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
Is it possible that Our universe could be a tiny spec in a say, sandbox?
- Minchken
- · Replies 5 ·
Graduate What Does t→0 Mean in Neutron Freeze-Out?
- AuraCrystal
- · Replies 2 ·
Graduate Would Jupiter steal matter from our Sun when it reach red giant phase?
- Czcibor
- · Replies 4 ·
Graduate What Causes Stellar Expansion During Hydrogen Fusion?
- ehabmozart
- · Replies 4 ·
Graduate Pair-instability supernova calculation
- Dinar
- · Replies 2 ·
Stargazing Solar and Lunar Eclipse - size of moon
- samona
- · Replies 2 ·
Undergrad Was There Matter or Energy at the Start of the Big Bang?
- grantwilliams
- · Replies 16 ·
Graduate One of the standard candle methodologies
- ehabmozart
- · Replies 3 ·
Graduate Do Neutron Stars Eventually Decay Into Black Holes?
- iced199
- · Replies 7 ·
Undergrad Why Are Red Giants More Luminous Than Other Stars?
- ehabmozart
- · Replies 4 ·
Graduate Neutron escaping to parallel universe
- billa12
- · Replies 1 ·
Graduate What does it mean for the universe to be flat?
- TonyTT
- · Replies 10 ·
Graduate What Physics Laws Govern the Rotation of Astronomical Structures?
- Paulibus
- · Replies 4 ·
Undergrad Are All Stars the Same Size Due to Nuclear Fusion?
- TonyTT
- · Replies 6 ·
High School Need Research Question Related to Multiverse (High School Level)
- shaz.662
- · Replies 46 ·
Undergrad Could distant galaxies be earlier positions of nearer ones?
- SolidHelix
- · Replies 13 ·
High School What should we call other universes besides 'parallel universes'?
- Imranfish
- · Replies 4 ·
Graduate What is the equation for high (cosmological) redshift?
- JArnold
- · Replies 1 ·
High School Can space act as a force pushing against matter?
- Timenspace
- · Replies 1 ·
Undergrad Is Oxygen More Abundant Than Carbon in the Universe Due to Nuclear Fusion?
- iced199
- · Replies 6 ·
Undergrad How to calculate g-forces on pilots in climbs, dives, outer space
- Albertgauss
- · Replies 3 ·
Graduate Could dark energy be used as an antigravity device?
- iced199
- · Replies 1 ·
Undergrad When does helium fusion occur in an evolution of star?
- ehabmozart
- · Replies 3 ·
High School Objects in Space: Does Microgravity Change the Rules?
- oumaima1
- · Replies 3 ·
Graduate Calculating Historical Positions of the Asteroid Belt's Orbit
- jackpelham
- · Replies 11 ·
Graduate Is Hawking Radiation inherently unimportant?
- Rorkster2
- · Replies 2 ·
Graduate Sunrise and sunset correction for astronomical and geographical factors
- Galip
- · Replies 8 ·
Graduate Can you see and touch the bubble in a warp drive?
- Reptile202
- · Replies 7 ·
Graduate Does the Total Energy of a Black Hole Change During Evaporation?
- DrZoidberg
- · Replies 3 ·
Graduate Is our universe the unique possible outcome of the big bang
- avery
- · Replies 11 ·
Graduate Is the speed of light the limit of our universe?
- bedsheet010
- · Replies 21 ·
Stargazing Can a 30x Tasco telescope see planets and moons?
- m~ray
- · Replies 8 ·
Graduate How can an observer fall into a black hole if it evaporates via Hawking radiation?
- Drakkith
- · Replies 37 ·
Graduate Size of fictional planet based on gravity and density
- rdanner3
- · Replies 3 ·
Graduate 'Density' of 2.73K Cosmic Microwave Background
- tasp77
- · Replies 3 ·
High School What happens to the missing time?
- amalmirando
- · Replies 1 ·
Graduate Redshift and Expansion of the Universe
- MattRob
- · Replies 27 ·
Finding an affordable lightweight communication satellite manufacturer
- CognitiveNet
- · Replies 2 ·
Graduate Can there be a place in space where no gravity exists?
- kamermans
- · Replies 6 ·
Undergrad Why isn't the universe spherical if it expanded from a singularity?
- TonyTT
- · Replies 16 ·
Graduate Why isn't the universe a big black hole?
- ncarron
- · Replies 21 ·
Graduate History of CMB measurements from balloons to Planck
- marcus
- · Replies 8 ·
Stargazing What creates the star points in telescope pictures of stars?
- rbj
- · Replies 24 ·
Graduate The universe total energy and the conservation of energy
- Gjovik10
- · Replies 2 ·
Graduate Questions about Parallel Worlds by Michio Kaku: the big bang
- ail
- · Replies 2 ·
Graduate Calculating Pluto's Orbital Time Above/Below Ecliptic
- Globe199
- · Replies 1 ·
Graduate Could the Visible Universe Be a Fuzzball in String Theory?
- Jonny_trigonometry
- · Replies 2 ·
Graduate Could our universe's expansion be caused by matter from white holes?
- EvanD
- · Replies 16 ·
Undergrad Why Do We See So Many Gamma Ray Bursts?
- SHISHKABOB
- · Replies 8 ·
High School Arc seen in Venus transit photo through telescope
- Neptulin
- · Replies 2 ·
Undergrad How delicate is the Earth's Orbit?
