Cosmology Forum

Post thread
Join in expert discussion on topics revolving around cosmology. Cosmology is the origin, evolution, structure and eventual fate of the universe.
High School Why doesn't dark matter reside in gas clouds?
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad Why Can We Still Observe the Cosmic Microwave Background?
  • · Replies 7 ·
Replies
7
Views
3K
Undergrad Curvature and the size of the Universe
  • · Replies 20 ·
Replies
20
Views
4K
Undergrad Is there a relationship between dark matter and anti-matter?
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad Math doesn't add up: stars + planets < particles in universe?
  • · Replies 9 ·
Replies
9
Views
2K
Graduate Understanding Expansion of Space
  • · Replies 54 ·
2
Replies
54
Views
8K
High School Will eLISA have the potential to detect early universe GWs?
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Energy-momentum tensor and Friedmann Equations
  • · Replies 8 ·
Replies
8
Views
4K
High School Naive Calculation of the Age of the Universe
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Big Bang timing: according to what frame of reference?
  • · Replies 5 ·
Replies
5
Views
3K
High School How can we see Background radiation
  • · Replies 2 ·
Replies
2
Views
2K
High School Is the Universe Truly Eternal or Just a Temporary Fluctuation?
  • · Replies 3 ·
Replies
3
Views
2K
High School Does every elementary particle eventually decay into quarks?
  • · Replies 13 ·
Replies
13
Views
3K
Undergrad New Wired article on "where's the antimatter"
  • · Replies 9 ·
Replies
9
Views
3K
High School Finite Universe vs. Uncertainty Principle
  • · Replies 15 ·
Replies
15
Views
2K
High School Just how Powerful is Computer Science + Astrophysics?
  • · Replies 3 ·
Replies
3
Views
2K
High School Space expanding or Time speeding up? Part 2
  • · Replies 3 ·
Replies
3
Views
2K
Graduate End of Inflation: Definition, Meaning & Models
  • · Replies 12 ·
Replies
12
Views
3K
High School Conservation of Energy and Expansion Redshift
  • · Replies 8 ·
Replies
8
Views
4K
Undergrad Inflation, horizon-problem and thermal equilibrium
  • · Replies 18 ·
Replies
18
Views
6K
High School Is it possible to compress the space without gravity?
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad How to embed the universe in R^4
  • · Replies 1 ·
Replies
1
Views
1K
High School Edge of the Universe: Is It Real?
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad Spacetime Relativity: Universe Expansion & Our Place in It
  • · Replies 21 ·
Replies
21
Views
3K
Undergrad Carolo Rovelli on infinity in LQC
  • · Replies 9 ·
Replies
9
Views
3K
Undergrad Dragging a wormhole into a black hole
  • · Replies 7 ·
Replies
7
Views
2K
High School Information paradox in black holes
  • · Replies 20 ·
Replies
20
Views
3K
Undergrad Probability of not entering de Sitter
  • · Replies 1 ·
Replies
1
Views
2K
High School Is the Earth Really 4.5 Billion Years Old or Much Older?
  • · Replies 13 ·
Replies
13
Views
3K
Undergrad Size and shape of a black hole singularity?
  • · Replies 13 ·
Replies
13
Views
3K
High School Are Black Holes linked to our Universe & Dark Energy/Matter?
  • · Replies 25 ·
Replies
25
Views
4K
High School Simplistic question about mass and gravity
  • · Replies 15 ·
Replies
15
Views
2K
High School Fine Tuning Constants: Understanding Variables and Ratios | Physics NIST
  • · Replies 2 ·
Replies
2
Views
2K
High School Is Dark Matter in the 100GeV range
  • · Replies 2 ·
Replies
2
Views
1K
Graduate What Does Prof Krauss Mean About False Vacuum Decay and Cosmology?
  • · Replies 8 ·
Replies
8
Views
2K
Graduate Angular power spectrum, bias from N weighted events
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Determining H value from scalefactor
  • · Replies 7 ·
Replies
7
Views
2K
Undergrad Expanding universe and the Boltzmann brain problem
  • · Replies 69 ·
3
Replies
69
Views
10K
Undergrad Why is it that Mercury rotates at a faster rate than say Pluto
  • · Replies 28 ·
Replies
28
Views
4K
High School Units for Entropy of Simple Black Holes
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Gravitational waves as means for communication
  • · Replies 5 ·
Replies
5
Views
2K
High School Cause of Inflation: Link to Dark Energy & Quintessence?
  • · Replies 21 ·
Replies
21
Views
3K
High School A question about an interesting article on dark matter
  • · Replies 1 ·
Replies
1
Views
2K
Graduate Observational evidence for accelerating universe
  • · Replies 2 ·
Replies
2
Views
1K
Undergrad Shape of the universe -- Does it change with time?
  • · Replies 27 ·
Replies
27
Views
4K
Undergrad Do Event Horizons always contain a singularity?
  • · Replies 25 ·
Replies
25
Views
3K
Undergrad How do we measure energy density of radiation?
  • · Replies 3 ·
Replies
3
Views
1K
Undergrad What Evidence Exists for the Universe Before the Cosmic Microwave Background?
  • · Replies 20 ·
Replies
20
Views
3K
Undergrad Big Freeze and Law of convervation of energy
  • · Replies 7 ·
Replies
7
Views
2K
High School A Long Time Ago in a Galaxy Far....
