New Proof Reveals Extremal Black Holes Are Possible

For decades, the existence of extremal black holes—those with maximum spin or charge relative to their mass—was deemed impossible by prominent physicists including Stephen Hawking. This belief was based on the assertion that a black hole's surface gravity could not decrease to zero in a finite time, which would be necessary for the formation of such black holes. However, recent work by Christoph Kehle and Ryan Unger has challenged this long-held view, demonstrating that the laws of physics do not preclude the formation of extremal black holes. Their research involved modeling a non-rotating, uncharged black hole placed in a scalar field, where they found that it was possible to increase the black hole's charge faster than its mass, thus achieving extremality. The implications of this discovery are significant, as it not only disproves the previous hypothesis but also suggests that extremal black holes can exist without leading to naked singularities, a concern among physicists. The researchers' findings indicate that by adding the right amount of charge to a dense cloud of charged matter, an extremal black hole could form. This breakthrough has been described as a counterexample to the third law of black hole thermodynamics, which had previously been thought to be unassailable. While the theoretical possibility of extremal black holes has been established, the researchers caution that proving their existence in nature will require new mathematical frameworks and ideas. The excitement surrounding this discovery reflects a shift in understanding the limits of black hole physics and opens new avenues for exploration in gravitational theory. In summary, Kehle and Unger's work not only challenges established beliefs but also invites further investigation into the nature of black holes and the fundamental laws governing them.