Reconnection of magnetic fields: magnetohydrodynamics and collisionless theory and observations
The reconnection of magnetic fields is one of the most fascinating processes in plasma physics, responsible for phenomena such as solar flares and magnetospheric substorms. The concept of reconnection has developed through recent advances in exploring the magnetospheres of the Sun and Earth through...
Gespeichert in:
| Weitere Verfasser: | , |
|---|---|
| Format: | Elektronisch E-Book |
| Sprache: | English |
| Veröffentlicht: |
Cambridge
Cambridge University Press
2007
|
| Schlagworte: | |
| Online-Zugang: | BSB01 FHN01 Volltext |
| Zusammenfassung: | The reconnection of magnetic fields is one of the most fascinating processes in plasma physics, responsible for phenomena such as solar flares and magnetospheric substorms. The concept of reconnection has developed through recent advances in exploring the magnetospheres of the Sun and Earth through theory, computer simulations and spacecraft observations. The great challenge in understanding it stems from balancing the large volumes of plasma and magnetic fields involved with the energy release with the physical mechanism which relies on the strongly localized behavior of charged particles. This book, edited by and with contributions from leading scientists in the field, provides a comprehensive overview of recent theoretical and observational findings concerning the physics of reconnection and the complex structures that may give rise to, or develop from, reconnection. It is intended for researchers and graduate students interested in the dynamics of plasmas |
| Beschreibung: | Title from publisher's bibliographic system (viewed on 05 Oct 2015) |
| Beschreibung: | 1 online resource (xii, 342 pages) |
| ISBN: | 9780511536151 |
| DOI: | 10.1017/CBO9780511536151 |
Internformat
MARC
| LEADER | 00000nmm a2200000zc 4500 | ||
|---|---|---|---|
| 001 | BV043945147 | ||
| 003 | DE-604 | ||
| 005 | 00000000000000.0 | ||
| 007 | cr|uuu---uuuuu | ||
| 008 | 161206s2007 |||| o||u| ||||||eng d | ||
| 020 | |a 9780511536151 |c Online |9 978-0-511-53615-1 | ||
| 024 | 7 | |a 10.1017/CBO9780511536151 |2 doi | |
| 035 | |a (ZDB-20-CBO)CR9780511536151 | ||
| 035 | |a (OCoLC)992887963 | ||
| 035 | |a (DE-599)BVBBV043945147 | ||
| 040 | |a DE-604 |b ger |e rda | ||
| 041 | 0 | |a eng | |
| 049 | |a DE-12 |a DE-92 | ||
| 082 | 0 | |a 538.6 |2 22 | |
| 084 | |a UR 7000 |0 (DE-625)146640: |2 rvk | ||
| 245 | 1 | 0 | |a Reconnection of magnetic fields |b magnetohydrodynamics and collisionless theory and observations |c edited by J. Birn and E.R. Priest |
| 264 | 1 | |a Cambridge |b Cambridge University Press |c 2007 | |
| 300 | |a 1 online resource (xii, 342 pages) | ||
| 336 | |b txt |2 rdacontent | ||
| 337 | |b c |2 rdamedia | ||
| 338 | |b cr |2 rdacarrier | ||
| 500 | |a Title from publisher's bibliographic system (viewed on 05 Oct 2015) | ||
| 505 | 8 | 0 | |g 1 |t Introduction |g 1.1 |t The sun |r E.R. Priest |g 1.2 |t Earth's magnetosphere |r J. Birn |g 2 |t Basic theory of MHD reconnection |g 2.1 |t Classical theory of two-dimensional reconnection |r T.G. Forbes |g 2.2 |t Fundamental concepts |r G. Hornig |g 2.3 |t Three-dimensional reconnection in the absence of magnetic null points |r G. Hornig |g 2.4 |t Three-dimensional reconnection at magnetic null points |r D.I. Pontin |g 2.5 |t Three-dimensional flux tube reconnection |r M.G. Linton |g 3 |t Basic theory of collisionless reconnection |g 3.1 |t Fundamentals of collisionless reconnection |r J.F. Drake and M.A. Shay |g 3.2 |t Diffusion region physics |r M. Hesse |g 3.3 |t Onset of magnetic reconnection |r P.L. Pritchett |
