Physical limits and the long-term future (with Anders Sandberg)
Spencer Greenberg speaks with Anders Sandberg about the relationship between energy use and economic growth, the theoretical limits of computation and physics (like the Landauer limit and speed of light), and the implications of these concepts for the long-term future of civilization.
Deep Dive Analysis
18 Topic Outline
The Relationship Between Global Energy Use and GDP Growth
Decoupling Energy Consumption from Economic Productivity
Jevon's Paradox and the Rebound Effect of Energy Efficiency
Hypothetical Impact of Early Nuclear Energy on Societal Trajectory
Biological Trade-offs: Energy for Speed vs. Efficiency in Healing
The Landauer Limit: Fundamental Energy Cost of Information Erasure
The Potential and Challenges of Reversible Computing
Using Physical Limits to Speculate About the Far Future
Understanding the Speed of Light Limit and Its Causality Implications
Wormholes, Quantum Gravity, and the Nature of Spacetime
Virtual Particles and Quantum Field Theory
Explaining Complex Scientific Concepts to a Lay Audience
The Second Law of Thermodynamics: Entropy and Probable States
Misinterpretations of Entropy in Societal and Futures Thinking
Energy Conservation and Noether's Theorem on Symmetries
Energy Conservation Breakdown in Cosmology and Expanding Universe
Long-Term Energy Sources: From Stars to Black Holes
Rapid Fire: Alien Civilizations, S-Risks, and Cultural Backups
8 Key Concepts
Landauer Limit
The Landauer Limit is the minimum amount of energy required to erase one bit of information in an irreversible computation. This energy is converted into waste heat, establishing a fundamental link between information processing and thermodynamics.
Reversible Computing
Reversible computing is a theoretical model where every operation can be inverted, meaning no information is lost and, in principle, no energy is expended due to entropy increase. It requires tracking extra information to allow operations to be unwound, but practical implementation faces challenges with speed and error correction.
Jevon's Paradox
Jevon's Paradox describes an economic phenomenon where increased efficiency in resource use, such as energy, leads not to a decrease in overall consumption but to an increase. This occurs because the resource becomes cheaper and more widely adopted, leading to greater total usage.
Speed of Light Limit
The speed of light limit is a fundamental constant in relativity theory, representing the invariant maximum speed at which information or matter can travel. Exceeding this speed would lead to causality violations, such as the theoretical ability to send information backward in time.
Second Law of Thermodynamics
This principle states that the total entropy (disorder or number of possible microstates) of an isolated system can only increase over time, or remain constant in ideal reversible processes. It implies that systems naturally tend towards more probable, disordered states, like mixed coffee and milk.
Noether's Theorem
Noether's Theorem is a mathematical theorem stating that for every continuous symmetry of a physical system, there is a corresponding conserved quantity. For instance, the time-invariance of physical laws leads to the conservation of energy, while spatial invariance leads to momentum conservation.
Suffering Risks (S-risks)
Suffering risks are scenarios where future advanced civilizations might generate vast amounts of extreme suffering, potentially outweighing any positive outcomes. This concept emphasizes the moral weight of suffering and suggests caution in actions like spreading life across the universe.
Panspermia
Panspermia is the hypothesis that life exists throughout the universe, distributed by cosmic bodies like meteoroids and asteroids. It suggests that bacterial spores or other forms of life could travel between planets or even star systems, potentially seeding new worlds.
12 Questions Answered
While historically GDP per capita and energy use per capita were tightly coupled, especially until the 1970s, it's possible to decouple them. Most of civilization's activities could be run more efficiently, as many processes are far from thermodynamic limits.
Some argue that focusing on energy efficiency rather than better energy extraction methods (like nuclear) after the 1970s may have led to a slowdown in productivity growth, potentially preventing advancements like flying cars. However, it's not clear why this would affect non-industrial sectors like marketing.
This phenomenon, known as Jevon's paradox, occurs because when a resource like energy becomes cheaper due to efficiency gains, people tend to use more of it rather than saving it, leading to a net increase in consumption.
Relativity theory postulates that the speed of light is an invariant speed that all observers agree upon. If something could move faster than light, it would lead to causality violations, such as sending information backward in time.
