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 Asteroid Sterilization: Size and Impact on Earth
- witze
- · Replies 4 ·
Graduate Time at the edge of the universe
- poeteye
- · Replies 10 ·
Graduate Impact of Free Will: How Much Can We Alter Universe?
- mzambani
- · Replies 3 ·
Undergrad Relationship between Altitude and Latitude
- Starboy>9000
- · Replies 2 ·
Graduate Dark Matter Distribution Around Galaxies
- RLutz
- · Replies 2 ·
Graduate Can High Temperatures Enable Silica Formation in Anaerobic Lunar Environments?
- cph
- · Replies 1 ·
Undergrad Have you ever taught orbital mechanics to middle schoolers?
- BobG
- · Replies 5 ·
Graduate Fine Structure Constant appears to vary across the distant sky
- Quisquis
- · Replies 1 ·
Graduate Is the Hubble Red-Shift Gravitational Instead of Doppler?
- ClamShell
- · Replies 14 ·
Graduate Where was the big bang singularity?
- jumpjack
- · Replies 58 ·
Graduate After Big Bang: What if Anti Mass Had Upperhand?
- picass
- · Replies 27 ·
Graduate The expanding universe and the conservation of energy
- mrspeedybob
- · Replies 2 ·
Graduate Cosmology Questions That Have Perplexed Me Over the Years
- RLutz
- · Replies 3 ·
Graduate Fine structure constant probably doesn't vary with direction in space
- bcrowell
- · Replies 124 ·
Graduate Quick question about the properties of dark matter/energy
- AntiQuarks
- · Replies 5 ·
Undergrad See the Light of Creation: Viewing the Big Bang
- arj67
- · Replies 4 ·
High School Why do stars appear to be white in color?
- RoughRoad
- · Replies 7 ·
Graduate Virtual particles and accelerated expansion
- skydivephil
- · Replies 10 ·
Graduate Accelerated Expansion of Space question
- Westernnate
- · Replies 31 ·
Undergrad How do distance and age relate in astronomical measurements?
- foxpoint11
- · Replies 3 ·
Graduate Curvature in a Universe with No Cosmological Constant and Zero Density
- nrqed
- · Replies 34 ·
Stargazing Is it Possible to Build a Simple Radiotelescope in Your Backyard?
- Frannas
- · Replies 3 ·
Undergrad What form of energy is lost when a planet changes orbit?
- Parbat
- · Replies 5 ·
Undergrad Universe from Nothing: The Mystery of the Big Bang Explained
- Outside
- · Replies 24 ·
Undergrad Prove Binary System Brighter by 3/4 Magnitude Than Single Star
- sheepcountme
- · Replies 4 ·
Graduate Converting HJD to BJD: Equation and Code Solutions | Natski
- natski
- · Replies 4 ·
Undergrad Susskind and Hawking on hard determinism
- schmitmg
- · Replies 47 ·
Graduate Why is the speed of light in a vacuum ~299,793 km/s?
- wondercosmos
- · Replies 24 ·
Undergrad Infinitely Old Earth: Cambridge A Level Physics Student
- Super-No0b
- · Replies 10 ·
Graduate Creation of Matter: Higgs Boson & Other Explanations
- brother time
- · Replies 2 ·
Graduate Evaporating black holes, a kind of flux of space?
- Spinnor
- · Replies 3 ·
Graduate How Does Hawking Radiation Affect Black Hole Energy Loss?
- jezz78
- · Replies 4 ·
Undergrad Distribution of stars in spiral galaxies
- MathsMonkey
- · Replies 2 ·
High School What is the maximum mass a planet can reach?
- tanzanos
- · Replies 4 ·
Richest Planetary System Discovered
- GoldNow
- · Replies 3 ·
Graduate CBR photon density at equilibrium temperature
- Orion1
- · Replies 1 ·
Graduate Explore Black Holes & Time: Is Time Stopping Possible?
- dogman 6126
- · Replies 16 ·
Graduate Hundreds of Rogue Black Holes May Roam Milky Way
- Astronuc
- · Replies 7 ·
High School My First Iridium Flare - Unexpected Bright Light in the Sky
- russ_watters
- · Replies 6 ·
Graduate Our Universe then and now, energy verses space.
- Spinnor
- · Replies 1 ·
Undergrad Telling time with Jupiters moons?
- Hoku
- · Replies 20 ·
Graduate Thoughts on Hawking's No-Boundary Proposal of Universe
- MrQG
- · Replies 9 ·
Undergrad How Would a Carrington Event Affect Modern Computers?
- jumpjack
- · Replies 5 ·
Undergrad Looking for data on the orbit of S2 star
- Moss Pauly
- · Replies 1 ·
Stargazing Can a Yukon 6-100X100 Spotting Scope View Jupiter's Stripes and Saturn's Rings?
- Hoku
- · Replies 2 ·
Graduate Black holes and the accelerating expansion of the Universe
- agreen
- · Replies 2 ·
Graduate HLX-1 brightest ultra-luminous X-ray source known.
- Philosophaie
- · Replies 3 ·
Undergrad Is Voyager 1 Approaching the Oort Cloud?
- cph
- · Replies 1 ·
Undergrad Gravitational effects of planets on each other
- Gully Foyle
- · Replies 9 ·
Graduate Is Entropy the Key to Understanding Time in an Expanding Universe?
