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
High School Why can't we see dark matter in the solar system?
- Leonardo Muzzi
- · Replies 22 ·
Undergrad What is the definition of the entropy of the Universe?
- AlexandreZani
- · Replies 7 ·
Undergrad What would the universe look like without dark matter?
- Ranku
- · Replies 5 ·
Undergrad Does the Friedmann vacuum equation have a linear solution?
- jcap
- · Replies 1 ·
Undergrad Is Late Water Flow on Mars Linked to Climate Change or Permafrost Melting?
- BillTre
- · Replies 3 ·
High School Absorption of electromagnetic radiation
- rashida564
- · Replies 16 ·
Undergrad Expanding universe needs a big bang?
- CHOP
- · Replies 101 ·
High School How does the Earth move through in 3 separate trajectories?
- Grazing Dogs
- · Replies 20 ·
High School Visual simulation of gravitational lensing
- roineust
- · Replies 5 ·
Undergrad Why can't LIGO detect collisions of super massive black holes?
- mitosis
- · Replies 16 ·
Undergrad Is the Minkowksi/Einstein Block Universe theory science?
- Pleonasm
- · Replies 8 ·
Undergrad Would a HEMP event cause the northern lights?
- thisisweak
- · Replies 3 ·
High School How Does Telescope Magnification Differ from Resolving Power?
- roineust
- · Replies 9 ·
Graduate Dark Matter Accretion Disk for Black Hole (Neutron Star)
- PSR1257II
- · Replies 1 ·
Undergrad Understanding Negative Inclination Orbits in Space Science
- Maher
- · Replies 3 ·
Stargazing Efficient Follow-Up of Exoplanet Transits Using Small Telescopes
- wolram
- · Replies 2 ·
Graduate Solving a Cipher: Celestial coordinates and precession
- Adam Laceky
- · Replies 2 ·
Undergrad Northern lights and the magnetic field
- windy miller
- · Replies 7 ·
High School 83 quasars right up against the Event Horizon
- Gfellow
- · Replies 6 ·
Undergrad Can the MOND theory be experimentally tested?
- KurtLudwig
- · Replies 8 ·
Undergrad How strictly defined is the main sequence on an HR diagram
- Saturn_V
- · Replies 2 ·
Undergrad What would a big crunch look like observationally?
- Jarvis323
- · Replies 4 ·
High School Is there a standard mapping of celestial coordinates to geo-coordinates
- Adam Laceky
- · Replies 7 ·
High School How to explain "the right hand rule" to an alien universe
- Rap
- · Replies 15 ·
High School Preventing tidal locking for an Earth-sized planet orbiting a red dwarf
- Althistorybuff
- · Replies 2 ·
High School Why do stars of different masses have different convection zone structures?
- Xforce
- · Replies 16 ·
Undergrad Exponential expansion and the Cosmological Constant
- Ranku
- · Replies 7 ·
High School What Drives the Gravitational Waves in Black Hole Ringdown?
- Lord Crc
- · Replies 13 ·
Graduate How deep in a gravitational well are we?
- Agerhell
- · Replies 3 ·
Undergrad Imaging galaxies receding at a velocity that exceeds c?
- hyksos
- · Replies 12 ·
High School Red Dwarf Stars - Planet Habitability around "Flare Stars"
- Althistorybuff
- · Replies 1 ·
High School Does being tidally locked affect a planet's magnetic field?
- Althistorybuff
- · Replies 2 ·
High School Is cosmic inflation faster than light a proven fact or a hypothesis?
- fbs7
- · Replies 24 ·
High School What is the most common/likely process of the Universe?
- Tap Banister
- · Replies 7 ·
Undergrad The use of 3D reconstruction techniques to build a galaxy model
- sbleuz
- · Replies 4 ·
Undergrad Will There Be a Solar System Navigation System for Space Travel?
- happyhacker
- · Replies 4 ·
Graduate Covariance matrix size: 3x3 or 4x4?
- fab13
- · Replies 5 ·
Undergrad Isn't planetary rock dating really supernova dating?
- swampwiz
- · Replies 5 ·
High School How Do High-Speed Objects Traverse High-Temperature Gaseous Nebulas?
- pedro the swift
- · Replies 3 ·
High School Can black holes truly be infinite?
- Dan4
- · Replies 6 ·
Graduate CMB as thermal radiation of cosmic dust?
- Vaclav Vavrycuk
- · Replies 8 ·
Undergrad Do protons from Hawking radiation form hydrogen and new stars?
- Cheng Fan Soon
- · Replies 28 ·
Graduate Where to Find the Best Records of Past Supernova Events
- Jarvis323
- · Replies 1 ·
Graduate Classical scalar field as Dark Matter
- fhenryco
- · Replies 14 ·
Undergrad Fine tuning and the multiverse
- John Oats
- · Replies 6 ·
Undergrad Is Bad Astronomy Using Bad Statistics?
- Vanadium 50
- · Replies 16 ·
High School Could singularities be just rips in the space-time fabric?
- Mlesnita Daniel
- · Replies 23 ·
Undergrad Why does the flag wave and where's the blast crater from the moon landing?
