Science
The Lincoln Memorial Reflecting Pool is treated with nanobubbles. What are they and how do they work?
Key Points
As the United States approaches its 250th birthday celebrations on July 4, Washington, DC's monuments, statues and fountains are being prepared to put on a show.
As the United States approaches its 250th birthday celebrations on July 4, Washington, DC's monuments, statues and fountains are being prepared to put on a show.