Dark Matter

Dark Matter Latest News

A recent study led by the Indian Institute of Astrophysics (IIA) has focused on the peculiar case of galaxy NGC 1052-DF2, which appears to lack dark matter—a component traditionally considered essential for galaxy formation.

About Dark Matter

• Dark matter is a hypothetical form of matter that does not emit, absorb, or reflect light, making it invisible and detectable only through its gravitational effects.
• It constitutes about 27% of the universe’s total mass-energy content, while visible matter accounts for only about 5%.
• Dark matter is essential for explaining the observed structure and formation of galaxies, galaxy clusters, and the overall large-scale structure of the universe.
• It acts as a cosmic “scaffolding,” holding galaxies together and influencing their rotation and movement.
• Unlike ordinary (baryonic) matter, dark matter does not interact with electromagnetic forces, only gravity.
• The leading candidates for dark matter include:
  • Weakly Interacting Massive Particles (WIMPs)
  • Axions (hypothetical ultralight particles)
  • Massive astrophysical compact halo objects (MACHOs) such as black holes, white dwarfs, and neutron stars.

Dark Energy

• Dark energy makes up approximately 68% of the universe and appears to be associated with the vacuum in space. It is distributed evenly throughout the universe, not only in space but also in time – in other words, its effect is not diluted as the universe expands. 
• The even distribution means that dark energy does not have any local gravitational effects, but rather a global effect on the universe as a whole. This leads to a repulsive force, which tends to accelerate the expansion of the universe. 
• The rate of expansion and its acceleration can be measured by observations based on the Hubble law. 
• These measurements, together with other scientific data, have confirmed the existence of dark energy and provide an estimate of just how much of this mysterious substance exists.

Dark Matter FAQs

Q1. What is dark matter in simple terms?

Ans. Dark matter is invisible matter that we can’t see but know exists because of its gravity.

Q2. Why is 95% of the universe invisible?

Ans. Because most of the universe is made up of dark matter and dark energy, which don’t emit light.

Q3. Does dark matter 100% exist?

Ans. Scientists are almost sure it exists due to its effects, but it hasn’t been directly detected yet.

Q4. Is dark matter a real thing?

Ans. Yes, it’s considered real because of the way it affects galaxies and cosmic structures.

Source: TH