Tag Archives: universe

Universe in the Dome Sunday, 12.01.2020

Dear Astro Enthusiast,

Nehru Planetarium, Nehru Memorial Museum and Library, invites you to a half day sky theatre Astronomy session at the planetarium, on Sunday, the 12th of January 2020, from 9:30 – 11:30 AM. The session will have discussions “Under the Stars” inside the sky theatre, and would cover basic positional Astronomy onwards to glimpses of cutting edge multi-wavelength/multi-messenger astronomy where we are now poised in our understanding of the Universe. The discussions will be for basic awareness. Please send a mail to nehruplanetarium@gmail.com and be there at the planetarium by 9:15 AM on the 12th.

Interested students and visitors are urged to see the website http://vigyansamagam.in/ to know about some of the cutting edge mega projects in Astronomy. Students should also register on the site (if not done already), if they wish to be a volunteer in an exciting exhibition in this connection, which will be at the National Science Center, Delhi from the 21st of January to the 18th of March 2020. This will be a tremendous learning opportunity to the students, if selected for volunteering for any of the megaprojects.

The Big Bang’s Lithium Problem

Whoever said that with the discovery of the Higgs boson, the field of cosmology suddenly became dull and everything of significance is known known.
Enter Lithium, a particle physicist’s worst nemesis. The reason why this simple element is such a big problem is that we know how stellar hydrogen fuses to become Lithium
in Big bang like conditions. We’ve verified this experimentally. However the amount of Lithium found in stars and the observable universe is much much lesser.

Scientists at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) studied how much lithium forms under Big Bang conditions for the first time and determined that the theoretical calculations were indeed correct. The phenomena under which Lithium is created has a rather fancy name called “primordial nucleosynthesis”. The things scientists do for getting grant money 😛

The experiment was performed in an underground lab called the Laboratory for Underground Nuclear Astrophysics (LUNA), shielded by cosmic particles using a lead barrier.
These are the extreme setup conditions needed to get correct results.

The question is, if the theory works what’s happening out there. Why do stars contain much lesser quantity that what we should have seen.

For the advanced reader See

M. Anders et al. (2014), First Direct Measurement of the 2H(a,?)6Li Cross Section at Big Bang Energies and the Primordial Lithium Problem. Physical Review Letters 113, 042501. DOI 10.1103/PhysRevLett.113.042501