Join in expert discussion on the topics of Astronomy, astrophysics and cosmology. This may include discussion on celestial objects, space, and the physical universe as a whole. Mainstream science only.
Threads
Undergrad Energy-momentum tensor and Friedmann Equations
- Diferansiyel
- · Replies 8 ·
High School Naive Calculation of the Age of the Universe
- jeffbarrington
- · Replies 3 ·
Undergrad Big Bang timing: according to what frame of reference?
- Sophrosyne
- · Replies 5 ·
Undergrad Is a superflare capable of changing a planets orbit?
- Edward Barrow
- · Replies 18 ·
Undergrad Can we predict the Sun's path accurately?
- Trainee Engineering
- · Replies 10 ·
High School Orbital mass ratio in the Milky Way using escape velocity vs gravitational force
- TreeLover
- · Replies 2 ·
Stargazing Considerations for size of telescope survey
- BOAS
- · Replies 2 ·
High School How can we see Background radiation
- Addez123
- · Replies 2 ·
High School Could the universe be eternal with the Big Bang as a fluctuation?
- mcronald
- · Replies 3 ·
Undergrad Can orbital motion substitute for rotation in maintaining a magnetic dynamo?
- Althistorybuff
- · Replies 7 ·
High School Does every elementary particle eventually decay into quarks?
- zinq
- · Replies 13 ·
Undergrad Defending the Earth from meteors using lasers
- Dovla
- · Replies 44 ·
Undergrad Does bone and muscle loss in microgravity matter if you stay in space?
- John Morrell
- · Replies 1 ·
Undergrad New Wired article on "where's the antimatter"
- jnorman
- · Replies 9 ·
High School Finite Universe vs. Uncertainty Principle
- Helios
- · Replies 15 ·
Insights Q&A with Universe Today's Fraser Cain
- Greg Bernhardt
- · Replies 4 ·
High School Does the Big Bang Expansion Include All Objects in the Universe?
- Vivek Siddarth K
- · Replies 3 ·
High School Finding Black Holes: Possible or Not?
- Tim Layton
- · Replies 2 ·
Undergrad Observation of photons from CMB by different observers
- BernieM
- · Replies 7 ·
High School How do black holes attract light?
- Nabin kalauni
- · Replies 8 ·
High School Just how Powerful is Computer Science + Astrophysics?
- Alex Shi
- · Replies 3 ·
High School Space expanding or Time speeding up? Part 2
- CosmologyHobbyist
- · Replies 3 ·
Graduate When does inflation end and what does the Hubble slow roll parameter mean?
- Figaro
- · Replies 12 ·
High School Conservation of Energy and Expansion Redshift
- John Morrell
- · Replies 8 ·
Undergrad Where on the Moon should the first Moonbase be?
- Al_
- · Replies 32 ·
High School Is Jupiter's Great Red Spot Hiding a Massive Volcano?
- CosmologyHobbyist
- · Replies 1 ·
Graduate What is the formula for calculating the Ascendant?
- Jerky Jesse
- · Replies 1 ·
Undergrad Inflation, horizon-problem and thermal equilibrium
- haushofer
- · Replies 18 ·
High School What do the letters in the solar sail equation denote?
- Enis
- · Replies 2 ·
High School Is it possible to compress the space without gravity?
- Sandip Kumar
- · Replies 5 ·
Undergrad How to embed the universe in R^4
- Kontilera
- · Replies 1 ·
High School Does the universe have an edge?
- John Morrell
- · Replies 6 ·
High School Black hole mass and sigma (velocity dispersion)
- Singlau
- · Replies 5 ·
Undergrad Why aren't we expanding along with the universe?
- Anujkumar
- · Replies 21 ·
High School The Best Spot to Set Up a Colony on Mars
- lifeonmercury
- · Replies 10 ·
Undergrad Explain the orbital physics of the JAXA Tether experiment?
- SteveO33
- · Replies 77 ·
Undergrad Would the rogue planet in this picture slow Earths spin?
- Edward Barrow
- · Replies 14 ·
Graduate Finding Space Radio software for ISS receiving at 145.800 MHz
- Shubham Jaydeokar
- · Replies 2 ·
Undergrad Carolo Rovelli on infinity in LQC
- windy miller
- · Replies 9 ·
Undergrad Length of lunar month immediately after moon's formation?
- Althistorybuff
- · Replies 1 ·
Undergrad Can a planet have multiple large moons?
- Sherwood Botsford
- · Replies 1 ·
High School Can we find the Big Bang's location and direction from observed cosmic expansion vectors?
- Colm
- · Replies 3 ·
High School How do we know the stars are not our own light falling back.
- Colm
- · Replies 4 ·
Graduate How is the Trappist 1 system stable?
- Sherwood Botsford
- · Replies 6 ·
Graduate Can range and Doppler measurements give both position and velocity?
- AT36
- · Replies 3 ·
Undergrad Mass and temperature relation in stars
- jamespompey2109
- · Replies 5 ·
High School How to determine star radii from the Hertzsprung-Russell diagram
- Meerio
- · Replies 2 ·
Graduate Is the matter-antimatter annihilation observable in priciple
- Gerinski
- · Replies 1 ·
Graduate Cosmological Redshift distance to where it begins?
