OpenLLM-France/wikimedia huggingface dataset:
# Introduction to graph theory/Proof of Theorem 4
## Statement

For a graph $G$, the following are equivalent:
* $G$ is a tree
* $G$ is a minimal connected graph, in the sense that the removal of any edge will leave a disconnected graph.
* $G$ is a maximal acyclic graph, in the sense that the addition of any missing edge will create a cycle.

## Corollary of

Corollary 3: A graph is a tree if and only if for every pair of distinct vertices $u,v$, there is exactly one $u,v$-path.

## Proof

Suppose $G$ is a tree, and let $uv$ be an edge not in $G$. By Corollary 3, there is exactly one $u,v$-path. If this path is $ux_{1}\ldots x_{k}v$, then adding the edge $uv$ will create the cycle $ux_{1}\ldots x_{k}vu$. As a tree is defined to be a connected forest and a forest is defined to be acyclic. A tree is therefore a maximal acyclic graph.
Now suppose $G$ is a tree, and let $uv$ be an edge of $G$. By Corollary 3, there is exactly one $u,v$-path. This path is clearly just the edge $uv$. Thus, in the graph $G-uv$, there is no $u,v$-path, and hence $G-uv$ is disconnected. Since a tree is defined to be a connected forest, a tree is therefore a minimal connected graph.
Now suppose $G$ is a maximal acyclic graph, but is not a tree. Since an acyclic graph is called a forest, and a tree is defined to be a connected forest, $G$ must be disconnected. Thus there exists vertices $u,v$ such that there is no $u,v$-path in $G$. In particular $uv$ is not an edge of $G$. As $G$ is a maximal acyclic graph, $G+uv$ must have a cycle. Since $G$ has no cycle, this cycle must include the edge $uv$. Let this cycle be $ux_{1}\ldots x_{k}vu$. Then $ux_{1}\ldots x_{k}v$ is a $u,v$-path in $G$. This contradiction shows that maximal acyclic graphs are trees.
Finally, suppose $G$ is a minimal connected graph, but is not a tree. As a tree is defined to be a connected forest, it follows that $G$ is not a forest, and hence (by definition), $G$ must have a cycle. Let $u,v$ be adjacent vertices on the cycle, and let the cycle be $ux_{1}\ldots x_{k}vu$. As $G$ is a minimal connected graph, $G-uv$ must be disconnected. Consider any vertex $x$. In $G$, there was a path from $x$ to $v$. If the path went through the edge $uv$, then in $G-uv$, there is clearly an $x,u$-path. Otherwise, there is clearly an $x,v$-path in $G-uv$. Either way, the connected component of $G-uv$ contains either $u$ or $v$. Since $ux_{1}\ldots x_{k}v$ is a $u,v$-path in $G-uv$, the connected component containing $u$ also contains $v$. Thus every vertex in $G-uv$ is contained in the same connected component, meaning that $G-uv$ is connected. This contradiction shows that minimal connected graphs are trees.
# Introduction to graph theory/Proof of Theorem 5
## Statement

A tree of order $n$ has $n-1$ edges.

## Corollary of

Theorem 4:For a graph $G$, the following are equivalent:
* $G$ is a tree
* $G$ is a minimal connected graph, in the sense that the removal of any edge will leave a disconnected graph.
* $G$ is a maximal acyclic graph, in the sense that the addition of any missing edge will create a cycle.

## Proof

For $n=1$, all graphs have $0=n-1$ edges. For $n=2$, there are two graphs, one with an edge and one without. The graph without an edge is disconnected, and therefore is not a tree, whereas the one with an edge is connected and has no cycles and therefore is a tree.
For $n=3$, there are 4 graphs, one each with 0, 1, 2 or 3 edges. The graphs with 0 and 1 edges are disconnected, while the graph with 3 edges has a cycle. The graph with 2 edges is connected and has no cycle, so the theorem is proved for $n\leq 3$.
Now suppose we have proved this theorem for all $n<k$, and let $T$ be a tree of order $k$. Remove an edge $e$ from $T$ to form a new graph $T-e$. By Theorem 4, $T$ is a minimal connected graph, and hence $T-e$ is disconnected. Any connected component of $T-e$ (by the connectedness of $T$) must have one of the vertices of $e$ in it, and hence $T-e$ has exactly two components.
The two components are connected, and have no cycles, and are therefore trees. Let there be $n_{1},n_{2}$ vertices in the two components of $T-e$. Then $n_{1}+n_{2}=k$. Further, there are $n_{1}-1,n_{2}-1$ edges in the components, so $T-e$ has $k-2$ edges in total. Therefore, putting edge $e$ back into the graph, $T$ has $k-1$ edges.
# PlanetPhysics/Topic on Axioms

