Loeb's perspective on emergence of structure

In summary: The metric expansion of space is the mathematical prediction that the distances between physical objects in the universe will increase over time, according to the general theory of relativity."In summary, this paper discusses how the universe has evolved and how the expansion of space has affected the distance between objects.
  • #1
marcus
Science Advisor
Gold Member
Dearly Missed
24,775
792
This is an invited review paper by a worldclass authority, so it could be useful.

http://arxiv.org/abs/0804.2258
Let there be Light: the Emergence of Structure out of the Dark Ages in the Early Universe
Abraham Loeb (Harvard)
32 pages, 18 figures, an invited review for the UNESCO EOLSS Encyclopedia
(Submitted on 14 Apr 2008)

"The initial conditions of our Universe can be summarized on a single sheet of paper. Yet the Universe is full of complex structures today, such as stars, galaxies and groups of galaxies. In this review I describe the standard theoretical model for how complexity emerged from the simple initial state of the Universe at early cosmic times through the action of gravity. In order to test and inform the related theoretical calculations, large-aperture telescopes and arrays of radio antennae are currently being designed and constructed. The actual transition from simplicity to complexity has not been observed as of yet. The simple initial conditions were already traced in maps of the microwave background radiation, but the challenge of detecting the first generation of galaxies defines one of the exciting frontiers in the future of cosmology. Once at hand, the missing images of the infant Universe might potentially surprise us and revise our current ideas."
 
Space news on Phys.org
  • #2
I think Loeb has done an admirable job assembling a state of the universe presentation. He captures the open issues well, IMO.
 
  • #3
"As the universe expands, photon wavelengths get stretched as well. The factor by which the observed wavelength is increased (i.e. shifted towards the red) relative to the emitted one is denoted by (1+z), where z is the cosmological redshift. Astronomers use the known emission patterns of hydrogen and other chemical elements in the spectrum of each galaxy to measure z. This then implies that the universe has expanded by a factor of (1 + z) in linear dimension since the galaxy emitted the observed light, and cosmologists can calculate the corresponding distance and cosmic age for the source galaxy."

I do not agree with that at all, where does general relativity demonstrate that the frequency of photons along the path between emission and absorption is modified by spacetime curvature?
 

1. What is Loeb's perspective on emergence of structure?

Loeb's perspective on emergence of structure is a theory that explains how complex systems and patterns can arise from the interaction of simple components. This theory is based on the concept of emergence, where new properties and behaviors emerge at a higher level of organization that cannot be predicted from the properties of the individual components.

2. How does Loeb's perspective on emergence of structure differ from other theories?

Loeb's perspective on emergence of structure differs from other theories in that it focuses on the role of self-organization and feedback loops in the emergence of structure. It also emphasizes the importance of non-linear interactions between components, rather than just the sum of their individual properties.

3. What are some examples of structures that can emerge from simple components?

Some examples of structures that can emerge from simple components include the formation of snowflakes from water molecules, the flocking behavior of birds, and the development of a human brain from a single fertilized egg. These structures exhibit emergent properties and behaviors that cannot be predicted from the properties of their individual components.

4. How does Loeb's perspective on emergence of structure relate to the study of complex systems?

Loeb's perspective on emergence of structure is closely related to the study of complex systems, as it seeks to understand how these systems can exhibit emergent properties and behaviors. It also emphasizes the importance of non-linear interactions and feedback loops in the behavior of complex systems.

5. What are the practical applications of Loeb's perspective on emergence of structure?

The practical applications of Loeb's perspective on emergence of structure are wide-ranging. It can be used to understand and predict the behavior of complex systems such as weather patterns, stock markets, and ecosystems. It also has applications in fields such as artificial intelligence, where emergent behaviors can be harnessed to create intelligent systems.

Similar threads

A New MOND Simulation: First Galaxy Formation Model in Milgromian Gravity
    • Cosmology
Replies
8
Views
2K
Did Black Holes appear in the first billion years?
    • Cosmology
Replies
4
Views
1K
B How constrained are the initial conditions of the universe?
    • Cosmology
Replies
1
Views
1K
B Quantum imprints left on cosmological structures in the very early Universe
    • Beyond the Standard Models
Replies
1
Views
1K
Inflationary paradigm in trouble after Planck2013 ? I doubt it, but
    • Cosmology
Replies
34
Views
7K
What is the true purpose of inflation in the early universe?
    • Cosmology
2
Replies
41
Views
4K
A MOND Theory Primer: Stacy McGaugh's Research Program Explored
    • Beyond the Standard Models
Replies
11
Views
2K
Mass in motivic quantum gravity
    • Beyond the Standard Models
Replies
2
Views
3K
Another *Life Might Be Rare* paper
    • Astronomy and Astrophysics
Replies
4
Views
4K
What are the mechanism implications of MECO?
    • Cosmology
Replies
7
Views
3K

Hot Threads

Recent Insights

Back
Top