- Godofgamblers
- · Replies 4 ·
Can Love Transcend Across Parallel Universes?
- Alphaville
- · Replies 17 ·
Graduate Where did the energy and mass in the singularity come from?
- ikos9lives
- · Replies 2 ·
High School Big Bang: Discovering the Reasons Behind Its Occurrence
- FizixFreak
- · Replies 105 ·
Graduate Gravitational Conditions: Dust Cloud vs Black Hole
- Austin0
- · Replies 2 ·
Graduate Calcluating the Hubble Radius for an open universe?
- CharlesB
- · Replies 9 ·
Graduate What happens to time when spacetime expands
- acepilot84
- · Replies 3 ·
Graduate Is the Universe in an Eternal Cycle of Expansion and Rebirth?
- procrastin
- · Replies 58 ·
Undergrad Quasars - how do they emerge from black holes?
- C_Dawg
- · Replies 3 ·
Undergrad Is Everything in the Universe Made of Wavelengths?
- confusedotcom
- · Replies 4 ·
Graduate Best review paper on the observational status of black holes?
- bcrowell
- · Replies 4 ·
Find Space Video: Gravityless Environment 5+ Mins
- Burrid
- · Replies 4 ·
Graduate Black hole size vs. neutron star size
- hkyriazi
- · Replies 12 ·
Undergrad Where in the sky do meteors come from at any arbitrary point in the year?
- dotancohen
- · Replies 2 ·
Undergrad What is the connection between Olber's paradox and the age of the universe?
- TheAlkemist
- · Replies 6 ·
Graduate What is the Limitation of Interstellar Communication for Humans?
- Orion1
- · Replies 2 ·
Graduate Temperature can it alter space time
- Naveen_B
- · Replies 16 ·
Undergrad Amount of iron in the solar system
- StellarBreeze
- · Replies 2 ·
Undergrad Why Don't Sunrise and Sunset Times Change Symmetrically?
- hodges
- · Replies 4 ·
Graduate Gravity center; Virtual particles near BH; Motion reality; Universe contracting
- Boy@n
- · Replies 24 ·
Undergrad Kepler's Third Law orbiting planet
- natski
- · Replies 8 ·
High School Doppler Effect Proven by Red Light from Distant Galaxies
- Kglocc
- · Replies 1 ·
Graduate What if the universe is shrinking instead of expanding?
- Tobbzn
- · Replies 6 ·
Graduate Searching for Sister Stars in Our Multistar System with Infrared Telescopes
- cph
- · Replies 9 ·
Graduate Time as the force carrier of mass
- sjbjava
- · Replies 1 ·
Graduate Does Mass Have Latency? Investigating Colliding Galaxies
- sjbjava
- · Replies 3 ·
Stargazing Galilean Telescope: Taking Photos with Digital Camera
- r.vittalkiran
- · Replies 3 ·
Graduate What Will Happen to Stars in the Distant Future?
- Angry Citizen
- · Replies 10 ·
Name of asteroid that'll pass very close
- rrw4rusty
- · Replies 2 ·
What gas giant, what moon(s) are split in half and.
- rrw4rusty
- · Replies 2 ·
Graduate Cosmological Constant and Conservation of Energy
- Jack21222
- · Replies 1 ·
Graduate White Holes: Connections to Other Universes?
- jumpjack
- · Replies 4 ·
Graduate Estimating the Sun's Present-Day Luminosity
- hasan_researc
- · Replies 8 ·
Graduate Lunar gravity assist en route to Mars
- Witan
- · Replies 8 ·
Graduate Bandwidth of Space: Threshold Capacity and Limitations
- .physics
- · Replies 11 ·
Undergrad What is the Hill Sphere and how is its formula derived?
- Ryan H
- · Replies 2 ·
Undergrad What is the diameter of star clusters?
- randa177
- · Replies 1 ·
Undergrad What Does Flat Universe Mean?
- Serpens
- · Replies 5 ·
Undergrad How Fast Is Earth Moving Through Space?
- Big Giant
- · Replies 15 ·
Graduate Expanding Universe: Cooling Matter, Gravity & Isotropy
- muser
- · Replies 2 ·
Graduate Is the Planck Density a Hopelessly Outdated View?
- Chronos
- · Replies 1 ·
Graduate Beyond brown dwarf mass to sustained fusion
- Quantum-lept
- · Replies 7 ·
Graduate Question about accelerated expanding universe theory.
- Ramon163
- · Replies 6 ·
Graduate Light Speed & Expanding Galaxies: A Cosmological Mystery
- binbots
- · Replies 5 ·
Graduate Discovering Chandra X-ray Field of View & Object Size at 500 pc Distance
- Astroyan
- · Replies 1 ·
Graduate How can the Universe be flat and isotropic?
- Jocko Homo
- · Replies 28 ·
Graduate Why does the Universe have a net charge of zero?
- seagull68
- · Replies 5 ·
Graduate Chalnoth case against Loop Quantum Cosmology
- marcus
- · Replies 24 ·
Undergrad What if the gravitational force is
- eranium
- · Replies 19 ·
Graduate Fine Structure Constant Varies With Direction in Space
- sanman
- · Replies 6 ·
Graduate Could Time Symmetry Explain the Arrow of Time?
- DrChinese
- · Replies 15 ·