Impaka hagati y’abemera ubuzima bwo hanze y’Isi n’ababihakana

Impaka ku buzima bw’ibivejuru byo hanze y’Isi(vie extraterrestre) zatangiye kera cyane mu mateka y’abantu uhereye mu gihe cy’abagereki ahagana mu kinyejana cya 4 mbere y’ivuka rya Yezu.
Zabayeho kubera kwibaza ku mwanya w’isi mu isanzure n’ukuntu ubuzima bushobora kubaho ahandi mu isanzure.

Nkubwo Abagiriki ba kera: Atomistes nka Epicure bavugaga ko hari izindi nyenyeri n’imibumbe ifite ubuzima, mu gihe uwitwa Aristote yabihakanye.

Mu gihe cy’Ubukirisitu bwo hambere, abantu bibazaga niba ubuzima bw’inyamahanga buhuye n’inyigisho z’iyobokamana.

Mu byiswe Copernican Revolution (mu kinyejana cya 16), Copernic yakuye isi ku mwanya wo kuba “mu ntebe y’isanzure ” ( centre de l’Unuvers) bituma abantu batangira kubona ko bishoboka ko ubuzima bushobora kubaho ahandi mu isanzure.

Naho muri iki gihe cya siyansi, impaka zishingira ku bushakashatsi bwa astrobiology (ni ishami rya siyansi ryiga ku nkomoko, iterambere ry’ibanze, ikwirakwira n’ejo hazaza h’ubuzima mu isanzure),  ariko nanone nta gihamya iraboneka ifatika ko haba hari ubuzima hanze y’Isi dutuyeho.

Muri icyo gihe ariko nano Abashakashatsi benshi bemera ko ubuzima hanze y’Isi bushoboka. Mu bushakashatsi bwakozwe muri  2024–2025, hafi 87% by’abahanga bemeje ko ubuzima bw’ibanze bushobora kubaho mu isanzure, naho 67% bemera ko bushobora kuba burimo ibinyabuzima bikomeye, ndetse 58% bemera ko bushobora kubaho mu buryo bw’ubwenge buhambaye.

Dore rero gihamya z’abemeza ko ubuzima bushoboka hirya y’Isi batanga ndetse n’izo ababihakana nabo batanga.

I.Gihamya zitangwa n’abemeza ubuzima hanze y’Isi.

1. Ubunini bw’isanzure ( immensité de l’Unuvers) 

Abahanga mu bumenyi bw’Isanzure bemeza ko Isanzure rifite galaxies zigera kuri miliyari ibihumbi bibiri ( 2 000 milliards) naho umubare w’inyenyeri wo bikaba bigoye kuwandika ni 3x 10exp22 ( 3 ikurikiwe n’amazeru 22).

Nko muri galaxie yacu: Voie Lactée (Milky Way), hari inyenyeri zibarirwa hagati ya miliyari 100 na 400.
Abashakashatsi rero ni aha bahera bemeza ko hari amahirwe menshi yuko hanze y’iyi Isi dutuye haba hari ibindi ibinyabuzima.

2. Ivumburwa ry’imibumbe igaragiye izindi nyenyeri.

Nkuko twabibonye Exoplanète ni ijambo rikoreshwa mu buhanga bwa astronomie risobanura imibumbe iri hanze y’urusobe rw’inyenyeri yacu (Système solaire), izenguruka izindi nyenyeri zitari izuba.

Ivumburwa ry’iyi mibumbe  ni imwe mu mpamvu zikomeye abeneza ko hari ubundi buzima hanze y’Isi bashingiraho bemeza ibyo.
Koko rero Exoplanète ya mbere yavumbuwe Mu mwaka wa 1992, abashakashatsi Aleksander Wolszczan na Dale Frail bavumbuye exoplanète ya mbere izenguruka inyenyeri ya pulsar (PSR B1257+12) naho mu mwaka 1995, Michel Mayor na Didier Queloz bavumbuye exoplanète ya mbere izenguruka inyenyeri isa n’izuba (51 Pegasi b).  Iri vumbura rya nyuma niryo ryemejwe  nka gihamya ikomeye ko imibumbe iri hanze ya Système solaire ibaho.

Abatanze iyi mpamvu bagaragaje ko inyenyeri nyinshi zifite exoplanètes ibi bigatuma amahirwe y’ubuzima ahandi hatari ku Isi aba menshi. Byongeye kandi  zimwe muri izo exoplanètes ziri mu gace gashobora guturwamo (zone habitable) , aho bishoboka ko haba amazi asukika ( liquide).

IFoto yakozwe n’umunyabugeni ishushanya exoplanete  LP 791-18d  iri hafi y’isi yacu ( 90  annees lumieres)

3. Ibaho rya Extrëmophiles

Extremophiles ni ni udukoko duto (micro-organismes) tubasha kubaho mu bice bisanzwe bizwi ko bitaberanye n’ubuzima ( conditions extremes), aho hatekerezwaga  ko ubuzima butashoboka.

