MADUBIN NA'URAR HANGEN NESA NA RUWA, DA ZAFI KE SANYA SHI SANTSI

Ganin duniya kai tsaye kusa da tauraronta yana buƙatar madubin na’urar hangen nesa mai faɗin mita da dama. James Webb Space Telescope, babbar cibiyar lura a sararin samaniya, tana da madubi mai mita 6.6 da aka yi da sassa 18 masu kusurwa shida waɗanda dole aka naɗe su don su shiga cikin rokarta sannan aka jera su da daidaito na nanomita. A cewar majiyoyin da marubutan suka ambata, wannan ƙalubalen jerawa ne ya tsayar da Webb a mita 6.6.

Madubai na ruwa suna ba da wata hanya dabam. A ƙasa, ruwa mai haske da aka juya a kewayen wani tsayayyen layi a tsaye yana ɗaukar siffar parabola, ba tare da wani goge-goge ba — amma irin wannan na’urar hangen nesa za ta iya duba sama kai tsaye ne kawai.

Madubi da ke siffanta kansa

Ryan Engle da Valeri Frumkin, na sashen injiniyan injina na Jami’ar Boston, suna aiki a cikin wani aiki mai suna FLUTE (Fluidic Telescope). Ra’ayinsa: a cikin rashin nauyi na sararin samaniya, a shafa wani babban tallafi mai lanƙwasa da ruwa mai haske mai kaurin milimita kaɗan. Ba tare da nauyi da ke jan sa ba, ƙarfin saman ruwa (surface tension) shi kaɗai yana jan layin zuwa siffar ƙwallo mai santsi — ko wace alƙibla na’urar hangen nesan ta fuskanta, kuma ba tare da juyawa ba.

Samfurin: siririn layin ruwa yana lulluɓe tallafi mai siffar ƙwallo, ana sanya zafi iri ɗaya q(t) daga baya kuma saman da ke buɗe yana fitar da zafi zuwa sararin samaniya. — Figure 1, Engle & Frumkin (2026), arXiv:2610.08654.

Akwai matsala. Ƙarfin saman ruwa yana aiki ne ta lanƙwasar saman a wurin. Yana goge ƙananan lanƙwasa da sauri, amma yana da jinkiri ƙwarai wajen daidaita raƙuman ruwa masu faɗi da laushi — irin waɗanda ke ragewa bayan an buɗe madubin ko lokacin da na’urar hangen nesan ta juya zuwa sabon abin dubawa. Ga babban madubi, jira su ɓace da kansu ya zama, a kalaman marubutan, jinkiri wanda ba za a iya jurewa ba.

Zafi da ke tayar da hankali, hutu da ke warkarwa

Marubutan sun koma ga wani ƙarfi dabam: tasirin zafi kan ƙarfin saman ruwa (thermocapillary effect). Ƙarfin saman ruwa yana raguwa idan ruwa ya yi ɗumi, don haka bambancin zafi a saman yana sa shi kwarara, daga wuri mai ɗumi zuwa mai sanyi.

Dumama siririn ruwa ba tare da tsayawa ba yawanci mummunan ra’ayi ne: wurare masu sirara suna ƙara zafi, ruwa yana janyewa daga gare su, kuma siririn ruwan na iya yagewa. Amsar tawagar ita ce a dumama madubin daidai-wa-daida, amma bi-da-bi. A kowane hutu, saman yana yin sanyi ta hanyar fitar da zafinsa zuwa sararin samaniya — kuma wurare masu sirara suna yin sanyi da sauri fiye da masu kauri. Daga nan ana jan ruwa zuwa wurare masu siraran. Waɗannan kwararar gaba da baya suna soke rashin daidaiton da dumama ya haifar kuma suna barin saman ya natsu zuwa kauri iri ɗaya.

Fitar da zafi (radiation) ce ke yin ragewar: wurare masu zafi suna fitar da makamashi fiye da masu sanyi, abin da ke goge bambance-bambancen zafi da lokaci.

Kwanaki ga wasu raƙuman, watanni ga wasu

Marubutan sun samar da lissafi (equations) na jinkirin sauyin saman a cikin zagaye da yawa na dumama, sannan wani ma’auni na lokacin da yake tsayawa daram. Yana rasa daidaito idan fitar da zafi ta yi rauni sosai ko kuma idan ana motsa ruwan da sauri. Ga kowane girman raƙumi, akwai zafin saman da ya fi dacewa wanda a cikinsa yake ɓacewa mafi sauri.

Daga nan sun yi kwaikwayon kwamfuta na madubin ruwa mai mita 6.6, girman na Webb, da zagayen dumama da ke sauyawa da kelvin 5:

• Ga kowane raƙumi da aka gwada, dumama bi-da-bi ya sanya saman santsi da sauri fiye da ƙarfin saman ruwa shi kaɗai.
• Wani raƙumi mai tsawon kusan mita 3 ya ragu sosai cikin kwanaki 4.5 kuma ana hasashen zai rasa kashi 95% na tsayinsa cikin kwanaki 8.6.
• Raƙumi mafi faɗi, kusan mita 6.9, ya rasa kusan kashi 6% kawai a cikin wannan lokaci. Lokacin da ake hasashen zai ɓace shi ne watanni 9.1.

Yadda raƙuman girma huɗu ke sauyawa a cikin kusan awanni 100: samfurin lissafi (shuɗi) da kwaikwayon kwamfuta (lemu) sun yi daidai, kuma dukkansu suna ɓacewa da sauri fiye da ƙarfin saman ruwa shi kaɗai (layin ɗigo-ɗigo) — sai dai raƙumi mafi faɗi, wanda da ƙyar yake motsawa. — Figure 6, Engle & Frumkin (2026), arXiv:2610.08654.

Raƙumi mafi faɗi har yanzu shi ne mafi wuya

Aikin ka’ida ne da lissafin kwamfuta kawai: ba a gwada wani madubin ruwa ta wannan hanya ba. Don saukar da raƙuman da suka fi faɗi zuwa kwanaki maimakon watanni, marubutan sun ce za a buƙaci sauyin zafi mafi girma ko zagayen dumama mai sarƙaƙiya — wanda shi ne batun bincikensu na gaba. Sun kuma lura cewa irin wannan lissafin zai iya amfani ga wasu siraran ruwa da ake dumamawa waɗanda sanyinsu ya dogara da zafinsu.