The Golden Gate Bridge, pictured above, is a suspension bridge. The cost was likely a major factor, as well as the distance and available materials (again, cost). The number of possible towers had to be considered, as well as required maintenance, fatigue, and, most importantly, the bridge had to be able to hold the dead and live load. Environmental factors, such as high winds and earthquakes, also had to be considered.
The video mainly talked about how engineering designs are constantly going through the cycle of success and failure: if it succeeds, it will be changed elaborated on until it fails, and if it fails, it will be improved so that it succeeds. Engineers try to anticipate failures and change the design to prevent them, but not everything can be caught and sometimes the structures do fail.
Some examples of these failures are the Challenger, which exploded just after take-off, the Tacoma Narrows Bridge which twisted in the wind and eventually collapsed when there were powerful winds, and the two sky-walks that collapsed at the hotel during the dance.
Stresses (pushing, pulling, bending, and tortion) and materials are important factors in these failures. Different materials have different strengths, so if a material that's too weak is used, this can cause a failure. In addition, stresses, if not considered and anticipated for, can also cause failure. For example, the engineers of the Tacoma Narrows Bridge were so focused on preventing it from bending that they completely forgot to plan for tortion, which caused its collapse.
However, this failure is necessary for success. When something fails, people analyze what went wrong and learn from it, so the same mistake is not made twice, as demonstrated by the pyramids. One was built too steep and failed, and all the ones built after that were built at a less steep angle.
Today, engineers can test structures using very detailed models in various conditions (such as wind chambers) to see if the actual structure would withstand those same conditions (on a bigger scale, of course). This is incredibly useful, especially because there are no human lives at risk. If the entire, full-size structure were built and it failed, it would result in casualties, but if the design fails in this testing stage, nobody is hurt, and the design can then be improved so that it succeeds.
I enjoyed learning about the history and design behind the Pantheon. All the innovations required to build it is fascinating, and made even more so by the fact it was built over 2000 years ago. I found the how the Romans had to create a completely new design structure to incorporate the oculus very impressive. In addition, I thought it was ingenious of them to put in the oculus so they could see the heavens, allow light in, and cool off the inside, even when it was sweltering outside.
This TED talk really inspired me to want to incorporate more art and design in my future engineering projects. I never thought of consciously combining art and engineering, but now I feel like it could make some awe-inspiring creations.