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krisztiantoth · 1 year

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Könyvek & Filmek 2022

Következzék az immár “szokásos”, hagyománnyá vált beszámolóm az elmúlt évről, melyet korábban kezdtem (2006), mint Szabados Ádám teológus, de természetesen az a minőség, ahogy a Divinity blog közreadja, inspirál. Én “csupán” egy felsorolást közök, de videós résszel kiegészülve. Íme:

2022 - könyvek

Martin Rizley: Preach The Gospel

Dobner Győző: A Bárka Baptista Gyülekezet története

Füzesi Manuéla: Ráháb zsoltára

Márton Zsolt: A szokolyai zsidóság története

Samuel Rutherfors: Levelek (P7)

Kerényi István és Kerényi Lajos: Csodás kalandok Jézussal

Gary Chapman és Shannon Warden: 12 dolog, amit jó lett volna tudni, mielőtt szülők lettünk

Joseph Alleine: Üdvösségre vezérlő kalauz (megtérésre segítő intelmek)

Joachim Gnilka: Biblia és Korán - Ami összeköti és ami elválasztja őket

Tim Keller: Az önmagunkról való megfeledkezés szabadsága

Greg Gilbert: What Is the Gos•pel?

A call to Faithful Mission: The Southgate fellowship statement

Al N. Martin: The Practical Implications of Calvinism

Joel R. Beeke: La Santidad - El llamamiento de Dios a la santificación

Melissa and Mike Kruger: Praying for your spouse

Joel R. és Mary Beeke: Hogyan Építsünk Istenfélő Házasságot?

Ray Ortlund: The Death of Porn - Men of Integrity Building a World of Nobility

Avi Jorisch: Made in Israel - Ahogyan az izraeli találékonyság jobbítja a világot

Kálvin: Római levél magyarázata

Justin Buzzard: Date Your Wife

Bognár Attila: A négy bibliai ősanya; Sára, Rebeka, Lea, Ráhel - a Messiás négy arcvonásának kiábrázolói

John MacArthur: Jézus a konfliktus hevében. Jézus merész konfrontációinak újszerű megközelítése

John MacArthur: Egyedül Jézus. Mit jelent valóban üdvösséget nyerni

Thabiti Anyabwile: What is a healthy Church member?

John Piper: Ne pazarold az életed!

Jonathan Leeman: A gyülekezeti tagság (magyar fordítás)

BEST: A baptista egyház stratégiai terve (Durkó István)

Túri Sándor: A Zarándok - A belső én felfedezése az El Camino úton

Szerettem egy leányt - Bizalmas levelezés (Evangéliumi Kiadó)

Énekek éneke (Európa kiadó) - Komoróczy Géza utószavával

Xeravits Géza: Zsidó és keresztény szent helyek a késő-ókori Palesztinában

Dr. Kovács György: Gyökerek és ágak

David Wilkerson: Kereszt az aszfaltdzsungelben

Phillip Keller: A 23. Zsoltár | egy juhpásztor tolmácsolásában

John Piper: Az öröm hajnala

🎶Bolyki László: Ragyogjon világosság (25 Adventi elmélk..)

John Piper: Hirdetek nektek nagy örömet

Turcsik György: Adventi mesék

Peter Masters: A Biblia Tanítása a Gyülekezeti Tagságról

2022 - filmek

Félvilág

BÚÉK

14 hegycsúcs: Semmi sem lehetetlen (Netflix)

Vadlovak

A feltaláló (Béres)

Ne nézz fel! (Netflix)

Viktória - A zürichi expressz

Én Georgina (Netflix sorozat)

Hiszel? (Teljes film magyar felirat)

A világ legrosszabb embere

A Tinder csaló (Netflix)

Csernobil (HBO) Чорнобиль

Halál a Níluson

Soros-akta

Könnyü leckék

Dawnton Abbey (mozifilm)

A legszebb ajándék (Diósjenő)

Mennyei Csodák (Videa)

Katinka KAT/NKA

Jézus Dosszié

AMADEUS

Lányok Dubaiban

Toscana / Toszkána (Netflix)

Zuhanás a csendbe

Münich / München (2005)

Schindler listája

Az izraeli kém (Netflix sorozat)

Szexfantáziák

Mennyit ér egy élet?

