From UPSC perspective, the following things are important :
Prelims level : Primordial Black Holes, Big Bang
Mains level : Black Holes
A scientist duo from Pune has studied primordial black holes that were born as a result of a tiny bump in the potential energy levels of the universe, at a time when it was expanding rapidly.
Strange space events are known to be the favourites of UPSC 🙂
Primordial Black Holes (PBH)
- PBH are a hypothetical type of black hole that formed soon after the Big Bang
- It is believed that they are formed as a result of collapsing radiations as opposed to the collapse of massive stars, which is the case of any other black holes.
- PBH can be massively large as 3000kms or be extremely tiny like nucleus of an atom.
What did the study conclude?
- The study has confirmed that this marginal rise in potential energy resulted in birth of several PBHs and also emitted very powerful gravitational waves.
- Approximately 14 billion years ago before the commencement of the Hot Big Bang phase, the very young universe was found to be active and expanding at a highly accelerated rate.
- This exponential growth in its size was fuelled by the presence of uniform energy field and density as the universe passed through the Cosmic Inflation phase.
- According to the scientists, as time passes, this uniform energy prevailing in the Inflation Field wanes out.
- As a result, the universe resumes its normal decelerating rate.
Expansion of universe
- Gravity is normally attractive in nature. The PBH did undergo rapid expansion due to the Inflation field which contrarily possessed repulsive gravity.
- This pushed the universe to expand at a much faster rate than normal.
- The universe had expanded to nearly 10^27 times its original size, that too, within just fraction of a second by the time Cosmic Inflation phase concluded.
- Thereafter, the remnant energy possessed by this gravitational force got converted mainly into photons (light) in addition to protons, electrons, neutrons and other particles.
- As the universe continued to grow exponentially during the Cosmic Inflation phase, it sent across tiny quantum jitters.
- These fluctuations, released in a specific fashion, when sufficiently large, slowly give birth to galaxies and stars. Among those that were significantly large, helped form PBHs.