Navigation Technology - Astrolabe, developed by Greek astronomers around 150 BCE, enabled sailors to navigate using the sun and stars, expanding exploration [2] - Astrolabe helps determine latitude by measuring the sun's angle at midday relative to the horizon [2][3] - The angle from the vertical is calculated to determine the sun's position in the sky [3] - The device requires adjusting for the time of year to calculate latitude [4] - An example measurement yields a latitude of approximately 38 degrees [4] - The actual latitude is verified as 37.7 degrees, demonstrating the astrolabe's accuracy [5] - Astrolabe is unusable in cloudy conditions [5]