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Category Archives: Astronomy
The Power of a Simple Magnifying Glass
Introduction My favorite radio program is Science Friday. Last week, their web page included an excellent video where Science Friday's resourceful intern, Flora Lichtman, gave a wonderful explanation behind the use of a lens to concentrate the Sun's power. Her … Continue reading
Posted in Astronomy, Fiber Optics
2 Comments
Super Full Moon
One of the engineers just stopped by and told me that Saturday (19-Mar-2011) we will have a "Super Full Moon". This means we will have a full moon and it will be unusually large (14% wider). See this link for … Continue reading
Neat Pictures from Mars and the Moon
One of my favorite blogs is written by Emily Lakadawalla for the Planetary Society. I was looking at some of her old material and found some pictures that I had never seen and I thought I would share with my … Continue reading
Daily Loss of Solar Mass
Introduction I occasionally work with customers on using solar power to drive some of their remote optical interfaces. These remote interfaces are used to monitor things like pipelines. In one case, it was used to provide Internet service to a … Continue reading
Posted in Astronomy
2 Comments
Calculating the Density of a Planet
Quote of the Day Democracy is the theory that the common people know what they want, and deserve to get it good and hard. — H. L. Mencken Introduction I have been reading some interviews with Michel Brown, an astronomer … Continue reading
Computing the Age of the Universe
Introduction While in the lunch room at work, I often look at the paper. The paper one day this week had an article on the farthest object that has yet been observed by astronomers. One of the guys in my … Continue reading
Posted in Astronomy
2 Comments
Pope Gregory XIII and Dual Modulus Counters
I discussed a recent dual-modulus counter design in a previous post. I had not thought much about the history of these counters, but I noticed that our calendar is really a dual-modulus counter. Pope Gregory XIII (Figure 1) established the Gregorian calendar (1582) to resolve issues with the Julian calendar. The reason that calendar development is complicated is because a solar year is 365.24219879 days long, which is not easily expressed in terms of simple integer ratios. Ideally, a calendar system is chosen that is simple and that has a mean year length exactly equal to that of a solar year. While not ideal, the Gregorian calendar provides a simple and fairly accurate approximation to a solar year through the use of a dual-modulus counter design based on years with durations of 365 and 366 days. Continue reading
Calculating the Earth's Age
I have been listening to the audio book The Disappearing Spoon, which is an excellent tale about all of the elements of the periodic table. Of particular interest to me was the discussion of how geologists date the age of the Earth using ratios of uranium and lead. The book also discusses determining the ages of meteorites and the Sun. The discussions were interesting enough that I thought I would look up some additional information. As frequently happens, I was amazed at the amount of information on the web about this subject. This technique has been around since 1956, when it was first used to date meteor fragments from a well-known impact site (Figure 1). Continue reading
Posted in Astronomy, General Science
Tagged Geology, Radioactive Dating
Comments Off on Calculating the Earth's Age
Solar Eclipse Math
A couple of weeks ago, I was watching the Wonders of the Solar System with Brian Cox on the Science channel.In this episode, he was talking about the Moon and solar eclipses. He made a comment that the region of totality (i.e. complete darkness) during a solar eclipse is only a few hundred kilometers across. To illustrate this point, I found a great picture (Figure 1) taken from the Mir space station of the moon's shadow on the Earth. Continue reading