What navigation equipment did europeans use in the 1400s

Among the oldest and most basic tools was the lead line, used since antiquity to measure depth. This measurement could tell sailors how far they were from land. Another low-tech device, the ka-mal, was developed in Asia and the Middle East. It used a piece of wood marked for the position of Polaris at the latitude of various ports. By 1400, more sophisticated versions used a length of knotted string so the navigator could, by placing the string in his mouth, sight the horizon and the height of Polaris to judge latitude.

Timepieces also aided in navigation. In 1400, mariners still used hourglasses. These, in connection with careful observation of shorelines and accurate logbooks, helped navigators estimate location and predict arrival times.

The video, "Before Cook's Voyage", shows early navigation tools such as compass, astrolabe, octant and back staff, telescopes and the need to solve the longitude problem (time). ... Celestial navigation requires the sailor to use an instrument, like a sextant, to find the angle between a star/planet and the horizon.

radioactive dating, also known as  radioisotope dating  is a process that in  estimating the approximate  age  of  rocks. these data can be analyzed from  the studies dealing with the  decay of the radioactive elements that are present in these rocks. in nature, there are a few types of materials or atoms which are quite unstable and they spontaneously decay or breakdown to form other kinds of atoms.

states

explanation:

as the old saying goes, all politics are local. state and federal governments affect our daily lives in numerous ways. yet, in our federal system, there is supposed to be a balance between federal and state power. as james madison envisioned it in federalist no. 51, “the power surrendered by the people” would be “divided between two distinct governments,” creating a balance of power that would enable the “different governments [to] control each other.”