Munich - Netflix

Tortured (R.Wumbrandt)

Man vs bee (Mr. Bean:)

Magasságok és mélységek

The next three days

A salemi boszorkányok (1996) The Crucible (Arthur Miller)

ÖN-TÉR-KÉP I-II. A Magyar Nemzet Lelkiállapota

A legszebb nemzeti parkok (Netflix sorozat - Obamával)

Luther

Kuba titokzatos története #8

Szöszi (Monroe - Netflix)

Jóreménység Sziget

What is woman? (doku)

Élősködők

Magyar Passió

Szívvel lélekkel | Portréfilm a bükki füvesemberről, Gyuri bácsiról

Avatar - víz (2.)

A FIFA titkai (uncovered) Netflix

Az unoka (2021) magyar thriller

Ida regénye (2022)

JÉZUS ÉS… (Mező Misi DunaTV)

Született hazudozó

+ HAMAROSAN KÖVETKEZNEK AZ ELMÚLT ÉVEK IDÉZETEI...

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spacetimewithstuartgary · 5 years

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Dark matter experiment finds no evidence of axions In its first run, ABRACADABRA detects no signal of the hypothetical dark matter particle within a specific mass range. Physicists from MIT and elsewhere have performed the first run of a new experiment to detect axions -- hypothetical particles that are predicted to be among the lightest particles in the universe. If they exist, axions would be virtually invisible, yet inescapable; they could make up nearly 85 percent of the mass of the universe, in the form of dark matter. Axions are particularly unusual in that they are expected to modify the rules of electricity and magnetism at a minute level. In a paper published today in Physical Review Letters, the MIT-led team reports that in the first month of observations the experiment detected no sign of axions within the mass range of 0.31 to 8.3 nanoelectronvolts. This means that axions within this mass range, which is equivalent to about one-quintillionth the mass of a proton, either don't exist or they have an even smaller effect on electricity and magnetism than previously thought. "This is the first time anyone has directly looked at this axion space," says Lindley Winslow, principal investigator of the experiment and the Jerrold R. Zacharias Career Development Assistant Professor of Physics at MIT. "We're excited that we can now say, 'We have a way to look here, and we know how to do better!'" Winslow's MIT co-authors include lead author Jonathan Ouellet, Chiara Salemi, Zachary Bogorad, Janet Conrad, Joseph Formaggio, Joseph Minervini, Alexey Radovinsky, Jesse Thaler, and Daniel Winklehner, along with researchers from eight other institutions. Magnetars and munchkins While they are thought to be everywhere, axions are predicted to be virtually ghost-like, having only tiny interactions with anything else in the universe. "As dark matter, they shouldn't affect your everyday life," Winslow says. "But they're thought to affect things on a cosmological level, like the expansion of the universe and the formation of galaxies we see in the night sky." Because of their interaction with electromagnetism, axions are theorized to have a surprising behavior around magnetars -- a type of neutron star that churns up a hugely powerful magnetic field. If axions are present, they can exploit the magnetar's magnetic field to convert themselves into radio waves, which can be detected with dedicated telescopes on Earth. In 2016, a trio of MIT theorists drew up a thought experiment for detecting axions, inspired by the magnetar. The experiment was dubbed ABRACADABRA, for the A Broadband/Resonant Approach to Cosmic Axion Detection with an Amplifying B-field Ring Apparatus, and was conceived by Thaler, who is an associate professor of physics and a researcher in the Laboratory for Nuclear Science and the Center for Theoretical Physics, along with Benjamin Safdi, then an MIT Pappalardo Fellow, and former graduate student Yonatan Kahn. The team proposed a design for a small, donut-shaped magnet kept in a refrigerator at temperatures just above absolute zero. Without axions, there should be no magnetic field in the center of the donut, or, as Winslow puts it, "where the munchkin should be. However, if axions exist, a detector should "see" a magnetic field in the middle of the donut After the group published their theoretical design, Winslow, an experimentalist, set about finding ways to actually build the experiment. "We wanted to look for a signal of an axion where, if we see it, it's really the axion," Winslow says. "That's what