It's easy to take good engineering for granted. After all, it's the bad engineering that gets the headlines: bridges falling down, buildings falling apart, tunnels collapsing.
When done right, good engineering can be beautiful to look at or beautifully functional or just amazing in its scale. Here's our tribute to a few projects that did more than just get the job done.
No. 01 - The Pyramids
Were they built by aliens? Probably not.
Most likely the Egyptian pyramids were just built by some very hardworking Egyptians who toiled in the desert heat over 4,000 years ago. Built by commoners, the pyramids were intended as crypts for the kings and their construction was a massive effort.
As many as 30,000 workers may have toiled at Giza, pushing and pulling stones up ramps and possibly floating limestone and granite along the Nile River from distant quarries. The Great Pyramid at Giza may have taken as little as 23 years to build – not bad for manual labor – and, all told, the Egyptians built over 100 during their thousand-year pyramid-building age.
The pyramids' perfect lines continue to inspire architects and engineers to this day.
No. 02 - Hoover Dam (and Three Gorges Dam)
It's not the world's biggest dam, but it was the one that changed the way we build them.
The first of the large concrete arch dams that dominated the 20th century, Hoover also marked the birth of America's dam-building boom. Its Depression-era construction cost &36;49 million and used so much concrete that engineers had to pipe cooled river water through the dam face to help the concrete cool faster.
The sweeping, 60-story-high concrete arch, along with its water works, power station and intake towers, were all designed in classic art deco style, reminding us of the days when plans for public works projects included intricate stone and metalwork, ornate plaques, and elegant statues of massive seraphs guarding the gates. They just don't build them like they used to.
No. 03 - Panama Canal
Almost 100 years after it was built, the Panama Canal still stands as a marvel of engineering.
What started as a French project in 1880 was completed as an American one in 1914, with 40,000 workers moving enough dirt to bury the entire island of Manhattan 12 feet deep.
Over 25,000 workers perished in the process, many due to tropical diseases, and the project cost the U.S. government somewhere around $375 million. The lucrative route between the Atlantic and Pacific was worth it back then and still is today.
The 50-mile-long canal route takes ships through a channel from one ocean, into an artificial lake, and out another channel to the other side. Three sets of locks draw water from that artificial lake to raise and lower boats, ranging from small yachts to giant freighters, over a total elevation change of 85 feet.
With each transit, the canal loses 52 million gallons of that fresh water to the ocean. With 13,000 to 14,000 passages each year, that's a lot of water.
No. 04 - Burj Dubai (Dubai Tower)
Everything is bigger in Dubai.
In this case, much bigger. The city known for indoor desert skiing, man-made islands and underwater hotels will now have a new tourist attraction in the 2,684-foot-tall Burj Dubai building, whose design borrows from traditional Islamic architecture as it punches a hole in the sky.
Scheduled for completion by the end of 2009, the building has already topped out at its finished height, making it the world's tallest freestanding structure (sorry, CN Tower) -- that's over 1,000 feet and 60 percent taller than the 1,671-foot Taipei 101 Tower.
How did they do it? With a little bit of steel (for the top portion) and a lot of reinforced concrete (for the lower portion). Some of that concrete was pumped almost 2,000 feet up during the Dubai nights to avoid the scorching daytime temps. An army of construction workers will help finish off the task: all told, 22 million man hours will go into the project.
No. 05 - Millau Viaduct
Leave it to the French to make engineering look good.
The elegant lines of the Millau Viaduct in the south of France stretch a mile and a half over the Tarn River and its valley. The viaduct is the longest cable-stayed bridge and the tallest road bridge in the world.
It's also perhaps the most beautiful, thanks to architect Norman Foster and structural engineer Michel Virlogeux's sweeping, curved design. Super-tall concrete pylons (at 1,125 feet, one is taller than the Eiffel tower) and steel cables support the world's highest vehicular road deck.
Engineers accomplished this feat in late 2004, proving that big doesn't always have to look brawny.
