northanger (northanger) wrote,

Bekenstein Bound

Bekenstein Bound via Corpus Mmothra

One piece of evidence that nature is discrete is something called the holographic principle. This leads some of us physicists to use the word information even when we don't really know what we're talking about but it is interesting and worth exposing. It comes from an idea called the Bekenstein Bound, a conjecture of Jacob Bekenstein that there is more and more theoretical evidence for. The Bekenstein Bound says that if I have a surface and I'm making observations on that surface —that surface could be my retina, or it could be some screen in front of me — I observe the world through the screen, at any one moment there's a limitation to the amount of information that could be observed on that screen. [Lee Smolin...]

Jacob David Bekenstein (born May 1, 1947) has contributed to the foundation of black hole thermodynamics and to other aspects of the connections between information and gravitation. Bekenstein was born in Mexico City. He is Polak Professor of Theoretical Physics at the Hebrew University of Jerusalem, a member of the Israel Academy of Sciences and Humanities, and a recipient of the Rothschild Prize. —Wikipedia

Elephants' odd shrieks preceded tsunami via darknews

Jongkrit now believes the elephants, which for centuries thrived in this region, have a sense of the sea that shouldn't be ignored. Some scientists think that elephants, as well as other animals, can tune in low- frequency vibrations that might precede a tsunami. Five minutes before the tsunami hit the coast, the elephants, secured by chains around their front ankles, began screaming again. One of them broke free and ran uphill. Another one carrying tourists on its back also bolted. [Denver Post...]

So who is conscious and who isn't? via the cabal

Here's a thought that some may find interesting. In the study of emergence, complex adaptive systems combine the work of relatively simple agents to organize themselves into something greater than the some of its parts. As examples in his book "Emergence: the Connected Lives of Ants, brains, cities and software," Steven Johnson discusses how the ant colony is smarter than any ant, how people organize themselves into cities and software into systems.

What features do all these systems share? In the simplest terms, they solve problems by drawing on masses of relatively stupid elements, rather than a single, intelligent "executive branch." They get their smarts from below. In a more technical language, they are complex adaptive systems that display emergent behavior. In these systems, agents residing on one scale start producing behavior that lies one scale above them: ants create colonies; urbanites create neighborhoods, simple pattern recognition software learns how to recommend new books. The movement from low-level rules to higher-level sophistication is what we call emergence.

The question I am posing here is what do you think will emerge from the connecting together of billions of brains over something like the internet? Will we even be aware of it? Think of the individual ant that doesn't understand the complexity of the colony it lives in. How will we even know when something like a world brain emerges and what kind of consciousness, or something greater than consciousness, takes over the global population?

The Moral Centre Doesn't Count by undercurrent

This is our problem. We are unable to submit ourselves to currency, believing it to be an empty and vacuous form of exchange (rather than the endlessly convoluting and fascinating numerical game that it obviously is). Rather than submitting to its magical power to elevate and ruin people and to create and dissolve bonds by purely arithmetical means, we invent this ironical dimension of interiority to save our souls.

Universal upper bound on the entropy-to-energy ratio for bounded systems

Gravitational entropy is one of the most intriguing concepts that have emerged from much recent work on quantum fields in curved space-time and quantum gravity. Its most striking manifestation occurs in Hawking’s radiation process by black holes, in which it is connected with the area of the event horizon. Even though this area behaves very much like entropy, two obstacles have stood in the way of attempts to understand the still mysterious connection between area, a geometrical quantity, and entropy, a thermodynamic one. First, since its very inception, black-hole entropy has seemed to be numerically much larger than the entropy of any ordinary system of like mass. Thus, a solar-mass black hole has black-hole entropy 1020 times the sun’s thermal entropy. Is it not preposterous to think there is a common denominator in two quantities so unlike in size? Second, even if the two entropies are of like origin, how can one hope to express black-hole entropy in statistical terms (the logarithm of a number of interior states or configurations) when that task evidently demands a full accounting of all that could possibly happen inside the hole?

In this paper we address only the first difficulty, We point out that it arises from the insistence in comparing black holes with nonrelativistic systems. When compared to relativistic systems of massless particles, black holes do not have inordinately large entropy. Rather, black-hole entropy is revealed as matching the maximal entropy for a given mass of more ordinary systems:

There is no gap in magnitude between black-hole entropy and ordinary entropy. This comes about because of the existence of a hitherto unnoticed upper bound to the entropy-to-energy ratio of non-black-hole systems of given effective radius R (see Sec. II for definition): {formula}. Making this bound plausible is our main task in this paper.

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