- The Bruce Vento Nature Sanctuary is a city park in the Mississippi River corridor in Saint Paul, Minnesota. Just east of the city’s downtown district, the sanctuary includes towering limestone and sandstone bluffs that date back more than 450 million years, spring-fed wetlands, abundant bird life, and dramatic views of the downtown Saint Paul skyline and Mississippi River. The park was opened to the public on May 21, 2005, and was named after its early supporter U.S. Representative Bruce Vento.
- On the dimensionality of spacetime (space.mit.edu)
Some superstring theories have more than one effective low-energy limit corresponding to classical spacetimes with different dimensionalities. We argue that all but the (3 + 1)-dimensional one might correspond to ‘dead worlds’, devoid of observers, in which case all such ensemble theories would actually predict that we should find ourselves inhabiting a (3 + 1)-dimensional spacetime. With more or less than one time dimension, the partial differential equations of nature would lack the hyperbolicity property that enables observers to make predictions. In a space with more than three dimensions, there can be no traditional atoms and perhaps no stable structures. A space with less than three dimensions allows no gravitational force and may be too simple and barren to contain observers.