was elegant about this experiment. Technically, if you saw this magnetic field, it could only be the axion, because of the particular geometry they thought of." In the sweet spot It is a challenging experiment because the expected signal is less than 20 atto-Tesla. For reference, the Earth's magnetic field is 30 micro-Tesla and human brain waves are 1 pico-Tesla. In building the experiment, Winslow and her colleagues had to contend with two main design challenges, the first of which involved the refrigerator used to keep the entire experiment at ultracold temperatures. The refrigerator included a system of mechanical pumps whose activity could generate very slight vibrations that Winslow worried could mask an axion signal. The second challenge had to do with noise in the environment, such as from nearby radio stations, electronics throughout the building turning on and off, and even LED lights on the computers and electronics, all of which could generate competing magnetic fields. The team solved the first problem by hanging the entire contraption, using a thread as thin as dental floss. The second problem was solved by a combination of cold superconducting shielding and warm shielding around the outside of the experiment. "We could then finally take data, and there was a sweet region in which we were above the vibrations of the fridge, and below the environmental noise probably coming from our neighbors, in which we could do the experiment." The researchers first ran a series of tests to confirm the experiment was working and exhibiting magnetic fields accurately. The most important test was the injection of a magnetic field to simulate a fake axion, and to see that the experiment's detector produced the expected signal -- indicating that if a real axion interacted with the experiment, it would be detected. At this point the experiment was ready to go. "If you take the data and run it through an audio program, you can hear the sounds that the fridge makes," Winslow says. "We also see other noise going on and off, from someone next door doing something, and then that noise goes away. And when we look at this sweet spot, it holds together, we understand how the detector works, and it becomes quiet enough to hear the axions." Seeing the swarm In 2018, the team carried out ABRACADABRA's first run, continuously sampling between July and August. After analyzing the data from this period, they found no evidence of axions within the mass range of 0.31 to 8.3 nanoelectronvolts that change electricity and magnetism by more than one part in 10 billion. The experiment is designed to detect axions of even smaller masses, down to about 1 femtoelectronvolts, as well as axions as large as 1 microelectronvolts. The team will continue running the current experiment, which is about the size of a basketball, to look for even smaller and weaker axions. Meanwhile, Winslow is in the process of figuring out how to scale the experiment up, to the size of a compact car -- dimensions that could enable detection of even weaker axions. "There is a real possibility of a big discovery in the next stages of the experiment," Winslow says. "What motivates us is the possibility of seeing something which would change the field. It's high-risk, high-reward physics."

#space #science #Astronomy #physics

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soycabcba · 3 years

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Belgrano y la distribución de las mesas para el sábado

El sábado 6 de febrero desde las 8 y hasta las 18, los socios de Belgrano podrán acceder al Gigante de Alberdi , por la tribuna Tomás Cuellar, para emitir allí su voto entre los candidatos Luis Fabián Artime de Belgrano Primero o Armando Valentín Pérez de Siempre Belgrano.

De acuerdo a lo informado por la Comisión Electoral del club se dispuso la utilización de 34 mesas, 33 de ellas para los socios activos y la restante para los vitalicios.

Además, es importante que los socios recuerden que solamente ingresarán al Gigante las personas que estén habilitadas para votar. Por ello se pide que no asistan con niños, niñas y/o cualquier persona ajena al acto electoral.

También quedó expresamente aclarado que está prohibido asistir al acto electoral con elementos identificatorios de las listas participantes y sus candidatos (carteles, remeras, camisetas, barbijos, gorras, etc).

