The Fulton Market Cold Storage Company building in Chicago has been, well, storing cold things since the 1920s. But last July, the company sold the building and moved to a more modern facility outside town, leaving the old cold storage warehouse to be turned into offices.

But first, the new owners had to defrost it.

The Fulton Market Cold Storage building has ice-covered walls for the same reason a freezer can get covered in hard, packed ice. When you put something into a freezer — say, a giant slab of beef fresh from a slaughterhouse — that thing contains moisture. There's liquid trapped inside it. Over time, especially if it's not sealed very well, that moisture will turn into water vapor in the air. When temperature changes cause that vapor to condense back into liquid, it instantly freezes — turning to ice anywhere it touches.

In your fridge at home, that's just an annoyance. At the Fulton Market Cold Storage building, it was epic.

Besides the video above, you should really check out the amazing photos taken for the ice, pre-melt, by photographer Gary Jensen.

Via This Is Colossal

Remember when you had to build a bridge out of popsicle sticks in high school science class? The goal was to construct the miniature bridge that could withstand the most physical stress. Your materials were just sticks and glue. So the real challenge was to find strong shapes.

On the day of testing, we all learned very quickly what those shapes were. Bridges built out of lots of squares collapsed almost instantly. Bridges built out of triangles made the finals.

This is a pretty basic lesson, but it's not one that the global construction industry has learned yet, says the US Geological Survey's Ross Stein. Last week at the meeting of the American Geophysical Union, he began a talk on "Defeating Earthquakes" by demonstrating the difference between the cube-centric structures we build all over the world and how much stronger those structures can be if you just add triangles in the corners. It's a powerful demonstration of how simply having the technology to solve a problem isn't enough. You have to get people to use it.

This whole video is worth watching and easy for laypeople to follow. And it's just one of a huge collection of lecture videos from AGU 2012 that are now available online. They cover everything from the chemistry of lighting to the geology of volcanoes to the effects of space storms and solar flares. Very cool stuff!

Exit signs are so ubiquitous that they're almost invisible. Every public building has them. In fact, they are so common that, taken together, these little signs consume a surprisingly large amount of energy.

Each one uses relatively little electricity, but they are on all the time. And we have a lot of them in our schools, factories, and office buildings. The U.S. Environmental Protection Agency estimates that there are more than 100 million exit signs in use today in the U.S., consuming 30–35 billion kilowatt-hours (kWh) of electricity annually.

That’s the output of five or six 1,000 MW power plants, and it costs us $2-3 billion per year. Individual buildings may have thousands of exit signs in operation.

To put this into a bigger context: This is just one small part of what makes buildings, in general, incredibly energy intense. In the United States, we use more energy powering our buildings—from the lights, to the heating, to the stuff we plug into the walls—than we use to do anything else. Because of that (and because of the fact that electricity is mostly made by burning coal or natural gas) buildings produce more greenhouse gas emissions than cars.

Read more about the energy consumption of exit signs and how we can use less energy, while still getting the same services, at Green Building Advisor

Take a look at some stats on energy use in buildings at the Architecture 2030 website

It sure seems like a completed structure at first glance. But look closer. Specifically, look at the piles of stone blocks stacked on top of the columns.

Those blocks were hauled up there during construction—around the turn of the 20th century. They were supposed to be carved into sculptures representing "Music", "Architecture", "Painting" and, ironically, "Sculpture". Instead, the stone has sat there for 110 years, through two major renovations, un-carved and largely ignored.

The Daytonian in Manhattan blog has the full story on this.

Via Amy Vernon

Yesterday was the 110th anniversary of air conditioning. The building pictured above—1040 Metropolitan Ave. in the Williamsburg neighborhood of Brooklyn, New York—was the first building in the world to enjoy the luxury of cold air blowing on a blisteringly hot day.

A junior engineer from a furnace company figured out a solution so simple that it had eluded everyone from Leonardo da Vinci to the naval engineers ordered to cool the White House when President James A. Garfield was dying: controlling humidity.

The junior engineer who tackled the problem was Willis Carrier, who went on to start Carrier Corporation. The solution he devised involved fans, ducts, heaters and perforated pipes ... Carrier’s plan was to force air across pipes filled with cool water from a well between the two buildings, but in 1903, he added a refrigerating machine to cool the pipes faster.

It's a neat technological story, and as the New York Times piece points out, Carrier's invention wasn't just about making people comfortable. In the beginning, it was about allowing a specific job to get done even when the weather was hot. In fact, air conditioning is still the tool that makes things like computers possible, by creating dust-free, low-humidity clean rooms where the parts can be manufactured.

Read the rest of James Barron's piece in the New York Times City Room blog

How do engineers know that the pillars supporting a bridge can withstand the force of thousands of cars driving over them for decades? How do we know what would happen to that bridge during an earthquake? What about an earthquake in winter?

