Three of the most anticipated and ambitious technological developments of the 21st century are artificial general intelligence (AGI), net positive nuclear fusion, and practical quantum computing. This question asks whether these three technologies will be realized by the end of 2039.

• AGI is a hypothetical machine that can perform any intellectual task that a human can, such as reasoning, learning, planning, and creativity. AGI is considered a major milestone in artificial intelligence research, as it would enable machines to understand and interact with the world at a human-like level. Some experts estimate that AGI could be achieved by 2030, while others are more skeptical.

• Nuclear fusion is a process that combines light atomic nuclei into heavier ones, releasing enormous amounts of energy. Unlike nuclear fission, which splits atoms and produces radioactive waste, nuclear fusion is clean and virtually limitless. However, achieving net positive nuclear fusion, where the energy output from the fusion process and the operations of the entire facility exceeds the energy input required to initiate it, has been a longstanding challenge for scientists and engineers. The most promising project in this field is the International Thermonuclear Experimental Reactor (ITER), which aims to produce 500 megawatts of fusion power from 50 megawatts of input power by 2035.

• Quantum computing is a paradigm that exploits quantum-mechanical phenomena, such as superposition and entanglement, to perform operations on data. Quantum computers have the potential to solve problems that are intractable for classical computers, such as cryptography, optimization, simulation, and machine learning. However, building a large-scale quantum computer that can run error-free algorithms is still a formidable task. Several companies and institutions, such as Google, IBM, Microsoft, and China’s University of Science and Technology, are competing to achieve quantum supremacy, which is the point where a quantum computer can outperform a classical one on a specific problem.