Por determinación del COE, en esta oportunidad, la elección se hará en el sector de la tribuna Cuellar. Se ingresará por los portones 16 y 17, mientras que la salida será por el portón 14.

De las 34 mesas habilitadas para votar. Las que van del 1 al 20 estarán ubicadas en el sector de la tribuna Cuellar Baja, ingresando al sector por las escaleras de la izquierda. Mientras que las mesas 21 a 33 se encontrarán en el sector de la Tribuna Cuellar Alta, accediendo por las escaleras de la derecha. La única que se encontrará sobre la explanada será la 34, disponible para vitalicios/as, discapacidad o casos especiales.

Así están distribuidas las mesas:

1 DESDE ABACA FRANCO ARIEL

HASTA ALGARBE RAUL EDUARDO

2 DESDE ALI PABLO ARIEL

HASTA ARCE PABLO EMILIANO

3 DESDE ARCE RAUL OSCAR

HASTA BARBOSA MARCELO ALEJANDRO

4 DESDE BARBOSA MARCELO DANIEL

HASTA BIANCHI MATIAS MANUEL

5 DESDE BIANCHINI AGOSTINA

HASTA BUSTOS CARLOS IVAN

6 DESDE BUSTOS CESAR ADRIAN

HASTA CARANA PEDRO

7 DESDE CARARO ALEJANDRO HUGO

HASTA CEBALLOS SOFIA ELENA

8 DESDE CEBALLOS SORIA LUCAS

HASTA CONTRERAS LEONARDO ARIEL

9 DESDE CONTRERAS LEONARDO DAVID

HASTA DAVILA CRISTHIAN EZEQUIEL

10 DESDE DAVILA DIEGO DAVID

HASTA DUBICKI ANDRES NICOLAS

11 DESDE DUCA HUMBERTO GABRIEL

HASTA FERRER VIEYRA MARTIN ALEJANDRO

12 DESDE FERRER VIEYRA NICOLAS BERNARDO

HASTA GAITAN THOMAS EZEQUIEL

13 DESDE GAITAN VICTOR MANUEL

HASTA GIGENA CRISTIAN GONZALO

14 DESDE GIGENA EVELYN DANIELA

HASTA GONZALEZ MARTIN

15 DESDE GONZALEZ MATIAS EZEQUIEL

HASTA HEREDIA GUSTAVO SEBASTIAN

16 DESDE HEREDIA HUGO FABRICIO

HASTA JURI VALERIA

17 DESDE JURMUSSI JORGE GUILLERMO

HASTA LOPEZ CRISTIAN D.

18 DESDE LOPEZ CRISTIAN HERNAN

HASTA MADERA JONATHAN CLAUDIO

19 DESDE MADERA RODRIGO GASTON

HASTA MARTINEZ GARRERA AGUSTIN ANTONIO

20 DESDE MARTINEZ GISELLA ANAHI

HASTA MININ DARDO ANTONIO

21 DESDE MINNIG MARCELO JOSE

HASTA MOYANO BECERRA JAVIER ERNESTO

22 DESDE MOYANO BRENDA SOLEDAD

HASTA NUÑEZ RODRIGO SIMON

23 DESDE NUÑEZ ROMINA ANAHI

HASTA OYHANARTE ALVARO

24 DESDE OYHANARTE MIGUEL ANGEL

HASTA PEÑALOZA HECTOR DAVID

25 DESDE PEÑALOZA PABLO ANDRES

HASTA PLOMER AYELEN MAGALI

26 DESDE PLOMER MELISA ANALIA

HASTA REARTES EDGARDO RUBEN

27 DESDE REARTES MIGUEL ANGEL

HASTA RODRIGUEZ PABLO ALEJANDRO

28 DESDE RODRIGUEZ PABLO ENRIQUE

HASTA SALEMI ARIEL FERNANDO

29 DESDE SALES CARLOS ALBERTO

HASTA SERRANO MATIAS

30 DESDE SERRANO MAURICIO

HASTA TECHERA CRISTINA BEATRIZ

31 DESDE TEJADA LUIS MAURICIO

HASTA VALE MARCOS GASTON

32 DESDE VALENTE MARTIN DANIEL

HASTA VILLANUEVA OSVALDO CESAR

33 DESDE VILLAREAL CARLOS MAXIMILIANO

HASTA ZURRIAN NESTOR E.

