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Research draft

dark matter

vr.tr.dark-matter · PHY.SPC

Let an agent describe dark matter with the evidence for it, the candidate explanations and what remains unknown, without overstating certainty.

Thing Registry Physical world and living systems

Research draft, second pass

A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.

written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify

Researched by: Claude

Purpose and description

Let an agent describe dark matter with the evidence for it, the candidate explanations and what remains unknown, without overstating certainty.

A hypothesised form of matter that does not emit, absorb or reflect light, inferred from its gravitational effects on galaxies, clusters and the cosmic microwave background, and making up most of the matter in the universe.

What it is for: Explaining galaxy rotation, gravitational lensing and cosmic structure.

It can be infer it, from gravitational effects; search for it, in direct detection and collider experiments; model it, in cosmological simulations; test alternatives, such as modified gravity.

Distinguishing features

Inferred from gravity, not seen

Not yet directly detected

Cold, warm and hot models differ

Modified gravity is an alternative explanation

What it looks like

Invisible; mapped indirectly through lensing and galaxy motions.

Physical character

share of matter: about 85 percent - of all matter, per standard cosmology

share of total energy density: about 27 percent

How it is recognised

Galaxy rotation curves flatter than visible matter predicts

Gravitational lensing maps

No direct detection so far

Related models

affects - structure

galaxy

is inferred from - evidence

curve such as rotation curves

is studied by - fields

astronomy and physics

is confused with - a different concept

dark energy

In practice

Families and kinds

cold dark matter

warm and hot dark matter

candidates: WIMPs, axions, primordial black holes

baryonic dark matter (largely excluded as main component)

Failure modes and hazards

Presenting dark matter as directly observed

Presenting speculative candidates as established

Confusing dark matter and dark energy

Also called

cold dark matterhot dark matterwarm dark matterbaryonic dark matterlight dark matterscalar field dark matterweakly interacting massive particleMeta-cold dark matterfuzzy cold dark matter

Where this came from

wikidata · CC0 1.0

Also registered as vr.tr.dark-matter

Drafted structure

Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.

Evidence Why it is inferred.

The evidence is indirect but strong.

Observations

Rotation, lensing, CMB.

Evidence

Lines of evidence.

  1. Which observations point to dark matter? provenance
  2. How strong is each line of evidence? measurement

Amount

How much.

Amount

Estimated amount.

  1. How much dark matter is inferred, from which data? measurement
  2. How uncertain is the figure? measurement
Nature What it might be.

Its nature is unknown.

Candidates

Particles and objects.

Candidates

Candidate explanations.

  1. Which candidates are considered, and what rules them in or out? definition
  2. Which are favoured, by whom? provenance

Alternatives

Modified gravity.

Alternatives

Alternative theories.

  1. How do modified gravity theories explain the evidence? definition
  2. Where do they fail? boundary
Searches Experiments.

Experiments test hypotheses.

Direct detection

Underground detectors.

Direct searches

Direct detection results.

  1. What have direct detection experiments found? provenance
  2. Which limits have they set? measurement

Indirect and collider

Other searches.

Other searches

Other search results.

  1. What do indirect and collider searches show? provenance
  2. Are there unconfirmed signals? boundary
Communication Explaining honestly.

Uncertainty must be stated.

Status

Known vs unknown.

Status

What is known.

  1. What is established and what is unknown? boundary
  2. How should that be worded? action

Confusion

Dark energy.

Clarification

Common confusions.

  1. Is dark matter being confused with dark energy? boundary
  2. How should the difference be explained? action

What the second pass must settle

  • How should the registry mark hypothesised entities?
  • Should candidates be separate entries?
  • How should alternative theories be represented fairly?