View previous topic | View next topic

H to He Who Am the Only One

Page 1 of 1

djgordy
583052.  Sun Jul 12, 2009 4:35 pm Reply with quote

In the beginning God created the heaven and the earth.
And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters.
And God said, Let there be light and there was light.



Quote:
Hydrogen is the most common element in the universe, 90% of all matter exists in the form of hydrogen. Helium constitutes the other 10% of matter, which is created from hydrogen through nuclear fusion reactions. It is the fuel of the stars as well as the element from which all other elements are created.


http://library.thinkquest.org/18188/english/universe/theory/hydrogen.htm

 
Davini994
583079.  Sun Jul 12, 2009 7:17 pm Reply with quote

The combination of neutrons, protons and electrons into hydrogen didn't happen until 'recombination' which was 300 - 400 thousand years after the big bang - quite a long time, especially by early universe standards.

Before this time, the particles had so much energy they remained free. This meant that the universe was opaque to light, it hit the protons and what have you, and was constantly reabsorbed. Hydrogen atoms are not nearly as efficient at absorbing light so light could then travel more than a tiddly distance in a straight line.

We can see the light from this time, called Cosmic Background Radiation, and we know how much the universe has expanded since then by measuring it's wavelength spectrum.

So djg, if 90% is Hydrogen and 10% is Helium, then the rest put together is statistically insignificant. Cool.

Bigger atoms generally have lower energy levels than their constituents in separate parts, until you get as big as Iron. This means that energy is given out when you stick things together, although they require an activation energy to get it going. This is quite high and why nuclear fusion is a bit tricky. Breaking up atoms bigger than iron is nuclear fission, with which we've had more success.

 
Davini994
583536.  Mon Jul 13, 2009 10:24 pm Reply with quote

Scientists may, or may not, have created human sperm cells from embryonic stem cells for the first time.

http://www.guardian.co.uk/science/2009/jul/08/sperm-grown-stem-cell-fertility

 
djgordy
583539.  Tue Jul 14, 2009 2:19 am Reply with quote

Quote:

Nayernia, of Newcastle University and the North East England Stem Cell Institute (Nesci), described the cells as "fully mature, functional" sperm, which he called In Vitro Derived (IVD) sperm.


http://www.guardian.co.uk/science/2009/jul/08/sperm-grown-stem-cell-fertility

There are scientists in Newcastle? Astonishing!

The story about sperm was in the newspapers. It was splashed all over page three of the Sun.

 
Ion Zone
584007.  Tue Jul 14, 2009 6:03 pm Reply with quote

Scientists with accents? :}

 
Stefan Linnemann
725774.  Mon Jul 05, 2010 2:45 am Reply with quote

And here I was thinking I'd found the first person beside myself familiar with
"H to He, who am the only one".


Stefan.

 
Spud McLaren
725834.  Mon Jul 05, 2010 8:21 am Reply with quote

Stefan Linnemann wrote:
And here I was thinking I'd found the first person beside myself familiar with
"H to He, who am the only one".


Stefan.
I'll own up to it, though. Around here we count Peter Hammill as a Derby lad.

 

Page 1 of 1

All times are GMT - 5 Hours


Display posts from previous:   

Search Search Forums

Powered by phpBB © 2001, 2002 phpBB Group