While quantum field theory models use concepts like virtual particles and wormholes (at the Planck scale) to make accurate predictions, these are often mathematical contrivances that describe how reality behaves, rather than direct evidence of their actual existence.
Energy conservation, explained by Noether's theorem as a consequence of the laws of physics being invariant over time, is generally true locally. However, on the largest cosmological scales, in an expanding universe, energy conservation breaks down, leading to phenomena like redshift where energy effectively disappears.
It is almost certain that technologically advanced alien civilizations exist due to the vastness of the universe, but they are likely very sparsely distributed, and we may not encounter them for billions of years.
A plausible explanation is that the universe is very sparsely inhabited because most biospheres struggle to evolve complex organisms, often getting stuck at the single-cell prokaryote stage.
While individuals have virtues, humanity as a whole may not currently be 'virtue-apt.' However, by creating coordination structures, societies could develop virtues like intellectual honesty or environmental care (e.g., not driving species to extinction), which are better ascribed to societies than individuals.
Both AI systems and societies/companies are complex adaptive systems with powerful optimization abilities. If their objectives are misaligned, they can produce dangerous outcomes. Understanding incentive design and structural mechanisms for good behavior in one domain can inform the other.
While spreading life might seem like a good idea, considering 'suffering risks' (S-risks) suggests caution. If spreading life could lead to vast amounts of suffering, it might be a very bad idea. It's advisable to develop the technology but hold off on deployment until the ethical implications are thoroughly considered.
Human civilization needs to significantly improve its methods for making backups of data and culture. Currently, much vital information is vulnerable due to reliance on private institutions and lack of cohesive preservation efforts, risking a 'digital dark age.'
25 Actionable Insights
1. Improve Digital & Cultural Backups
Actively work to create more robust and cohesive systems for backing up digital data and cultural information, moving beyond reliance on single private institutions or corporate data centers. This ensures the preservation of critical knowledge for future generations and as a safeguard against civilizational disruptions.
2. Assess Suffering Risks in Expansion
Before expanding life across the universe, carefully evaluate the potential for generating immense suffering, especially if adopting an ethical framework that prioritizes the avoidance of suffering. Consider the moral implications of creating vast amounts of conscious experience.
3. Deliberate Before Spreading Life
Do not rush to spread life into the universe without careful consideration. The moral stakes are extremely high, and a thorough ethical and practical assessment is warranted before taking such a potentially irreversible action.
4. Utilize Open Systems for Order
Recognize that in an open system, you can locally reduce entropy and organize things by leveraging energy flow and expelling waste heat to the wider universe. This principle allows for complex organization despite the overall increase in universal entropy.
5. Leverage Limits for Future Rigor
When making predictions or decisions about the future, especially the long-term, seek out and understand fundamental theoretical limits (e.g., laws of physics). These limits provide a solid, rigorous foundation for analysis, even if current understanding of them might evolve.
6. Bound Civilization by Energy Budget
Understand that the amount of useful work a civilization can do is fundamentally bounded by its available mass-energy and its ability to dump waste heat. Use this principle to assess the potential activities and limits of future civilizations.
7. Explore Black Hole Power Potential
Recognize that fusion, while powerful, only converts a small fraction of mass into energy. For ultimate energy extraction, consider methods like carefully dumping mass into black holes, which can convert a much larger percentage of mass into usable energy.
8. Use Incentives for AI Alignment
Leverage principles of incentive design, typically used to ensure good behavior in companies and markets, to align complex AI systems. Foster interdisciplinary collaboration between AI safety, economics, and political science to develop effective alignment mechanisms for both AI and human-cyborg composite systems.
9. Foster Civilizational Virtues
Recognize that virtues can be ascribed to groups and societies, not just individuals. Actively work to create coordination structures within humanity that enable the development of ‘virtue-apt’ civilizations capable of embodying virtues like intellectual honesty or environmental stewardship.
10. Optimize Services for Efficiency
Recognize that many services and computing processes are tremendously inefficient and far from thermodynamic limits. Actively seek to improve efficiency in terms of energy, transport, and organization within services to achieve decoupling and run civilization more efficiently.
