by Jenny L. Nielsen
"Almost every kind of object in space spins," says Tod Strohmayer of NASA's Goddard Space Flight Center, from "planets and stars [to] galaxies." Yet, until very recently, some of the most massive objects in space--the ever omniprescent black holes--were considered a possible exception.
Essentially, a black hole is a great, cosmic whirlpoorl in the fabric of space-time, typically formed by a collpased super-massive star. Anything passing beyond a black hole's event horizon is sucked into the black hole's singularity, a point of infinite density and curvature of space at the hole's center. Thanks to Dr. Tod Strohmayer, astronomers now have evidence that at least some black holes also spin--sometimes very quickly--wrapping the fabric of space-time around them as they go.
Dr. Strohmayer made his discoveries while studying black holes using NASA's Rossi X-Ray Timing Explorer. While observing one black hole given the rather impressive label "GRO J1655-40," a microquasar* 10,000 light years from Earth, he noticed unusual patterns in its X-Ray radiation previously observed only in spinning neutron stars. According to astronomers, this type of radiation could only have been produced by incredibly hot gas dancing around the black hole in a very lively orbit--in this case, oscillating at a speed of 450 hertz (cycles per second). As Stroymayer himself puts it, "the only way for it [GRO J1655-40] to produce [these] oscillations is if it is spinning."
What is the significance of this new spin factor? Just ask astrophysicist and popular science writer, John Gribbin. Dr. Gribbin, who had anticipated the discovery of rotating (or "Kerr") black holes long ago, wrote about their many tantalizing possibilities in his book Unveiling The Edge of Time. As he explains in Chapter 6 of this book, a rotating black hole has "a peculiarity all of its own--the singularity in its center is not a point [as in the traditionally static, non-rotating black hole models], but a ring." Point-like singularities are highly dangerous; anything passing through them would undoubtedly be "spaghettified"--astrophysicist jargon for strung out through space-time like an infinitely long piece of spaghetti. On the other hand, in the case of rotating black holes, "a daring space traveler may even dive [through the ring singularity] and live to tell the tale" (see Unveling the Edge of Time, page 160). At least in the realm of theory, rotating black holes may actually be traversible.
If you make it a habit of hanging out with theoretical astrophysicists in your free time--or at least if you're a great fan of science fiction--you would know that this opens up infinite horizons of possibility. No one knows what's on the other side of black holes, but modern theories imply that they may bridge different areas of our universe, or even--as Stephen Hawking postulates--different universes. As John Gribbin puts it, if you had a spinning black hole at your finger-tips, "in principle it would be possible for you to travel from where you are sitting now to any place in the Universe and any time past, present, or future that you wish, if only you could find the right route to follow."
Unfortunately, the only known rotating black hole being approximately 10,000 light years from Earth, the current prospects for this sort of intergalactic time travel is very low .One cannot help wondering, however, if someday, scientists may have sufficient technology to actually create one of these cosmic whirlpools for themselves. It actually is not outside the realm of possibility; many valid papers in the scientific community, most notably those by Dr. Kip S. Thorne, have postulated that--for a significantly advanced civilization--artificial black holes could be made and put to use.
Yes, indeed--the unsailed seas beyond the event horizon have just gotten much more interesting.
©2002 Jennifer L. Nielsen
All Rights Reserved
*A microquasar is a specific type of black hole with jets of high-speed particles shooting perpendicularly from the plane of matter that orbits it.