| 520 | |a The reconnection of magnetic fields is one of the most fascinating processes in plasma physics, responsible for phenomena such as solar flares and magnetospheric substorms. The concept of reconnection has developed through recent advances in exploring the magnetospheres of the Sun and Earth through theory, computer simulations and spacecraft observations. The great challenge in understanding it stems from balancing the large volumes of plasma and magnetic fields involved with the energy release with the physical mechanism which relies on the strongly localized behavior of charged particles. This book, edited by and with contributions from leading scientists in the field, provides a comprehensive overview of recent theoretical and observational findings concerning the physics of reconnection and the complex structures that may give rise to, or develop from, reconnection. It is intended for researchers and graduate students interested in the dynamics of plasmas | ||
| 650 | 4 | |a Magnetohydrodynamics | |
| 650 | 4 | |a Magnetic reconnection | |
| 650 | 0 | 7 | |a Feldlinienverschmelzung |0 (DE-588)4252842-2 |2 gnd |9 rswk-swf |
| 650 | 0 | 7 | |a Magnetohydrodynamik |0 (DE-588)4130803-7 |2 gnd |9 rswk-swf |
| 655 | 7 | |8 1\p |0 (DE-588)4006432-3 |a Bibliografie |2 gnd-content | |
| 689 | 0 | 0 | |a Magnetohydrodynamik |0 (DE-588)4130803-7 |D s |
| 689 | 0 | |8 2\p |5 DE-604 | |
| 689 | 1 | 0 | |a Feldlinienverschmelzung |0 (DE-588)4252842-2 |D s |
| 689 | 1 | |8 3\p |5 DE-604 | |
| 700 | 1 | |a Birn, J. |4 edt | |
| 700 | 1 | |a Priest, E. R. |d 1943- |4 edt | |
| 776 | 0 | 8 | |i Erscheint auch als |n Druckausgabe |z 978-0-521-85420-7 |
| 856 | 4 | 0 | |u https://doi.org/10.1017/CBO9780511536151 |x Verlag |z URL des Erstveröffentlichers |3 Volltext |
| 912 | |a ZDB-20-CBO | ||
| 999 | |a oai:aleph.bib-bvb.de:BVB01-029354117 | ||
| 883 | 1 | |8 1\p |a cgwrk |d 20201028 |q DE-101 |u https://d-nb.info/provenance/plan#cgwrk | |
| 883 | 1 | |8 2\p |a cgwrk |d 20201028 |q DE-101 |u https://d-nb.info/provenance/plan#cgwrk | |
| 883 | 1 | |8 3\p |a cgwrk |d 20201028 |q DE-101 |u https://d-nb.info/provenance/plan#cgwrk | |
| 966 | e | |u https://doi.org/10.1017/CBO9780511536151 |l BSB01 |p ZDB-20-CBO |q BSB_PDA_CBO |x Verlag |3 Volltext | |
| 966 | e | |u https://doi.org/10.1017/CBO9780511536151 |l FHN01 |p ZDB-20-CBO |q FHN_PDA_CBO |x Verlag |3 Volltext | |
Datensatz im Suchindex
| _version_ | 1804176891001700352 |
|---|---|
| any_adam_object | |
| author2 | Birn, J. Priest, E. R. 1943- |
| author2_role | edt edt |
| author2_variant | j b jb e r p er erp |
| author_additional | E.R. Priest J. Birn T.G. Forbes G. Hornig D.I. Pontin M.G. Linton J.F. Drake and M.A. Shay M. Hesse P.L. Pritchett |
| author_facet | Birn, J. Priest, E. R. 1943- |
| building | Verbundindex |
| bvnumber | BV043945147 |
| classification_rvk | UR 7000 |
| collection | ZDB-20-CBO |
| contents | Introduction The sun Earth's magnetosphere Basic theory of MHD reconnection Classical theory of two-dimensional reconnection Fundamental concepts Three-dimensional reconnection in the absence of magnetic null points Three-dimensional reconnection at magnetic null points Three-dimensional flux tube reconnection Basic theory of collisionless reconnection Fundamentals of collisionless reconnection Diffusion region physics Onset of magnetic reconnection |
| ctrlnum | (ZDB-20-CBO)CR9780511536151 (OCoLC)992887963 (DE-599)BVBBV043945147 |
| dewey-full | 538.6 |
| dewey-hundreds | 500 - Natural sciences and mathematics |
| dewey-ones | 538 - Magnetism |
| dewey-raw | 538.6 |
| dewey-search | 538.6 |
| dewey-sort | 3538.6 |
| dewey-tens | 530 - Physics |
| discipline | Physik |
| doi_str_mv | 10.1017/CBO9780511536151 |
| format | Electronic eBook |
