“Space”, Douglas Adams said, “is big.
Really big. You just won't believe how vastly, hugely, mind-bogglingly big it
is. I mean, you may think it's a long way down the road to the chemist, but
that's just peanuts to space.” And it is, but too often our sense of
perspective of how big it really is, is warped by the various models we’ve seen
in life, or pictures we’ve seen in textbooks. To see our place in this world,
it is perhaps necessary to get a glimpse of where we are, just to gain a
measure of perspective.
About a month ago, I employed a device to
show how short our lives really are, by compressing the entirety of existence
into a year. Space, however, is so big, that this device can’t be used for all
of space. Instead, I’ll try to show the vastness of just our solar system, by
compressing it into a space perhaps a bit more familiar to us. I’ll place our
solar system, to scale, within the borders of Namibia.
The solar system is comprised of 8 planets,
the four inner, rocky planets, and the outer four gas giants. Several more
dwarf planets orbit the sun, of which the most well-known is Pluto. But the
solar system extends way past the orbits of these planets, and since most of us
are not quite as well acquainted with those features of our solar system, I’ve
picked an arbitrary limit to our exercise today – the distance the Voyager 1
space probe was at in 1990, when it took the famous ‘Pale Blue Dot’ photograph.
This implies a scale of about 1 to 8
million. In other words, for every 1 kilometre in Namibia, the solar system has
8 million kilometres. Since Windhoek is almost at the centre of Namibia, let’s
place the Sun there. The sun makes up 99.86% of the total mass in the solar
system, so perhaps you’d expect it to be big compared to Windhoek, but no.
If the sun was placed to scale on the
Christuskirche in Windhoek, it would be quite large, but it would not even
reach the Tintenpalast. It would be a mere 174 meters across, but it’s mass,
even if also scaled down by 8 000 000, would be approximately 250
billion billion tons.
But let us move out from the Sun. The
closest planet from the sun, Mercury, is also the smallest planet. On our
scale, it would be a mere 7km from Windhoek’s centre, or about at the Lafrenz
turn-off if driving northwards. The planet would be a mere 60cm across, or two
standard size rulers.
The next planet on our journey out of the
solar system is Venus, the hottest planet in our solar system. If we had
continued to drive northwards, it would be at Elisenheim from Windhoek, and
about a meter and a half across, or approximately one and a half strides.
The next planet should be quite familiar to
all of you, the planet Terra, colloquially known as Earth. Travelling outwards
from Windhoek, it would orbit at about the location of Herbothsblick on the way
to the airport. The planet of life and water would be about 1.6 meters across,
or about my height.
Next up, we have the Red Planet, known as
Mars. Mars would orbit at about halfway between Windhoek and the Hosea Kutako
Airport, entirely inhabited by robots, namely the two Mars Rovers, Opportunity
and Curiosity. Mars is quite a bit smaller than Earth, being a mere 85
centimeters across at our scale.
The four inner planets is comparatively
quite close to the sun. But now the distances start to escalate. The biggest
planet in our solar system, Jupiter, named after the Roman god of the sky,
orbits at a distance just beyond that of Rehoboth from Windhoek. A truly
massive planet, Jupiter has a mass of two and half times that of all the other
planets combined. At our scale, it would be almost 18 meters across, or about
the size of a bus and a half.
Next on our journey outwards, we encounter
Saturn, the least dense planet of the solar system, as well as the most
beautiful to behold. A massive cloud of gas, with rings surrounding it, you’d
find it orbiting about 20km before Gobabis from Windhoek. The planet itself
would be 15 meters across, about a bus and a quarter in size, but its rings
would extend from 16.5 meters around it to 47 meters around it. Truly a
spectacular sight.
But now the distances really stretch. Our
second to last planet, Uranus, is more than double that distance away. Orbiting
at a distance of 360 km from Windhoek according to our scale, it would be
between Tsumeb and Grootfontein. Uranus, a blue ice giant, is nevertheless
smaller than our previous two planets, and it would measure a mere 6.4 meters
across, or about half a bus-length.
And if you thought that was far, the
furthest planet outward from the sun, Neptune, named after the Roman god of the
seas, would be orbiting a mere 20km from Rundu around the sun in Windhoek. It
is the only planet found not by initial observation, but by mathematical
prediction due to the gravitational effects it had on Uranus’s orbit. The
furthest planet is still only a 6.2m sphere at our scale, orbiting around the
174m sphere of the sun in Windhoek.
Even further out, is the dwarf planet
Pluto, a mere 30cm ruler across, orbiting at the Orange river, our Southernmost
border from Windhoek. But the Voyager 1 space probe was even further out, at
the equivalent of the Kunene River mouth from Windhoek, when Carl Sagan
convinced NASA to turn the spacecraft’s imaging sensors back towards Earth, and
take that fateful photo.
To quote Carl: “We succeeded in taking that
picture, and, if you look at it, you see a dot. That's here. That's home.
That's us. On it, everyone you ever heard of, every human being who ever lived,
lived out their lives. The aggregate of all our joys and sufferings, thousands
of confident religions, ideologies and economic doctrines, every hunter and
forager, every hero and coward, every creator and destroyer of civilizations,
every king and peasant, every young couple in love, every hopeful child, every
mother and father, every 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 in 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 the dot on scarcely distinguishable inhabitants of
some other corner of the dot. 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.”
“To my mind, 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 and
compassionately with one another and to preserve and cherish that pale blue
dot, the only home we've ever known.”
No comments:
Post a Comment