Quatr.us Study Guides has more than 2500 original articles on everything from Aachen to zygotes. What would you like to learn today?

Where things are?

Africa (with Ancient Egypt)
Europe (with Ancient Greece and Ancient Rome)
West Asia (Mesopotamia, the Persian Empire, and the Islamic Empire)
Central Asia
India
Southeast Asia
China
Japan
Americas (South America, Native Americans, American history)

When things happened?

Prehistory
Bronze Age
Iron Age
Ancient
Medieval
Renaissance and Modern

How things work?

Biology (with the parts of a cell)
Chemistry (including atoms, the elements and reactions)
Geology (with the geological eras, plate tectonics and types of rocks)
Math (numbers, geometry, and proofs)
Physics (with space, weather, simple machines, and the laws of motion)

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Quatr.us Study Guides Projects and Articles for mid May:

Islamic astronomers taking observations

RAMADAN (Thursday, May 17) – Ramadan Mubarak! This week begins the month-long Islamic holiday of Ramadan. You can find out more about the Islamic religion, the Quran, and the holiday of Ramadan here. The end of Ramadan is Eid al-Fitr, and a few months after that many people make the hajj to Mecca to celebrate Eid al-Adha.

A safety bicycle

BIKE TO WORK DAY: (Friday, May 18) – Bike to work or school on Friday – or maybe all week? or maybe all year? – a great way to save time by exercising while you commute. Biking’s often faster than driving your car in morning traffic. Check out our pages on how wheels and levers work, and our new page on the history of the bicycle and how bikes let women get around more safely.

TEACHER APPRECIATION: We’ll feature some famous teachers: Lao Tzu, Confucius, and the Zen masters in China, the Buddha in India, Sappho, Socrates, and Plato from ancient Greece, Jesus, al-Tabari in medieval Baghdad, Maimonides and Rashi, Mary Astell and Damaris Masham in the 1600s, and Mary Wollstonecraft in the 1700s. What was school like in ancient Egypt, or ancient Rome, or ancient China, or medieval Islam?

This week in history:

Alexander the Great

ALEXANDER – May 22, 334 BC – Alexander the Great defeated the Persian King of Kings, Darius, at the Battle of Granicus. This victory, and Alexander’s eventual conquest of the Persian Empire, brought the Hellenistic period to West Asia.

Julia Maesa

JULIA MAESA – May 16, 218 AD – Julia Maesa, as regent for her grandson Elagabalus, seizes control of the Roman Empire. Julia Maesa ruled for eight years, from 218 to 226 AD, and her daughter Julia Mammaea ruled after her, in the name of Alexander Severus.

RHODE ISLAND ENDS SLAVERY: May 18 1652 – Under the influence of the Quakers, Rhode Island became the first of the European colonies to ban slavery for African-Americans (and everybody else).

WHAT TO DO THIS WEEK: Bike to school or to work, or wherever you can, for Bike to Work Day on Friday. Leave the car at home! How many simple machines does your bike use, in addition to wheels?

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History Gifts – what to get with your Amazon gift card!

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New articles this week:

The history of Paraguay and Chile – we already had articles about the Guarani and the Mapuche and the Nazca, but now we’ve added what happened after the Spanish colonizers arrived. This is part of a project to have short articles on the colonial history of every country in South America. So far we have these two, Brazil and the Caribbean (and Mexico in Central America).

New discoveries this week:

TATTOOS: Infrared digital imaging of Egyptian mummies now shows that men as well as women were tattooed in ancient Egypt. Read more about Egyptian art, slavery in ancient Egypt, and Egyptian religion.

ABRAHAM AND ISAAC: An interesting Gnostic papyrus from Roman Egypt tells the story of Abraham and Isaac – only in this version, Abraham just goes ahead and sacrifices Isaac to God. Apparently this version was pretty common in Roman times, including among early Christians.

EGYPTIAN TRADE: Egypt’s economy was booming in the 1100s under Saladin and the Ayyubids. So maybe it’s not too surprising that traders were selling Egyptian pottery as far north as Bulgaria, where a bunch of it was found last week.

Seasonal food of the week:

CILANTRO: It’s a good time of year for cilantro and coriander (which is crushed cilantro seeds). Sure, use coriander in curries and sweet potato pie, but use handfuls of chopped cilantro in our brand-new ricotta dip (an ancient Roman recipe), or in chimichurri sauce recipe, to dip crackers in, or in spicy Thai pork salad, or in Thai lettuce wraps, homemade salsa, falafel, or wonton soup. So many cultures! So much good food!