34 VITALICIOS/AS, DISCAPACIDAD, CASOS ESPECIALES

Las mesas. Ya está el detalle de las 34 mesas dispuestas. (La Voz / Archivo)

source https://mundod.lavoz.com.ar/futbol/belgrano-y-la-distribucion-de-las-mesas-para-el-sabado

#mundoD #Belgrano

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untitled42566 · 5 years

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Per FanoTeatro da venerdì a domenica Dracula con Sergio Rubini e Luigi Lo Cascio

FANO – Da venerdì 29 novembre a domenica 1 dicembre un nuovo appuntamento con FANOTEATRO, stagione della Fondazione Teatro della Fortuna realizzata con AMAT e con il contributo del Comune di Fano, della Regione Marche e del MiBACT.

Dopo il successo di Delitto/castigo, Sergio Rubini e Carla Cavalluzzi si cimentano nella riscrittura di un altro capolavoro letterario, l’ultimo grande romanzo gotico, Dracula di Bram Stoker che arriva in scena a Fano al termine di una residenza di riallestimento in città nell’interpretazione dello stesso Rubini – che firma anche la regia – con Luigi Lo Cascio.

Dracula è prima di tutto un viaggio notturno verso l’ignoto. Non solo un viaggio tra lupi che ululano, grandi banchi di foschia e croci ai bordi delle strade. Ma è anche un viaggio interiore che è costretto a intraprendere il giovane procuratore londinese Jonathan Harker, incaricato di recarsi in Transilvania per curare l’acquisto di un appartamento a Londra effettuato da un nobile del luogo. Il giovane avvocato non immagina la sciagura che lo attende, ma immediatamente, appena ha inizio il suo viaggio, sprofonda in un clima di mistero e di scongiuri. È proprio in questo clima di illusione, di oscurità e paura che il giovane Harker verrà calato prima ancora di conoscere il Conte e quando si accosterà al cancello del Castello, come chi sopraggiunto nell’Ade comprenderà di essere finito in una tomba.

Ma il viaggio che compie il giovane Harker non si limita a quell’esperienza fatta di angoscia e paura. L’orrore di ciò che ha vissuto al Castello deborda e finisce con l’inghiottire tutta quanta la sua esistenza, diventa un’ossessione che contamina tutto ciò che ha di più caro, destabilizzando irrimediabilmente ogni certezza. Di questo contagio ne è vittima in primo luogo sua moglie Mina, a cui Jonathan inizialmente non ha il coraggio di raccontare quanto accaduto. È dalla lettura del diario redatto durante il soggiorno-prigionia di Jonathan al Castello che Mina viene a conoscere l’origine di quel malessere, che sembra essersi impossessato del suo giovane sposo e averlo mutato profondamente. Un malessere che come una malattia incurabile finirà per consumare anche lei. Una dimensione dove il buio prevarrà sulla luce, il chiarore ferirà come una lama lo sguardo, il cupo battere di una pendola segnerà il tempo del non ritorno, uno scricchiolio precederà una caduta e il silenzio l’arrivo della bestia che azzanna e uccide. Una realtà malata dove sarà impossibile spezzare la tensione e da cui sembrerà difficile uscirne vivi.

Completano il cast dello spettacolo – prodotto da Nuovo Teatro – Lorenzo Lavia, Roberto Salemi, Geno Diana, Alice Bertini. Regista collaboratore è Gisella Gobbi, la scena è di Gregorio Botta, i costumi di Chiara Aversano, le musiche di Giuseppe Vadalá, il progetto sonoro di G.U.P. Alcaro e le luci di Tommaso Toscano.