No. 06 - Large Hadron Collider
Any engineering project has a margin of error, but when you're trying to aim a beam of subatomic particles at another beam of subatomic particles, that margin of error is just ridiculously small.
The Large Hadron Collider, housed in a 17-mile-long circular tunnel buried some 570 feet under the French and Swiss Alps, is an enormous scientific experiment designed to observe minuscule subatomic particles. How? By re-creating the (terrifying) conditions that existed right after the Big Bang.
What's more, a small handful of people really believe that it could destroy the world by creating a black hole that could swallow us whole. Well, probably not, but the collider will harness huge amounts of energy, using 1,600 high-power, superconducting magnets to bend and manipulate beams of protons as they travel at 99.99 percent the speed of light.
Now, if you're going to use superconducting magnets, you have to cool them to superconducting temperatures (that would be â€"271 degrees Celsius (-456 F)), and that takes a lot of liquid helium. So much, in fact, that the facility is not just the largest particle accelerator in the world, but the largest cryogenic facility as well.
No. 07 - The Chunnel
England and France have been so close yet so far away for so long that it gets you wondering: why on earth didn't this Chunnel idea happen sooner?
People had been floating about the idea of a tunnel under the English Channel since the 1800s, but it wasn't until 1988 that anyone actually started actually digging one. And when they did get started, it was serious business:Â it took 11 tunnel-boring machines, a lot of concrete, and workers from both the French and English sides almost six years to complete the 31-mile-long, 250-foot-deep tunnel.
Today, high-speed trains roar through the two main tubes so quickly that huge valves must open and close ahead of the trains to vent the pressure that builds up as the trains push air through the tube. The Chunnel today contains the longest undersea portion of any tunnel and is the second-longest tunnel in the world (second only to Japan's Seikan Tunnel).
No. 08 - Qingzang-Tibet Railway
China's railroad to Tibet may be marred by the political tensions associated with the project, but few can knock its engineering prowess, or its title of the world's highest railroad.
The train tracks on top of the world slide through Himalayan peaks and over rugged tundra along their 1,200-mile path, passing through their highest point at the 16,640-foot Tanggula pass. The path was full of challenges, including a not-so-permanent permafrost with a tendency to thaw just to the point of becoming soggy.
To address that, engineers borrowed some tricks from the Alaskan oil pipeline: they elevated the tracks to allow cool air to pass between the fast-moving, heat-generating trains and the ground, and supported the elevated rail with columns mounted deep enough to hit cooler, more stable earth.
The altitude also caused some problems, both in construction (you try building train tracks at 16,000 feet) and in operation. To keep passengers relatively healthy, the trains use an innovative oxygen-recharge system that captures oxygen from outside air to supplement the cabin air. The result? It seems like you're only two miles above sea level, as opposed to three. Hey, take what you can get.
No. 09 - Netherlands Delta Works
When over a quarter of your country and more than half your population lies below sea level, it probably makes sense to take some protective measures against flooding.
The Dutch have been putting up dikes for 1,000 years now, but the sea just keeps coming like some horror-movie psychopath. About 60 years ago, the Dutch started getting serious, building a series of dams, dikes and storm-surge barriers that may comprise the world's largest flood-control system.
Over 10,000 miles of dikes and 13 dams manage to protect lives while also protecting the fragile estuary habitat. The environmentally-friendly water works allow fresh and salt water to flow and mix, but their gates can be closed quickly when storms come and sea levels rise, allowing people to control water and not the other way around.
No. 10 - Great Wall of China
At first glance, the Great Wall doesn't seem so amazingly difficult to build - I mean, it's just a big stone wall, right?
But take a step back to grasp its length and you might get a different perspective. Stretching 4,000 miles across China, the wall is actually a series of several walls that were built, rebuilt, merged and expanded over the course of 2,000 years, which certainly makes it the lengthiest undertaking of any engineering project.
While the first versions of the wall were built as early as 400 B.C., the version of the wall that we see today dates back only as far as the A.D. 15th to 17th centuries.
And by the way, it's not all that visible from space.