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Science
Friday > Archives
> 1998
> September
> September 4, 1998:
Hour One: Internet Isolation / Snowball Earth
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Are people that use the Internet better off
socially than those that use it less? The on-line
services would certainly like you to think so. Ads
for internet service providers almost always
mention the increased chances for social
interaction that are available through e-mail, chat
rooms, and messaging services. "On-line
communities" like Geocities pitch themselves as
virtual neighborhoods, offering companionship and a
cyber-picket fence to lean against and gossip over.
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But now not everyone is so sure about the social
benefits of Internet use. Researchers at Carnegie Mellon
University's Human Computer Interaction Institute have
recently completed a two-year, $1.5 million study called
"HomeNet" that found that increased use of the Internet is
associated with increases in depression and loneliness. The
authors followed the same group of people over time to
control for the possibility that depressed people were more
drawn to the internet than others. They found a linear
relationship - the more net time, the less talking among
family members, the fewer friendships that users kept up
with, and the more depression. Their findings will be
published in the September issue of the American
Psychologist.
The results surprised many of the scientists involved, as well as the
technology companies that helped fund the study, and may start an interesting
debate at a time when many people are pushing for all schools to be
connected to the Internet - or even for all Americans to receive government-provided
electronic mail service. Are on-line relationships as useful as those
in the real world? What is the connection between networking and depression?
And how much Internet is too much? We'll talk about it...
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Then...what could have been enough to snap a prehistoric Earth
out of a deep freeze? Volcanic eruptions and the actions of some
snails and worms were the key, according to a report in last week's
Science magazine.
A controversial theory, called the "snowball Earth" hypothesis,
holds that 550-750 million years ago, the Earth may have been
largely ice-covered. As the theory goes, a slight cooling in the
atmosphere let ice sheets begin to advance from the polar regions.
Those ice sheets reflected back a good part of the sunlight hitting
the Earth, cooling the atmosphere more... which allowed the ice
sheets to advance further... and so on.
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Researchers have found clues that suggest that the ice may have reached
deep into the tropics, effectively shutting down most of the life on Earth.
The levels of organic carbon present in Nambian rocks, a sign of productivity
by organisms in the area, drops off severely near the times of these ice
ages, and then only slowly recovers, according to researchers at Harvard
University and the University of Maryland. Volcanic eruptions may have
released enough carbon to create a temporary greenhouse effect, melting
the ice -- but the sheets advanced again, bringing on a series of at least
four freeze-thaw cycles. The authors suggest that the actions of a growing
population of sea-dwelling snails and worms may have helped to break the
cycle. By stirring up carbon in ocean sediments, the sea critters may
have kept enough carbon in circulation to prevent a permanent freeze.
The freezing conditions may have also put enough stress on existing organisms
to cause a wide variety of adaptations.
The theory isn't accepted by everyone, but it's certainly interesting.
Do we have snails to thank for our relatively temperate conditions today?
Guests:
Robert Kraut
Professor of Social Psychology and Human-Computer
Interaction
Human
Computer Interaction Institute
Carnegie Mellon University
Pittsburgh, PA
Tora Bikson
Senior Scientist
Behavior Sciences
RAND Corporation
Santa Monica, CA
Paul Hoffman
Sturgis Hooper Professor of Geology
Department of Earth and Planetary
Science
Harvard University
Cambridge, MA
Books/Articles Discussed:
Related Links:
The Carnegie Mellon
University Homenet Project
The Rand Corporation
study about Email Access
The Center For Online Addiction
Depression News and Information
on the Web
The National Institute of Mental
Health
Discover
Magazine Story "Snowball Earth"
Information on
"Ice Ages"
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