  • · Replies 19 ·
Replies
19
Views
2K
High School Where Was Dark Energy Before the Accelerated Expansion Began?
  • · Replies 29 ·
Replies
29
Views
3K
High School Exactly how quantum tunneling leads to a Big Bang?
  • · Replies 29 ·
Replies
29
Views
9K
Undergrad Q re early universe matter-antimatter annihilation
  • · Replies 8 ·
Replies
8
Views
2K
Undergrad Predicted sizes of (observable) universe
  • · Replies 13 ·
Replies
13
Views
3K
High School What are the most likely ways of finding Dark Matter?
  • · Replies 10 ·
Replies
10
Views
2K
Graduate Space time expnasion, age of universe.
  • · Replies 4 ·
Replies
4
Views
2K
High School Is 200my enough for galaxies to form
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad Does Dark Energy drive up Entropy?
  • · Replies 7 ·
Replies
7
Views
2K
High School The Center of the Milky Way Galaxy?
  • · Replies 16 ·
Replies
16
Views
2K
High School How Did the Universe Create Itself from Nothing?
  • · Replies 5 ·
Replies
5
Views
2K
High School Was there ever a state of nothingness?
  • · Replies 5 ·
Replies
5
Views
2K
High School What Happens When a Black Hole Interacts with Antimatter?
  • · Replies 10 ·
Replies
10
Views
2K
High School Is Time's Flow Affected by Cosmic and Quantum Scales?
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad Do we need Dark Matter or are we just time blind
  • · Replies 30 ·
2
Replies
30
Views
5K
Undergrad Understanding Hubble's Graph: Velocity and Time Relationship Explained
  • · Replies 28 ·
Replies
28
Views
3K
High School Why is vacuum energy assumed to be uniform?
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad Object moving out of the Observable Universe due to Expansion
  • · Replies 12 ·
Replies
12
Views
3K
Undergrad Exact expression for the tensor-to-scalar ratio
  • · Replies 3 ·
Replies
3
Views
2K
High School What can we see from the farthest reaches of the universe?
  • · Replies 5 ·
Replies
5
Views
2K
Graduate Does the Hadronic Era Alter the Equation of State?
  • · Replies 12 ·
Replies
12
Views
2K
High School Black holes are creating galaxies with their gravitational force
  • · Replies 11 ·
Replies
11
Views
2K
High School What would a timeline for the Big Rip look like?
  • · Replies 2 ·
Replies
2
Views
4K
High School What is the appropriate time/matter model for the universe?
  • · Replies 18 ·
Replies
18
Views
2K
Undergrad Can a finite universe end in heat death?
  • · Replies 32 ·
2
Replies
32
Views
6K
Undergrad Problems with the theory of inflation
  • · Replies 13 ·
Replies
13
Views
5K
Undergrad How Does Gravity and Density Influence the Flow of Time?
  • · Replies 12 ·
Replies
12
Views
2K
High School The known universe is expanding?
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad Are Galaxies Moving or is Space-Time Expanding?
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad Big Bang nucleosynthesis Wiki Equation for t x T^2
  • · Replies 20 ·
Replies
20
Views
3K
Undergrad Question about expansion and photon fatigue
  • · Replies 12 ·
Replies
12
Views
3K
High School Is Time Expanding Along with Space in the Expanding Universe?
  • · Replies 6 ·
Replies
6
Views
2K
High School Why does expansion redshift light if....
  • · Replies 16 ·
Replies
16
Views
2K
High School Is the center of the universe empty?
  • · Replies 39 ·
2
Replies
39
Views
7K
Undergrad How Would Future Species Understand a Dynamic Universe?
  • · Replies 34 ·
2
Replies
34
Views
4K
Graduate Question about the age of the universe
  • · Replies 10 ·
Replies
10
Views
2K
High School The distribution of normal matter precisely determines gravity
  • · Replies 4 ·
Replies
4
Views
1K
High School Does the Frequency of Gravitational Radiation Alter the Cosmological Constant?
  • · Replies 11 ·
Replies
11
Views
2K
High School Book recommendations for Big Bang Model?
  • · Replies 10 ·
Replies
10
Views
4K
High School Why do we assume the existence of time (flow)?
  • · Replies 2 ·
Replies
2
Views
1K
Undergrad What Is the Cosmic Horizon and Its Relation to Black Holes?
  • · Replies 11 ·
Replies
11
Views
3K
Undergrad Are we living in a Boltzmann box ?
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad A possible solution to the cosmic lithium problem
  • · Replies 15 ·
Replies
15
Views
6K
High School Is Everything outside the local group moving away from us?
  • · Replies 2 ·
Replies
2
Views
1K
Graduate Detection of 6th Force of Nature: Zhang & Feng Claims
  • · Replies 6 ·
Replies
6
Views
3K
Undergrad Variations in the local value of Hubble constant
  • · Replies 9 ·
Replies
9
Views
3K
Undergrad How is the value of tT^2 calculated for neucleosynthesis
  • · Replies 1 ·
Replies
1
Views
1K
Undergrad What is the link between dark matter and antimatter in the universe?
  • · Replies 11 ·
Replies
11
Views
3K
High School Animation to explain the balance of celestial bodies of the universe
  • · Replies 22 ·
Replies
22
Views
3K
High School Perhaps a silly analogy - hologram light source retreating?
  • · Replies 1 ·
Replies
1
Views
1K
Undergrad At which time did the CMB become dark?
  • · Replies 6 ·
Replies
6
Views
2K