AmateurRadio.com

Take a front-seat view of the Sun in this 30-minute ultra-high definition movie in which NASA SDO gives us a stunning look at our nearest star.

This movie provides a 30-minute window to the Sun as seen by NASA’s Solar Dynamics Observatory (SDO), which measures the irradiance of the Sun that produces the ionosphere. SDO also measures the sources of that radiation and how they evolve.

SDO’s Atmospheric Imaging Assembly (AIA) captures a shot of the sun every 12 seconds in 10 different wavelengths. The images shown here are based on a wavelength of 171 angstroms, which is in the extreme ultraviolet range and shows solar material at around 600,000 Kelvin (about 1 million degrees F.) In this wavelength it is easy to see the sun’s 25-day rotation.

The distance between the SDO spacecraft and the sun varies over time. The image is, however, remarkably consistent and stable despite the fact that SDO orbits Earth at 6,876 mph and the Earth orbits the sun at 67,062 miles per hour.

Scientists study these images to better understand the complex electromagnetic system causing the constant movement on the sun, which can ultimately have an effect closer to Earth, too: Flares and another type of solar explosion called coronal mass ejections can sometimes disrupt technology in space. Moreover, studying our closest star is one way of learning about other stars in the galaxy. NASA’s Goddard Space Flight Center in Greenbelt, Maryland. built, operates, and manages the SDO spacecraft for NASA’s Science Mission Directorate in Washington, D.C.

Charged particles are created in our atmosphere by the intense X-rays produced by a solar flare. The solar wind, a continuous stream of plasma (charged particles), leaves the Sun and fills the solar system with charged particles and magnetic field. There are times when the Sun also releases billions of tons of plasma in what are called coronal mass ejections. When these enormous clouds of material or bright flashes of X-rays hit the Earth they change the upper atmosphere. It is changes like these that make space weather interesting.

Sit back and enjoy this half-hour 4k video of our Star!  Then, share.  🙂

73 dit dit

Economists see scarcity, supply and demand as fundamental forces in a market. Items that are scarce demand a higher price while items that are easy to obtain tend to have a lower price.  A diamond is an example of something that is relatively scarce (and in demand) so it commands a high price. In contrast, wood is generally available and is much less expensive than diamonds.

Then there’s the concept of artificial scarcity. If some items can be made scarce (or even just appear scarce), the price will tend to increase. For example, if I own all of the banana trees on an isolated island, I could reduce the available supply of bananas and command a higher price from all of the banana eaters there. Or maybe I start screening bananas for quality and I put a special sticker on them to brand them as special.

We have a case of artificial scarcity in ham radio, called the DXCC list. This list defines what is considered a separate country when chasing DX. (Actually, the correct term is entity, not country.) For example, Hawaii (KH6) and Alaska (KL7) are considered separate entities even though they are part of the United States. (See Is Alaska a Country?) For someone chasing DXCC entities, because Alaska is on The List, a radio contact with Alaska becomes more desirable. It’s kind of like putting a “premium sticker” on a banana to indicate that it is special.

In my imagination, the DXCC list resulted from a bunch of hams sitting around drinking beer and bragging about how many countries they had worked. One guy, Larry says he just worked Hawaii, bringing his total to 125 countries. His buddy Leroy says, “You can’t count Hawaii because it’s part of the US of A.”  To which Larry says, “You bet I can count Hawaii…and Texas too. It’s a whole ‘nuther country.” Clearly, we are going to need an official list to keep track of what counts as a country.  A more credible version of how the list got established is captured in this article from the October 1935 QST.

Of course, the two main factors that drive scarcity of DXCC entities is the ham radio population and ease of access. Radio contacts are easy to make with entities that have an active ham population. If an entity doesn’t have many active hams but is easy to get to, someone will probably put that location on the air once in a while.  On the other hand, some locations are unpopulated and really difficult to get to. These are not only on The List, they are on The Most Wanted List.

Kingman Reef (KH5) was just deleted from The List, instantly changing it from one of the most desired contacts in amateur radio to a big giant Why Bother. You see, there used to be 340 countries on the list but now there’s only 339. Kingman Reef will now be considered part of Palmyra/Jarvis, so it still has value for DXCC, just a lot less.

As I write this article, there is a major DXpedition (VKØEK) operating from Heard Island, an unpopulated island near Antartica. The only reason those guys are there is that Heard Island is on The List. Take a look at their web site and you’ll see how much time and energy has gone into activating this lonely island. Drop it from the list and suddenly a radio contact with this location is a lot less in demand.

So try to keep this all in perspective. There are lots of radio contacts out there to be made, some more interesting and desirable than others. It is appropriate and necessary that we have the DXCC list, to provide consistency in how we count countries, I mean entities. But really, it all traces back to Larry and Leroy arguing about who worked the most countries.

Thanks to the dedicated DXpeditioners that put these rare locations on the air.

73, Bob K0NR

The post DX, Artificial Scarcity and The List appeared first on The KØNR Radio Site.