Nakon desetljeća planiranja, testiranja i bušenja ogromnih rupčaga u ledu Antarktika pomoću ogromne bušilice na vruću vodu, znanstvenici National Science Foundationa i njihovi partneri završili su rad na IceCube opservatoriju - neutrino detektoru na Južnom polu ove subote, ucrtavši početak nove ere u neutrino astrofizici. Ovaj projekt na kojeg je sprašeno 279 milja dolara omogućit će istraživačima potragu za subatomskim pračesticama u najvećem svjetskom neutrino detektoru. Obzirom da neutrini vrlo rijetko imaju interakciju s normalnom materijom, IceCube je dizajniran tako da detektira interakcije između molekula vode u ledu i subatomskih čestica. Icecube se sastoji od 5.160 umreženih optičkih senzora koji su spušteni u 86 rupa u ledu do dubina od 2400 metara na kojima je led vrlo taman i vrlo proziran. Senzori su umreženi na području od 800x800 metara, što uvelike povećava mogućnost da detektiraju neutrino koji će udariti atom vodika ili kisika, izbacujući novu česticu naziva muon i zasjati plavim svjetlom. Temeljem tih podataka o kolizijama, istraživači se nadaju kako će im to olakšati potragu u svemiru za raznim izvorima neutrina, što kasnije može dovesti do ubrzanog razvoja istraživanja tamne tvari ili supersimetričnih čestica.
To je zakon. Istraživanje neutrino čestica je jedno od područja koje ima nebrojeno mnogo primjena u budućnosti.
Znam da po Kini i Indiji imaju dosta podzemnih bazena u bivšim rudnicima, i da oni imaju male sferične akvarije za detekciju, ali njihova ukupna površina/volumen nije ni približno jednaka ovoj.
Najbrži pištolj Policije Okusa. Može da pogodi sve od bilo gdje. Također piše i poeziju.
Kaj su čak i tamo otišli istraživat neutrine? Ludo. Znam da se gužvaju po raznoraznim napuštenim rudnicama i da do dana današnjeg nisu našli niti jedan jedini neutrino al ipak, lijepo je vidjet da se ulaže lova u takvo nešto.
"Extinction is the rule. Survival is the exception." - Carl Sagan
Rekao bih da su do sada našli tone, ali neutrino nema masu/ima nezamjetnu masu.Izvorno postao Aral
Najbrži pištolj Policije Okusa. Može da pogodi sve od bilo gdje. Također piše i poeziju.
Hmmm, mislim da ih baš i nisu otkrili, pošto prolaze kroz normalnu materiju. U biti, jako teško ih je otkriti ali možda su u međuvremenu imali srećeJedno je sigurno, jako ih je teško otkriti i zato šibaju tak dugo pod zemlju da nema utjecaja kozmičkih zraka koje bi to mogli poremetit. Čim ovo čudo grade, očito su se dobro zakačili na to
"Extinction is the rule. Survival is the exception." - Carl Sagan
Postojanje neutrina je odavno dokazano, već su dvije Nobelove nagrade dodijeljene za to. Evo zbog čega su nam neutrini konkretno važni:
Motivation for scientific interest in the neutrino
The neutrino is of scientific interest because it can make an exceptional probe for environments that are typically concealed from the standpoint of other observation techniques, such as optical and radio observation.
The first such use of neutrinos was proposed in the early 20th century for observation of the core of the Sun. Direct optical observation of the solar core is impossible due to the diffusion of electromagnetic radiation by the huge amount of matter surrounding the core. On the other hand, neutrinos generated in stellar fusion reactions interact very weakly with matter, and pass through the Sun with few interactions. While photons emitted by the solar core may require some 40,000 years to diffuse to the outer layers of the Sun, neutrinos are virtually unimpeded and cross this distance at nearly the speed of light.[39][40]
Neutrinos are also useful for probing astrophysical sources beyond our solar system. Neutrinos are the only known particles that are not significantly attenuated by their travel through the interstellar medium. Optical photons can be obscured or diffused by dust, gas, and background radiation. High-energy cosmic rays, in the form of swift protons and atomic nuclei, are not able to travel more than about 100 megaparsecs due to the GZK cutoff. Neutrinos can travel this and greater distances with very little attenuation.
The galactic core of the Milky Way is completely obscured by dense gas and numerous bright objects. Neutrinos produced in the galactic core will be measurable by Earth-based neutrino telescopes in the next decade.
Another important use of the neutrino is in the observation of supernovae, the explosions that end the lives of highly massive stars. The core collapse phase of a supernova is an almost unimaginably dense and energetic event. It is so dense that no known particles are able to escape the advancing core front except for neutrinos. Consequently, supernovae are known to release approximately 99% of their energy in a quick (10-second) burst of neutrinos. As a result, neutrinos are a very useful probe for these important events.
