The evidence of dark matter is seen clearly in the CMB, which was emitted before any compact objects could have formed.Quds Akbar said:I have been thinking about this quite often, and I know that usually WIMPs are taken more seriously than MACHOs, and I know it is because MACHOS don't exist in such huge amounts, but why are they considered better candidates for Dark Matter?
Thanks for sharing! The last page of that piece is one of the very best summaries that I've seen on the subject of the CMB.Chronos said:See http://background.uchicago.edu/~whu/intermediate/driving2.html for discussion.
Dark matter is a type of matter that cannot be observed directly because it does not emit or absorb light. It is thought to make up about 85% of the total matter in the universe and plays a crucial role in the formation and evolution of galaxies. By studying dark matter, scientists hope to gain a better understanding of the structure and evolution of the universe.
WIMPs and MACHOs are two of the most widely studied candidates for dark matter. WIMPs (Weakly Interacting Massive Particles) are theoretical particles that interact with regular matter through weak nuclear forces. MACHOs (Massive Compact Halo Objects) are objects such as black holes, neutron stars, or brown dwarfs that are too small to emit light but have enough mass to affect the motion of stars and galaxies.
Scientists are using a variety of methods to detect WIMPs and MACHOs. One approach is to search for the indirect effects of dark matter, such as the radiation produced when dark matter particles annihilate. Another method is to look for the gravitational lensing effect caused by dark matter on the light from distant objects. Direct detection experiments involve looking for collisions between dark matter particles and regular matter in underground detectors.
There are several theories about the nature of dark matter, but the most widely accepted one is the Cold Dark Matter (CDM) theory. This theory suggests that dark matter is made up of slow-moving particles that were created in the early stages of the universe. Other theories propose that dark matter is made up of particles that interact with each other through additional forces beyond the known fundamental forces of nature.
Studying WIMPs and MACHOs will help us understand the structure and evolution of the universe on a large scale. By learning more about the properties and behavior of dark matter, we can gain insights into the formation of galaxies, the distribution of matter in the universe, and the overall fate of the universe. Additionally, the discovery of new dark matter particles could also have implications for our understanding of particle physics and the fundamental laws of nature.