‘Closed time-like curves’ are just the ticket if you want to travel in time. Theoretically, a sufficient distortion of spacetime could make a time machine possible, but Irina Aref’eva and Igor Volovich (Steklov Mathematical Institute, Moscow) take the idea out of the purely theoretical by suggesting that the Large Hadron Collider set to debut this summer at CERN may provide sufficient energy to create a tunnel through time. A tiny tunnel, to be sure, sufficient solely for subatomic particles, but a possible demonstration of wormhole concepts that on a far larger scale could one day prove productive for fast transportation to distant places and remote times.
But as to the argument that the LHC’s operations could establish Year Zero for time travelers (creating the needed first instance of a time machine to which future travelers would be able to return), I’ll take a pass. Surely if massive energies are what it takes to establish such a wormhole (itself a purely theoretical concept, and one that requires yet another theoretical idea — phantom energy — to hold it open), then the universe has supplied us with previous instances of ‘closed time-like curves’ in highly energetic events reaching back to the Big Bang. Does that mean a time traveler could only travel back 13.7 billion years? If so, that’s plenty of temporal territory to play in, but the Fermi question equivalent for time travelers is, where are they?
Every time I run an Enceladus story, another one emerges, this time a demonstration that that on-again, off-again subterranean ocean may actually be there. Or maybe, given the size of the Saturnian moon, we should call it a subterranean ‘lake.’ Cassini team member Jürgen Schmidt (University of Potsdam) and team have been studying the process by which ice particles from the moon’s geysers form and work their way through cracks in the crust to reach the surface. Says Schmidt:
“Since Cassini discovered the water vapor geysers, we’ve all wondered where this water vapor and ice are coming from. Is it from an underground water reservoir or are there some other processes at work? Now, after looking at data from multiple instruments, we can say there probably is water beneath the surface of Enceladus.”
According to Schmidt’s study, an internal lake at a temperature of about 273 degrees Kelvin (O degrees Celsius) is the best way to make sense of what we see coming out of Enceladus’ geysers. The model invokes ice grains condensing in a vent following evaporation from a liquid body of water, consistent with the steady production of ice particles Cassini sees. The possibilities for life within Enceladus seem to shift with every passing paper, but that’s to be expected as we work out a model that multiplies conceivable biospheres in the outer Solar System. The paper is Schmidt et al., “Slow dust in Enceladus’ plume from condensation and wall collisions in tiger stripe fractures,” Nature 451 (February 7, 2008), pp. 685-688 (abstract).
Speaking of outer planet moons, I see that NASA will be running tests on a robotic probe called the Environmentally Non-Disturbing Under-ice Robotic Antarctic Explorer (ENDURANCE) in a few days at Lake Mendota (on the campus of the University of Wisconsin). The long-range goal is to establish whether the autonomous vehicle’s systems might be suitable for operating under the ice of Europa, mapping the local environment and taking samples of microbial life. The plan is to ship the probe to Antarctica for further tests later in the year. All of which takes on growing significance as we work out the huge theoretical question of whether life may not take hold in environments once thought barren, with implications that are obvious for what is going on around other stars.
Orbiting Frog has the 40th Carnival of Space, and while I usually try to point to stories of particular interest for interstellar purposes, the highlight of this week’s carnival may well be the collection of space wallpapers on the Orbiting Frog site itself. Most are simply gorgeous, reminding me that in addition to the beauties of theory, a deeper response to the glories of the cosmos must also include simple awe.