconfirmed [1–5].
• “Your mind is connected to the universe, so your thoughts shape reality.” Penrose and Hameroff speculate that consciousness is tied to the structure of space-time [1]. That is a far cry from saying intentions steer events or bodies. See “Quantum healing” and the observer effect.
• “Microtubule research proves meditation or energy healing works.” None of the studies cited here tested meditation, Qigong or healing.
• “Consciousness survives because it is quantum information.” That idea goes well beyond anything Orch-OR experiments have tested.

For the wider picture of quantum effects in living things, see Quantum biology: what’s real, and why your body isn’t a quantum computer. For what entanglement can and cannot do, see Quantum entanglement explained, without the mysticism.

How this relates to the Six Healing Sounds, Qigong and neigong

Label for this section: Tradition only (for Qigong concepts) · Speculative (for any quantum link).

Resonance Heritage Qi makes no quantum claims, and nothing in our practice depends on whether Orch-OR turns out to be right or wrong. Qigong and neigong work with attention, intention (yi), breath and movement. Their ideas about mind and qi come from Chinese tradition. They are traditional concepts, not scientific findings.

It can be tempting to read Orch-OR as scientific backing for inner practices. We think any such link is, at most, a metaphor: the hypothesis is unconfirmed, and even if it were confirmed it would describe how brains produce experience, not show that a particular practice has particular effects. If the vibrations in microtubules make you think of sound, What resonance really is explains the everyday physics of vibration and resonance, which is a different and much better understood topic.

Resonance Heritage Qi is a personal, music-assisted practice inspired by Liu Zi Jue: connected to it, not a replacement for the traditional form or for study with a teacher of that tradition.

Sources

1. Hameroff S, Penrose R, 2014. Consciousness in the universe: a review of the “Orch OR” theory. Physics of Life Reviews 11(1):39–78. https://doi.org/10.1016/j.plrev.2013.08.002
2. Tegmark M, 2000. Importance of quantum decoherence in brain processes. Physical Review E 61:4194–4206. https://doi.org/10.1103/PhysRevE.61.4194
3. Hagan S, Hameroff SR, Tuszyński JA, 2002. Quantum computation in brain microtubules: decoherence and biological feasibility. Physical Review E 65:061901. https://doi.org/10.1103/PhysRevE.65.061901
4. Reimers JR, McKemmish LK, McKenzie RH, Mark AE, Hush NS, 2009. Weak, strong, and coherent regimes of Fröhlich condensation and their applications to terahertz medicine and quantum consciousness. Proceedings of the National Academy of Sciences 106:4219–4224. https://doi.org/10.1073/pnas.0806273106
5. Donadi S, Piscicchia K, Curceanu C, Diósi L, Laubenstein M, Bassi A, 2021. Underground test of gravity-related wave function collapse. Nature Physics 17:74–78. https://doi.org/10.1038/s41567-020-1008-4
6. Khan S, Huang Y, Timuçin D, Bailey S, Lee S, Lopes J, et al., 2024. Microtubule-stabilizer epothilone B delays anesthetic-induced unconsciousness in rats. eNeuro 11(8):ENEURO.0291-24.2024. https://doi.org/10.1523/ENEURO.0291-24.2024
7. Huang Y, Qiu Z, Yu X, Lee S, Zeng X, Chang A, Wiest MC, 2026. Brain-penetrant microtubule-stabilizer epothilone B delays isoflurane-induced unconsciousness in mice. Neuropharmacology 287:110834. https://doi.org/10.1016/j.neuropharm.2026.110834
8. Kalra AP, Benny A, Travis SM, Zizzi EA, Morales-Sanchez A, Oblinsky DG, et al., 2023. Electronic energy migration in microtubules. ACS Central Science 9(3):352–361. https://doi.org/10.1021/acscentsci.2c01114
9. Babcock NS, Montes-Cabrera G, Oberhofer KE, Chergui M, Celardo GL, Kurian P, 2024. Ultraviolet superradiance from mega-networks of tryptophan in biological architectures. Journal of Physical Chemistry B 128(17):4035–4046. https://doi.org/10.1021/acs.jpcb.3c07936
10. Craddock TJA, Kurian P, Preto J, Sahu K, Hameroff SR, Klobukowski M, Tuszynski JA, 2017. Anesthetic alterations of collective terahertz oscillations in tubulin correlate with clinical potency: implications for anesthetic action and post-operative cognitive dysfunction. Scientific Reports 7:9877. https://doi.org/10.1038/s41598-017-09992-7

Source quality note: [1] is a review by the hypothesis’s authors; [3], [8] and [10] include Hameroff and/or Penrose as co-authors; [6] and [7] come from one research group and explicitly interpret their results in favour of Orch-OR. [2] and [4] are critical theoretical analyses, and [5] is an independent experiment on the collapse model that Orch-OR relies on. [6] and [7] are animal studies; [8] and [9] use purified proteins; [10] is computer modelling. No source measured quantum coherence in a living brain. None studies health or Qigong.