Roby Greenwald

@roby.bsky.social

512 Followers 481 Following

Associate Professor in the Georgia State University School of Public Health (any views expressed are my own). I measure the effect of urban environments on public health, especially the role of transportation on air pollution and physical activity.

A Craftsman brand battery-powered angle-grinder with a retail price of $65.
Purple Air PM2.5 sensor map showing levels in the 100-200 ug/m3 range.
Map showing the problems and solutions for bicycle infrastructure near Oakland Cemetery in Atlanta.
Google Earth screenshot of a mountainous desert peninsula with a very complicated shoreline.
Green by R.E.M.
A site plan for 47 micro units on two parcels currently zoned single family.
A mockingbird chasing away a hawk.
A mockingbird chasing a hawk
A GMC Hummer EV that weighs 9063 ln Bs according to the manufacturer.
A sign indicating that vehicles over 6000 lbs are not allowed.
Figure showing the rankings of U.S. cities based on reductions in social connections associated with the presence of urban freeways.
Pollen covered tire
Map showing a dip in the jet stream reaching the Gulf Coast on January 22, 2025.
1863 photograph of Fredericksburg, Virginia along the Rappahannock River.
Illustration from a 19th century edition of Robert Drury's journal.
Rappahannock slave caravan
Slave labor in sugar cane field, Jamaica
Slave ship, the Mercury
Austronesian outrigger sailing vessel
River reeds, central Madagascar.
Field preparation in central Madagascar, early-1900's.
Near the Mahafaly-Fiherenana border (from Google Earth).
Illustration from a 19th century edition of Robert Drury's journal.
Example of a Malagasy "sampy" amulet.
Tandoor warriors dancing with lances.
Traditional beehive
Malagasy written in Arabic script (https://commons.wikimedia.org/wiki/File:Sorabe_malagasy.jpg)
King Andrianampoinimerina of the Imerina kingdom.
Map of Robin Drury's travels in southern Madagascar.
Southern Madagascar nobility, reproduced from Flacourt, 1661.
Illustration of Robin Drury's capture from the first edition of Drury's journal (1729).
Engraving of a crocodile.
Engraving of a fossa.
Zebu bull
Illustration of fortified villages from Flacourt, 1661.
Tandroy warrior.
Google Earth view of Mahafaly countryside.
Illustration of the wreck of the Degrave from the first edition of Drury's journal (1729).
Google Earth view of Angavo.
Annotated map of southern Madagascar
Illustration of an "oly" charm used by Tandoor shaman.
Map of Madagascar from Robin's journal.
Illustration from Robin Drury's journal.
Robin Drury's journal
Abraham Samuells.
Engraving of southern Madagascar warrior, 1823.
Photograph of Antanosy warriors from the Adventure Series edition (early 1900's)