Cuvant despre noi, romanii


S-ar parea ca nu suntem  singuri in Univers, mai mult, acesta s-a ciocnit cu alte cosmosuri de cel putin patru ori in trecutul sau indepartat,spun mai multi specialisti care au studiat ecourile Big Bang-ului si modul in care acestea s-au  propagat prin spatiul cosmic….

Roger Penrose, specialist in cadrul Universitatii Oxford si omologul sau Vahe Gurzadyan de la Universitatea de Stat de Erevan, Armenia, au anuntat ca microundele detectate de ei in spatiul cosmic se deplaseaza in cercuri concentrice, o dovada clara a faptului ca Universul este ciclic. Teoria sustine ca odata cu sfarsitul fiecarui univers are loc un alt Big Bang care da nastere unui nou cosmos. Este, daca preferati, ca un model al papusilor rusesti, fiecare continand o alta.

In plus, in urma cu numai cateva zile, un grup de specialisti de la Colegiul Universitar din Londra, grup condus de Stephen Feeney, a reusit sa identifice patru valuri distincte de microunde, descoperire ce indica faptul ca universul nostru s-a regenerat de cel putin patru ori pana acum. Totusi, ipoteza sustinuta de Feeney si colegii sai arata ca fiecare Univers se sparge in mai multe cosmosuri mici, aceasta stand ca intr-o celula, in alte cosmosuri mai mari.

Astronomers Find First Evidence Of Other Universes

There’s something exciting afoot in the world of cosmology. Last month, Roger Penrose at the University of Oxford and Vahe Gurzadyan at Yerevan State University in Armenia announced that they had found patterns of concentric circles in the cosmic microwave background, the echo of the Big Bang.

This, they say, is exactly what you’d expect if the universe were eternally cyclical. By that, they mean that each cycle ends with a big bang that starts the next cycle. In this model, the universe is a kind of cosmic Russian Doll, with all previous universes contained within the current one.

That’s an extraordinary discovery: evidence of something that occurred before the (conventional) Big Bang.

Today, another group says they’ve found something else in the echo of the Big Bang. These guys start with a different model of the universe called eternal inflation. In this way of thinking, the universe we see is merely a bubble in a much larger cosmos.

This cosmos is filled with other bubbles, all of which are other universes where the laws of physics may be dramatically different to ours.

These bubbles probably had a violent past, jostling together and leaving „cosmic bruises” where they touched. If so, these bruises ought to be visible today in the cosmic microwave background.

Now Stephen Feeney at University College London and a few pals say they’ve found tentative evidence of this bruising in the form of circular patterns in cosmic microwave background. In fact, they’ve found four bruises, implying that our universe must have smashed into other bubbles at least four times in the past.

Again, this is an extraordinary result: the first evidence of universes beyond our own.

So, what to make of these discoveries. First, these effects could easily be a trick of the eye. As Feeney and co acknowledge: „it is rather easy to fifind all sorts of statistically unlikely properties in a large dataset like the CMB.” That’s for sure!

There are precautions statisticians can take to guard against this, which both Feeney and Penrose bring to bear in various ways.

But these are unlikely to settle the argument. In the last few weeks, several groups have confirmed Pernose’s finding while others have found no evidence for it. Expect a similar pattern for Feeney’s result.

The only way to settle this will be to confirm or refute the findings with better data. As luck would have it, new data is forthcoming thanks to the Planck spacecraft that is currently peering into the cosmic microwave background with more resolution and greater sensitivity than ever.

Cosmologists should have a decent data set to play with in a couple of years or so. When they get it, these circles should either spring into clear view or disappear into noise (rather like the mysterious Mars face that appeared in pictures of the red planet taken by Viking 1 and then disappeared in the higher resolution shots from the Mars Global Surveyor).

Planck should settle the matter; or, with any luck, introduce an even better mystery. In the meantime, there’s going to be some fascinating discussion about this data and what it implies about the nature of the Universe. We’ll be watching.


http://arxiv.org/abs/1012.1995: First Observational Tests of Eternal Inflation

http://arxiv.org/abs/1011.3706: Concentric Circles In WMAP Data May Provide Evidence Of Violent Pre-Big-Bang ActivityOur cosmos was „bruised” in collisions with other universes. Now astronomers have found the first evidence of these impacts in the cosmic microwave background

13/ 12//2010



17/12/2010 Posted by | DIVERTSMENT | , , , , , , , , , , , , , , | Lasă un comentariu



ID: #99-pamant galerie de wallpapere

Un nou studiu al Agentiei Spatiale Europene (ESA) este pregatit pentru a anunta prezenta semnelor de viata de pe Terra si posibilitatea ca planeta sa fie locuita, anunta LiveScience.

La o prima vedere, anuntul facut de astronomii europeni ar putea reprezenta o pierdere de timp si de fonduri. Cu toate acestea, proiectul de a monitoriza Pamantul din apropierea planetei Venus in cautarea vietii are o importanta majora, sustin oamenii de stiinta. In esenta, daca se intentioneaza descoperirea vietii pe o alta planeta, cercetatorii trebuie sa cunoasca elementele care pot trada potentialele urme de viata, iar pentru aceasta a fost aleasa singura planeta cunoscuta care a permis evolutia vietii, Terra.

„ESA a initiat acest proiect, primul de acest gen, prin care urmareste monitorizarea Pamantului de pe o platforma indepartata. Vrem sa cunoastem si sa aflam cat mai multe despre capacitatea Pamantului de a sustine viata, pentru a putea aplica apoi toate aceste informatii in cautarea unor noi planete locuibile”, sustine David Grinspoon, unul dintre cercetatorii implicati in proiect.

Inca de la lansarea sa din noiembrie 2005, sonda spatiala Venus Express a fotografiat Pamantul de la peste 3,5 milioane de kilometri in cautarea semnelor care pot trada prezenta vietii. „In atmosfera Terrei sunt vizibile apa si oxigenul dar nu trebuie sa uitam ca si Venus are aceleasi caracteristici. Observarea acestor molecule nu este suficienta, astfel ca trebuie sa cautam informatii cat mai detaliate”, declara acelasi Grinspoon.

Din 1995 si pana in prezent, astronomii au descoperit peste 300 de exoplanete. O misiune a agentiilor spatiale europene si americane, care va avea loc in 2009, va incerca sa identifice Graalul oamenilor de stiinta, o planeta asemanatoare Terrei.

Terra este monitorizata din spatiu in cautarea vietii

Sursa: Livescience si Descopera ro.

29/01/2010 Posted by | DIVERTSMENT | , , , , , , , , , , , | Lasă un comentariu


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