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Solar eclipses have been recorded since ancient times, often misunderstood by early observers as a dragon eating the Sun or some omen of things to come. Although we have learned the true nature of eclipses in modern times, they never cease to amaze astronomers and the public alike. You can visualize solar and lunar eclipses using a Wolfram Demonstration.
Solar eclipses happen when the Moon moves between the Earth and the Sun. The Moon blocks the Sun’s light, which puts a kink into our daily expectations, making it get dark during the day. A fuzzy estimate puts the frequency of total solar eclipses at about one or two per year. This number can vary quite a bit. Often, these eclipses are only visible along narrow paths that are in out-of-the-way places that make it difficult for them to be observed (e.g. over the open ocean). Cruise ships are often booked for the sole purpose of chasing these solar eclipses for those people willing to set sail and pay the money to do so.
On May 20 of this year, people in the western United States and Pacific Ocean islands will be in a position to observe one of these solar eclipses without having to travel on the high seas.
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Since its creation, Wolfram|Alpha has constantly grown to cover more and more topic areas. Now, it includes some functionality that may be useful for people interested in lumber. Most of us are used to going into a local home improvement store and seeing large collections of construction lumber, but before it gets into those stores, it has to be cut from logs. An important step in the process is determining how much lumber can be obtained from a log of a given size. There is no single method for estimating this, but there are a number of empirical formulas that are commonly used to estimate the volume of lumber that can be obtained from a log given its diameter and length. Typically, these estimates are rounded to the nearest 5 or 10 board feet. Three of the most common empirical rules are the Doyle Rule, the Scribner Rule, and the International 1/4-inch log rule. Different regions tend to use different rules, so it’s up to users to decide which one they want to use.
It’s spring and I am ready for it. In the last few years I have come to love gardening and the general outdoors more so than I ever have in the past. Something about spending time in the warm sunlight, getting your hands dirty, and being in touch with nature is relaxing. I’ve found myself paying more attention to many green things around my yard that I would have previously just dismissed as a “weed.” Now I find that many of these things are not only beneficial, but in some cases edible. We at Wolfram|Alpha recently decided that we needed to beef up our plant coverage to include more than just, primarily, taxonomic information. Wolfram|Alpha now makes use of data from the USDA that includes information, mainly qualitative, that gardeners and botanists might find more useful. More »
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At about 6pm CST on March 6, there was a very powerful X 5.4 solar flare. This triggered a coronal mass ejection (CME). Indications were that the CME wasn’t squarely directed at Earth, but that a strong glancing blow to the Earth’s magnetosphere was possible. Here’s the data in Wolfram|Alpha for the flare:
There are two X-class flares during this time range. The effects of the first flare hit the Earth on March 7 and was a minor glancing blow, but caused a geomagnetic storm with effects visible in northern latitudes. More »
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(Update: You can now find this data in the Wolfram Cat Breeds Reference App for iOS.)
Famed amateur astronomer David H. Levy once stated, “Comets are like cats; they have tails, and they do precisely what they want.” I’m a cat person and this seems to fit. Comets have a somewhat unpredictable nature to them, making it nearly impossible to determine how they will perform from one apparition to the next. This seems like a fitting description of cats as well, based on personal experience with my three cats. After recently diving into data on dog breeds, the natural next step would be to explore cat breeds.
Cat fancy is a rather popular activity, perhaps only slightly less popular than dog competitions. As with dog breeds, there are a number of accepted breeds that take part in competitions. We have gathered data from Cat Fanciers’ Association (CFA) and The International Cat Association (TICA) along with other sources to provide coverage on a majority of cat breeds.
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(Update: You can now find this data in the Wolfram Dog Breeds Reference App for iOS.)
Since prehistoric times, mankind has kept certain animals nearby for companionship, assistance in hunting tasks, and defense. Dogs are probably the most well-known examples of companion animals. This habit has continued to modern times and has resulted in a high number of dog breeds created for a variety of purposes. One modern convention is the concept of dog competitions. With the 2012 Westminster Kennel Club Dog Show beginning today (more on this below), we thought this would be a good time to highlight some of the information Wolfram|Alpha has to offer concerning dog breeds:
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Early on June 7, 2011, the Sun once again showed signs of waking up from the last solar minimum: it unleashed a powerful solar flare. The x-ray emission from this flare can be seen in Wolfram|Alpha:
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We humans often notice the passage of time by observing our watches; the movement of the Sun, Moon, and stars across the sky; or by the records left by our ancestors in diaries or other historical records—but these are just fleeting moments in the eyes of geological time. We are used to thinking about recorded history. But recorded history is just a blink when compared to the length of time called pre-history. Recorded history only goes back a few thousand years. The Earth is far older.
It’s hard for humans to grasp just how long the Earth has been here. Using a variety of methods, geologists have been able to put together many pieces of a very complicated puzzle. After all, how do you assemble a puzzle when you’re not sure what the finished picture should look like? From studying processes that are happening today, such as geological composition, rates of deposition, weathering, climatology, biology, and Earth’s magnetic field, geologists can extend these processes back to ancient times and learn what the Earth was like billions of years ago. When combined with data points such as those found in the fossil record, these extrapolations can be constrained, and the picture starts to emerge from the puzzle. More »
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As you go about your day, especially during the hot summer season, you probably don’t think much about the Sun other than that it makes you want to go for a quick dip in the swimming pool to cool off. After all, the Sun rises and sets every day (for those of us outside the Arctic and Antarctic Circles), and people just take it for granted without much thought.
The Sun is far more dynamic than you might think, although thankfully we don’t usually feel direct effects of its activity from Earth’s surface. The atmosphere and magnetic field of the Earth provide a nice buffer zone that protects us.
Every 11 years, the Sun completes a cycle that is fairly regular. During solar maximum, the number of sunspots is higher than usual, and during solar minimum (which we are just coming out of), it is relatively spot free.
The Sun is still coming out of solar minimum, but activity is slowly returning. At about 8:55 UTC on August 1, a measurable solar flare triggered an event known as a coronal mass ejection (CME). This is where the “atmosphere” of the Sun sends out a burst of energized plasma. In this case, nearly the entire Earth-facing side of the Sun was involved, so effects on the Earth are more likely. Here’s the X-ray signature of the solar flare that triggered the CME:
Wolfram|Alpha’s coverage of the universe continues to grow. We have now added a large collection of observed supernovae in the universe to our ever-expanding compendium of astronomical knowledge.
What exactly is a supernova? It’s a catastrophic event in the life of a star.
The full details are very complex, but basically supernovae are the visible signs of the deaths of stars more massive than the Sun. As with all other stars, massive stars spend most of their lives fusing hydrogen gas into helium in their cores. This results in a buildup of “ash” (end product of fusion reactions) in the core that eventually chokes off the hydrogen fuel from the hottest area of the core. With no new fuel, there is less energy being produced to counter the gravity trying to squeeze the star’s huge mass more tightly together. The result is that the star’s core begins to collapse as gravity overtakes the outward pressure. This results in heating the core—eventually enough that the ash can begin fusing into heavier molecules, initially carbon and oxygen. The cycle repeats, each time beginning and ending with different products and creating the next fuel source. Eventually, the core contains iron. Iron cannot liberate energy from fusion, so at this point, energy generation in the core suddenly stops, and the full mass of the star comes crashing down and a shock wave rips the star apart. This explosion is called a Type II supernova and results in the formation of a neutron star (or more rarely a black hole). More »