\section{Topic on axioms in mathematics, logic algebra, mathematical physics and mathematical biophysics}

### Introduction

In classical logic, an axiom or postulate is a `simple', fundamental proposition that is neither proven nor demonstrated (within a theory) "but considered to be self-evident"; furthermore, the choice of an axiom or system of axioms is justified by the large number of consistent consequences or mathematical propositions derived from such axioms. One needs, however, to distinguish between `physical axioms' (often called `postulates' that apply to various fields of physics), and mathematical axioms that have both a meaning and scope of applicability which is distinct from that of physical postulates (or physical axioms). On the other hand, physical axioms, or postulates, are ultimately also expressed in a mathematical form, albeit without becoming axioms of mathematics, or specific fields of mathematics. (In the remainder of this entry the attribute `axiomatic' will be employed only with the meaning of `physical-axiomatic', or `physically-postulated'.)
Furthermore, physical postulates, unlike mathematical ones, emerged as a result of numerous experimental studies and crucial physical experiments that can be logically and consistently explained on the basis of such fundamental, physical postulates; often, mathematical formulations of such fundamental physical postulates are referred to as (physical) `axioms', as in the case of `axiomatic' QFTs.

### Axioms in Mathematics

* Axioms of Set theory
* Axioms of Number theory
* Axioms of Geometry
* Axioms of Topology
* Axioms of Homology and cohomology theories
* Axioms of topos theory
* Axioms for categories; axioms of category theory
* Axioms of algebraic K-theory
* Axioms of higher dimensional algebra (HDA)
* Axioms of Meta- and super- categories

### Axioms of Logic and Logic Algebras

* Axioms of Boolean logic algebra
* Axioms of $LM_{n}$ logic algebras
* Axioms of quantum logics
* Axioms of XYZ

### Axioms and Postulates in Mathematical Physics

* Postulates of Relativity theories: Special and general relativity
* Axioms of quantum geometry
* Axioms of local quantum physics (algebraic quantum field theories (AQFT))
* Axioms of XYZ

### Axioms and Postulates of Mathematical biology/Mathematical Biophysics

* Axiom of Organismic Selection
* Axioms of Genetics
* Postulate of Optimal Design
* Postulate of Relational `forces'
* Axioms of organismic complete self-reproduction
* Axioms of organismic supercategories
* Axiom of Fuzziness
* epimorphism axioms and homology
* adjointness axioms
* Axioms of XYZ
# PlanetPhysics/Topic on Axioms and Foundations of Homology and Cohomology Theories
### Axioms for Homology and Cohomology theories

* Axioms for homology theory and uniqueness theorems #Cech types #$K$-theory
* Generalized cohomology
* Generalized (extraordinary) homology and cohomology theories
* Galois Cohomology and Categorical Galois theories
* (Co)homology of commutative rings and algebras (e.g., Hochschild, Andr\'e-Quillen, cyclic, dihedral, etc.)
* Bordism and cobordism theories, formal group laws
* Homology with local coefficients, equivariant cohomology
* Sheaf cohomology
* Cohomology in noncommutative algebraic geometry
* Classifying spaces for foliations; Gelfand-Fuks cohomology
* Intersection homology and cohomology
* Elliptic cohomology
* Equivariant homology and cohomology
* Homology and homotopy of topological groups and related structures
* Homotopy quantum field theories and Axiomatic Quantum Field Theories
* non-Abelian Homological Algebra
* Grothendieck's `Anabelian Geometry' #Other homology theories--Your new additions
\begin{thebibliography} {99}
</ref></references>
* ↑ Hatcher, A. 2001. Algebraic Topology (textbook on line)., Cambridge University Press; Cambridge, UK., 405 pages.
* ↑ Ronald Brown: Topology and Groupoids, BookSurge LLC (2006).
* ↑ Ronald Brown R, P.J. Higgins, and R. Sivera.: "Non-Abelian algebraic topology" , (2008).
* ↑ R. Brown and J.-L. Loday: Homotopical excision, and Hurewicz theorems, for n-cubes of spaces, Proc. London Math. Soc., 54:(3), 176-192, (1987).
* ↑ R. Brown and J.-L. Loday: Van Kampen Theorems for diagrams of spaces, Topology , 26: 311-337 (1987).
* ↑ R. Brown and C.B. Spencer: Double groupoids and crossed modules, Cahiers Top. G\'eom. Diff. , 17 (1976), 343-362.
* ↑ Allain Connes: Noncommutative Geometry , Academic Press 1994.
* ↑ May, J.P. 1999, A Concise Course in Algebraic Topology. , The University of Chicago Press: Chicago
# PlanetPhysics/Topic on Equations in Mathematical Physics