Determining the mass of the neutrino (see above) is also an important test of cosmology (see Dark matter). Many other important uses of the neutrino may be imagined in the future. It is clear that the astrophysical significance of the neutrino as an observational technique is comparable with all other known techniques, and is therefore a major focus of study in astrophysical communities.
In particle physics the main virtue of studying neutrinos is that they are typically the lowest mass, and hence lowest energy examples of particles theorized in extensions of the Standard Model of particle physics. For example, one would expect that if there is a fourth class of fermions beyond the electron, muon, and tau generations of particles, that the fourth generation neutrino would be the easiest to generate in a particle accelerator.
Neutrinos could also be used for studying quantum gravity effects. Because they are not affected by either the strong interaction or electromagnetism (unless they have a magnetic moment), and because they are not normally found in composite particles (unlike quarks) or prone to near instantaneous decay (like many other standard model particles) it might be possible to isolate and measure gravitational effects on neutrinos at a quantum level.
Pa to sam i rekao, ima ih na milijarde ali ih je užasno teško otkriti jer nemaju mase, odnosno prolaze kroz normalnu materiju.
"Extinction is the rule. Survival is the exception." - Carl Sagan
Evo im i soundtrack by IceCube...
Stari ''bolje reći bilošto kad nemaš što pametno,a?''
Inače, možda nema previše veze s neutrinima, ali u ''božjoj čestici'' je to bilo u tom istom poglavlju (brijem) . Sastav čestica od kojih je građen svaki čovjek se tokom života promjeni i do četri puta. Znači sve čestice od kojih si sastavljen se promjene oko četri puta, STRAŠNO.
Look at us. Everything is backwards; everything is upside down. Doctors destroy health, lawyers destroy justice, universities destroy knowledge, governments destroy freedom, the major media destroy information and religions destroy spirituality
Otići će im to sve u klnac za par godina... globalno zatopljene XD
Wolf guy - The author seems to be playing a game called "how many murder, rape, and torture scenes involving minors can I stick in a book before people stop reading completely"
Nije bitan led
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[center:chmelrcv]BITCH, IT IS 5:30![/center:chmelrcv]
-kazem ti, nisu sredeni.
Zbunjuje me izraz "prolaze kroz materiju". Neutrini nisu bozoni, pa da doslovno prolaze kroz materiju (tj. da mogu biti istovremeno na potpuno istom kvantnom položaju kao neka druga čestica)... Očigledno se tu i tamo moraju sudariti s nekom česticom i izgubiti energiju/zapeti, yes? O_o
Ne možeš postati tako brzo iza zadnjeg posta kojeg si postao/la.
Imaš u grackoj
Look at us. Everything is backwards; everything is upside down. Doctors destroy health, lawyers destroy justice, universities destroy knowledge, governments destroy freedom, the major media destroy information and religions destroy spirituality
Mislim, kužim razliku između fermiona i bozona, pa zato i pitam
Neutrino kao lepton, tj. fermion, ne bi trebao "prolaziti" kroz tvar..
(kladim se da ima neke veze s prokletim spinom; uvijek sam mrzio taj koncept)
Ne možeš postati tako brzo iza zadnjeg posta kojeg si postao/la.
Da, ali jakojakojako rijetko. Zato se i "obzervatoriji" za neutrine rade na polu. Nije stvar u ledu, nego da tamo hvataju netrine koji prođu kroz cijelu Zemlju i zapnu u tom supergustom gelu
[center:chmelrcv]
[center:chmelrcv]BITCH, IT IS 5:30![/center:chmelrcv]
-kazem ti, nisu sredeni.
Aha, I see
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Da malo citiram neke zanimljivosti vezane uz neutrine i njihovu interakciju s nama:
S * Our body contains about 20 milligrams of Potassium 40, which is beta radioactive. As a consequence, we emit about 340 millions neutrinos per day without knowing that. Neutrinos interact very few, there are thus 340 millions neutrinos per day, which run from our body at the speed of light until the end of the universe!...
* An experiment like NOMAD detects about one neutrino every 10 seconds. This one deposits a mean of 27 GeV in the detector. Thus, for all the duration of the experiment, neutrinos will have deposited a little more than 0.03 Joules, that is 10 times less than a sneeze.
* Still in NOMAD, the detector is "active" only during some milliseconds, at each arriving of neutrinos burst from the particles accelerator. For all the duration of the experiment (from 1994 to 199, the detector was thus "active" only for 15 hours.
* Always in NOMAD, the detector uses a magnet of 0.4 Tesla (2000 times the earth magnetic field) created by a current of 5713 A. This gives from 1994 to 1998, an energetic consumption greater than 200.000 billions Joules, that is about 10.000 times your electricity consumption in the same time period (4 years).
* Wherever you are on the earth, even deeply underground, you receive per second about 400.000 billions neutrinos from the sun, but also 50 billions neutrinos (but this number is not well known!) from the natural radioactivity of the earth, and 10 to 100 billions neutrinos from nuclear plants all over the world. Fortunately for us, neutrinos interact very few and you can live as if they are not there!...
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