Well, we are on our way back to the observatory and look forward to catching up on the current schedule of physics colloquia and OCA events. We didn't quite get to see the glorious auroras that we were able to see in Edmonton, Canada, now almost 20 years ago, where the aurora appeared as curtains of light that shimmered and moved about as if they were actually going to come down and touch us. Oh, well we hope to see that on our future Northern Lights cruise up the coast of Norway in 2019. But while we were on the ship we were always glad to look for the aurora in Sharon.
Now, Sharon is not a constellation, but she was one fun lady, who we always liked seeing aboard the ship. Check out her green aurora streaks below. Especially after staying up and checking the sky for auroras every hour or so on many nights and not seeing anything, it was always nice to notice Sharon about the ship in the morning.Thanks for sharing your fun loving self, Sharon! Now, Resident Astronomer Peggy is considering this hair treatment the next time she is at the hair dressers.
|Fun-loving Sharon's aurora streaks were always visible aboard the ship, even if not visible outside|
Our flight path back to the observatory brought us in view of the Ivanpah solar power towers outside of Las Vegas, Nevada. The three towers and surrounding heliostats generate about 392 MW of electric power. This is the second time that our flight paths brought us over this region and when we can't get aisle seats, looking out the window is usually enjoyable.
|All three towers, at Ivanpah Solar Power Facility near Las Vegas, glow as seen from airplane (Source: Palmia Observatory)|
Now, back at the observatory, we can review some of the DSLR long time exposures of the northern lights. The previous presentation of some of the photos of September 24 and 27 was posted by taking an IPhone photo of the DSLR Liveview screen. I had hoped that being able to review the actual DSLR images would provide more detail. It seems the ship motion is apparent especially even when the ship was at anchor at Qaqortoq, Greenland, The lights of the city can be seen to dance back and forth and up and down in the 15 second exposure.
|10-second exposure shows visible aurora from Viking Sea stateroom (Source: Palmia Observatory)|
|15-second exposure from Viking Sea at anchor in Qaqortoq, Greenland (Source: Palmia Observatory)|
We received several questions and comments regarding our previous discussion of the latest cosmic ray research. Remember that we had discussed an article in Astronomy Magazine that reported how the latest observations indicated that the source of the cosmic rays is indeed mostly outside of our own Milky Way galaxy.
Gravity Guy, Ken, raised he issue regarding the statistical nature of the evidence and the predicted location, while establishing that the sources are mainly outside the Milky Way, might eventually be found to not be significant. Telescope still packed in the Garage, Frank, wondered about the source of cosmic rays and, given how energetic they are at our distance, what impact it might have on the host galaxy and anything living there. Since no one knows the source of cosmic rays or the process under which such energetic particles are produced, we will just have to wait and see. Modern physics as probed at the Large Hadron Collider, is so much lower in energy than that of these high energy cosmic rays, that the physics of generating such high energy is not understood. Thanks for those comments and questions, Ken and Frank!
Well, now back in the observatory, I looked up my copy of the original article, which was published in Science, 22 September 2017. The original article by the Pierre Auger Collaboration described the evidence collected at the Pierre Auger Observatory in Malargue, Argentina, over the last 12 years of operation. The data consisted of 30,000 cosmic rays detection events and the anisotropy and predicted location of the source significant to 5.2 sigma, which is very good significance. The also discussed the method used to establish the predicted location, which includes doing a Fourier analysis of the measured right ascension of each event and then calculating where the most probable location was to be found.
I can't help to wonder that 30,000 events measured from a moving Earth, in a galaxy with a magnetic field that will cause some deflection of all but the highest energy cosmic rays, is perhaps just not enough data to establish firmly the actual nature of the source. Could it be the case that the predicted location is just now the location of one of the events that produce high energy cosmic rays and that maybe a 100 years or thousands of years from now, another source will pop off in a different location so that eventually the sources are distributed uniformly about the universe? I obviously don't know, but it is what I wonder about. The article talks about the need for more data. They report that the measured Z value, which is the number of protons in the atom, was found to lie between 1.7 and 5.0. Again we just have to wait and see.
Moved to the mountains for better seeing, David, commented on the white parallel streaks described in the previous post and how he has seen many photos of streaks. Yes, the streaks seem to be quite common and my first Google search just identified Langmuir as the first to describe how they are caused by the wind. He apparently also observed seaweed trapped in the vortices in the surface sea water and the whiteness apparently caused by the same as for white caps on wind driven waves. Thanks for following up on that David!
Finally, as we got back to the observatory, our friends at Amazon had already delivered a copy of the textbook, "Physics from Planet Earth", that Searching for Gravity Waves, Dr. Gary , had found and recommended. Indeed it is a great physics textbook covering classical mechanics and its benefit for astronomer wannabes is that the examples used are from recent and old astronomical observations and really help to see how the observations are interpreted in terms of the physics. The associated website, now posted on this blog site's recommended website list, shows more discussion and homework and often covers more of the technical details. Pretty neat, so check out your own copy if it fits your interest.
|Great new textbook that covers classical mechanics with examples from astrophysics|
Ok, and finally, on a personal note, for those of you wondering what the weight damages were on the cruise, I can say that in my case it was only 5 pounds weight gain. It's hard to be in a fun environment where the staff makes your bed, cleans up the cabin, makes all sorts of delicious food and drink and desert and serves included wine with lunch and dinner. Now we are back in this alternate reality where we have to do all the daily chores ourselves go back on a revised eating plan to let go of those five pounds or more.
Until next time,