| fullrecord | <?xml version="1.0" encoding="UTF-8"?><collection xmlns="http://www.loc.gov/MARC21/slim"><record><leader>03909nmm a2200553zc 4500</leader><controlfield tag="001">BV043945147</controlfield><controlfield tag="003">DE-604</controlfield><controlfield tag="005">00000000000000.0</controlfield><controlfield tag="007">cr|uuu---uuuuu</controlfield><controlfield tag="008">161206s2007 |||| o||u| ||||||eng d</controlfield><datafield tag="020" ind1=" " ind2=" "><subfield code="a">9780511536151</subfield><subfield code="c">Online</subfield><subfield code="9">978-0-511-53615-1</subfield></datafield><datafield tag="024" ind1="7" ind2=" "><subfield code="a">10.1017/CBO9780511536151</subfield><subfield code="2">doi</subfield></datafield><datafield tag="035" ind1=" " ind2=" "><subfield code="a">(ZDB-20-CBO)CR9780511536151</subfield></datafield><datafield tag="035" ind1=" " ind2=" "><subfield code="a">(OCoLC)992887963</subfield></datafield><datafield tag="035" ind1=" " ind2=" "><subfield code="a">(DE-599)BVBBV043945147</subfield></datafield><datafield tag="040" ind1=" " ind2=" "><subfield code="a">DE-604</subfield><subfield code="b">ger</subfield><subfield code="e">rda</subfield></datafield><datafield tag="041" ind1="0" ind2=" "><subfield code="a">eng</subfield></datafield><datafield tag="049" ind1=" " ind2=" "><subfield code="a">DE-12</subfield><subfield code="a">DE-92</subfield></datafield><datafield tag="082" ind1="0" ind2=" "><subfield code="a">538.6</subfield><subfield code="2">22</subfield></datafield><datafield tag="084" ind1=" " ind2=" "><subfield code="a">UR 7000</subfield><subfield code="0">(DE-625)146640:</subfield><subfield code="2">rvk</subfield></datafield><datafield tag="245" ind1="1" ind2="0"><subfield code="a">Reconnection of magnetic fields</subfield><subfield code="b">magnetohydrodynamics and collisionless theory and observations</subfield><subfield code="c">edited by J. Birn and E.R. Priest</subfield></datafield><datafield tag="264" ind1=" " ind2="1"><subfield code="a">Cambridge</subfield><subfield code="b">Cambridge University Press</subfield><subfield code="c">2007</subfield></datafield><datafield tag="300" ind1=" " ind2=" "><subfield code="a">1 online resource (xii, 342 pages)</subfield></datafield><datafield tag="336" ind1=" " ind2=" "><subfield code="b">txt</subfield><subfield code="2">rdacontent</subfield></datafield><datafield tag="337" ind1=" " ind2=" "><subfield code="b">c</subfield><subfield code="2">rdamedia</subfield></datafield><datafield tag="338" ind1=" " ind2=" "><subfield code="b">cr</subfield><subfield code="2">rdacarrier</subfield></datafield><datafield tag="500" ind1=" " ind2=" "><subfield code="a">Title from publisher's bibliographic system (viewed on 05 Oct 2015)</subfield></datafield><datafield tag="505" ind1="8" ind2="0"><subfield code="g">1</subfield><subfield code="t">Introduction</subfield><subfield code="g">1.1</subfield><subfield code="t">The sun</subfield><subfield code="r">E.R. Priest</subfield><subfield code="g">1.2</subfield><subfield code="t">Earth's magnetosphere</subfield><subfield code="r">J. Birn</subfield><subfield code="g">2</subfield><subfield code="t">Basic theory of MHD reconnection</subfield><subfield code="g">2.1</subfield><subfield code="t">Classical theory of two-dimensional reconnection</subfield><subfield code="r">T.G. Forbes</subfield><subfield code="g">2.2</subfield><subfield code="t">Fundamental concepts</subfield><subfield code="r">G. Hornig</subfield><subfield code="g">2.3</subfield><subfield code="t">Three-dimensional reconnection in the absence of magnetic null points</subfield><subfield code="r">G. Hornig</subfield><subfield code="g">2.4</subfield><subfield code="t">Three-dimensional reconnection at magnetic null points</subfield><subfield code="r">D.I. Pontin</subfield><subfield code="g">2.5</subfield><subfield code="t">Three-dimensional flux tube reconnection</subfield><subfield code="r">M.G. Linton</subfield><subfield code="g">3</subfield><subfield code="t">Basic