It is believed that dreams sometimes help us solve problems. It is also proposed that a critical aspect of dreaming lies in the processing of memories.

       Researcher Erin Wamsley designed a study in which participants explored a virtual maze, trying to learn its layout. Then she let them take a 90-minute nap. After their nap, she asked them whether they remembered dreaming about the task and then tested them on the maze again. The results were astonishing. Participants who had no memory of dreaming about the task took, on average, one and a half minutes longer to find their way out of the maze after their naps. However, those who reported that they had dreamed about it found their way out two and a half minutes faster than before. Erin then repeated the experiment by actually waking subjects to collect dream reports and identify those whose dreams were related to the task. She found that the latter showed almost 10 times more improvement after their naps compared with the participants who reported no related dreams.

       What exactly did they dream about? One participant reported: “I was thinking about the maze…, and then that led me to a cave trip I had a few years ago. The cave is maze-like.” Another recalled hearing the music played in the background while exploring the maze.

       Dreams like these seemed unlikely to help participants enhance their memories of the maze’s layout. And yet they were reported by the very participants who showed the greatest improvement. The sleeping brain was both enhancing its memory of the maze layout and creating related dreams. So, these dreams must be serving some other function. But what?

       Perhaps some strategy you learned while exploring a cave will help you the next time you try the maze task. Conversely, maybe something you learned from the maze task will help you next time you’re down in a cave. Your brain suddenly realizes, hey, exploring mazes and caves is really the same thing. It is a perfect example of the function of dreaming that researchers like Erin Wamsley propose: the extraction of new knowledge from existing information through the discovery of unexpected associations.

       On September 11th, 2001, tragedy struck the city of New York when terrorists crashed airplanes into the twin towers of the World Trade Center in lower Manhattan. From the ashes of those iconic buildings, however, would rise a new city landmark – the glimmering One World Trade Center.                      Construction on 1 WTC began in April of 2006, but it wasn’t until May of 2015 that the doors were finally open to the public. This was due to the numerous challenges facing architects, engineers, and construction crews while they worked on the project. First and foremost were the cleanup efforts in and around the area where the twin towers came down. This is the site that would come to be known as Ground Zero. This alone took eight long months.

     After the cleanup, architects and engineers had to put their heads together to determine how they would make this new structure fit in with the infrastructure that was already in place. Beneath the site there were already train and subway tracks to take into consideration, all at different depths. To make things even more complicated, construction of 1 WTC could not interrupt train or a subway service. This meant they would have to work around the train and subway tunnels. It wasn’t easy, but after analyzing everything that was there underground in four dimensions, the team was able to figure it out.

    Yet another challenge was the sheer size of the building, and how to put together its massive beams and columns, some weighing as much as 72.5 metric tons. In order to get this done, two of the largest cranes ever used in the history of New York City had to be brought in to lift them up.

    The result of all this time, planning, and effort is one of the safest and strongest towers ever built. In the end, the estimated price tag for the building was US$3.9 billion. However, for many New Yorkers, seeing a new tower rise up where the twin towers once stood is something no one can put a price on.