A recent paper claims Earth's rotation could be harnessed for power using a "gravity engine," theoretically generating terawatts of energy by raising and lowering massive weights as the Earth rotates. This concept, building on decades-old physics, hinges on the Coriolis effect. However, many physicists are skeptical, arguing that the proposed mechanism violates fundamental laws of physics, particularly conservation of angular momentum. They contend that any energy gained would be offset by a minuscule slowing of Earth's rotation, effectively transferring rotational energy rather than creating it. The debate highlights the complex interplay between gravity, rotation, and energy, with the practicality and feasibility of such a gravity engine remaining highly contested.
A recent scientific discourse has ignited a debate within the physics community regarding the potential to harness energy from the Earth's rotation. The central argument revolves around a proposed device, conceived by researchers at the U.S. Army Engineer Research and Development Center, which seeks to exploit the Coriolis force, an inertial effect observed in rotating reference frames like our planet. This force, responsible for the deflection of moving objects (like air currents and projectiles) to the right in the Northern Hemisphere and to the left in the Southern Hemisphere, is typically considered a "fictitious force" in classical mechanics, meaning it arises from the frame of reference itself rather than a direct physical interaction.
The proposed mechanism, as detailed in the researchers' published work, envisions a large, rotating platform analogous to a carousel. Theoretically, by carefully controlling the angular velocity of this platform relative to the Earth’s rotation, one could potentially generate usable energy from the interaction with the Coriolis force. This concept, while seemingly intriguing, has drawn considerable skepticism from other physicists who argue that the Coriolis force is not a true source of energy but rather a consequence of the Earth’s rotational inertia. They contend that any apparent energy extracted from the Coriolis effect would, in reality, be derived from the energy required to maintain the rotation of the platform itself, ultimately resulting in a zero-sum or even negative energy gain when accounting for system losses.
The core of the disagreement stems from differing interpretations of the Coriolis force and its role in energy transfer. Proponents of the energy-harvesting concept posit that the Earth’s rotation represents a vast reservoir of kinetic energy, a portion of which could be tapped into via a cleverly engineered device. Their calculations suggest that under specific conditions, the Coriolis force could induce a net torque on the rotating platform, thereby generating mechanical energy. However, critics argue that this interpretation misrepresents the fundamental nature of the Coriolis force. They maintain that while the Coriolis force can influence the motion of objects within a rotating frame, it cannot perform work in the same way as a true force like gravity or electromagnetism. Therefore, they argue, any attempt to extract energy from the Coriolis effect would be analogous to attempting to extract energy from inertia itself, a fundamentally flawed proposition.
The ongoing debate highlights the complexities of understanding and applying fundamental physical principles, particularly in rotating reference frames. While the possibility of harnessing the Earth’s rotation for energy generation remains a tantalizing prospect, the current consensus within the physics community leans towards skepticism. Further research and rigorous experimental validation are necessary to definitively settle the controversy and determine the true potential, if any, of this novel approach to energy harvesting.
Summary of Comments ( 130 )
https://news.ycombinator.com/item?id=43526443
Hacker News users discuss a Nature article about a controversial claim that Earth's rotation could be harnessed for power. Several commenters express skepticism, pointing to the immense scale and impracticality of such a project, even if theoretically possible. Some highlight the conservation of angular momentum, arguing that extracting energy from Earth's rotation would necessarily slow it down, albeit imperceptibly. Others debate the interpretation of the original research, with some suggesting it's more about subtle gravitational effects than a large-scale power source. A few commenters mention existing technologies that indirectly utilize Earth's rotation, such as tidal power. The overall sentiment seems to be one of cautious curiosity mixed with doubt about the feasibility and significance of the proposed concept. A few users engage in more playful speculation, imagining the distant future where such technology might be relevant.
The Hacker News post "Can Earth's rotation generate power? Physicists divided over controversial claim" sparked a discussion with several interesting comments. Many commenters engaged with the core concept of extracting energy from Earth's rotation, exploring its theoretical feasibility and practical implications.
Several commenters pointed out the existing methods of harnessing energy derived from Earth's rotation, primarily through tidal power. Tides are a direct consequence of the gravitational interaction between Earth, the Moon, and the Sun, and their cyclical nature allows for predictable energy generation. This led to discussions about the distinction between directly tapping into rotational energy versus utilizing its indirect effects.
Some users questioned the novelty of the proposed mechanism in the linked Nature article, arguing that any method of extracting energy from Earth's rotation would necessarily involve interaction with another celestial body, thereby slowing Earth's rotation. They emphasized the fundamental principle of conservation of angular momentum, implying that extracting usable energy would require transferring some angular momentum away from the Earth.
A significant point of contention revolved around the scale of energy that could realistically be extracted and its impact on Earth's rotation. Some commenters expressed skepticism about the practicality of generating substantial power without causing significant, albeit extremely gradual, changes to the length of a day.
A few commenters delved into more technical aspects, referencing concepts like Lenz's law and the inherent inefficiencies involved in energy conversion processes. They also discussed the potential environmental impact of any large-scale attempt to harness rotational energy.
Finally, some users expressed a general sense of caution regarding sensationalized scientific claims, emphasizing the importance of peer review and rigorous validation before drawing definitive conclusions. They also highlighted the difference between theoretical possibilities and practical, economically viable implementations.