Inizio spettacoli: venerdì e sabato ore 21, domenica ore 17. Info botteghino del teatro 0721 800750.

Per FanoTeatro da venerdì a domenica Dracula con Sergio Rubini e Luigi Lo Cascio Per FanoTeatro da venerdì a domenica Dracula con Sergio Rubini e Luigi Lo Cascio FANO - Da venerdì 29 novembre a domenica 1 dicembre un nuovo appuntamento con FANOTEATRO, stagione della Fondazione Teatro della Fortuna realizzata con AMAT e con il contributo del Comune di Fano, della Regione Marche e del MiBACT.

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ca-se-passe-la-haut · 5 years

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Un détecteur de matière noire plus qu'improbable...

C'est une expérience de recherche de matière noire pas comme les autres : elle est dédiée à la détection des axions, et elle a été nommée par ses concepteurs (défense de rire) ABRACADABRA. Oui, je sais, les physiciens sont des gens parfois surprenants. Trouver de la matière noire relève parfois de la magie, il semblerait... Les tous premiers résultats de cette nouvelle expérience viennent d'être publiés et s'avèrent négatifs (vous l'aurez compris), mais ce n'est qu'un petit début pour cette nouvelle expérience magique qui n'a pas fini d'explorer le monde des axions.

Les axions, rappelons-le sont des particules encore hypothétiques, nées d'une théorie issue de la chromodynamique quantique (la physique des quarks) à la fin des années 1970 pour expliquer tout autre chose que la masse manquante de l'Univers (la brisure de la symétrie CP par la force nucléaire forte dans les nucléons). Mais comme cette particule aurait une masse, certes petite, voire toute petite, mais qu'elle existerait en grand nombre, il se pourrait que ce soit en même temps la solution pour expliquer la matière noire.

Plusieurs expériences de part le monde, surtout aux Etats-Unis, ont été montées pour tenter de détecter la présence d'axions, qui devraient se manifester en se transformant en photon lorsqu'ils traversent un intense champ magnétique. ABRACADABRA est l'une d'entre elles. Il s'agit bien sûr d'un acronyme, trouvé après coup semble-t-il qui signifie A Broadband/Resonant Approach to Cosmic Axion Detection with an Amplifying B-field Ring Apparatus. Elle a été imaginée en 2016 par trois physiciens théoriciens américains au MIT pour reproduire en laboratoire ce qui se passe autour d'un magnétar, une étoile à neutrons fortement magnétisée. C'est en effet dans les champs magnétiques les plus intenses que les axions peuvent le plus facilement interagir, plus exactement se transformer en rayonnement électromagnétique dans la longueur d'onde radio. Lorsque les axions se retrouvent en présence d'un champ magnétique, ils induisent donc la production d'un autre champ magnétique. Et c'est cet effet que les physiciens de ABRACADABRA exploitent dans leur détecteur, en mesurant le champ magnétique avec un magnétomètre ultra-précis.

Lindley Winslow et son équipe ont proposé une machine utilisant un aimant supraconducteur en forme de tore, refroidi à une température proche du zéro absolu dans un cryostat. Si aucun axion n'est présent, le centre du tore doit montrer un champ magnétique exactement nul. En revanche, si des axions sont présents et interagissent, un tout petit champ magnétique doit apparaître au centre du tore, dont l'intensité doit dépendre de la masse des axions. On parle ici de champs magnétiques extrêmement faibles, d'environ 20 attoTesla (20.10-18 T). Pour comparer, on peut se rappeler que votre cerveau génère un champ magnétique de 10-12 T, donc 50000 fois plus fort que le signal recherché, et que le champ magnétique terrestre vaut 30 microTesla (1500 milliards de fois plus que le signal recherché...). Un des gros challenges de cette expérience abracadabrantesque pas plus grosse qu'un ballon de basket était donc son blindage électromagnétique contre tous les bruits de fond magnétiques environnants, de la station radio du coin à la petite LED incluse dans l'oscilloscope utilisé à côté du cryostat.