This is a contributed topic on equations in mathematical physics.

## List of Physical/Mathematical Physics Laws and Equations

* Newton's laws of classical dynamics (laws of motion)
* Law of conservation of energy
* Conservation of angular momentum
* Classical and Quantum Hamiltonian Equations
* Einstein's law of mass-energy conservation (or `mass--energy equivalence')
* Einstein's field equations
* Euler--Lagrange equations
* Kepler's laws
* Navier-Stokes equations of fluid dynamics
* Snell's law in optics
* Newton's law of gravitation
* Coulomb's law
* Gauss's Law of magnetostatics
* Curie law in magnetism
* Ohm's law
* Faraday's law
* Amp\`ere's law
* Kirkhoff electrical circuit equations
* Lorentz force law
* Hook's law (elasticity equation)
* Lambert-Beer law
* wave equations
* Maxwell's equations
* Li\'enard-Wiechert Potentials and electrodynamic equations
* Schr\"odinger equation
* Heisenberg's quantum dynamics equation
* Gaussian metric (equation)
* Relativistic energy-momentum equation
* Relativistic center-of-mass theorem
* Relativistic equality of gravitational and inertial mass
* Thomson scattering cross section equation
* Compton scattering equation and
* Klein--Nishina equation for the differential cross section for Compton scattering
* Lorentz transformation
* Einstein's (GR) field equations
* Klein-Gordon equation
* Planck's equation for black body radiation
* Dirac equation
* Josephson effect/ tunneling equation
* d'Alembert equation
* Heat transfer equations
* Diffusion equations
* Yukawa's nuclear force equation
* Goldstone's theorem and symmetry breaking
* Bloch equations in Nuclear Magnetic resonance (NMR)
* Resonance equations
* Dispersion equations
* de Broglie equation
* Laws of Thermodynamics
* Boltzmann distribution law in statistical mechanics
* ideal gas laws
* Gibbs equation
* Boltzmann equation
* Debye equation
* Onsager's principle (flux equations)
* Kirkwood proton and dipole fluctuation equations
* Doppler effect equation
* Red shift equation
* Thompson equation for the period of electrical oscillation
* Bragg diffraction equation
* heat equation
* heat radiation equation
* Heat conduction equation
* kinetic energy equation
* physical laws as consequences of symmetry
* Chaotic dynamics equations
* Y
* W
* Z
# PlanetPhysics/Topic on Computational Physics

This is a contributed topic on Computational Physics .
Computational Physics is broadly defined as the application of computer programming, as well as of other computational means, such as: algebraic, topological, categorical, logical (including quantum logics, many-valued logics, automata theory), and so on, to obtain physically relevant results --that are often numerical.
One notes that computational physics can also be considered as a major area of applied (computational) mathematics and/or applied physics.
This term is often employed in the more restricted, practical sense of applying computers to obtain numerical solutions to physics problems, or as an illustration to physical processes, phenomena or theories. At the top end of computing resources, supercomputers are beginning to be very widely employed in physics for a variety of reasons, including relatively inexpensive simulations of very important physics problems that cannot be solved at present by any other means. Other, several contributed examples will be considered next in this topic, and are also more precisely defined in the following bibliography (available in part for download from the book and expositions/paper sections of PlanetPhysics.org).

