Mazur has this to say on the history of the equals sign:
The ideas of algebra brought on the symbols, not the other way around. Robert Recorde had written the words “is equal to” almost two hundred times in his book(1557) before noticing that he could easily “avoid the tedious repetition” of those three words by designing the symbol = to represent them.
OttomanHistoryPodcast discusses the Jews of North Africa, including a group that is ignored in history, those who lived in the Southern Sahara region who are ethnically different from those Jews who lived along the coast.
alas, I listened to 20 minutes and it all seems to be talking about how the intellectuals view these people rather than about these folks themselves.
but learning about the ethic groups in the Sahara countries is not something one learned in school. This valley is not Arab but Mozabite (Berber) ethnic group that dates to 1000 acccording to wikipedia:Ghardaïa (population of 93,423) is the capital of the confederacy
the town is a UN World heritage site.
so why should we care about this small town?
In Ghardaia the violence between Arab and Berber residents is all about water rights, jobs, land, ethnicity and religion. Arabs also accuse the 800,000 Berbers in the south of supporting al Qaeda. The province of Ghardaia is on the edge of the Sahara Desert and contains only 200,000 people. The unrest has been going on since late 2013. Over a hundred people have been arrested and there have been over 400 casualties (including at least 15 dead). Over a hundred building has been burned down along with dozens of vehicles. Thousands have fled the city and many businesses stay closed for days or weeks at a time. The police, who are largely Arab, are accused of being biased against the Berbers. The ethnic tensions in this area, 600 kilometers south of the capital, have been growing since 2008 and there was another outbreak of violence in October 2013 that was put down violently. As bad as the ethnic tensions have been there are also disagreements over religion. The Arabs belong to the Maliki school of Islam while the Berbers are largely from the smaller Ibadi sect.
About 30 percent of Algerians are Berber, but the percentage is higher in the south. Ghardaia is an ancient Berber city of 90,000 that contains many Ibadi shrines. Berbers are found throughout North Africa, west of Egypt and down to the semi-desert Sahel (where the closely related Tuareg tribes live). The six million Berbers of Algeria are considered the most abused in the region. Ghardaia Arabs got the recent unrest started by desecrating some of these shrines. This led to violent Berber reprisals, especially when images of the damage appeared on the Internet. The government is concerned for several reasons. For one thing there are oil fields are nearby. Worse, the sustained unrest among the Berbers could be the first breeze in an uprising that could engulf the entire country.
Pumpkin pie week at Epicurious blog.