theory of collisionless reconnection</subfield><subfield code="g">3.1</subfield><subfield code="t">Fundamentals of collisionless reconnection</subfield><subfield code="r">J.F. Drake and M.A. Shay</subfield><subfield code="g">3.2</subfield><subfield code="t">Diffusion region physics</subfield><subfield code="r">M. Hesse</subfield><subfield code="g">3.3</subfield><subfield code="t">Onset of magnetic reconnection</subfield><subfield code="r">P.L. Pritchett</subfield></datafield><datafield tag="520" ind1=" " ind2=" "><subfield code="a">The reconnection of magnetic fields is one of the most fascinating processes in plasma physics, responsible for phenomena such as solar flares and magnetospheric substorms. The concept of reconnection has developed through recent advances in exploring the magnetospheres of the Sun and Earth through theory, computer simulations and spacecraft observations. The great challenge in understanding it stems from balancing the large volumes of plasma and magnetic fields involved with the energy release with the physical mechanism which relies on the strongly localized behavior of charged particles. This book, edited by and with contributions from leading scientists in the field, provides a comprehensive overview of recent theoretical and observational findings concerning the physics of reconnection and the complex structures that may give rise to, or develop from, reconnection. It is intended for researchers and graduate students interested in the dynamics of plasmas</subfield></datafield><datafield tag="650" ind1=" " ind2="4"><subfield code="a">Magnetohydrodynamics</subfield></datafield><datafield tag="650" ind1=" " ind2="4"><subfield code="a">Magnetic reconnection</subfield></datafield><datafield tag="650" ind1="0" ind2="7"><subfield code="a">Feldlinienverschmelzung</subfield><subfield code="0">(DE-588)4252842-2</subfield><subfield code="2">gnd</subfield><subfield code="9">rswk-swf</subfield></datafield><datafield tag="650" ind1="0" ind2="7"><subfield code="a">Magnetohydrodynamik</subfield><subfield code="0">(DE-588)4130803-7</subfield><subfield code="2">gnd</subfield><subfield code="9">rswk-swf</subfield></datafield><datafield tag="655" ind1=" " ind2="7"><subfield code="8">1\p</subfield><subfield code="0">(DE-588)4006432-3</subfield><subfield code="a">Bibliografie</subfield><subfield code="2">gnd-content</subfield></datafield><datafield tag="689" ind1="0" ind2="0"><subfield code="a">Magnetohydrodynamik</subfield><subfield code="0">(DE-588)4130803-7</subfield><subfield code="D">s</subfield></datafield><datafield tag="689" ind1="0" ind2=" "><subfield code="8">2\p</subfield><subfield code="5">DE-604</subfield></datafield><datafield tag="689" ind1="1" ind2="0"><subfield code="a">Feldlinienverschmelzung</subfield><subfield code="0">(DE-588)4252842-2</subfield><subfield code="D">s</subfield></datafield><datafield tag="689" ind1="1" ind2=" "><subfield code="8">3\p</subfield><subfield code="5">DE-604</subfield></datafield><datafield tag="700" ind1="1" ind2=" "><subfield code="a">Birn, J.</subfield><subfield code="4">edt</subfield></datafield><datafield tag="700" ind1="1" ind2=" "><subfield code="a">Priest, E. R.</subfield><subfield code="d">1943-</subfield><subfield code="4">edt</subfield></datafield><datafield tag="776" ind1="0" ind2="8"><subfield code="i">Erscheint auch als</subfield><subfield code="n">Druckausgabe</subfield><subfield code="z">978-0-521-85420-7</subfield></datafield><datafield tag="856" ind1="4" ind2="0"><subfield code="u">https://doi.org/10.1017/CBO9780511536151</subfield><subfield code="x">Verlag</subfield><subfield code="z">URL des Erstveröffentlichers</subfield><subfield code="3">Volltext</subfield></datafield><datafield tag="912" ind1=" " ind2=" "><subfield code="a">ZDB-20-CBO</subfield></datafield><datafield