In a week of historical happenings, this article on black holes and “naked singularities” (i.e., whereupon singularities, the tiniest prick of what’s left of a star collapsed upon itself, is without the veil-like event horizon that separates us from any encounter with or knowledge about it) is easily the most interesting thing I’ve encountered all week.
Another possibility is that singularities may really have an infinite density after all that they are not things to be explained away by quantum gravity but to be accepted as they are. The breakdown of general relativity at such a location may not be a failure of the theory per se but a sign that space and time have an edge. The singularity marks the place where the physical world ends. We should think of it as an event rather than an object, a moment when collapsing matter reaches the edge and ceases to be, like the big bang in reverse.
In that case, questions such as what will come out of a naked singularity are not really meaningful; there is nothing to come out of, because the singularity is just a moment in time. What we see from a distance is not the singularity itself but the processes that occur in the extreme conditions of matter near this event, such as shock waves caused by inhomogeneities in this ultradense medium or quantum-gravitational effects in its vicinity.
Obviously, considering the crowd this blog draws, this idea has some potential philosophical relevance. Or, as Adam said when we were talking about this, “Quick, somebody email Agamben this article, NOW!”
I rather like this bit especially:
To explore how naked singularities might provide a glimpse into otherwise unobservable phenomena, we recently simulated how a star collapses to a naked singularity, taking into account the effects predicted by loop quantum gravity. According to this theory, space consists of tiny atoms, which become conspicuous when matter becomes sufficiently dense; the result is an extremely powerful repulsive force that prevents the density from ever becoming infinite [see "Follow the Bouncing Universe," by Martin Bojowald; Scientific American, October 2008]. In our model, such a repulsive force dispersed the star and dissolved the singularity. Nearly a quarter of the mass of the star was ejected within the final fraction of a microsecond. Just before it did so, a faraway observer would have seen a sudden dip in the intensity of radiation from the collapsing star a direct result of quantum-gravitational effects.
Would that we all, upon our demise, effectively exploded.
There is something rather beautiful, and indeed ecological, about the notion of death, the singularity that is fully our own, and thus in a way where we are fully ourselves, as a similar “extreme condition,” whose effects on everything surrounding is without adequate measure.
Monday, January 26, 2009 at 2:22 pm
Lee Smolin speculates in Life of the Cosmos that black hole singularities involve the generation of another universe, which is really fascinating.
I just read this story last week, suggesting the universe is a giant hologram, which blew me away:
http://www.newscientist.com/article/mg20126911.300-our-world-may-be-a-giant-hologram.html?page=1
For many months, the GEO600 team-members had been scratching their heads over inexplicable noise that is plaguing their giant detector. Then, out of the blue, a researcher approached them with an explanation. In fact, he had even predicted the noise before he knew they were detecting it. According to Craig Hogan, a physicist at the Fermilab particle physics lab in Batavia, Illinois, GEO600 has stumbled upon the fundamental limit of space-time – the point where space-time stops behaving like the smooth continuum Einstein described and instead dissolves into “grains”, just as a newspaper photograph dissolves into dots as you zoom in. “It looks like GEO600 is being buffeted by the microscopic quantum convulsions of space-time,” says Hogan.
If this doesn’t blow your socks off, then Hogan, who has just been appointed director of Fermilab’s Center for Particle Astrophysics, has an even bigger shock in store: “If the GEO600 result is what I suspect it is, then we are all living in a giant cosmic hologram.”
The idea that we live in a hologram probably sounds absurd, but it is a natural extension of our best understanding of black holes, and something with a pretty firm theoretical footing. It has also been surprisingly helpful for physicists wrestling with theories of how the universe works at its most fundamental level.
The holograms you find on credit cards and banknotes are etched on two-dimensional plastic films. When light bounces off them, it recreates the appearance of a 3D image. In the 1990s physicists Leonard Susskind and Nobel prizewinner Gerard ‘t Hooft suggested that the same principle might apply to the universe as a whole. Our everyday experience might itself be a holographic projection of physical processes that take place on a distant, 2D surface.
More…
Monday, January 26, 2009 at 7:01 pm
Time to dust off that old forgotten copy of Flatland.