Urknall

Urknall

 

Vor 15 bid 20 Milliarden Jahren,so wird heute angenomen, hat alles mit einem groen Knall.dem Big Bang, angefangen. Wie gelangt man yu dieser Zahlvorstellung?

 

Die Erklärung lieferte der amerikanische astronom Edwin Hubble.

Er entwickelte die mathematische Konstante, nach der sich Galaxien schneller voneinander entfernen, je weiter sie auseinander liegen.

Danch beträgt die Fluchtgeschwindigkeit pro eine Million parsec ( 1 parsec = 3,25 Lichtjahre ) Entfernung ca. 75 Kilometer/Sekunde. Wenn jetzt aber alles auseinander driftet, so muss die Materie des weltalls früher an einem Punkt vereinigt gewesen sein.

 

Kehrt man den Hubble-Effekt um, erreichen wor anhand der konstanten den Zeitraum, der als Geburtszeit des Universums bezeichnet werden kann. Das die Wissenschaft kein genaues Datum liefern kann, liegt auf der Hand.

 

Zu viel ungewissheit herrscht über die erste Zeit nach dem Urknall. So ist zum Beispiel nicht geklärt, ob es womöglich Verzögerungenin der Ausdehnung gegeben hat.

Sicher ist man sich darin, dass die gesamte Materie (Wasserstoff und Helium) in den ältesten Sternen zu finden ist. Zum anderen gibt es gewissermaβen noch Nachwehen des Big Bang. Dabei handelt es sich um die kosmische Hintergrundstrahlung, die 1965 mit Hilfe eines Radioteleskopes von den Amerikanern Penzias und Wilson entdeckt wurde.

 

Unmittelbar nach dem Urknall, in der Blitzphas, also nach weniger als einer Millionstel Sekunde, ist trotz beginnender Expansion die Temperatur noch unendlich hoch (50 000 Milliarden Grad Kelvin).

 

Aus der Strahlung bilden sich Teilchen und Antiteilchen. Diese werden zu Photonen, also Strahlung, aus der wiederum Teilchen und Antiteilchen entstehen. Die Ausdehnung erfolgt unvorstellbar schnell.

Bereits nach einer Sekunde beträgt der Radius vier Lichtjahre.

 

Verglichen mit der anfangsphase ist es richtig kalt geworden 

( 10-15 Milliarden Grad Kelvin).

Nach wenigen Minuten sinkt die Hitze auf eine Milliarde Grad, die Dichte liegt bei der von Eisen. Aus Protonen und Neutronen bilden sich erste Heliumkerne.

 

Der Urknall endet nach 100 000 Jahren. Der Ausdehnungsradius liegt jetzt bei sieben Millionen Lichtjahren. Von nun an entsteht Materie und die Zeit des Strahlungsuniversums ist vorüber. 

 

 

 

Nach der kosmologischen Theorie

the perks of being a wallfelower

I can see it…this moment when you know you’re not a sad story…You are alive…You stand up and see the lights on the buildings…And everything that makes you wonder…And you’re listening to that song on that drive…With the people you love most in this world…And in this moment, I swear…WE ARE INFINTE.
My doctor said we can’t choose where we come from…but we can choose where we go from there…I know it’s not all the answers…But it was enough to start putting these pieces together…

big bang

As everything begun with Big Bang=Urknall=مهبانگ(انفجار بزرگ) I start with this too.

The Big Bang theory is the prevailing cosmological model for the early development of the universe.[1] The key idea is that the universe is expanding. Consequently, the universe was denser and hotter in the past. Moreover, the Big Bang model suggests that at some moment all matter in the universe was contained in a single point, which is considered the beginning of the universe. Modern measurements place this moment at approximately 13.8 billion years ago, which is thus considered the age of the universe.[2] After the initial expansion, the universe cooled sufficiently to allow the formation of subatomic particles, including protons, neutrons, and electrons. Though simple atomic nuclei formed within the first three minutes after the Big Bang, thousands of years passed before the first electrically neutral atoms formed. The majority of atoms that were produced by the Big Bang are hydrogen, along with helium and traces of lithium. Giant clouds of these primordial elements later coalesced through gravity to form stars and galaxies, and the heavier elements were synthesized either within stars or during supernovae.

The Big Bang theory offers a comprehensive explanation for a broad range of observed phenomena, including the abundance of light elements, the cosmic microwave background, large scale structure, and Hubble’s Law.[3] As the distance between galaxies increases today, in the past galaxies were closer together. The known laws of nature can be used to calculate the characteristics of the universe in detail back in time to extreme densities and temperatures.[4][5][6] While large particle accelerator scan replicate such conditions, resulting in confirmation and refinement of the details of the Big Bang model, these accelerators can only probe so far into high energy regimes. Consequently, the state of the universe in the earliest instants of the Big Bang expansion is poorly understood and still an area of open investigation. The Big Bang theory does not provide any explanation for the initial conditions of the universe; rather, it describes and explains the general evolution of the universe going forward from that point on.

Georges Lemaître proposed what became the Big Bang theory in 1927. Over time, scientists built on his initial idea of cosmic expansion, which, his theory went, could be traced back to the origin of the cosmos and which led to formation of the modern universe. The framework for the Big Bang model relies on Albert Einstein’s theory of general relativity and on simplifying assumptions such as homogeneity and isotropy of space. The governing equations were formulated by Alexander Friedmann, and similar solutions were worked on by Willem de Sitter. In 1929, Edwin Hubble discovered that the distances to far away galaxies were strongly correlated with their redshifts. Hubble’s observation was taken to indicate that all distant galaxies and clusters have an apparent velocity directly away from our vantage point: that is, the farther away, the higher the apparent velocity, regardless of direction.[7] Assuming that we are not at the center of a giant explosion, the only remaining interpretation is that all observable regions of the universe are receding from each other.

While the scientific community was once divided between supporters of two different expanding universe theories—the Big Bang and the Steady State theory,[8]observational confirmation of the Big Bang scenario came with the discovery of the cosmic microwave background radiation in 1964, and later when its spectrum (i.e., the amount of radiation measured at each wavelength) was found to match that of thermal radiation from a black body. Since then, astrophysicists have incorporated observational and theoretical additions into the Big Bang model, and its parametrization as the Lambda-CDM model serves as the framework for current investigations of theoretical cosmology.

mexico

Muy Interesante México
¡Imponente bosque de piedras!
El Parque Nacional Tsingy de Bemaraha está situado en la región Melaky, en el país africano de Madagascar. Tsingy, en malgache significa ‘donde no se puede caminar descalzo’.

daily life

Different generations daily life…younge ones drowned in social networks old ones worry about their daily life

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