Help me obi Juan whoever you are, you’re my only Ho Unless you’ve been living under a rock, your first introduction to the concept of holograms was probably Leia’s message to Obi-Wan in Star Wars IV: A New Hope (unless your first introduction to holograms was Tupac, in which case. . . I feel old). Although to be clear, Tupac’s Coachella performance in 2012 was not actually a hologram—it was a 2D video projected on a seemingly invisible screen. We don’t actually have the technological capability yet to create real holograms—that is a 3D image projected from a 2D light…
Comments closedTag: Hawking radiation
The last couple of weeks, I’ve been discussing the potentially destructive implications of Hawking radiation, the mechanism by which black holes slowly decay. One of the most pressing implications is the information paradox. A core tenet of quantum physics, the conservation of quantum information, demands that quantum information is not ever destroyed or created. But Hawking radiation seems to defy this rule. Information that enters a black hole becomes irretrievable, but it’s not destroyed. But, when a black hole evaporates into random thermal radiation, what happens to that information? One of the most popular theories involves all the information inside…
Comments closedFrom my last two blog posts on Hawking radiation and the conservation of quantum information, it’s clear that we have a major problem on our hands—the information paradox. We know that black holes decay over unimaginable timescales, seemingly erasing quantum information in the process. But we also know that quantum information has to be conserved. Theoretically, at least, we have to be able to trace particles back through their quantum histories. If black holes were entirely stable, then we could consider this condition met. While the information in a black hole would be inaccessible, it wouldn’t be destroyed. But if…
Comments closedHave you ever thought about what happens to all the information you delete from your computer’s hard drive? You might be surprised to discover that deleted files aren’t actually erased. Even when you delete a file from your computer’s trash folder, your computer holds onto the file while erasing the file name and its listing in any directories. The file itself remains on your hard drive, functionally irretrievable (without special software) until it is overwritten when the hard drive needs that data space. At that point, your data is actually irretrievable. That portion of the hard drive’s disk space has…
Comments closedIn last week’s post on entropy, I blithely referred to black holes as spontaneously increasing in entropy. This may seem counterintuitive (as much as anybody can have “intuition” about black holes). If we view the increase in entropy as a system moving from order to disorder, how would a singularity become more disordered? How could the contents of a black hole spread out in a more disordered manner if they are supposed to take up an infinitely small amount of space? If we use the other definition of entropy, the dispersal of energy, then that would imply that a black…
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