Pour cette première campagne expérimentale qui a eu lieu à l'été 2018, dont les résultats négatifs font l'objet d'une publication dans Physical Review Letters, les chercheurs ont exploré (et donc exclu) la plage de masse comprise entre 0,31 neV et 8,3 neV (nano-électronvolts). Mais ce n'est qu'un début, car ABRACADABRA est conçue pour détecter des potentiels axions dont la masse peut s'étaler entre 1 femtoelectronvolt (10-15 eV) et 1 microeV (10-6 eV).

Les physiciens américains sont optimistes pour le futur de leur expérience avec cette installation qui n'est aujourd'hui qu'un prototype pour un détecteur de plus grande dimension, financé aux Etats-Unis par la National Science Foundation et le Department of Energy. Ils savent que ce qu'ils font est très risqué techniquement, mais que ça peut rapporter très très gros scientifiquement...

(bien que ce billet ait été rédigé peu avant le 1er avril, les informations données sont rigoureusement exactes, il ne s'agit pas d'une blague!) Source

First Results from ABRACADABRA-10 cm: A Search for Sub-μeV Axion Dark Matter Jonathan L. Ouellet, Chiara P. Salemi, Joshua W. Foster, Reyco Henning, Zachary Bogorad, Janet M. Conrad, Joseph A. Formaggio, Yonatan Kahn, Joe Minervini, Alexey Radovinsky, Nicholas L. Rodd, Benjamin R. Safdi, Jesse Thaler, Daniel Winklehner, and Lindley Winslow Phys. Rev. Lett. 122, 121802 – (29 March 2019) https://doi.org/10.1103/PhysRevLett.122.121802 Illustrations 1) Le détecteur prototype ABRACADABRA-10 cm utilisé dans cette étude (Ouellet et al.) 2) Diagramme de la désintgration d'un axion en deux photons.

via https://ift.tt/2OzSevD

#science #astrophysique #astroparticules #axions #matière noire

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dorcasrempel · 5 years

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Dark matter experiment finds no evidence of axions

Physicists from MIT and elsewhere have performed the first run of a new experiment to detect axions — hypothetical particles that are predicted to be among the lightest particles in the universe. If they exist, axions would be virtually invisible, yet inescapable; they could make up nearly 85 percent of the mass of the universe, in the form of dark matter.

Axions are particularly unusual in that they are expected to modify the rules of electricity and magnetism at a minute level. In a paper published today in Physical Review Letters, the MIT-led team reports that in the first month of observations the experiment detected no sign of axions within the mass range of 0.31 to 8.3 nanoelectronvolts. This means that axions within this mass range, which is equivalent to about one-quintillionth the mass of a proton, either don’t exist or they have an even smaller effect on electricity and magnetism than previously thought.

“This is the first time anyone has directly looked at this axion space,” says Lindley Winslow, principal investigator of the experiment and the Jerrold R. Zacharias Career Development Assistant Professor of Physics at MIT. “We’re excited that we can now say, ‘We have a way to look here, and we know how to do better!’”

Winslow’s MIT co-authors include lead author Jonathan Ouellet, Chiara Salemi, Zachary Bogorad, Janet Conrad, Joseph Formaggio, Joseph Minervini, Alexey Radovinsky, Jesse Thaler, and Daniel Winklehner, along with researchers from eight other institutions.

Magnetars and munchkins

While they are thought to be everywhere, axions are predicted to be virtually ghost-like, having only tiny interactions with anything else in the universe.

“As dark matter, they shouldn’t affect your everyday life,” Winslow says. “But they’re thought to affect things on a cosmological level, like the expansion of the universe and the formation of galaxies we see in the night sky.”

