Simultaneity: Astronaut Mark Uri Is Space-Traveling from Planet X to Planet

question 39

Multiple Choice

Simultaneity: Astronaut Mark Uri is space-traveling from planet X to planet Y at a speed of relative to the planets, which are at rest relative to each other. When he is precisely halfway between the planets, a distance of 1.0 light-hour from each one as measured in the planet frame, nuclear devices are detonated on both planets. The explosions are simultaneous in Mark's frame. What is the difference in the time of arrival of the flashes from the explosions as observed by Mark?

• A) 0 min
• B) 180 min
• C) 90 min
• D) 360 min
• E) 113 min

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Definitions:

Earthworks

Large-scale outdoor artworks created by altering the landscape, often using natural materials such as soil, rocks, and plants.

Land

The solid surface of the Earth that is not covered by water, playing a crucial role in human habitation, agriculture, and natural ecosystems.

High-Tech Architecture

A contemporary architectural style calling for buildings that incorporate the latest innovations in engineering and technology and expose the structures’ component parts.

Renzo Piano's Tjibaou Cultural Centre

A landmark of contemporary architecture in Nouméa, New Caledonia, designed by Renzo Piano, which celebrates the culture of the Kanak people.