The Lake House on the Pale Blue Dot
Recently I
watched the 2006 movie The Lake House
starring Keanu Reeves and Sandra Bullock about a couple separated by two years
of time and yet connected by an old mail box outside of a lake house, perhaps
near Chicago, to which they both drive, inside an hour, in order to deposit and
collect letters from each other. They of
course fall in love and she, living two years ahead of him, is able to warn him
to avoid a certain accident which she knows about, and saves his life. Then somehow
they break through the time barrier and physically meet. Quite a nice movie.
By
coincidence I was at the same time reading Pale
Blue Dot: a vision of the human future in space by the late great science
publicist Carl Sagan. I’ll try and
explain the connection. We can be separated by time as we’ll as distance,
determined by the speed of light which is very fast but still has a velocity
beyond which nothing can go faster. [I wonder if the same folk who are climate
deniers will find fault with this J] When Neil Armstrong and ‘Buzz’
Aldrin walked on the Moon in July 1969 they were 1.3 seconds out of sync with
us. But for Keanu Reeves and Sandra Bullock to be out of sync by two years they’d
have to be 11.76 trillion miles apart.
That’s a long way to go to a letter drop.
Carl Sagan’s
book takes its title from an extraordinary photograph that was taken by the Voyager
1 space-probe in 1990 as it was leaving our solar system after 13 years travel
from launch.
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This is what
our home planet looks like from 3.7 billion miles away – a pale dot (encircled
to help you see it) caught in a dusty sunbeam. It took five and half hours to
beam the picture home. Let me quote what
this dim photo meant to Carl Sagan as expressed in the beginning of his book.
“Look again
at that dot. That’s here. That’s home. That’s us. On it everyone you love,
everyone you know, everyone you ever heard of, every human being who ever was,
lived out their lives. The aggregate of our joy and suffering, thousands of
confident religions, ideologies, and economic doctrines, every hunter and
forager, every hero and coward, every creator and destroyer of civilization, every
king and peasant, every young couple in love, every mother and father, hopeful
child, inventor and explorer, every teacher of morals, every corrupt
politician, every “superstar”. Every “supreme leader”, every saint and sinner
in the history of our species lived there – on a mote of dust suspended in a
sunbeam.”
“The Earth is a very small
stage in a vast cosmic arena. Think of the rivers of blood spilled by all those
generals and emperors so that in glory and triumph they could become the
momentary masters of a fraction of a dot. Think of the endless cruelties
visited by the inhabitants of one corner of this pixel on the scarcely
distinguishable inhabitants of some other corner. How frequent their
misunderstandings, how eager they are to kill one another, how fervent their
hatreds. Our posturings, our imagined self-importance, the delusion that we
have some privileged position in the universe, are challenged by this point of pale
light. Our planet is a lonely speck in the great enveloping cosmic dark. In our
obscurity – in all this vastness – there is no hint that help will come from
elsewhere to save us from ourselves. “
“It has been said that
astronomy is a humbling and character-building experience. There is perhaps no
better demonstration of the folly of human conceits than this distant image of our
tiny world. To me, it underscores our responsibility to deal more kindly with
one another and to preserve and cherish the pale blue dot, the only home we’ve ever
known.”
As I’ve been preparing this essay in
recent days we’ve marked the 150th anniversary of the end of the
American Civil War which killed approximately 700,000; then the 70th anniversary of the ‘liberation’
of the Nazi death camps; and the centenary of the Armenian genocide. Oh, and
Earth Day, at a time when the overwhelming evidence of climate change is being
denied by too many politicians, and other species are being annihilated at the
greatest rate since the last big asteroid hit and killed off approximately 90%
of all species, but not obviously and fortunately for us – our own ancestors.
In Pale
Blue Dot Sagan worried, 21 years ago,
about human destruction of this planet and wondered if we’d need to move somewhere
else. The question is –where? There’s nothing very habitable in our solar
system and the nearest other solar system to us is 24.7 trillion miles away,
which at the speed of the Voyager spacecraft would take 6,675 years to get
there. That’s a long time to be cooped up in a spaceship, and especially if
there’s no habitable planet once you get there.
When Sagan was writing we didn’t know
much about planets in other solar systems. Now, perhaps not too surprisingly,
we’re discovering that many stars, i.e. other suns, have planets going around
them. This information has been pouring in in the last few years thanks to the
Kepler telescope which was launched into orbit in 2009 and has been looking for
planets orbiting other stars in our Milky Way galaxy which is estimated to have
approximately 300 billion stars in it. And then remember there are well over
100 billion galaxies. With four or five planets per star this could mean
trillions of planets. Therefore the chances of quite a few of them being of similar
size and composition and distance from their sun as we are from ours – in the ‘goldilocks’
setting - is overwhelming; and thus the
likelihood of life on some of these other planets almost certain.
That’s the good news. Tantalizing
questions and challenges then arise. How do we find out if indeed there is life
on some goldilocks planet in another solar system? They’re so far away. As we
saw, the nearest possible one is 24.7 trillion miles away. Our telescope
technology will of course improve with time, but at present we can’t actually
see these other planets, simply detect the extremely tiny affect we can detect
some orbiting object is having on its star.
Supposing there’s not only life but
intelligent life. Since the 1980s we’ve been beaming messages out into space.
So far no one has replied, nor have we picked up anyone else’s message. And
what would we do if we did? After taking this picture of how earth looks from
the edge of our solar system, Voyager has continued off into outer space and we’ve
lost contact with it. But on it goes, and just in case ‘someone’ comes across
it they will find on board photos of what earth creatures (us) look like, a map
of our solar system locating Earth, and some music and messages. Well, you
know, just in case some extraterrestrials appreciate the Beatles.
The thing it’s difficult for any of us
to get our heads around are the distances between us and other solar systems. The
nearest other solar system to us takes light four years to get to us. That
would apply to radio waves as well, leading to a boringly slow conversation,
but nonetheless possible. However, there’s no ‘goldilocks’ planet there. The
Kepler telescope has discovered a promising planet with water on it, so
therefore it could have life on it; but what we’re seeing of it has taken
124,000 years for the planet’s image to get here. And likewise, if there is a
technologically advanced civilization there looking at us with powerful
telescopes, they’ll be chuckling as they watch a few apelike creatures running
around looking for food, because the picture reaching them will be of us 124,000
years ago. So if there are intelligent folk out there who have solved all the
problems of poverty, discrimination, war etc. it’s going to be difficult to ask
them for advice, because by the time they send us that good advice we’ll have
buggered everything up long since.
