Out in Space and Inside a Collider
CHAPTER 64 Knowns and Hypotheticals
At the end of the year I look forward to Discover magazine's choices of the 100 top stories of the year. I was pleased to see in the January/February 2016 issue of Discover the choice as the number one top story is NASA's New Horizons probe of the demoted planet Pluto. The most recent photos I've seen indicate the possibility of towering ice volcanoes, indicating that Pluto once was warm enough to harbor liquid water. With much more data scheduled to be downloaded in the coming year, we can look forward to more fascinating findings about Pluto and its moons.
I was intrigued and amused by the number 100 story, headlined "This Is the End", telling of a study involving the use of the fabulous time machine we call the telescope. Using the telescope we can see what was happening in distant galaxies billions of years ago or look at closer galaxies and see what was happening just thousands or millions of years ago. An international team of astronomers studied over 200,000 galaxies, measuring the light from these galaxies at 21 different wavelengths of light from the infrared to the ultraviolet. These studies showed that 2 billion years ago the galaxies were producing twice as much energy as they are today. This fits in with the scenario that our universe will end up as cold, empty darkness. Not to worry. Our sun will burn out long before that happens.
Speaking of endings, on the Discover Web site there was a report by Nathaniel Scharping about a star being swallowed by a black hole. It was the first time that a star had been detected being sucked towards a black hole and the astronomers actually followed the star as it headed to its demise. When the star disappeared into the black hole there was what was described as a "cosmic burp", a flare of radiation! While such flares had been seen before around black holes, to have followed the star being gulped down was a real plus.
In contrast to the actual observation of a stellar event, there are cases where a leap of faith is required, not to mention a high level of imagination and scientific expertise. Let's say we're looking for a new planet orbiting a star outside our solar system. One of the methods we've discussed before is straightforward. We look at the light from the star continuously and if a planet orbits the star between us and the star, as it passes between us it will dim the light coming from the star. So, if we monitor the light we will see a dip in the light every time the planet comes between us and the star. We have to be careful that the star doesn't have "sunspots" that can lighten or darken, looking like a planet is passing by. That's one reason NASA wants several orbits before confirming the presence of a planet from Kepler or other spacecraft data.
Well, in an article titled "Rings of a Super Saturn" in the January 2016 issue of Scientific American, Matthew Kenworthy describes his work with Eric Mamajek and Mark Pecaut on a star they call J1407 in the constellation Centaurus. The light curve for this star was very odd in that the light would flicker unpredictably for many nights and then fade to be almost invisible for days and the return to its usual brightness. The article shows the plot of the light intensity over a period of months and it's totally unintelligible to me, with lots of irregular dips and periods of low levels of light. The researchers were totally puzzled by the curve but finally thought what about a giant Saturn-like ringed system?
Sure enough, when they made computer models of such a ringed system, tilted at an angle to the orbit around the star, the dips and rises in the light curve began to fall into place. When they match dips in the light with their model they count at least 24 rings but think the actual number is more like a hundred. Because of poor observing conditions they can't monitor the light continuously. Even more interesting is that their model shows a gap in the rings that suggests the formation of a moon. If so, it would be the first moon found outside our solar system.
The article stresses that the existence of the ringed planet and a possible moon is hypothetical but points out that J1407 is a bright star easily visible in the Southern Hemisphere and observers with small telescopes can monitor the brightness on a more continuous basis. The researchers are also searching archives of stargazing for data that might reveal other ringed systems.
I'll mention another hypothetical item - a claim that a super Earth planet in our solar system is out there way beyond Pluto. This claim has been met with major skepticism so I won't dwell on it further.
I've marveled in the past about the patience needed by members of the space community when it comes to waiting years or decades for their project to come to fruition. The many years the New Horizons crew had to wait to see if it got to Pluto in working condition is an example. Another example requiring the utmost patience is the quest to detect the gravitational waves predicted by Einstein's general theory of relativity, which he published on December 2, 1915. How appropriate that, almost to the day 100 years later, on December 3, 2015, the European Space Agency (ESA) launched its LISA Pathfinder mission, a mission designed to pave the way for a LISA mission, possibly to be launched about 20 years from now! The purpose of the LISA mission will be to detect those elusive gravity waves. I first learned of the Pathfinder launch from our Christmas card from the Webers in California. Earlier this year I mentioned a surprise visit from Bill and Barbara Weber, whose son is working in Italy and is involved in the LISA Pathfinder project.
LISA stands for Laser Interferometer Space Antenna, the laser interferometer being the instrument that will be used in the mission find gravity waves. A visit to the ESA Website boggled my mind with what they hope to accomplish. In the Pathfinder two identical gold-platinum cubes about the size of golf balls will be released to float in a free-fall state 38 centimeters apart and the job of the laser instrument is to measure the distance between the cubes. The laser interferometer is a complex system of laser beams bouncing off the surfaces of the cubes and is expected to be able to measure the distances between the cubes to within a billionth of a millimeter! If the experiment is successful, it would pave the way for ultimate LISA launch decades from now to actually detect gravity waves.
Finally, finishing on another hypothetical note, just a couple of weeks ago it was announced that two teams working at the Large Hadron Collider (LHC) may (underscore "may") have found a new particle. After finding the Higgs boson last year, the LHC was upgraded to bang particles together at even higher energies and finding a new particle could end up being a game changer in the world of physics. It might even be a particle involved in carrying those gravity waves or perhaps a particle related to the mysterious dark matter. I gather that normally the scientists would not have announced their findings at this stage but, because the two teams have both observed some cases of the same result, it's more likely the result is significant. You can be sure the teams at the LHC will be banging particles together at a furious pace to confirm the existence of this new particle.
Happy New Year. Let's hope 2016 treats humanity and our environment more kindly than it did this past year. Next column, hopefully, on or about February 1.
Allen F. Bortrum