In April and May we wrote about “inflation” and the latest claim for observational evidence. To recap briefly, inflation is the exponential expansion of the early universe during the earliest fraction of a second after the Big Bang. Theory tells us that it should leave a telltale observational signature in the polarization of the cosmic microwave background radiation (CMB). In March a team from the Harvard Smithsonian Center for Astrophysics (CfA) in Cambridge, Massachusetts claimed that they had unambiguously detected the polarization signature using a specialized instrument at the South Pole known as BICEP2. (In the land of all things acronym, that stands for the 2nd generation Background Imaging of Cosmic Extragalactic Polarization instrument!) In last month’s column we noted that there were still questions to be answered before accepting the result, and that it might be fun to watch the arguments to ensue. Here we go!
It seems the BICEP2 team processed their data by subtracting foreground polarization by dust within our own galaxy from their signal. The foreground measurements came from a European Space Agency (ESA) probe called Planck. However they didn’t have access to the actual Planck data, which have not yet been published. Rather, they scanned a map of the Planck results from a slide presented at a talk, assuming that the map showed only radiation from local dust. Apparently, it did not … which would make the map they used look less polarized, and make the BICEP2 team’s results look more polarized. In other words, the results presented with great fanfare in March may themselves be spurious. Oops.
We need to remember here that scientific research is a self-correcting enterprise. The CfA team is standing by their results. The Planck data will be released in October, including a corrected map of local contributions. Then we’ll have a better idea of whether we’ve seen direct evidence for inflation or not. Even if the answer is “not” – inflation still remains the best explanation for the vast body of indirect evidence for the character of the very early universe.
Lunar phases for June: First Quarter on the 5th, at 3:40 pm EDT; Full Moon on the 12th, at 11:12 pm (the rest of US time zones will see this on the 13th!); Last Quarter on the 19th, at 1:40 pm; New Moon on the 27th, at 3:10 am.
Predawn planet watchers will find Venus rising to the east about 90 minutes before sunrise early in the month. It rises a bit earlier each day and appears higher in the sky. It will be hard to miss, outshining the rest of the “stars” fading with the twilight. In the evening you should easily find Saturn to the southeast as darkness gathers. Mars is higher to the south, and Jupiter is setting to the west. Later in the month Saturn will emerge from twilight higher and to the south, with Mars a touch lower to the southwest.
Our mid-month view, about three hours after sunset, will find Hercules the closest constellation to zenith. This is not a constellation marked by any exceptionally bright stars, rather your eye will probably be drawn about 30 degrees toward the eastern horizon where Vega is the brightest star in the constellation Lyra. Ursa Major is to the northwest, with the “handle of the Big Dipper” high above the “bowl” – follow this curved line westward to Arcturus, which is above the west-southwest horizon. Low to the northeast you’ll see the familiar crooked W shape of Cassiopeia. Turning to the east, look for Cygnus, with Deneb marking the tail of the Swan to the left and Albireo marking the head to the right. Altair is below Albireo, to the east-southeast.
Find Saturn to the south, and note that it is flanked by two reddish stars. The one to the left and a bit below is Antares, the brightest star in Scorpius. Its name means “rival of Mars” and it’s easy to see why this month, since Mars itself is to the right of Saturn, just past Spica in the constellation Virgo.
If readers have questions about astronomy or science in general that you would like to see covered in one of these columns, please feel free to contact me at email@example.com.
Copyright 2014George Spagna