What are the mathematics newsgroups and how busy are they? There are two major problems: to define "mathematics" and to define "newsgroup"! In the first case we accept the broad definition and list below all the newsgroups which appear relevant to any of the index pages at this site. The list of "real" newsgroups is fairly fixed for groups in the major hierarchies (including sci, comp, etc.), but the groups in the alt.* hierarchy can emerge and disappear spontaneously. There are also national and local newsgroup hierarchies which are harder to trace, and some mailing lists and internet forums have what appears to be a newsgroup front-end. The list below probably includes all the non-transient newsgroups archived at Dejanews in which posts with a significant mathematical content can be expected to appear at least occasionally. The number preceding each is the number of hits Dejanews reports to a query for posts in the given newsgroup with a date in the range (Mar 1 1995 to Nov 30 1998): [=1340 days; so sci.math is "very busy" at 160 posts/day, sci.math.research is "moderately busy" at 7 posts/day, geometry.research is "quiet" at less than one post per day] Main hierarchies: 11466 comp.ai.fuzzy 29729 comp.compression 68530 comp.graphics.algorithms 281 comp.graphics.research 29764 comp.infosystems.gis 8002 comp.parallel 14505 comp.soft-sys.math.mathematica 1117 comp.soft-sys.math.scilab 36351 comp.soft-sys.matlab 44638 comp.soft-sys.sas 11511 comp.soft-sys.stat.spss 3806 comp.soft-sys.stat.systat 83330 comp.text.tex 12721 comp.theory 3452 comp.theory.cell-automata 1261 comp.theory.dynamic-sys 4092 comp.compression.research 5746 rec.games.abstract 72766 rec.puzzles 61898 sci.crypt 1402 sci.crypt.research 78962 sci.econ 7653 sci.econ.research 17877 sci.engr.control 9672 sci.fractals 85749 sci.geo.satellite-nav 33278 sci.logic 214246 sci.math 27211 sci.math.num-analysis 8606 sci.math.research 14975 sci.math.symbolic 7704 sci.mech.fluids 8094 sci.nonlinear 9305 sci.op-research 275829 sci.physics 4629 sci.physics.computational.fluid-dynamics 27238 sci.physics.particle 12204 sci.physics.research 24319 sci.stat.consult 14880 sci.stat.edu 18199 sci.stat.math 1737 sci.systems 28345 talk.politics.crypto Other hierarchies: 1390 bionet.biology.computational 279 geometry.announcements 575 geometry.college 337 geometry.forum 555 geometry.institutes 3492 geometry.pre-college 1555 geometry.puzzles 1329 geometry.research 473 geometry.software.dynamic 21716 k12.ed.math Stable groups in the alt hierarchy: 36054 alt.algebra.help 694 alt.math 4229 alt.math.recreational 2700 alt.math.undergrad 465 alt.sci.math.combinatorics 705 alt.sci.math.probability Active national and local groups: 5514 aus.mathematics 700 brasil.ciencia.matematica 1957 can.schoolnet.math* 4 colombia.curiosidades-matematicas 17977 de.sci.mathematik 207 ee.ut.matemaatika 3682 es.ciencia.matematicas 5630 fj.sci.math 15828 fr.sci.maths 952 han.sci.math 4506 it.scienza.matematica 204 maus.wissenschaft.mathematik 3941 pl.sci.matematyka 1828 sfnet.tiede.matematiikka 25677 tw.bbs.sci.math 155 ucb.math.undergrads 5 uniandes.circulo-matematico 4002 uk.education.maths 14 uta.matematiikka Other newsgroups I have been told of but have not traced: alt.math.moderated alt.uu.math.misc bln.lehre.mathematik bln.sci.mathematik csu.math japan.sci.math schule.mathe z-netz.wissenschaft.mathematik Note that there is often significant cross-posting, so the number of posts is hard to determine. Total posts in mathematics groups (in a limited sense): 451867 *math* or *matem* and not *aroma* (The last qualification is necessary because there is a group alt.aromatherapy !) Assuming each post averages 1Kb this puts the size of the DejaNews archive at about 500Mb in mathematics groups. Actual mathematical content may be lower... There are search tools appropriate for the mathematical newsgroups; see e.g. index/search.html