Questions Show: Galactic Dust, the Speed of Photons, and the Big Bang Calculations

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 info@astronomycast.com and we’ll try to tackle it for a future show. Please include your location and a way to pronounce your name.

  • Galactic Dust, the Speed of Photons, and the Big Bang Calculations
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  • Shownotes

    What is galactic dust and where does it come from?

    Why can photons move at the speed of light?

    How can astronomers know what happened right after the Big Bang?

    Is there an upper limit to the size of black holes?

    What is vacuum?

    Is dark matter antimatter, and is there dark antimatter?

    How are gravitational waves detected?

    Isn’t it impossible for black holes to merge?

    Does time dilation come from speed or distance?

    Are there areas of astronomy in which persons with limited sight could participate?

    Will the sun release a huge solar flare and kill us all?