Äîêóìåíò âçÿò èç êýøà ïîèñêîâîé ìàøèíû. Àäðåñ îðèãèíàëüíîãî äîêóìåíòà : http://www.astronomy.com/magazine/2010/12/how-the-big-bang-forged-the-first-elements
Äàòà èçìåíåíèÿ: Unknown
Äàòà èíäåêñèðîâàíèÿ: Sun Apr 10 07:21:41 2016
Êîäèðîâêà: ISO8859-5

Ïîèñêîâûå ñëîâà: ï ï ï
How the Big Bang forged the first elements | Astronomy.com
Tonight's Sky
Sun
ò??
ò??
Sun
Moon
ò??
ò??
Moon
ò??
ò??
Mercury
ò??
ò??
Mercury
ò??
Venus
ò??
ò??
Venus
ò??
Mars
ò??
ò??
Mars
ò??
Jupiter
ò??
ò??
Jupiter
ò??
Saturn
ò??
ò??
Saturn
ò??

Tonight's Sky ò?? Change location

OR

Searching...

Tonight's Sky ò?? Select location

Tonight's Sky ò?? Enter coordinates

ÒÀ '
ÒÀ '

How the Big Bang forged the first elements

The paltry amount of lithium in ancient stars raises questions about exactly how nucleosynthesis played out in the early universe. But cosmologists have a pretty good handle on how nuclear reactions created hydrogen and helium.
NGC6397
Nearby globular cluster NGC 6397 contains hundreds of thousands of ancient metal-poor stars (those that have few elements heavier than helium). Observations of a few hundred of these stars show that those burning hydrogen into helium all have about the same abundance of lithium.
ESO
Hydrogen and helium ò?? the two lightest elements ò?? make up some 98 percent of the universeò??s mass. It may seem surprising, then, to learn that scientists figured out where the heavier elements came from before they understood the big two.

Already a subscriber? Register now!

Registration is FREE and takes only a few seconds to complete. If you are already registered on Astronomy.com, please log in below.
ADVERTISEMENT

FREE EMAIL NEWSLETTER

Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter.

ADVERTISEMENT
ADVERTISEMENT
asy_gravitational_eguide

Click here to receive a FREE e-Guide exclusively from Astronomy magazine.

Find us on Facebook