Myth: Mount Everest is the Tallest Mountain on Earth

While Mount Everest is the highest point above sea level, Mauna Kea is indeed taller when measured from its base on the ocean floor. This makes it the tallest mountain on Earth in terms of total height.

Here's a breakdown of the two:

Mount Everest:

Height above sea level: 29,031.7 feet (8,848.86 meters)  
Base elevation: Sea level

Mauna Kea:

Height above sea level: 13,796 feet (4,205 meters)
  Base elevation: Approximately 19,700 feet (6,000 meters) below sea level
  Total height: Approximately 33,500 feet (10,210 meters)

  So, while Everest holds the record for the highest point above sea level, Mauna Kea takes the crown for the tallest mountain from base to summit.

Myth: Dropping a Penny from a Skyscraper Can Kill Someone

While the idea of a penny dropped from a skyscraper might seem dangerous, it's actually a common misconception.

Here's why:

Terminal Velocity: A penny quickly reaches its terminal velocity, which is the maximum speed it can attain due to air resistance. This speed is relatively low, around 25-30 mph.
Impact Force: At this speed, the impact force of a penny isn't enough to cause serious injury or death. It might sting if it hits you, but it won't penetrate the skin or cause significant damage.

So, while it's not advisable to drop things from tall buildings, you don't need to worry about a falling penny causing harm.

Myth: The Great Wall of China is Visible from Space

It's a common misconception that the Great Wall of China is visible from space with the naked eye. While it's a massive structure, its width is relatively small compared to the vastness of space.  

Here's a breakdown of why it's difficult to see:

Width: The Great Wall is not uniformly wide. While some sections are wider, many parts are quite narrow, making them difficult to distinguish from the ground below, especially from the vastness of space.
Color: The wall's color blends in with the surrounding landscape, further hindering its visibility from orbit.
Distance: Even from low Earth orbit, the distance is significant enough to make it challenging to discern such a narrow structure.

While it's not visible to the naked eye, high-resolution satellite images can capture the wall due to their advanced imaging capabilities.

It's a fascinating topic that highlights the limitations of human perception when compared to the scale of the universe.