The hull of your spacecraft is breeched as it drifts through the vacuum. The air around you and inside you rushes into the void. You have one chance to scream as your final breath escapes your lungs and the air around you accelerates your body toward the hole.
The vacuum of space makes space travel dangerous and difficult. But the pressures felt by a person exposed to the vacuum are minute when compared to those experienced by a person at the bottom of the world’s oceans. The physical pressure of exploring the deep sea can be 400 times that of the vacuum of space, but that should not deter us. For our ultimate survival, we must overcome the difficulties of getting to the bottom of the oceans. We must go deep.
In our daily lives, the atmosphere weighs on us; at the surface, the pressure due to the air above us is called “one atmosphere”. In space there is a vacuum and the pressure is null. The difference in pressure between your chair and space is one atmosphere.
Going underwater adds the weight of the (much heavier) water to that of the atmosphere. (That’s why your ears hurt when you dive too deep—the weight of the atmosphere plus the weight of the water press on you). If you were to swan dive into the ocean and swim straight down until you get to 10 meters deep (about the height of a three-storey building), you would have over top of you one atmosphere’s worth of water.
For every 10 meters you descend into the ocean, what’s known as hydrostatic pressure increases by one atmosphere. The average depth of the deep ocean is 3.7 km. If you dove Alvin—the manned submarine vehicle operated by Woods Hole Oceanographic Institute (WHOI) that discovered the wreckage of the Titanic—to 3.7 km depth, the force of compression on Alvin would be 370 times the force of the vacuum in space.
Pressure is an obstacle that must be overcome when creating an environment in which humans can live while exploring these unknown worlds. While it is exciting for humans to venture into new territory, deep-sea exploration can be done much more effectively and efficiently using remotely operated vehicles (ROVs). Today, most exploration is done by ROVs (which collect data to send back to us), but getting these machines to work under the sea is at times a nearly insurmountable challenge.
Salt water is corrosive to many materials, not to mention conductive, which means it can carry a current. Electronics quickly short-circuit if not protected from the water. Light doesn’t have an easy time either because it is absorbed or reflected by molecules of water. The result is that we can only see a short distance in front of us.
There is also the problem of energy and data transmission. Satellite transmission only works in air, so without cables it is difficult to send information to, or receive information from, submarine instruments and ROVs. Project Neptune off the coast of British Columbia has made use of kilometers of cable running underwater, delivering power to, and returning data from, instruments measuring tectonic activity (movements in the Earth’s crust, such as earthquakes), monitoring local ecosystems, measuring the properties of the water (temperature, how salty it is, etc.) and much more.
Learning about our oceans is not a simple task. It is a wonderful problem for humankind to tackle, if we choose to do so. Despite the difficulties of working underwater and at high pressures, the biggest obstacle to deep-sea exploration is ourselves.
Humans have a fascination with space that has lead us to send manned craft to the moon. We dream of visiting creatures like us on other planets, in other galaxies. We even talk of moving to other planets as a solution to the environmental catastrophe we are pursuing on our planet. This is backward thinking. We need to pin our hopes on our own planet, but there is much left to learn.
In the 1970s, “black smoker” hydrothermal vents were discovered near the Galapagos Islands by a team from WHOI using Alvin, where colonies of tube worms, clams and other treasures prosper. They exist, not by using energy from the sun—as all other known life—but by using energy emanating from the centre of our planet. There is life beneath the waves of which we know nothing about.
In space, we learn more about our universe, but more importantly, we learn about our planet and ourselves. If we really want to learn about the Earth we should focus our energy on the oceans. They cover three quarters of the surface of the Earth and affect almost all of the Earth’s systems: carbon dioxide, global warming, food chains, storm events and much more.
We need to become enthralled with the oceans the way we are with space. Into our own world, our oceans, we must go deep.
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