The reference point for determination of GMT...

Question 1 / 2707066636ee928f7522a1c519fa8

Question 1 of 2707066636ee928f7522a1c519fa8

The reference point for determination of GMT is the passage of the mean sun over what line?

Question 1 of 27070

The reference point for determination of GMT is the passage of the mean sun over what line?

🔍 Key Concepts

• Greenwich Mean Time (GMT) and what location on Earth it is based on • The definition of a prime meridian in navigation and timekeeping • How the mean sun is used as a reference in determining time zones and standard time

💭 Think About

• Ask yourself: At what specific longitude is the world’s standard time reference established for GMT? • Consider which line is internationally agreed upon as the starting point (0°) for measuring longitude east and west. • Think about whether GMT is tied to the observer’s local position, a celestial reference point, or a fixed Earth-based meridian.

✅ Before You Answer

• Identify which choice corresponds to the prime meridian used for world timekeeping. • Confirm whether GMT is based on a fixed Earth meridian rather than on the observer’s changing position. • Be sure not to confuse a celestial reference point (used in celestial navigation) with the Earth-based meridian used to define GMT.

Question 1 of 27070

The reference point for determination of GMT is the passage of the mean sun over what line?

180° longitude

Observer's meridian

First point of Aries

0° longitude

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