Dark Matter Holds Sway: Challenges to MOND
Dark Matter: The Mysterious Candidate
Dark matter is a hypothetical form of matter that is invisible to our current instruments and does not interact with light or the electromagnetic field.
It is estimated to comprise about 85% of the matter in the universe, with visible matter making up only a small fraction.
Dark Matter's Role in Rotation
Galaxies rotate much faster than expected based on the gravity of their visible stars and gas.
Dark matter is theorized to form a massive halo around galaxies, providing the additional gravity needed to explain their observed rotation speeds.
This invisible halo would have a much larger distribution than the visible matter, explaining the constant rotation velocities even at far distances from the galactic center.
MOND: A Rival Theory
Milgromian dynamics (MOND) proposes a breakdown of Newtonian gravity at low accelerations, potentially explaining galactic rotation without dark matter.
Testing MOND
Recent studies using data from the Cassini mission and observations of binary star systems and distant Solar System objects contradict MOND's predictions.
Further Challenges to MOND
MOND struggles to explain the motions within galaxy clusters, requiring inconsistent gravitational effects in different regions.
The Future of Dark Matter
Despite challenges, the standard dark matter model is still favored over MOND due to its ability to explain various observations.
The nature of dark matter might be different from what we currently understand in the Standard Model of particle physics.
MOND may require reformulation to be a viable alternative, but the possibility of modified gravity on large scales remains open for exploration.
Conclusion
Current evidence suggests dark matter remains the most likely explanation for galactic discrepancies. MOND faces significant challenges in explaining various astronomical phenomena. The search for a comprehensive theory that incorporates dark matter or a refined theory of gravity is ongoing.
Dark Matter Theory vs MOND Theory
Comments