Show Notes for February 6, 2014

"can detect up to two-bit errors or correct one-bit errors without detection of uncorrected errors. By contrast, the simple parity code cannot correct errors, and can detect only an odd number of bits in error. Hamming codes are perfect codes, that is, they achieve the highest possible rate for codes with their block length and minimum distance 3."
"Due to the limited redundancy that Hamming codes add to the data, they can only detect and correct errors when the error rate is low. This is the case in computer memory (ECC memory), where bit errors are extremely rare and Hamming codes are widely used."
"Hamming codes can be extended by an extra parity bit. This way, it is possible to increase the minimum distance of the Hamming code to 4, which allows the decoder to distinguish between single bit errors and two-bit errors. Thus the decoder can detect and correct a single error and at the same time detect (but not correct) a double error. If the decoder does not attempt to correct errors, it can detect up to 3 errors."
"Hamming ECC is commonly used to correct NAND flash memory errors"

"codes are non-binary cyclic error-correcting codes […] described a systematic way of building codes that could detect and correct multiple random symbol errors. By adding t check symbols to the data, an RS code can detect any combination of up to t erroneous symbols, or correct up to ⌊t/2⌋ symbols. As an erasure code, it can correct up to t known erasures, or it can detect and correct combinations of errors and erasures."
"have since found important applications from deep-space communication to consumer electronics. They are prominently used in consumer electronics such as CDs, DVDs, Blu-ray Discs, in data transmission technologies such as DSL and WiMAX, in broadcast systems such as DVB and ATSC, and in computer applications such as RAID 6 systems"

creation of the world
Flood
Abraham, Isaac, Jacob/Israel, Joseph
"Genesis ends with Israel in Egypt, ready for the coming of Moses and the Exodus"

The Jewish diaspora "was the historical exile and dispersion of Jews from the region of the Kingdom of Judah and Roman Judaea, as well as the later emigration from wider Eretz Israel."

"began with the 6th century BCE conquest of the ancient Kingdom of Judah by Babylon, the destruction of the First Temple (c. 586 BCE), and the expulsion of the population, as recorded in the Bible."
"The Jews began to revolt against the Roman Empire in 66 CE during the period known as the First Jewish–Roman War which culminated in the destruction of Jerusalem in 70CE. During the siege, the Romans destroyed the Second Temple and most of Jerusalem."
"In 135, Hadrian’s army defeated the Jewish armies and Jewish independence was lost."

Photosynthetic efficiency "is the fraction of light energy converted into chemical energy during photosynthesis in plants and algae"

"For actual sunlight, where only 45% of the light is in the photosynthetically active wavelength range, the theoretical maximum efficiency of solar energy conversion is approximately 11%"
"In actuality, however, plants do not absorb all incoming sunlight (due to reflection, respiration requirements of photosynthesis and the need for optimal solar radiation levels) and do not convert all harvested energy into biomass, which results in an overall photosynthetic efficiency of 3 to 6% of total solar radiation."
Efficiencies of various biofuel crops: "if it delivered the claimed 600 gallons of biodiesel per acre per year, would be converting 0.3% of the incident solar energy to chemical fuel"
"the photosynthetic efficiency of sugar cane is 0.38%"

The Show Notes