### Examples and Tools in Computational Physics

* Computational fluid dynamics-in rheology; $(PAC:02.70.-c)$
* Computational methods in classical mechanics ($45.10.-bxx$; see also $02.70.-c$)
* Computational techniques in mathematical methods in physics
* Programming languages (Fortran, Basic/TurboBasic/AppleBasic, Algol, Pascal, $C/C^{++}$), programs (Mathematica, Maple, Systat) and OS systems ($UNIX$, $Linux$, Windows, $OS-X$) employed in Computational Physics
* concepts: UTM, quantum automata concepts
* Quantum Computations in: QCD, QFT, AQFT, QED, LQED, LQFT, Quantum Gravity (QG, LQG) computations on a lattice, quantum molecular dynamics (QMD) and quantum chemistry (QC)
* F
* G
* H
* K
# PlanetPhysics/Topic on Computer Programming
### Definition

computer programming is the process of creating, generating, and implementing programs and algorithms that control the operation of a computer, usually in digital form.

### Examples:

* programming languages: Fortran, Basic, TurboBasic, AppleBasic, Algol, Pascal, $C/,and\,C^{++}$, Tex, Java,...
* Algorithms: FT, FFT, TowerofHanoi, Linpack,
* Programs: "FFT-OS-X", MiKTeX, Mathematica, Maple, Systat, STATS, MathType, Word, WordPerfect, Latex2e, Acrobat, Internet Explorer, Eudora, Outlook Express, jQuantum,...(all {\mathbf $TM\,!$}s )
* Operating systems (OS): $UNIX$, $Linux$, Windows, $OSX$, $DOS.v.x$, AppleDOS,...
* B
# Parkinson's Symptoms/Shaking Palsy

( To subpage for editing >> )
Shaking Palsy
An early name for Parkinson's Disease.
# Parkinson's Symptoms/Stalevo

( To subpage for editing >> )

## Active ingredients

Carbidopa, is an inhibitor of aromatic amino acid decarboxylation, and is a white, crystalline compound, slightly soluble in water, with a molecular weight of 244.3. It is designated chemically as (—)-L-α-hydrazino-α-methyl-β-(3,4-dihydroxybenzene) propamic acid monohydrate. Its empirical formula is C$_{10}$H$_{14}$N$_{2O4}$•H$_{2O}$.
Entacapone is somewhat similar to carbidopa or benserazide, in that it is an inhibitor of an enzyme that converts L-DOPA into a compound that cannot cross the blood brain barrier.
Levodopa, an aromatic amino acid, is a white, crystalline compound, slightly soluble in water, with a molecular weight of 197.2. It is designated chemically as (—)-L-α-amino-β-(3,4-dihydroxybenzene) propanic acid. Its empirical formula is C$_9$H$_{11}$NO$_4$

## Inactive ingredients

croselcarmellose sodium
magnesium stearate
maize starch]
manitol (E421)
povidone K30 (E1201)
glycerol (422)
hypromellose
polysorbate 80
red iron oxide (E172)
sucrose
titanium dioxide (E171)
yellow iron oxide (E172)

## Most common adverse reactions to STALEVO

Dystonia (Uncontrolled movements)
Nausea
Paranoia and psychotic symptoms
Depression (possibly with thoughts of suicide)
Amnesia and cognitive deficits

## Less common adverse reactions to STALEVO

Irregular heart rate and rhythm
Light headedness or fainting due to low blood pressure
Dizziness
Drowsiness
Sudden worsening of Parkinson's symptoms
Loss of appetite
Vomiting
Bleeding in the gut
Ulcers
Abdominal pain
Dry mouth
Constipation
Diarrhoea
High blood pressure
Inflammation of the veins in the legs
Insomnia
Hallucinations
Confusion
Unpleasant dreams
Tiredness
Muscle cramps
Sweating
Falls postural instability)
Changes in blood cells
Fainting
Infections
Bleeding
Chest pain
Shortness of breath
Tingling or numbness
Convulsions

## Rare or very rare effects

Agitation
Itching and rashes
Weight loss or gain
vision disturbances
Muscle cramps

