What are the different types of dark matter?

How many types of dark matter are there? And what are these Non-baryonic dark matter? 

Also what does it mean when they say planets in space moves relativistically vs some than move ultrarelativistically?

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  • 2 months ago

    Types of "dark matter" are unseen and unknown.  Only gravity effects are definite.

    Have not seem anyone describe planets that way.  Who are they?

  • 2 months ago

    It's not even confirmed that *any* dark matter exists... There were two proposals several years ago - I haven't heard of any new proposals:

    WIMPs:  Weakly Interactive Massive Particles - (From wikipediia): are hypothetical particles that are one of the proposed candidates for dark matter. There exists no clear definition of a WIMP, but broadly, a WIMP is a new elementary particle which interacts via gravity and any other force (or forces), potentially not part of the Standard Model itself, which is as weak as or weaker than the weak nuclear force, but also non-vanishing in its strength.

    and

    MACHOs: Massive Astrophysical compact Halo Objects: A MACHO is a body that emits little or no radiation and drifts through interstellar space unassociated with any planetary system (and may or may not be composed of normal baryonic matter). 

    So far, neither particle has been detected nor confirmed to exist. 

    Non-baryonic matter is a hypothetical form of matter; it doesn't have protons or neutrons; it could be zillions of lighter-massed particles (like Neutrinos) or electron-positron pairs, or it could be a very non-reactive massive single particle that can only be detected by its gravity....  

    Relativistically movement vs ultra-relativistically movement is usually used in reference to particles - like those found in the Van Allen belts, as opposed to planets.. as you'd expect, both references are about very high speeds; and ultra-relativistic speeds are those approaching very close to the speed of light. 

  • 2 months ago

    Dark matter doesn't really exist in the sense conceived of by most scientists, although that's not an orthodox opinion.  The different ideas regarding it are that there is hot dark matter, which is exotic particles moving at high speed, cold dark matter, which is again exotic particles but able to form structures and generally behaving like atomic matter to some extent, and baryonic dark matter, which is stuff like dust and rogue planets.  Non-baryonic dark matter is the most problematic because almost by definition there can be no direct evidence for it other than that it accounts for large-scale discrepancies in movement associated with gravitation.

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