Ask a Spaceman!

What powers Cepheid variable stars? What about Mira variables and pulsating stars? And are there variable stars that don’t actually vary at all? I discuss these questions and more in today’s Ask a Sp…

What would the Sun sound like if we could hear it? Does any noise at all happen in the universe? What’s the biggest sound of all? I discuss these questions and more in today’s Ask a Spaceman!

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Why does the vacuum of spacetime have energy? How much energy does it have? What prevents us from using it to do anything useful? I discuss these questions and more in today’s Ask a Spaceman!

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How do we actually define voids? Are there regions within them that are truly empty? What would it be like to be inside one? I discuss these questions and more in today’s Ask a Spaceman!

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Part 2 of 2! What are the modern constants of nature? Is the universe fine-tuned for life? Does the multiverse or string theory explain the origins of the constants? I discuss these questions and mor…

Part 1 of 2! How do fundamental constants appear in physics? Why are they so important? Why do we care where they come from? I discuss these questions and more in today’s Ask a Spaceman!

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What’s inside a neutron star? What strange states of matter do we encounter? And what mysteries will we find deep in the core? I discuss these questions and more in today’s Ask a Spaceman!

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How do we explain the giant black holes appearing in the young universe? Is it possible to directly collapse a black hole, skipping the formation of stars? What does ultraviolet radiation have to do …

How do you measure the impact of a scientist? Does Stephen Hawking compare to Newton or Einstein? What were his contributions to black holes, the big bang, and quantum gravity? I discuss these questi…

Why is the moon so special? Why do we think a giant impact created it? Why didn’t the same thing happen to other planets? I discuss these questions and more in today’s Ask a Spaceman!

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What is 21-cm radiation? What (and who) produces it? What causes it, and what does it tell us about the universe? I discuss these questions and more in today’s Ask a Spaceman!

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What is an Alcubierre warp drive? What would it take to make it work? Could it propel spacecraft even below the speed of light? I discuss these questions and more in today’s Ask a Spaceman!

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What is an axion? How could axions make a star, and what does that have to do with dark matter? What would these stars look like? I discuss these questions and more in today’s Ask a Spaceman!

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Where do parallel universes exist? Could we use wormholes to travel to them? What does time travel have to do with all this? I discuss these questions and more in today’s Ask a Spaceman!

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What is the Fermi Paradox? How rare is non-intelligent vs intelligent life? What are the challenges a species must overcome to colonize the galaxy? Where is everybody? I discuss these questions and m…

Are dark photons as sinister as they sound? What did the curvaton do in the early universe? And is everything really made of preons? I discuss these questions and more in today’s Ask a Spaceman!

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How can the solar corona be hotter than the surface? What has the Parker Solar probe learned so far? What do magnetic fields have to do with all this? I discuss these questions and more in today’s As…

Are we “in range” of any potential supernovae? Has the Earth ever been hit in the past? And what about gamma-ray bursts from across the galaxy, are we safe from those? I discuss these questions and m…

How do black holes get close enough to merge? What causes them to emit gravitational waves, and where do the waves come from? What does the merger process look like? I discuss these questions and mor…

How did Pluto get demoted? What makes a planet a planet anyway? Why do we now have so many different kinds of planets, and should we make things simpler? I discuss these questions and more in today’s…