WORMHOLE
Source: TheHindu
Introduction:
Discussions between theoretical physicists can sound very other-worldly and often seem to buzz around highly abstract concepts and ideas. It seems like a science-fiction.
Wormhole:
A wormhole is a bridge or shortcut between two points in curved space-time which are well separated in practical terms from the inhabitants of the universe.
Interstellar Travel:
- Let us imagine, sitting in a four-dimensional world and observing a 2-dimensional sub-universe embedded in the universe.
- This universe is like a sheet of paper/ ribbon on which tiny bugs live, and crawl.
- When the paper/ribbon is flat, there is only one way to get from one point to another.
- But if the paper/ ribbon is bent like ‘U’, the observer can see that some parts of the folded paper may appear to be close to other parts.
- According to the observer, to get from one of these points to the other, it would be quicker if the bug could jump across the intervening space.
- The bug being a 2-dimensional creature cannot see this closeness.
- Also, it is constrained to move on the surface of the ribbon. So, it has to traverse the whole length of the ribbon to reach the other point, it cannot jump across the fold and make a shortcut to the second point.
Observations:
- Our universe when viewed from a higher dimension is like a ribbon and we are the bugs constrained by its limits.
- When there is no gravity, our universe will be flat like a sheet.
- When there is a strong gravitational field, this sheet will bend so that a portion of it may look like the piece of ribbon which was folded.
- We, like bugs on the ribbon, are constrained to take the long route through space-time to reach points that appear close to the higher dimensional observer.
Cutting Across Spacetime:
- Imagine if a bridge is built connecting the two points on the ribbon, the bugs can crawl over the bridge to the target point instead of crawling down the entire length of the ribbon.
- This clearly explains the mechanism of the wormhole.
- In the universe, a wormhole can act as a bridge or a shortcut between two points in curved space-time which are well separated in practical terms from the inhabitants of the universe.
Wormhole fiction/ fact:
- Just like black holes predicted by Einstein’s theory of gravity long before, wormholes are also not fictitious.
- Ludwig Flamm, in 1916, first discovered that wormholes may exist, soon after Einstein proposed the General Theory of Relativity which explains gravitational field.
- The presence of wormholes has not yet been established through observation or inference by astronomers.
Conclusion:
With rapid advances in observational cosmology like the detection of gravitational waves by LIGO-VIRGO collaborations, Einstein’s theory is coming to the fore.
