More on the Solar Storm

There are some pictures of the active region at discovermagazine.com as well as some information here and here.

I hope they don’t mind if I use this picture, but I thought it was interesting.

See how small the Earth is compared to a sunspot.

Here is a picture of the whole region.

And a warning.

That region is pretty feisty, and the odds of us getting more flares from those spots are pretty good. The Sun’s rotation is currently taking them toward the center of the disk, where a good sized explosion is then directed toward us, and particle waves from the blast can then interact more efficiently with our magnetic field. We may be getting aurorae from them, and if things go well that’s all we’ll get! A big blast can damage satellites, and even put astronauts on the ISS at risk. We on the ground are pretty safe, since the Earth’s air absorbs the radiation — that’s why we have to launch satellites like SDO into space, so they can detect that energy in the first place!

However, a big blast can shake the Earth’s magnetic field, inducing a current in the ground that can actually overload power lines. We can get blackouts from such things, and it’s happened before. This is a real problem that can do millions or even billions of dollars of infrastructure damage (including money in the economy lost during the blackout). I know a lot of solar physicists are concerned about this eventuality, and are trying to get both the power companies and the government to take it seriously. I hope they do. We’re still approaching the peak of the solar cycle sometime in mid-2013 or so, and flares like the one Saturday will most likely be more common.

Although, I am actually glad the Sun is getting more active. There were practically no sunspots during the period known as the Maunder Minimum, from 1645-1715, which coincided with the Little Ice Age. This last solar cycle, the Sun seemed to be a little too quiet and there was some speculation that we might be entering into another minimum.

Here is a chart of sunspot activity over the last few centuries. It is probably a better indicator of global climate changes than human carbon emissions, but don’t tell Al Gore that.

 

Rosh Hashanah

Today is Rosh Hashanah, the Jewish New Year and the first of the High Holy Days. To be more precise, Rosh Hashanah actually began yesterday evening, since the Jews have traditionally begun a new day at sunset. This holiday takes place on the first two days of the month of Tishrei in the Hebrew calender. Because the Hebrew calendar is a lunar calendar, the dates wander a bit in our Gregorian calendar. This year it takes place on  September 28-30. The New Year is celebrated for two days because of the difficulty of determining the precise day of the new moon.

Rosh Hashanah, which means “the head of the year”,  is not mentioned as such in the Bible. Instead the day is called “Zikaron Teru’ah” a memorial of the blowing of horns in Leviticus 23:24 and “Yom Teru’ah” the day of blowing the horn in Numbers 23:9.

 23 The LORD spoke to Moses: 24 “Tell the Israelites, ‘In the seventh month, on the first day of the month, you must have a complete rest, a memorial announced by loud horn blasts, a holy assembly. 25 You must not do any regular work, but you must present a gift to the LORD.’”  (Lev. 23:23-25)

1 “‘On the first day of the seventh month, you are to hold a holy assembly. You must not do your ordinary work, for it is a day of blowing trumpets for you. 2 You must offer a burnt offering as a sweet aroma to the LORD: one young bull, one ram, and seven lambs one year old without blemish.  3 “‘Their grain offering is to be of finely ground flour mixed with olive oil, three-tenths of an ephah for the bull, two-tenths of an ephah for the ram, 4 and one-tenth for each of the seven lambs,note 5 with one male goat for a purification offering to make an atonement for you; 6 this is in addition to the monthly burnt offering and its grain offering, and the daily burnt offering with its grain offering and their drink offerings as prescribed, as a sweet aroma, a sacrifice made by fire to the LORD. (Num 29:1-6)

I mentioned that the Hebrew calendar is a lunar calendar. That is not quite correct. A fully lunar calendar would be based solely on the phases of the moon would cycle through the year, as the Islamic Calender does. Instead, the Hebrew calendar is a lunisolar calendar. The twelve months add up to 354 days, so to keep up with the seasons extra, intercalary months are added in a nineteen year cycle. Seven intercalary months are added during the cycle so that a thirteenth month is added every two or three years. This means that the dates wander a bit compared to the Gregorian calendar but stay within the appropriate seasons.

Anyway, Shana Tova everyone.