In the Seventies, there
were major fears that the world was running out of stuff. Food, metals, energy resources, you name
it. A 1972 book called The Limits to Growth portrayed a future
in which population growth, industrialization, pollution, food production and
resource depletion ended in tears unless we learned to curb our appetite for
In 2001, a Danish
statistician and environmentalist named Bjørn Lomborg published The Skeptical Environmentalist.
He made a startlingly different case, based on numbers. If we are running out of everything, he
wrote, then why are the costs of almost everything going down? The laws of supply and demand say that the
scarcer a commodity, the higher a price it will fetch. But in case after case he presented, the
opposite had happened.
Innovation explains the difference. We have become much better at finding and
extracting raw materials, and at making more efficient use of them. The global supply of useful stuff keeps
expanding because our ability to get at it continues to grow.
Of course, there are
limits, whether to the supply of oil and gas or to the Earth’s ability to
absorb greenhouse gases. There are
always limits – but we don’t seem to be very good at forecasting them.
Which brings me to the
laws of physics. Currently, the number
one discussion on WTA’s LinkedIn
Group is about bandwidth. It started
when we posted news of Newtec announcing a new speed record by helping Yahsat
deliver 310 Mbps over a 36 MHz transponder.
Group members weighed in with questions and answers about the
achievement, and a NovelSat executive described delivering 365 Mbps over a 72
Mhz transponder for SES, which helped the company win our Teleport Technology of the Year Award in March.
This is important
work. Satellite technology can provide
high bandwidth capacity to places that no other technology can reach as cost
effectively. It can deliver one-to-many
better than anything else. But the total
bandwidth available remains bound by the laws of physics. Every advance that lets us send more bits per
hertz – from frequency re-use to adaptive coding – is of great
This discussion, however,
raised an interesting question in my mind.
Practically speaking, just how seriously do we need to take those laws
of physics? We know there are
limits. Claude Shannon of Bell Labs
defined the theoretical maximum information transfer rate of a communications
channel, for a particular noise level, and it became known as the Shannon
Limit. His son was a childhood friend of
mine and I remember Dr. Shannon as a quiet, courteous gentlemen quite absorbed
in his own remarkable thinking process.
I am no more equipped to dispute his Limit now than I was at the age of
ten. But I wonder. In the manufacture of
silicon chips, we read every few years that we are coming up against a
theoretical limit which will prevent us from squeezing any more transistors or
wiring onto that tiny square of high-quality sand. And every few years, regular as clockwork, we
find that the forecast date for reaching that theoretical limit has been pushed
a few more years into the future.
I suspect that, in the
back rooms of the technology companies in our membership, there are wild-eyed visionaries
conceiving the next impossible bandwidth breakthrough and making it work. Which means that there are a lot more interesting
discussions waiting to happen.