---
title: "Tidal hypothesis"
subject: "Engineering Geology I"
chapter: 2
key: "semester_3/engineering_geology_i:tidal-hypothesis"
source: https://www.bctengineer.com/q/semester_3/engineering_geology_i/tidal-hypothesis
site: BCT Engineering
---

# Tidal hypothesis

Engineering Geology I · Chapter 2: Basic Reviews of the Earth

- Asked in: 2081 Chaitra (new course), 1 marks
- Video: [Tidal hypothesis](https://www.youtube.com/watch?v=GS3XbwDrpys) — The BigBang Geology
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/engineering_geology_i/tidal-hypothesis
- Whole chapter: https://www.bctengineer.com/md/semester_3/engineering_geology_i/chapter-2

## Question

Define the tidal hypothesis for the origin of the earth.

## Short answer

A passing star pulled a cigar-shaped gas filament from the Sun, which broke into pieces that condensed into planets. Earth formed from a hot gaseous mass that gradually cooled.

## Answer

The **tidal hypothesis** (Jeans and Jeffreys, 1919) says that a huge star passed near the Sun, and its gravity pulled a long, cigar-shaped filament of hot gas out of the Sun. This filament broke into pieces as the star moved away, and the pieces condensed into the planets, which revolve around the Sun. The Earth thus formed from a hot gaseous mass that gradually cooled.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. In the tidal hypothesis, planets formed from:
   A. A rotating nebula ring
   B. Collision of planets
   C. Gas pulled out of the Sun by a passing star
   D. Cold dust
   Answer: C. Cigar-shaped filament broke up. (Key point: Cause)

2. Tidal hypothesis is credited to:
   A. Kant
   B. Laplace
   C. Wegener
   D. Jeans and Jeffreys
   Answer: D. 1919. (Key point: Proposers)

3. The material pulled out was:
   A. Cigar-shaped filament
   B. A ring
   C. A sphere
   D. A disc
   Answer: A. Filament broke into pieces. (Key point: Shape)

## Related in Engineering Geology I

- [Nebular hypothesis](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Anebular-hypothesis) — Engineering Geology I, chapter 2