Context:
Recently, astronomers detected 7 potential ‘ghost particles’ that passed through planet.
Ghost Particles:
- Neutrinos (tiny subatomic particles) that barely interact with anything else other than water molecule
- Discovery of astrophysical tau neutrinos – Provides a strong confirmation of IceCube’s earlier discovery of the diffuse astrophysical neutrino flux
- Astrophysical neutrinos – High-energy neutrinos that come from the farthest reaches beyond our galaxy
- Particles come in 3 different flavours – Electron, muon and tau
- Significance –
- Helps in detecting cosmic rays and understanding universe
- Can travel massive distances undisturbed
- Easier to trace them back to their source
Difference between Electron, Muon and Tau:
| Electron | Muon | Tau | |
| Mass | Less massive lepton (0.511 MeV/c2) | 105.66 MeV/c2 | Most massive lepton (1776.86 MeV/c2) |
| Stability | Stable and participate in the creation of atoms | Unstable and decay through weak interaction | Unstable and decay through weak interaction and decay into hadrons |
| Visibility | Easily detected in everyday life | Harder to detect | Harder to detect |
| Interactions | Primarily interact via the weak nuclear force | Interacts via strong nuclear force and the gravitational force. | Interacts via strong nuclear force and the gravitational force. |
IceCube Neutrino Observatory:
- Detector encompassing a cubic kilometer of ice and designed to search for the nearly massless neutrinos.
- Designed – To observe the cosmos from deep within the South Pole ice
- Location – Antarctica
- Significance – Provides information to probe the most violent astrophysical sources
- Events like – Exploding stars, gamma-ray bursts, and cataclysmic phenomena involving black holes and neutron stars
- Observatory uses “strings” (cables) of digital optical modules (DOMs) to detect neutrinos embedded deep within Antarctic ices
- Maintenance and Operations – The University of Wisconsin–Madison
- Collaborators – Approximately 300 physicists from 59 institutions in 14 countries
- Funding – National Science Foundation (NSF)
- With assistance from partner funding agencies around the world
Related articles: Antimatter, Leptons and Leptonic atoms
Source: Indian Express
Previous Year Question
Consider the following statements:
1. Light is affected by gravity.
2. The Universe is constantly expanding.
3. Matter warps its surrounding space-time.
Which of the above is/are the prediction/predictions of Albert Einstein’s General Theory of Relativity, often discussed in media?
[UPSC Civil Services Exam – 2018 Prelims]
(a) 1 and 2 only
(b) 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Answer: (d)
