Nastanek sonca

On 7 April 1795, the gram was decreed in France to be equal to "the absolute weight of a volume of water equal to the cube of the hundredth part of the meter, at the temperature of melting ice."[5] The concept of using a specified volume of water to define a unit measure of mass was first advanced by the English philosopher John Wilkins in 1668.[6][7]
Since trade and commerce typically involve items significantly more massive than one gram, and since a mass standard made of water would be inconvenient and unstable, the regulation of commerce necessitated the manufacture of a practical realization of the water-based definition of mass. Accordingly, a provisional mass standard was made as a single-piece, metallic artifact one thousand times more massive than the gram--the kilogram.
At the same time, work was commissioned to precisely determine the mass of a cubic decimeter (one liter) of water.[Note 6][5] Although the decreed definition of the kilogram specified water at 0 °C--its highly stable temperature point--the French chemist, Louis Lef?vre-Gineau and the Italian naturalist, Giovanni Fabbroni after several years of research chose to redefine the standard in 1799 to water's most stable density point: the temperature at which water reaches maximum density, which was measured at the time as 4 °C.[Note 7][8] They concluded that one cubic decimeter of water at its maximum density was equal to 99.9265% of the target mass of the provisional kilogram standard made four years earlier.[Note 8][9] That same year, 1799, an all-platinum kilogram prototype was fabricated with the objective that it would equal, as close as was scientifically feasible for the day, the mass of one cubic decimeter of water at 4 °C. The prototype was presented to the Archives of the Republic in June and on 10 December 1799, the prototype was formally ratified as the kilogramme des Archives (Kilogram of the Archives) and the kilogram was defined as being equal to its mass. This standard stood for the next ninety years.

Matev je 9. jun 2011 ob 14:29 izjavil:

ali pa enote seženj, ped, palec ... itd

ker drugace "pregazi" izbruhe s svojo svetlobo...

antonija je 11. jun 2011 ob 19:02 izjavil:

Kter spekter EM pa je pol tole?

The Sun let loose with an enormous explosion on the morning of June 7, 2011. The entire eruption was captured by NASA's Solar Dynamics Observatory. The animation here is from the ultraviolet camera, colored orange to make it viewable.

Pyrobeast
Samo opazil sem problem, da fuzijski material nekako blazno rad 'hlapi'. Za vodik ga ni variante, da ga spraviš že vsaj na 500°C. Superkritična temperatura kateregakoli elementa pa je daleč pod temperaturo potrebno za samovžig.

Ali bi bilo možno, da bi se morala protozvezda dejansko ohladiti preden bi se vžgala ?

V SI sistemu sta edini taki enoti sekunda, ki je trenutno definirana kot 9 milijard in še nekaj nihajev valovanja cezijevega atoma,

In te atomi vodika začnejo tvorit helij?

Seveda ne samo vodika, ampak tud vsega, iz česar smo sestavljeni in kar nas obdaja (C,N,O,Si,...U).

Matev je 5. jul 2011 ob 15:03 izjavil:

Seveda ne samo vodika, ampak tud vsega, iz česar smo sestavljeni in kar nas obdaja (C,N,O,Si,...U).

noše sonce je nastalo iz ostankov supernove