While researching a topic, a student has taken the following notes:Gravitational waves are powerful ripples that originate in deep space...
GMAT Expression of Ideas : (Expression) Questions
While researching a topic, a student has taken the following notes:
- Gravitational waves are powerful ripples that originate in deep space and eventually pass through Earth.
- The Laser Interferometer Gravitational Wave Observatory (LIGO) is a physics study that began in 2002.
- LIGO's goal is to detect and analyze gravitational waves.
- LIGO uses a pair of massive gravitational wave detectors called interferometers that are thousands of miles apart.
- In 2015, for the first time in history, LIGO researchers detected a gravitational wave passing through Earth.
The student wants to present LIGO's aim and methodology. Which choice most effectively uses relevant information from the notes to accomplish this goal?
In 2015, LIGO's massive interferometers detected a powerful ripple that originated in deep space and eventually passed through Earth.
Though the physics study LIGO began in 2002, its massive interferometers didn't detect a gravitational wave until 2015.
To achieve its aims, LIGO uses a pair of massive interferometers that are thousands of miles apart.
A physics study designed to detect and analyze gravitational waves, LIGO uses a pair of massive interferometers that are thousands of miles apart.
Step 1: Decode and Map the Passage
Create Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| "Gravitational waves are powerful ripples that originate in deep space and eventually pass through Earth." |
|
| "The Laser Interferometer Gravitational Wave Observatory (LIGO) is a physics study that began in 2002." |
|
| "LIGO's goal is to detect and analyze gravitational waves." |
|
| "LIGO uses a pair of massive gravitational wave detectors called interferometers that are thousands of miles apart." |
|
| "In 2015, for the first time in history, LIGO researchers detected a gravitational wave passing through Earth." |
|
Provide Passage Architecture & Core Elements
Main Point: LIGO is a physics project that uses specialized equipment to detect gravitational waves and achieved its first successful detection in 2015.
Argument Flow: The notes start by establishing what gravitational waves are, then introduce LIGO as the study designed to investigate them. We learn LIGO's specific goal and methodology, followed by its historic achievement.
Step 2: Interpret the Question Precisely
What's being asked? We need to find which choice most effectively presents LIGO's aim AND methodology using information from the notes.
What type of answer do we need? A sentence that combines both the purpose (what LIGO is designed to do) and the method (how it does it).
Any limiting keywords? None specified.
Step 3: Prethink the Answer
- From our analysis, we know LIGO has a clear aim: to detect and analyze gravitational waves
- We also know its methodology: using two massive interferometers positioned thousands of miles apart
- The right answer needs to present both pieces of information clearly and effectively
In 2015, LIGO's massive interferometers detected a powerful ripple that originated in deep space and eventually passed through Earth.
✗ Incorrect
- This focuses entirely on the 2015 detection result
- While it mentions interferometers (methodology), it completely ignores LIGO's aims
Though the physics study LIGO began in 2002, its massive interferometers didn't detect a gravitational wave until 2015.
✗ Incorrect
- This is primarily about timeline
- Mentions methodology (interferometers) but doesn't explain LIGO's aims
To achieve its aims, LIGO uses a pair of massive interferometers that are thousands of miles apart.
✗ Incorrect
- Mentions methodology clearly but says "to achieve its aims" without stating what those aims actually are
A physics study designed to detect and analyze gravitational waves, LIGO uses a pair of massive interferometers that are thousands of miles apart.
✓ Correct
- Clearly states LIGO's aim: "designed to detect and analyze gravitational waves" and methodology: "uses a pair of massive interferometers that are thousands of miles apart"