Final answer:
True, numbers and letters are used on blueprints to locate specific points or parts, similar to how latitude and longitude are used on maps. This system is essential for navigation and accurate representation of positions either on the Earth or in the sky.
Step-by-step explanation:
The use of letters and numbers to locate a specific point or part on a blueprint is indeed a practice in engineering and drafting. These characters are part of a coordinate system that is crucial for accurately describing the location of different aspects of a design. For example, on blueprints of buildings, grids are often used with alphanumeric codes to pinpoint specific locations. Similarly, on maps, latitude and longitude provide a grid system that uniquely identifies any location on Earth. These coordinates are essential for navigation and for understanding the apparent motion of celestial objects as well.
Mapmakers also rely on additional elements like scale, orientation, and symbols to convey the correct information. Scale refers to the ratio of distance on the map to the actual distance on the ground, which can be represented in both kilometers and miles. Orientation is typically indicated by a north arrow, and any symbols or colors used on the map are usually accompanied by a legend or key for reference. Both terrestrial and astronomical mapmakers utilize these tools to create accurate representations of our world and the sky.