- rmpearlman
- · Replies 5 ·
Undergrad How Can I Improve My 2D Newtonian Gravity Simulator?
- Ben S
- · Replies 7 ·
Undergrad Dragging a wormhole into a black hole
- CA Mason
- · Replies 7 ·
High School Information paradox in black holes
- Blue Scallop
- · Replies 20 ·
Undergrad Observational constraints on the net lepton number of the universe
- snorkack
- · Replies 1 ·
Undergrad Clusters at center and periphery
- nomadreid
- · Replies 2 ·
Undergrad What causes the deceleration of a satellite? Space dust?
- Robert Scott
- · Replies 4 ·
Undergrad Probability of not entering de Sitter
- durant35
- · Replies 1 ·
High School Is the Earth Really 4.5 Billion Years Old or Much Older?
- geraud
- · Replies 13 ·
Undergrad Size and shape of a black hole singularity?
- kris kaczmarczyk
- · Replies 13 ·
High School Is There an Arctic Circle on the Moon?
- lifeonmercury
- · Replies 1 ·
High School How fast is Earth traveling due to the Hubble constant?
- Nick Levinson
- · Replies 43 ·
Undergrad Will interstellar travel become more possible in future
- Steven Hansel
- · Replies 22 ·
Undergrad On the Moon, could you melt dirt by focussing sunlight?
- Al_
- · Replies 1 ·
Undergrad Connection between libration and Lagrange points
- nomadreid
- · Replies 4 ·
High School Could the universe have originated from a black hole?
- HARVEYU1E1
- · Replies 25 ·
High School Would a 4 Earth mass planet have 4 times Earth's gravity?
- Noisy Rhysling
- · Replies 15 ·
Undergrad Big rip - order of distintegration?
- janq
- · Replies 1 ·
High School Which NIST constants appear in fine-tuning ratios?
- name123
- · Replies 2 ·
High School Could Microbes Really Thrive in the Clouds of Venus?
- lifeonmercury
- · Replies 12 ·
High School Is Dark Matter in the 100GeV range
- wolram
- · Replies 2 ·
High School What would happen to the Moon if (at full moon) the Earth disappeared?
- lifeonmercury
- · Replies 7 ·
Graduate What Does Prof Krauss Mean About False Vacuum Decay and Cosmology?
- Trollfaz
- · Replies 8 ·
High School How do you know the size/maximum area of a gravity field
- Steven Hansel
- · Replies 4 ·
High School What are the applications of solar sails?
- Enis
- · Replies 1 ·
Graduate Angular power spectrum, bias from N weighted events
- ChristianS
- · Replies 2 ·
High School Need Martian Regolith/Soil Simulant. JSC Mars-1
- jack h
- · Replies 2 ·
Undergrad Determining H value from scalefactor
- JohnnyGui
- · Replies 7 ·
Undergrad Have you ever wondered why we can't see the other side of the moon?
- akashpandey
- · Replies 10 ·
Undergrad Expanding universe and the Boltzmann brain problem
- analyst5
- · Replies 69 ·
Undergrad Do Red Dwarfs Favor Rocky Planets and Host Life?
- virgil1612
- · Replies 4 ·
Undergrad Why is it that Mercury rotates at a faster rate than say Pluto
- Sean
- · Replies 28 ·
Undergrad Can we colonize the Kuiper Belt?
- Al_
- · Replies 11 ·
High School Units for Entropy of Simple Black Holes
- muzukashi suginaiyo
- · Replies 3 ·
Undergrad Gravitational waves as means for communication
- Karlox
- · Replies 5 ·
High School What are the chances of evolution of organisms in space
- mohau tshekoeng
- · Replies 3 ·
High School Could inflation have been caused by matter-antimatter annihilation?
- Tanelorn
- · Replies 21 ·
High School Did early galaxies contain less dark matter than modern galaxies?
- Tanelorn
- · Replies 1 ·
Graduate Observational evidence for accelerating universe
- Gort
- · Replies 2 ·
Undergrad Shape of the universe -- Does it change with time?
- MathematicalPhysicist
- · Replies 27 ·
Undergrad Do Event Horizons always contain a singularity?
- FallenApple
- · Replies 25 ·
Undergrad How do we measure energy density of radiation?
- binbagsss
- · Replies 3 ·
Undergrad What Evidence Exists for the Universe Before the Cosmic Microwave Background?
- laymanB
- · Replies 20 ·
Undergrad Big Freeze and Law of convervation of energy
- Rodrigo Olivera
- · Replies 7 ·
Undergrad Guarding Mars' atmosphere with a magnetic shield
- infinitebubble
- · Replies 24 ·
Undergrad Effect of planetary layer densities on trajectories of a satellite
- Tahmeed
- · Replies 1 ·
High School When did the first life-enabling solar systems form after the Big Bang?
- mieral
- · Replies 19 ·
High School How can gravity act on a photon?
- Simon Peach
- · Replies 4 ·
Undergrad Did another dimension create time before our dimension formed?
- Fais
- · Replies 6 ·
High School Does seeing Mars through a telescope mean we're looking back in time?
- Bammitzcam
- · Replies 6 ·
High School Cosmological Redshift: Where Has the Energy Gone?
- Glenn G
- · Replies 3 ·
High School Where Was Dark Energy Before the Accelerated Expansion Began?
- mieral
- · Replies 29 ·