Zenith Grant Awardee
Donald Marolf
University of California, Santa Barbara
Project Title
Black hole information and firewall singularities
Project Summary
In 1976, Stephen Hawking discovered that black holes evaporate, radiating away their energy over extremely long periods of time. According to his calculations, this radiation contains essentially no information regarding the formation of the initial black hole. This is in sharp contrast to familiar processes such as burning a piece of paper where, though extremely difficult to accomplish in practice, fundamental principles of physics tell us that that full information about the paper can in principle be reconstructed from the full set of debris (including all heat, light, sound, ashes, etc) produced in the paper\'s demise. This work reexamines the question of whether Hawking radiation contains similar information and explores associated consequences. A positive answer, as apparently predicted by string theory, would likely have dramatic consequences for spacetime at the edge of a black hole. A negative answer would likely involve something like the production of new universes. With either result, studies of this information problem lead to fundamental lessons that may impact our understanding of space, time and physics far beyond black holes themselves.
Technical Abstract
Recent developments have emphasized the dramatic consequences of the idea that Hawking radiation might carry information out of black holes. This work will therefore revisit foundational aspects of the black hole information problem. It will first attempt to improve models of and/or sharpen criticisms of the idea that black-hole evaporation might be non-unitary (i.e., that information falling into a black hole is \'lost,\' in the sense that it is not re-emitted in the Hawking radiation). Second, it will study the way the AdS/CFT correspondence encodes quantum information in order to better determine whether it provides a good model for all possible theories of gravity, especially in regard to black hole information. Third, it will explore the extent to which generalizations of quantum mechanics (or other structures) can/cannot alleviate tensions surrounding black hole evaporation. Finally, it will attempt to extract further lessons from the assumption that horizons of sufficiently old black holes undergo the kind of dramatic change that seems to be required for information to be emitted.
QSpace Latest
PressRelease: Shining a light on the roots of plant “intelligence”
All living organisms emit a low level of light radiation, but the origin and function of these ‘biophotons’ are not yet fully understood. An international team of physicists, funded by the Foundational Questions Institute, FQxI, has proposed a new approach for investigating this phenomenon based on statistical analyses of this emission. Their aim is to test whether biophotons can play a role in the transport of information within and between living organisms, and whether monitoring biophotons could contribute to the development of medical techniques for the early diagnosis of various diseases. Their analyses of the measurements of the faint glow emitted by lentil seeds support models for the emergence of a kind of plant ‘intelligence,’ in which the biophotonic emission carries information and may thus be used by plants as a means to communicate. The team reported this and reviewed the history of biophotons in an article in the journal Applied Sciences in June 2024.