tag="999" ind1=" " ind2=" "><subfield code="a">oai:aleph.bib-bvb.de:BVB01-029354117</subfield></datafield><datafield tag="883" ind1="1" ind2=" "><subfield code="8">1\p</subfield><subfield code="a">cgwrk</subfield><subfield code="d">20201028</subfield><subfield code="q">DE-101</subfield><subfield code="u">https://d-nb.info/provenance/plan#cgwrk</subfield></datafield><datafield tag="883" ind1="1" ind2=" "><subfield code="8">2\p</subfield><subfield code="a">cgwrk</subfield><subfield code="d">20201028</subfield><subfield code="q">DE-101</subfield><subfield code="u">https://d-nb.info/provenance/plan#cgwrk</subfield></datafield><datafield tag="883" ind1="1" ind2=" "><subfield code="8">3\p</subfield><subfield code="a">cgwrk</subfield><subfield code="d">20201028</subfield><subfield code="q">DE-101</subfield><subfield code="u">https://d-nb.info/provenance/plan#cgwrk</subfield></datafield><datafield tag="966" ind1="e" ind2=" "><subfield code="u">https://doi.org/10.1017/CBO9780511536151</subfield><subfield code="l">BSB01</subfield><subfield code="p">ZDB-20-CBO</subfield><subfield code="q">BSB_PDA_CBO</subfield><subfield code="x">Verlag</subfield><subfield code="3">Volltext</subfield></datafield><datafield tag="966" ind1="e" ind2=" "><subfield code="u">https://doi.org/10.1017/CBO9780511536151</subfield><subfield code="l">FHN01</subfield><subfield code="p">ZDB-20-CBO</subfield><subfield code="q">FHN_PDA_CBO</subfield><subfield code="x">Verlag</subfield><subfield code="3">Volltext</subfield></datafield></record></collection> |
| genre | 1\p (DE-588)4006432-3 Bibliografie gnd-content |
| genre_facet | Bibliografie |
| id | DE-604.BV043945147 |
| illustrated | Not Illustrated |
| indexdate | 2024-07-10T07:39:23Z |
| institution | BVB |
| isbn | 9780511536151 |
| language | English |
| oai_aleph_id | oai:aleph.bib-bvb.de:BVB01-029354117 |
| oclc_num | 992887963 |
| open_access_boolean | |
| owner | DE-12 DE-92 |
| owner_facet | DE-12 DE-92 |
| physical | 1 online resource (xii, 342 pages) |
| psigel | ZDB-20-CBO ZDB-20-CBO BSB_PDA_CBO ZDB-20-CBO FHN_PDA_CBO |
| publishDate | 2007 |
| publishDateSearch | 2007 |
| publishDateSort | 2007 |
| publisher | Cambridge University Press |
| record_format | marc |
| spelling | Reconnection of magnetic fields magnetohydrodynamics and collisionless theory and observations edited by J. Birn and E.R. Priest Cambridge Cambridge University Press 2007 1 online resource (xii, 342 pages) txt rdacontent c rdamedia cr rdacarrier Title from publisher's bibliographic system (viewed on 05 Oct 2015) 1 Introduction 1.1 The sun E.R. Priest 1.2 Earth's magnetosphere J. Birn 2 Basic theory of MHD reconnection 2.1 Classical theory of two-dimensional reconnection T.G. Forbes 2.2 Fundamental concepts G. Hornig 2.3 Three-dimensional reconnection in the absence of magnetic null points G. Hornig 2.4 Three-dimensional reconnection at magnetic null points D.I. Pontin 2.5 Three-dimensional flux tube reconnection M.G. Linton 3 Basic theory of collisionless reconnection 3.1 Fundamentals of collisionless reconnection J.F. Drake and M.A. Shay 3.2 Diffusion region physics M. Hesse 3.3 Onset of magnetic reconnection P.L. Pritchett The reconnection of magnetic fields is one of the most fascinating processes in plasma physics, responsible for phenomena such as solar flares and magnetospheric substorms. The concept of reconnection has developed through recent advances in exploring the magnetospheres of the Sun and Earth through theory, computer simulations and spacecraft observations. The great challenge in understanding it stems from balancing the large volumes of plasma and magnetic fields involved with the energy release with the physical mechanism which relies on the strongly localized behavior of charged particles. This book, edited by and with