Buildings, roads and bridges are all designed with a buffer of safety—basically, engineers round up on the numbers, a lot, and design these things to be far more sturdy than they actually have to be. But to make those decisions, they first have to know the physical limits of the materials they're working with. The best way to do that: Take a scaled version of a girder, pillar, or concrete slab and push it past the breaking point. Yes, this is, in fact, as awesome as it sounds.

The Constructed Facilities Laboratory at North Carolina State University is one of the places in the United States where this kind of research happens. In this lab, engineering researchers shake, bend, freeze, and crush the stuff that supports our world. I got to take a tour of this lab back in January, led by lab manager, Greg Lucier.

The videos here will take you through the 4500-square-foot lab and introduce you to the equipment these engineers use—from giant compression machines to something called a "Thermotron environmental chamber."

We'll start with a quick spin around the lab, just to get acquainted with the space. Then, you'll learn how some of the systems you see here work and why they're so important. Finally, you'll get to watch the lab in action.

The Constructed Facilities Laboratory is more than just a big room where engineers break stuff. The lab itself is designed to make it easy to set up experiments and apply both vertical and horizontal pressures to materials. In this video, Greg Lucier explains why the walls and the floors matter, and shows off the results of a bridge column strength test.

A building that can survive an earthquake is a building that will save lives. Shake tables are moving platforms that allow engineers to mimic the effects of an earthquake, or even recreate the shaking of a historic earthquake. In this video, Lucier shows off the lab's shake table, which is set up to test a scale model of a steel building frame.

The weather conditions a structure has to deal with in Minnesota are not the same as the conditions in coastal Alabama. That's where the Thermotron environmental chamber comes in. This metal box, which looks a lot like a walk-in freezer at a restaurant, allows engineers to cool and heat materials as they physically stress them. The Thermotron is also where the researchers make messes—spraying materials with salt water, for instance.

The Constructed Facilities Laboratory has a geotechnical side, as well. This is where researchers mock up the soil a building sits on, helping them understand what happens to different types of construction on different types of geology. It involves a deep, round pit.

Sure, you can take a piece of pipe and rig it up to some pistons and bend it around until it breaks—but how do you collect the data? In this video, Greg Lucier shows us one of the ways that engineers monitor the materials they're destroying.

What works in the laboratory is not always the same thing as what works in the real world. So how do engineers know that the results of tests like these actually apply for a real-life bridge, or a building that actually has people in it? In this video, we learn a little about the verification system that connects data to the bigger context.

Of course, I know that you all really came to this feature to see stuff actually get destroyed in the name of science. Now that we've got all the educational bits out of the way, you will get your reward. Here is one-and-a-half minutes of exploding girders, walls, columns and pylons—naturally, it's all set to the tune of the 1812 Overture, aka, "that song we play while we blow things up."

You might also enjoy this live webcam from the Constructed Facilities Laboratory.

Anechoic chambers are pretty damn awesome. Basically, they're rooms designed to be sound-proofed against outside noise, while, inside, sound is prevented from bouncing off the walls. There's no echo. There's a number of ways you can build this, but one system at the University of Salford in England, is actually a room within a room, with the innermost chamber actually mounted on springs, rather than the floor of the outer room.

Anechoic chambers are often used to test out audio equipment or to get accurate audio measurements on systems that are supposed to operate very quietly.

Minnesota Public Radio recently went inside the room that holds the title for world's quietest—an anechoic chamber at Orfield Laboratories in Minneapolis.

To get into the anechoic chamber, you go through two bank vault-like doors. The floor in the room is mesh like a trampoline so there's nothing on the floor for the sound to bounce off of. The walls are lined with sound-proofing wedges that are a meter long so they absorb the sound.

...A typical quiet room you sleep in at night measures about 30 decibels. A normal conversation is about 60 decibels. This room has been measured at -9 decibels.

Listen to the rest of the story at Minnesota Public Radio's website.

Read about the history of anechoic chambers.

Still think that something other than a mere plane crash brought down the World Trade Center towers? According to a Norwegian materials expert, you may be right. Just ... you know ... not in the way most Truthers probably expect.

Christian Simensen thinks the Twin Towers were ultimately felled by a thermite reaction.

"If my theory is correct, tonnes of aluminium ran down through the towers, where the smelt came into contact with a few hundred litres of water," Christian Simensen, a scientist at SINTEF, an independent technology research institute based in Norway, said in a statement released Wednesday.

"From other disasters and experiments carried out by the aluminium industry, we know that reactions of this sort lead to violent explosions."

Given the quantities of the molten metal involved, the blasts would have been powerful enough to blow out an entire section of each building, he said. This, in turn, would lead to the top section of each tower to fall down on the sections below.

The sheer weight of the top floors would be enough to crush the lower part of the building like a house of card, he said.

I honestly don't know how plausible an idea this is. It sounds reasonable to a layperson, but I'm curious what those of you with more engineering expertise think.

The AFP has a write-up about the theory. There's also a more-detailed explanation on the website of SINTEF, the Norwegian research lab where Simensen works. Finally, this appeared in the trade journal Aluminum International Today, and they've got an email address where you can request a copy of the story.