11. Prioritize Reversible Operations
Understand that only irreversible operations, where information is lost, inherently cost energy due to entropy increase. Aim to design systems and processes with reversible operations where possible to minimize energy expenditure.
12. Budget for Error Correction Energy
Understand that error correction is an inherently irreversible and energy-costly operation. Even in highly efficient or reversible systems, account for the energy budget required for error correction, as it will likely be a significant long-term cost.
13. Factor Imperfection into Design
Recognize that ‘in principle’ theoretical efficiencies (like reversible computing) are often limited by real-world imperfections and constraints like temperature and speed. Be prepared to make trade-offs, potentially using less efficient irreversible processes, to achieve practical results within time limits.
14. Anticipate Surprises, Use Current Limits
While using current understanding of physical limits as a starting point for future planning, remain open to the possibility that these limits might be revised or proven wrong. Expect ’nasty surprises’ and adapt as new knowledge emerges.
15. Consider Early Life Great Filter
When contemplating the sparsity of alien civilizations (Fermi paradox), consider the hypothesis that the ‘Great Filter’ might occur early in the evolution of life, where most biospheres fail to evolve beyond simple single-cell organisms.
16. Balance Green Efficiency with Speed
When pursuing green initiatives or energy efficiency, be aware of the trade-off between energy consumption and speed. Achieving high efficiency (e.g., lower temperature processes) often requires sacrificing speed.
17. Embrace Slower, Controlled Growth
Understand that rapid growth, while seemingly efficient, can invite problems (e.g., cancer in biological systems). A slower, more controlled approach to building or developing things might be beneficial to avoid unintended negative consequences.
18. Manage Internal Resource Competition
Recognize that even within a unified mission, different parts of an organization or system will compete for resources when priorities are set. Acknowledge the ‘grumbling’ that arises when resources are constrained, even if the overall decision is rational.
19. Heed Counter-Intuitive Math
Learn from historical examples where counter-intuitive mathematical predictions (like antiparticles) turned out to be real. Be willing to take mathematical results seriously, even if they suggest very strange or unexpected aspects of reality.
20. Distinguish Model Failure from Reality
Develop the ability to discern whether a model is simply broken and producing nonsense, or if it’s accurately reflecting a weird pattern of reality. This critical discernment is a hallmark of high-quality thinking.
21. Prioritize Clear, Objective Explanations
Strive for explanations that are robust and hold true regardless of personal beliefs or biases. Use analogies carefully, ensuring they clarify rather than introduce ’noise’ or confusion into understanding.
22. Beware Misapplied Scientific Metaphors
Be cautious of taking scientific results (especially from physics or math) metaphorically and then reifying them as literal truths to justify unrelated concepts. Ensure that scientific principles are applied accurately and not just for rhetorical convenience.
23. Declare Intuition’s Role Explicitly
When constructing arguments, especially in philosophy, be transparent about where intuitions are being relied upon. Unacknowledged reliance on intuition can weaken arguments and make them less apparent.
24. Differentiate Truth from Behavior
Understand that if you cannot distinguish between something being truly X and merely behaving as if it were X, then you don’t truly know if X is correct. This highlights the importance of empirical testability and avoiding premature conclusions about underlying reality.
25. Strive for Utmost Clarity
In any complex discussion or explanation, the most effective approach is to be as clear as possible. This helps mitigate biases and ensures that arguments and concepts are understood accurately.
6 Key Quotes
The noise in the background of a reality, that's all erased bits. They're still here, but they're kind of impossible to unscramble from each other.
Anders Sandberg
Reality is under no obligation to obey beautiful mathematics.
Anders Sandberg
Shut up and calculate.
Anders Sandberg
You know, funnily enough, I find that when people have kind of crackpot theories of physics, they're usually less weird than the real theories of physics. They're usually trying to make things less confusing than actual reality.
Spencer Greenberg
Well, it's a lesson that sometimes we've got to take the math seriously, even if the math says very weird stuff.
Spencer Greenberg
But expressing it so it doesn't sound like the ravings of a lunatic or somebody very high on Mariana is tricky.
Anders Sandberg