- esmeralda4
- · Replies 2 ·
Graduate Multiple collections of energy, very far apart
- coktail
- · Replies 4 ·
Graduate Calculating Tithis in the Hindu Calendar - Petrix108's Query
- petrix108
- · Replies 2 ·
Undergrad Classification of stars by spectrum
- ehabmozart
- · Replies 1 ·
Undergrad Measuring Radial Velocity with Amateur Equipment
- Drakkith
- · Replies 1 ·
High School The dereference between; astrophysics, astronomy, cosmology and space science
- wolfspirit
- · Replies 2 ·
Graduate Can Different Vacuum States in Curved Spacetime Appear Thermal to Each Other?
- grammophon
- · Replies 3 ·
High School Gravity between the Earth and the Moon
- mynameistessa
- · Replies 3 ·
Venus passes in front of our sun
- Naty1
- · Replies 9 ·
Undergrad How are panatery Nebula formed and when do they die
- ehabmozart
- · Replies 1 ·
Graduate How to Compute the Length of a Year on Earth in a Two-Body System?
- nikolafmf
- · Replies 6 ·
Undergrad The stellar evolution. Low Mass stars
- ehabmozart
- · Replies 5 ·
Graduate Accretion disk/black hole/gas jets
- bassplayer142
- · Replies 21 ·
Undergrad Why Do We Use Angular Size Instead of Steradian for Objects in the Night Sky?
- 4everphysics
- · Replies 1 ·
Graduate Is anything falling into a black hole *now*?
- ith
- · Replies 7 ·
Graduate First VLBI SETI search of the Gliese 581 system
- Chronos
- · Replies 6 ·
Undergrad Why do stars show absorption spectral lines if they emit as blackbodies?
- ehabmozart
- · Replies 2 ·
Undergrad Why can neutron stars resist compression without becoming black holes?
- lntz
- · Replies 15 ·
Undergrad How do spectral line widths show if a star is on the main sequence?
- ehabmozart
- · Replies 1 ·
Undergrad So much of diversity in universe.
- rishi.sharma
- · Replies 5 ·
Graduate Why do pulsars emit beamed radiation in radio and X-rays?
- RHK
- · Replies 11 ·
Graduate How do accretion disks and black holes interact with electromagnetic forces?
- Holesarecool
- · Replies 9 ·
Graduate Why is the scale factor derivative divided by the scale factor in the Friedmann equation?
- robertjford80
- · Replies 14 ·
Graduate How Do Low Mass Stars Evolve After Exhausting Hydrogen Fuel?
- ehabmozart
- · Replies 1 ·
Graduate Messenger particles and black holes
- Warp
- · Replies 10 ·
Undergrad Definition of a Planet (and other stuff)
- paldin
- · Replies 6 ·
High School Can you slow down in space by throwing objects backward?
- kris_yo
- · Replies 2 ·
Graduate Where does −a'²(t₀) come from in Roos' density parameter derivation?
- robertjford80
- · Replies 9 ·
High School Astronomical-objects outside our own galaxy
- johann1301
- · Replies 5 ·
Graduate What Happens If We Travel in One Direction in the Universe?
- robertjford80
- · Replies 11 ·
Graduate Higgs Field, Big Bang, and Spacetime
- coktail
- · Replies 7 ·
Graduate Patched Conics Trajectory from Initial Orbit State
- TheHarvesteR
- · Replies 9 ·
Graduate How Does an Infinite Static Arrangement Collapse Under Gravity?
- Rear Naked
- · Replies 8 ·
Graduate Universe structure, movement, creation/destruction
- Eurakhunt
- · Replies 1 ·
Graduate Could a new type of compass be created using a rotating permanent magnet?
- Robin07
- · Replies 1 ·
Graduate The WMAP objective is to measure the temperature differences in the
- azizlwl
- · Replies 1 ·
Graduate The big bang model, time, and general relativity
- Hypatio
- · Replies 17 ·
What is the scale of our universe?
- goldsax
- · Replies 2 ·
Graduate Asteroid orbit determination from observations
- solarblast
- · Replies 3 ·
Graduate Are objects disappearing as the universe expands?
- 4everphysics
- · Replies 19 ·
Graduate Cosmic Microwave Background Radiation, why from 380,000?
- 4everphysics
- · Replies 8 ·
Undergrad Astronomy books on stellar evolution, pulsars, quasars, and the solar system
- Astronomyboy
- · Replies 1 ·
Graduate What did superstring theory say existed before 10^-36 seconds after the Big Bang?
- robertjford80
- · Replies 12 ·
Graduate Is Time an Irrational Concept in Space-Time Understanding?
- shotgun
- · Replies 13 ·
Graduate How does frame dragging cause a stick to rotate in the opposite direction?
- Holesarecool
- · Replies 1 ·
Graduate More exact prediction of collision with Andromeda galaxy
- marcus
- · Replies 1 ·
Graduate The flatness of the observable and unobservable univ
- robertjford80
- · Replies 24 ·
Undergrad Transiting Exoplanet Light Curve
- Drakkith
- · Replies 10 ·
Graduate Can alternate radiation model explain redshift?
- shotgun
- · Replies 15 ·
Undergrad What Does a Redshift Calculation of 2.5 Mean?
- eggman100
- · Replies 8 ·