Showing posts with label meteorology. Show all posts
Showing posts with label meteorology. Show all posts

Thursday, November 5, 2009

The Sky is Falling (on Sedom)!!!

Is it possible that an ancient tablet, currently in the British Museum, is actually a copy of what Avraham Avinu recorded the morning that Sedom was annihilated? Tablet K8538 is a clay tablet that many have referred to as "The Planisphere". It is clearly depicting some astronomical event that occurred many years ago as it contains a snapshot of the sky at a specific moment in time.

Although the tablet dates back to 700 B.C.E., the author of its cryptic message, clearly, was copying from an older text. The positions of the stars clearly show a date that is much older than the one attributed to the age of the tablet itself. If so, then one can conclude that the author was actually copying from a much earlier text.

Why would someone have bothered to copy some archaic and senseless picture of a night sky? Rather, it seems that this specific event must have been known and recorded over and over and the event recorded must have been something fantastic. With this in hand, one can appreciate some of the theories that have come about.

The tablet shows stars, planets and something streaking across the sky. Many have suggested that this must be a comet of some sort. It is clear that the observer was coming close to daytime based on the timing that can be seen from the celestial objects. There is also a plume of smoke that was drawn on one edge of the tablet.

The actual night in question and the exact year is subject to dispute. This mainly comes about because of the poor condition of the tablet and the inability to decipher all of the objects on the tablet. However, two scientists, Alan Bond and Mark Hempsell, have proposed that this observer saw a meteor entering the atmosphere. They suggest that he was located in the Middle East and, based on the trajectory of the object streaking across the sky, he saw a meteor that eventually impacted at Koefels in the Austrian Alps. This impact caused a massive plume of smoke that would have made its way all the way back to the Middle East.

This plume would have caused mass destruction and it was burning hot. It is fascinating, because it appears that Kofels has an impact crater that could match this exact scenario. I must concede, Bond and Hempsell place this event at a much earlier date than Avraham Avinu's lifetime (actually it would be in Enosh's lifetime, perhaps, the "flood" of his time since it came from the direction of the sea), but it is of note that the date is hotly contested. Also, with this event happening within biblical times and within the vicinity where the biblical events were recording, one would think that such a massive and destructive event would be recorded somewhere in the Torah.

The pesukim (Bereishis 19:27-28) record Avraham Avinu rising at dawn and watching toward the direction of Sedom and witnessing a pillar of smoke arising from that area. It is fascinating that the Torah records that aspect of the event and that Avraham Avinu would care to watch. Perhaps, he recorded it in order to have a document to share with others to convince them not to sin like those of Sedom. This may have become a famous document and been copied from generation to generation. Perhaps, this tablet is actually a copy of the original done by Avraham Avinu.

Monday, November 2, 2009

Davening at Neitz is Sometimes Just WRONG

The early bird may get the worm, but the late worm gets to live!!! Being early doesn't always mean better. While it is certainly true that one who davens right at neitz (sunrise, more properly called haNeitz) is doing something noble, one who davens right as he sees the sun rising may actual be worse off than someone who slept late. This is especially true this time of the year!

No, I am not talking about the silliness of having atomic clocks at a neitz minyan. While it is true that by davening at the exact time of listed sunrise (no matter how precise to the location one has calculated it for) is the most statistically improbable time for actual visible sunrise (based on barometric pressure and other weather disturbances), that is not what I am talking about. I am talking about someone who goes out and davens at the first visible sign of sunrise; the way it was done back in the times of the Gemara.

There is a phenomenon known as the Novaya Zemlya effect. Back in 1596 Willem Barentsz, the famous explorer, was sailing through the Arctic in search of a northeast passage. His unlucky crew got stuck in Novaya Zemlya (just north of Siberia), and had to stay there through the winter. As is the case above the Arctic Circle, the sun does not rise for a portion of the winter. The eager crew waited for sunrise and were anxious to be able to leave this frozen tundra.

Then in January of 1597 one of the crewmembers, Gerrit de Veer saw the sun peaking above the horizon. The fantastic thing about this was that this was TWO WEEKS before it was supposed to happen. Gerrit was the first person to record in writing what has now become known as the Novaya Zemlya effect.

The basic concept is that when there is a duration of warm weather immediately after a cold spell a mirage can appear on the horizon. This happens most often in spring and fall as the temperatures fluctuate a lot. The warm air creates a current near the horizon. It can be focussed right near the spot where the sun will rise (that is a warmer area). This current then acts as a lens and refracts the image of the sun from below the horizon to above it. Meaning, the sun looks like it rose even though it is really below the horizon. This sunrise often looks a little distorted, but someone with no knowledge of the effect would just think he was seeing a sunrise in a hazy patch in the sky.

While it seems clear that we take into account weather disturbances when calculating neitz, these are only the ones that are realtively small. Things like small weather disturbances and barometric pressure can affect visible sunrise and it seems that in the times of teh Gemara they based sunrise on visiblity. However, these only change sunrise by small amounts. The Novaya Zemlya effect can be very pronounced! So, before you get upset that you woke up early for nothing, make sure you know the difference between true and fake sunrise!!!

Another VERY VERY important fact that de Veer recorded. In fact, this one can even be life threatening!!! Eating polar bear livers can cause hypervitaminosis and can be fatal!!!