## Drug interactions

Selective MAO-A plus MAO- inhibitors
>non-selective MAO inhibitors (e.g. Moclobemide-aka Aurorix and Manerix.}
noradrenaline re-uptake inhibitors (e.g. Desipramine- aka Desmethylimipramine; Maprotiline aka -Deprilept, Ludiomil, Psymion; Venlaxafine - aka Effexor or Efexor )
tricycline antidepressants (e.g. Amitryptiline - aka Tryptomer, Elavil, Tryptizol, Laroxyl, Saroten, Sarotex, Lentizol, Endep)
Paroxetine aka Aropax, Paxil, Pexeva, Seroxat, Sereupin
Isoprenaline aka Isoproterenol, Medihaler-Iso and Isupre
Dopamine
Dobutamine
Alpha-methyldopa
Apomorphine aka Apokyn, Ixense, Spontane, Uprima]]
rimiterole
Dopamine antagonists
Phenytoin
Papaverine
iron supplements
Adrenaline
# Parenting driver's license

Wikiversity parenting driver's license

## Preparatory notes
### Structure

The links below can be used to make notes for the parent education course following the structure of kess-erziehen or Starke Eltern - Starke Kinder. The final structure of the course to be written has not yet been determined.
The course will have a focus on intercultural competence to make it appropriate for the OLPC laptop
    kess-erziehen (Example)
   * See the child - recognize basic social needs
   * Understand behavior patterns - react appropriately
   * Encourage children - allow children to experience the consequences of their own actions
   * Resolve conflicts - solve problems
   * Promote autonomy - develop cooperation
    Starke Eltern - Starke Kinder (Example)
   * Consider values and educational goals: What is important for me in upbringing and education?
   * Find your identity as educators: Do I know myself and my role as educator?
   * Strengthen self-confidence to support the development of the child: How do I listen and encourage my child?
   * Determine clear communication rules in the family: How do I express my needs?
   * Empower to recognize problems and to solve problems: How do we solve problems in the family?

### Literature

* Literature for the course: Parent Education Course Writer's Guide (Wikibook)
* UN Convention on the Rights of the Child (Wikipedia article: Convention on the Rights of the Child)

#### Programs

* Parent Effectiveness Training is based on person-centered psychotherapy
** Gordon, Thomas (October 2000). Parent Effectiveness Training: The Proven Program for Raising Responsible Children (1st rev. ed.). New York: Three Rivers Press. ISBN 0609806939.
* Kess-erziehen is based on individual psychology and the work of Rudolf Dreikurs
** Horst, Christof; Erika Maaß-Keibel; Rudolf Mazzolla; Regina Raulfs (2005). Erziehen mit Kess – Der Elternkurs (in German) (1. ed.). München: Droemer/Knaur. ISBN 3426667681.
* Starke Eltern - Starke Kinder is based on humanistic psychology
** Honkanen-Schoberth, Paula (2003). Starke Kinder brauchen starke Eltern: der Elternkurs des Deutschen Kinderschutzbundes (in German) (2. ed.). Freiburg: Urania. ISBN 3332013467.
* Systematic Training for Effective Parenting (STEP) is based on individual psychology
** Dinkmeyer, Don; Gary D. McKay; Don C Dinkmeyer, Jr (August 2007). The Parent's Handbook: Systematic Training for Effective Parenting. Impact Pub. ISBN 0979554209.
# Parkinson's Symptoms/Strabismus

(To subpage for editing >> )
Strabismus
Divergent squint of the eyes
(See also Exotropia = Outward divergence and Esotropia = Inward Divergence. Also Tic)
The following references are relevant:-
Rascol et al (1991) Square wave jerks in parkinsonian syndromes
Scoditti, et al (1993) Peroneal muscular atrophy with parkinsonism, ptosis, and congenital strabismus.
Almer et al (2011) Ocular Motor and Sensory Function in Parkinson Disease
# Parkinson's Symptoms/Tachycardia