contributions from leading scientists in the field, provides a comprehensive overview of recent theoretical and observational findings concerning the physics of reconnection and the complex structures that may give rise to, or develop from, reconnection. It is intended for researchers and graduate students interested in the dynamics of plasmas Magnetohydrodynamics Magnetic reconnection Feldlinienverschmelzung (DE-588)4252842-2 gnd rswk-swf Magnetohydrodynamik (DE-588)4130803-7 gnd rswk-swf 1\p (DE-588)4006432-3 Bibliografie gnd-content Magnetohydrodynamik (DE-588)4130803-7 s 2\p DE-604 Feldlinienverschmelzung (DE-588)4252842-2 s 3\p DE-604 Birn, J. edt Priest, E. R. 1943- edt Erscheint auch als Druckausgabe 978-0-521-85420-7 https://doi.org/10.1017/CBO9780511536151 Verlag URL des Erstveröffentlichers Volltext 1\p cgwrk 20201028 DE-101 https://d-nb.info/provenance/plan#cgwrk 2\p cgwrk 20201028 DE-101 https://d-nb.info/provenance/plan#cgwrk 3\p cgwrk 20201028 DE-101 https://d-nb.info/provenance/plan#cgwrk |
| spellingShingle | Reconnection of magnetic fields magnetohydrodynamics and collisionless theory and observations Introduction The sun Earth's magnetosphere Basic theory of MHD reconnection Classical theory of two-dimensional reconnection Fundamental concepts Three-dimensional reconnection in the absence of magnetic null points Three-dimensional reconnection at magnetic null points Three-dimensional flux tube reconnection Basic theory of collisionless reconnection Fundamentals of collisionless reconnection Diffusion region physics Onset of magnetic reconnection Magnetohydrodynamics Magnetic reconnection Feldlinienverschmelzung (DE-588)4252842-2 gnd Magnetohydrodynamik (DE-588)4130803-7 gnd |
| subject_GND | (DE-588)4252842-2 (DE-588)4130803-7 (DE-588)4006432-3 |
| title | Reconnection of magnetic fields magnetohydrodynamics and collisionless theory and observations |
| title_alt | Introduction The sun Earth's magnetosphere Basic theory of MHD reconnection Classical theory of two-dimensional reconnection Fundamental concepts Three-dimensional reconnection in the absence of magnetic null points Three-dimensional reconnection at magnetic null points Three-dimensional flux tube reconnection Basic theory of collisionless reconnection Fundamentals of collisionless reconnection Diffusion region physics Onset of magnetic reconnection |
| title_auth | Reconnection of magnetic fields magnetohydrodynamics and collisionless theory and observations |
| title_exact_search | Reconnection of magnetic fields magnetohydrodynamics and collisionless theory and observations |
| title_full | Reconnection of magnetic fields magnetohydrodynamics and collisionless theory and observations edited by J. Birn and E.R. Priest |
| title_fullStr | Reconnection of magnetic fields magnetohydrodynamics and collisionless theory and observations edited by J. Birn and E.R. Priest |
| title_full_unstemmed | Reconnection of magnetic fields magnetohydrodynamics and collisionless theory and observations edited by J. Birn and E.R. Priest |
| title_short | Reconnection of magnetic fields |
| title_sort | reconnection of magnetic fields magnetohydrodynamics and collisionless theory and observations |
| title_sub | magnetohydrodynamics and collisionless theory and observations |
| topic | Magnetohydrodynamics Magnetic reconnection Feldlinienverschmelzung (DE-588)4252842-2 gnd Magnetohydrodynamik (DE-588)4130803-7 gnd |
| topic_facet | Magnetohydrodynamics Magnetic reconnection Feldlinienverschmelzung Magnetohydrodynamik Bibliografie |
| url | https://doi.org/10.1017/CBO9780511536151 |
| work_keys_str_mv | AT birnj reconnectionofmagneticfieldsmagnetohydrodynamicsandcollisionlesstheoryandobservations AT priester reconnectionofmagneticfieldsmagnetohydrodynamicsandcollisionlesstheoryandobservations |