Because of their interaction with electromagnetism, axions are theorized to have a surprising behavior around magnetars — a type of neutron star that churns up a hugely powerful magnetic field. If axions are present, they can exploit the magnetar’s magnetic field to convert themselves into radio waves, which can be detected with dedicated telescopes on Earth.

In 2016, a trio of MIT theorists drew up a thought experiment for detecting axions, inspired by the magnetar. The experiment was dubbed ABRACADABRA, for the A Broadband/Resonant Approach to Cosmic Axion Detection with an Amplifying B-field Ring Apparatus, and was conceived by Thaler, who is an associate professor of physics and a researcher in the Laboratory for Nuclear Science and the Center for Theoretical Physics, along with Benjamin Safdi, then an MIT Pappalardo Fellow, and former graduate student Yonatan Kahn.

The team proposed a design for a small, donut-shaped magnet kept in a refrigerator at temperatures just above absolute zero. Without axions, there should be no magnetic field in the center of the donut, or, as Winslow puts it, “where the munchkin should be.” However, if axions exist, a detector should “see” a magnetic field in the middle of the donut

After the group published their theoretical design, Winslow, an experimentalist, set about finding ways to actually build the experiment.

“We wanted to look for a signal of an axion where, if we see it, it’s really the axion,” Winslow says. “That’s what was elegant about this experiment. Technically, if you saw this magnetic field, it could only be the axion, because of the particular geometry they thought of.”

In the sweet spot

It is a challenging experiment because the expected signal is less than 20 atto-Tesla. For reference, the Earth’s magnetic field is 30 micro-Tesla and human brain waves are 1 pico-Tesla. In building the experiment, Winslow and her colleagues had to contend with two main design challenges, the first of which involved the refrigerator used to keep the entire experiment at ultracold temperatures. The refrigerator included a system of mechanical pumps whose activity could generate very slight vibrations that Winslow worried could mask an axion signal.

The second challenge had to do with noise in the environment, such as from nearby radio stations, electronics throughout the building turning on and off, and even LED lights on the computers and electronics, all of which could generate competing magnetic fields.

The team solved the first problem by hanging the entire contraption, using a thread as thin as dental floss. The second problem was solved by a combination of cold superconducting shielding and warm shielding around the outside of the experiment.

“We could then finally take data, and there was a sweet region in which we were above the vibrations of the fridge, and below the environmental noise probably coming from our neighbors, in which we could do the experiment.”

The researchers first ran a series of tests to confirm the experiment was working and exhibiting magnetic fields accurately. The most important test was the injection of a magnetic field to simulate a fake axion, and to see that the experiment’s detector produced the expected signal — indicating that if a real axion interacted with the experiment, it would be detected. At this point the experiment was ready to go.

“If you take the data and run it through an audio program, you can hear the sounds that the fridge makes,” Winslow says. “We also see other noise going on and off, from someone next door doing something, and then that noise goes away. And when we look at this sweet spot, it holds together, we understand how the detector works, and it becomes quiet enough to hear the axions.”

Seeing the swarm

In 2018, the team carried out ABRACADABRA’s first run, continuously sampling between July and August. After analyzing the data from this period, they found no evidence of axions within the mass range of 0.31 to 8.3 nanoelectronvolts that change electricity and magnetism by more than one part in 10 billion.

The experiment is designed to detect axions of even smaller masses, down to about 1 femtoelectronvolts, as well as axions as large as 1 microelectronvolts.

The team will continue running the current experiment, which is about the size of a basketball, to look for even smaller and weaker axions. Meanwhile, Winslow is in the process of figuring out how to scale the experiment up, to the size of a compact car — dimensions that could enable detection of even weaker axions.

“There is a real possibility of a big discovery in the next stages of the experiment,” Winslow says. “What motivates us is the possibility of seeing something which would change the field. It’s high-risk, high-reward physics.”

This research was funded, in part, by the National Science Foundation, the Department of Energy, and the Simons Foundation.

Dark matter experiment finds no evidence of axions syndicated from https://osmowaterfilters.blogspot.com/

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