Another week, another roundup of your questions. This week listeners asked: what is galactic dust anyway, and where does it come from? Why can photons move at the speed of light? And how can astronomers know what happened right after the Big Bang? And there’s even more. If you’ve got a question for the Astronomy Cast team, please email it in to firstname.lastname@example.org and we’ll try to tackle it for a future show. Please include your location and a way to pronounce your name.
What is galactic dust and where does it come from?
- Dust in Galaxies — Bill Keel/U of Alabama
- The Interstellar Medium
- Nitrous Oxide — Just Say N2O
- Chlorofluorocarbons — NOAA
- Acetylene — Wiki
Why can photons move at the speed of light?
- Do photons move slower in a solid medium? — Physics Forum discussion
- Is the speed of light constant? — Astronomical Society of South Africa
How can astronomers know what happened right after the Big Bang?
Is there an upper limit to the size of black holes?
- Pamela’s Star Stryder post on the size of black holes
- Black Holes Can Only Get So Big — Universe Today
- Paper: Is There an Upper Limit to Black Hole Masses? — arXiv
- How big can black holes get? — Virginia Tech
What is vacuum?
Is dark matter antimatter, and is there dark antimatter?
- Dark matter — Goddard Space Flight Center
- Primer on Dark Matter –– UTK
- Antimatter — CERN
- Astronomy Cast Episode 106: The Search for the Theory of Everything
- Lightest Super symmetric particle — Wiki
- Intro to Super Symmetry — Berkeley
How are gravitational waves detected?
Isn’t it impossible for black holes to merge?
- What Happens When Black Holes Collide? — Universe Today
- What Happens When Three Black Holes Collide? — Universe Today
- Watching something go into a black hole –– Berkeley
Does time dilation come from speed or distance?
- Time dilation and length contraction in Special Relativity — U of New South Wales
- Relativity tutorial
Are there areas of astronomy in which persons with limited sight could participate?
- Retinitis Pigmentosa
- Contact by Carl Sagan
- Fourier Analysis
- Astronomy for the Blind and Visually Impaired — Astronomy Education Review
- Hands On Astronomy book: Touch the Universe –– HubbleSite
Will the sun release a huge solar flare and kill us all?