UPSC Prelims 2019 Q97: Science & Technology – Space Technology & Astronomy
- (a) 'Higgs boson particles' were detected.
- (b) 'Gravitational waves' were detected.
- (c) Possibility of inter - galactic space travel through 'wormhole' was confirmed.
- (d) It enabled the scientists to understand 'singularity'.
Answer: (b) 'Gravitational waves' were detected.
Explanation
Black Hole Mergers Observed: Significance
| Option | Significance | Correct? |
|---|---|---|
| (a) Higgs boson detected | LHC (CERN) work, not black holes | NO |
| (b) Gravitational waves detected | YES - LIGO's landmark 2015 detection GW150914 was from merger of two black holes ~1.3 billion light-years away. Confirmed Einstein's 1916 general-relativity prediction. Nobel 2017 (Weiss, Barish, Thorne). | CORRECT |
| (c) Wormhole space travel | Speculative, not confirmed | NO |
| (d) Understanding singularity | Singularity remains unresolved | Not the primary significance |
Black hole merger observations enable detection of gravitational waves - Einstein's century-old prediction. Answer: (b).
Answer: (b) 'Gravitational waves' were detected.
Why each option is right or wrong
- (a) Incorrect. Higgs boson was detected at CERN's LHC in 2012 - a different experiment.
- (b) CORRECT. LIGO's detection of gravitational waves from black hole mergers (GW150914, 2015) was the landmark observation - confirming Einstein's 1916 prediction and awarded Nobel Prize 2017.
- (c) Incorrect. Wormhole travel is theoretical speculation, not confirmed.
- (d) Incorrect. Singularity remains one of physics' unsolved problems.
Key point
LIGO detected gravitational waves from black hole mergers (2015, GW150914). Confirmed Einstein GR. Nobel 2017 (Weiss, Barish, Thorne). India-based LIGO under construction in Maharashtra.
Remember
The observation of black hole mergers billions of light-years from Earth (by LIGO, first detection GW150914 in 2015) is significant because it confirmed the detection of gravitational waves - a century-old prediction of Einstein's General Relativity (1916). The discovery was awarded the 2017 Nobel Prize in Physics.
Common mistakes
- Confusing gravitational waves (LIGO) with gravitational lensing (bending of light by mass).
- Assuming Higgs discovery is LIGO's - Higgs = LHC 2012, gravitational waves = LIGO 2015.
- Not knowing India is building the LIGO-India detector (Maharashtra, target ~2030).
Exam tip
LIGO milestones: 2015 = first GW detection (GW150914, BH-BH merger). 2017 = neutron star merger (GW170817) + electromagnetic counterpart = 'multi-messenger astronomy'. Ongoing: LIGO-Virgo-KAGRA network. Upcoming: LIGO-India (Maharashtra).
Sources
- LIGO Scientific Collaboration - First detection paper (Physical Review Letters, 2016)
- Nobel Prize 2017 - Rainer Weiss, Barry Barish, Kip Thorne