- Nick tringali
- · Replies 3 ·
High School Johns Hopkins study: asteroid cores reform within 2 hours after nuclear impact
- Mlesnita Daniel
- · Replies 10 ·
Graduate Cosmological fluctuations (Weinberg's cosmology, p. 284)
- jouvelot
- · Replies 10 ·
Undergrad A very small object following Earth in the same orbit
- Michaela SJ
- · Replies 9 ·
Undergrad Would we know if the Milky Way were a quasar?
- swampwiz
- · Replies 8 ·
High School Can black holes be too slow to observe from Earth?
- Clay Bartlett
- · Replies 3 ·
High School If Quark stars exist why do Neutron stars become Black holes?
- wolram
- · Replies 17 ·
High School What is the 'proof' of the no-hair theorem of black holes?
- Cerenkov
- · Replies 5 ·
Stargazing Accelerating universe - luminosity data
- Bosko
- · Replies 2 ·
Undergrad How Do We Determine the Sun's Generation?
- hkyriazi
- · Replies 6 ·
High School CMBR: Is It Constant or Changing Over Time?
- Bill McKeeman
- · Replies 2 ·
High School Can astronauts feel centripetal acceleration on the Moon's surface?
- Atari_Me
- · Replies 18 ·
Graduate Could longer Hubble exposures reveal exoplanet features?
- vinven7
- · Replies 5 ·
Undergrad Cross-correlations: what size to select for the matrix?
- fab13
- · Replies 4 ·
High School How far back can we see with light?
- wolram
- · Replies 1 ·
High School Questions regarding energy in the universe
- Brunolem33
- · Replies 3 ·
High School Does the formula t = x/v apply in special relativity?
- Nadeen
- · Replies 9 ·
Graduate Dark matter and the fabric of space time,
- Mike Bristow
- · Replies 2 ·
Undergrad Is Tabby's Star Dimming Due to an Alien Megastructure?
- zuz
- · Replies 12 ·
High School Which Hawking paper? (no singularity at the beginning of the universe)
- Cerenkov
- · Replies 2 ·
Graduate Is "Broken Symmetry" truly foundational?
- Eugene Ulrich
- · Replies 4 ·
High School Photon Decoupling: Effects on Universe Expansion
- Adhruth Ganesh
- · Replies 2 ·
Graduate Decoupling of SVT Metric Perturbations
- Zag
- · Replies 2 ·
High School Help with when expansion acceleration began
- Rodney-Believes
- · Replies 23 ·
Undergrad How is Dark Matter distributed around our galaxy?
- KurtLudwig
- · Replies 6 ·
Undergrad Confusion about absorption spectra - cool gases absorb?
- Cool4Kat
- · Replies 17 ·
High School Can a single photon make up a universe?
- sgphysics
- · Replies 1 ·
Undergrad What is the pressure gradient towards the centre of a large planet?
- kevindin
- · Replies 4 ·
Undergrad Why ##\omega=0## for a matter dominated universe?
- Apashanka
- · Replies 4 ·
Undergrad Is a "collision" of galaxies noticeable on a planetary scale
- maxjon77
- · Replies 3 ·
Undergrad Expansion of positively and negatively curved universe
- Apashanka
- · Replies 2 ·
Undergrad If dark energy density varies with time, does pressure remain constant?
- Ranku
- · Replies 17 ·
Undergrad Humanity: Master fusion reactors or build a dyson sphere?
- Luke Geller
- · Replies 1 ·
Undergrad Is Something Missing in the Expansion of Our Flat Universe?
- Apashanka
- · Replies 17 ·
Undergrad Too Much Dark Matter In CEG Mrk 1216
- ohwilleke
- · Replies 2 ·
High School Does matter accelerate to light speed at a black hole's event horizon?
- Steve1954
- · Replies 5 ·
Undergrad How would the DSG orbit the Moon?
- happyhacker
- · Replies 1 ·
Undergrad Two gravitational events might be a single lensed one
- mfb
- · Replies 8 ·
High School Andromeda Collision VS Expansion
- newrd
- · Replies 3 ·
Undergrad Space docking using the Meissner effect
- YoungPhysicist
- · Replies 3 ·
Undergrad Expanding universe or tired light in a static universe?
- Ennio
- · Replies 6 ·
Undergrad New Problems I have with Dark Matter
- neonred
- · Replies 13 ·
Undergrad What Is the Singularity and Its Role in the Big Bang?
- Michaela SJ
- · Replies 26 ·
Stargazing Stellar Eclipse on Feb 18/19, 2019
- OmCheeto
- · Replies 1 ·
High School Is the Rover Mission Halted Due to Dust-Covered Solar Panels?
- hagopbul
- · Replies 11 ·
New Horizons flyby of Pluto [updated for Ultima Thule]
- rootone
- · Replies 192 ·
Undergrad Why do galaxy rotation curves require dark matter rather than dark energy?
- Apashanka
- · Replies 6 ·
Undergrad How Does the Sun's Position Affect the Earth-Moon Barycenter?
- bunburryist
- · Replies 4 ·
High School How exactly inflation solves the Horizon Problem
- Arman777
- · Replies 13 ·
Undergrad Relative Amount of Hydrogen in the Universe
- Jim Lundquist
- · Replies 8 ·
Undergrad Galaxy at z=11.1, farthest yet, unusually bright (GN-z11)
- marcus
- · Replies 16 ·
High School How hard is it to track moon cycles
- SNOUSSI Anis
- · Replies 28 ·
Undergrad Inflation resolves the horizon problem
- Apashanka
- · Replies 7 ·