NOVA: The Elegant Universe - Released on Internet

  • Thread starter Thread starter dduardo
  • Start date Start date
  • Tags Tags
    Internet Universe
Space news on Phys.org

Thread 'Matter density right after the decoupling'

https://en.wikipedia.org/wiki/Recombination_(cosmology) Was a matter density right after the decoupling low enough to consider the vacuum as the actual vacuum, and not the medium through which the light propagates with the speed lower than ##({\epsilon_0\mu_0})^{-1/2}##? I'm asking this in context of the calculation of the observable universe radius, where the time integral of the inverse of the scale factor is multiplied by the constant speed of light ##c##.
View full post »

Thread 'Rutgers finds a transparent Einstein Cross - apparently a dark matter "halo".'

The formal paper is here. The Rutgers University news has published a story about an image being closely examined at their New Brunswick campus. Here is an excerpt: Computer modeling of the gravitational lens by Keeton and Eid showed that the four visible foreground galaxies causing the gravitational bending couldn’t explain the details of the five-image pattern. Only with the addition of a large, invisible mass, in this case, a dark matter halo, could the model match the observations...
View full post »

Thread 'Hubble Constant, Dark Energy and the Expanding Universe'

Why was the Hubble constant assumed to be decreasing and slowing down (decelerating) the expansion rate of the Universe, while at the same time Dark Energy is presumably accelerating the expansion? And to thicken the plot. recent news from NASA indicates that the Hubble constant is now increasing. Can you clarify this enigma? Also., if the Hubble constant eventually decreases, why is there a lower limit to its value?
View full post »

Similar threads

Guns, Germs, and Steel -- and Latin script?
Replies
2
Views
1K
C: "The Big Bang Machine" on Nova: A Critique
Replies
7
Views
1K
The Elegant Universe- string theory documentary
Replies
4
Views
9K
I Continuous vs discrete Universe
Replies
29
Views
4K
Is the 2006 edition of The Elegant Universe DVD worth the extra features?
Replies
5
Views
4K
Seriously gritty videojournalism applied to cosmology by Skydive
Replies
4
Views
2K
Stephen Hawking's Universe '97 - Physics & Astronomy Videos for Entertainment
Replies
13
Views
10K
B Clarification on how old the Universe is
Replies
11
Views
3K
Fine-tuned Universe; let's find out
Replies
3
Views
2K
NOVA special on String/cosmology
Replies
1
Views
2K

Hot Threads

Recent Insights

Back
Top