Utu dukokora twavumbuwe bwa mbere mu myaka ya 1960–1970, ubwo abashakashatsi batangiye kubona ko hari mikorobe zibasha kubaho mu bice bigoye ubuzima  nk’amazi ashyushye cyane cyangwa ahantu hari acide nyinshi.
Ibyo byahindutse gihamya ikomeye ko ubuzima bushobora kwihanganira ibidukikije bigoranye guturwaho n’ibinyabuzima, bituma abantu batekereza ko bushobora kubaho no mu isanzure kabone nubwo haba ari ahantu hataberanye n’ubuzima dusanzwe tuzi ku Isi.

II. Gihamya z’abahakana ubuzima bwo hanze y’Isi

1. Ihurizo ( paradoxe) de Fermi

Paradoxe de Fermi ni ikibazo cyibajijwe n’umuhanga Enrico Fermi mu 1950 kugira kiti: “Niba hari amahirwe menshi bwo kubona ib’ivejuru , kuki tutarababonabose ?”(If extraterrestrial civilizations are common in the galaxy, why haven’t we seen any signs of them? Where is everybody?”).

Iri hurizo, paradoxe riteye ritya: ”Mu isanzure hari inyenyeri nyinshi zisa n’izacu, zifite imibumbe ishobora  kuba iriho ubuzima, Ku buryo bw’imibare, byari bikwiye kuba hari izindi nyamaswa zifite ubwenge nkatwe, ariko kugeza ubu, nta kimenyetso na kimwe cyerekana ko hari izindi nyamaswa zifite ubwenge twabonye cyangwa twumvise.”

Paradoxe de Fermi ntivuga ko nta buzima hirya y’Isi bubaho, ahubwo ni ikibazo cyibaza impamvu tutarabubona.
Iyi paradoxe yashyizwe mu mpamvu zihakana ibaho ry’ubu buzima kubera impamvu 2:
1. Iyi paradoxe ihinyuza impamvu zatanzwe n’abemeza ko ubwo buzima buriho harimo impamvu y’ubwinshi bw’inyenyeri.
2. Iri paradoxe niyo abahakana ubuzima hirya y’Isi baheraho batanga impamvu zabo ku kuba ubwo buzima budashoboka.

2. Igitekerezo (Hypothèse) cy’uko Isi yaba ari imwe rukumbi :Hypothèse de la Terre Rare (Rare Earth Hypothesis)

Ni igitekerezo cyashyizwe ahagaragara n’abashakashatsi Peter Ward na Donald Brownlee mu gitabo Rare Earth: Why Complex Life Is Uncommon in the Universe (2000).

Ivuga ko ubuzima nk’ububoneka ku Isi ari ubuzima buhambaye ( complexe),  ko bushobora kuba buboneka hake mu isanzure  kandi ko Isi ari umubumbe udasamzwe  watumye ibyo bishoboka ( Complex life is extremely rare in the universe, and Earth is an exceptional planet where the right combination of conditions made it possible.)

Imiterere y’isi yihriye ivugwa ni ukuba:
1. iri hafi y’inyenyeri yacu (izuba) mu ntera ikwiye, ituma amazi aba mu buryo busukika;
2.  Ari Umubumbe ufite ubunini buri mu rugero rukwiye;  i
3. Iri hamwe n’umubumbe wa Jupiter ukora nk’“umurinzi”, ikabuza asteroids nyinshi kugera ku Isi.
4. Kuba ifite e ukwezi kunini bituma isi iterera mu mihindagurikire y’ikirere.
5. Igizwe na  Plate tectonics ( ibipande bigize igice cy’inyuma cy’isi, bihora bitembera , byimuka buhoro buhoro), bigatuma habaho ra ikirere gikwiye n’ubuzima burambye.

3. Igitekerezo cy’akayunguruzo gahambaye ku buzima bwo mu isanzure ( Grand filtre, Filtre exceptionnel)

Iki gitekerezo cyemeza ko hari ikintu kigoye cyane (inzitizi) mu muvuduko  w’iterambere ry’ubuzima  kibuza imiryango y’ibiriho (civilisations) gukura ngo igere ku rwego rwo gukwirakwira mu isanzure ry’ikirere. Iyi nzitizi ikaba ishobora kuganisha ku mperuka ku binyabuzima, bigashyira byose, cyangwa hakarokoka mbarwa.

• Niba “Grand Filtre” iri mu bihe byashize 

Menya ibyangombwa umubumbe ugomba kuba wujuje kugira ngo urangweho ubuzima nk’uko bimeze ku Isi