( To subpage for editing >> )
Tachycardia
Rapid heart rate
The following references are relevant:-
Wilcox and Aminoff (1976) Blood pressure responses to noradrenaline and dopamine infusions in Parkinson's disease and the Shy-Drager syndrome
Riley and Chelimsky (2003) Autonomic nervous system testing may not distinguish multiple system atrophy from Parkinson's disease
Shimizu and Ohno (2013) Improving the Treatment of Parkinson’s Disease: A Novel Approach by Modulating 5-HT$_{1A}$ Receptors
Further Research
References
<references>
* ↑ Wilcox, C.S. and Aminoff, M.J.(1976) Full Text Br. J. Clin. Pharmacol 3 (2) 207 – 214 Blood pressure responses to noradrenaline and dopamine infusions in Parkinson's disease and the Shy-Drager syndrome. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1428863/
* ↑ Riley, D. and Chelimsky, T. (2003) Full TextJ. Neurol. Neurosurg. Psychiatry 74 (1) 56 – 60.Autonomic nervous system testing may not distinguish multiple system atrophy from Parkinson's disease http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1738185/
* ↑ Shimizu, Saki and Ohno, Yukihiro (2013) Full Text Aging Dis. 4 (1) 1 – 13 Improving the Treatment of Parkinson’s Disease: A Novel Approach by Modulating 5-HT$_{1A}$ Receptors http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3570136/
# Parenting/Parents

This usergroup is for Wikiversity participants who are parents.

## Parents

* --SB_Johnny 18:33, 18 October 2009 (UTC)
* --Gbaor 09:11, 19 October 2009 (UTC)
* --Abd (discuss • contribs) 19:42, 24 August 2015 (UTC) (7 children)

## Grandparents

* --Abd (discuss • contribs) 19:42, 24 August 2015 (UTC) (5 grandchildren)
# Parkinson's Symptoms/Tachykinesia

( To subpage for editing >> )
Tachykinesia
Rapid Movement
The following references are relevant:-
Ellis et al (2011) Which Measures of Physical Function and Motor Impairment Best Predict Quality of Life in Parkinson’s Disease?
Ellis et al (2011) Factors Associated With Exercise Behavior in People With Parkinson Disease
Espay et al(2012) “On” state freezing of gait in Parkinson disease - A paradoxical levodopa-induced complication

## Further Research

References
* ↑ Ellia, T.; Cavannaugh, J.T.; Earhart, G.M.; Ford,M.p.; Forrman, K.B. and Dible, l.E., (1999) Full Text Parkinsonism Relat. Disord. 17 (9) 693 – 697. Which Measures of Physical Function and Motor Impairment Best Predict Quality of Life in Parkinson’s Disease? http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3200468/
* ↑ Ellis, Terry; Cavanaugh, James T.; Earhart, Gammon M.; Ford, Matthew P.; Foreman, Bo; Fedman, Lisa; Boudreau, Jennifer K. and Dibble, Leland E. (2011) Full Text Phys. Ther. 91 (12) 1838 – 1848 Factors Associated With Exercise Behavior in People With Parkinson Disease http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3229047
* ↑ Espay, A.J.; Fasano, A.; van Nuenen, A.; Payne, M.M.; Snijders, A.H. and Bloem, B.R. (2012) Full Text Neurology 78 (7) 454 – 457. “On” state freezing of gait – A paradoxical levodopa-induced complication http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3466608/
# Parkinson's Symptoms/Sialorrhoea

( To subpage for editing >> )
Sialorrhoea
Increased salivation
Alternative term:- Drooling
The following references are relevant:-
Kalf et al (2009) Prevalence and definition of drooling in Parkinson’s disease: a systematic review
Bloem et al (2009) Debilitating consequences of drooling
Kalf et al (2011) Diurnal and nocturnal drooling in Parkinson’s disease
Further Research
# Landforms

A landform is a natural or anthropogenic land feature on the solid surface of the Earth or other planetary body.

## Features

Def. the "cast or structure of anything, or of any part of a thing, as of a landscape, a picture, a treaty, or an essay; any marked peculiarity or characteristic" is called a feature.

## Lands

Def. the "part of Earth which is not covered by oceans or other bodies of water" or an area of ground that is a part of the Earth's or other planetary body's solid surface is called land.

## Landscapes

Def. a "portion of land or territory which the eye can comprehend in a single view, including all the objects it contains" is called a landscape.

## Theoretical landforms

Def. each continuous surface of a landscape that is observable in its entirety and has consistence of form or regular change of form or any "geomorphological [geological] feature, such as a mountain or valley" is called a landform.

## Resources

* Continental shelves
* Geomorphology
* Glaciers
* Hydrogeomorphology
* Radiation astronomy/Craters
* Radiation astronomy/Visuals
* Rocks/Rocky objects

## See Also

* Wikipedia:Landform