Slight delay on today's release - it'll be out tomorrow! In the meantime, here's a graphics mockup I (Matt) put together for next week's episode, in which we show that the looking-glass universe is as strange as the stories tell us.

With the bizarreness of string dualities, is it possible for string theory to be at the same time both right and wrong? Our followup to Why String Theory is Right explores the other option. youtu.be/IhpGdumLRqs

Reflect our universe in the mirror, flip it to antimatter, OR reverse the direction of time and you break physics. But do all three and you get back to where you started. CPT symmetry is weird. youtu.be/L2idut9tkeQ

What does the near future of human space travel look like? @RichardBranson shared some surprising insights with me at his beautiful island home. Soon on PBS SpaceTime! Thanks for the warm welcome, Richard

Galaxies also fall into constellations - rings on the sky that are echoes of the first sound waves to reverberate through the universe youtu.be/PPpUxoeooZk

The measure of all matter and energy in the universe is inscribed in the fiery speckles of the cosmic microwave background. It's crazy that we've learned how to read this secret language. You can too. youtu.be/C4CKtEQJGMY

"Why, sometimes I've believed as many as 6 impossible things before breakfast." I feel just like the Queen of <3s - the 6 winners of our perpetual motion challenge are the most believable impossible things ever youtu.be/rckrnYw5sOA Full winning entries on Insta Matt O'Dowd

The most spectacular possible end of the universe has got to be The Big Rip. Happily there's only a *little* bit of evidence that it could happen. youtu.be/gEyXTQ9do-c

Join us this week for practical DIY instructions on how to enclose an infinite universe into a finite boundary. A conformally compactified hyperbolic cosmos makes great wall art or a special gift for someone who already has everything! youtu.be/tJevBNQsKtU

Second interstellar rock possibly discovered by Amir Siraj and Avi Loeb in NASA's CNEOS catalog of past meteors. It vaporized in our atmosphere in 2014, but came in fast enough that it may have come from beyond the solar system. 'Oumuamua has friends! arxiv.org/abs/1904.07224

Fighting quantum weirdness with quantum weirdness. Quantum cryptography may be our only defence against the encryption-cracking threat of quantum computers youtu.be/pi7YwxxZQ5A

This was such a fun conversation with ًًً🐉🐉🐉🐉🐉🐉🐉🐉 and @rainnwilson. Check it out!

In case you missed it: youtu.be/iozCwyjxhyY Matt O'Dowd and Prof. Brian Keating are bringing together leading physicists to discuss our long quest for the deepest layers of reality. Part 1 of 2 tomorrow! (July 28 4pm EDT) with Lisa Randall, Stephon Alexander, Max Tegmark, James Beacham

Arecibo helped form so much of our modern understanding of the universe. It will be missed, but the knowledge it gave us will last forever. We were lucky enough to visit last year. We made this VR 180 tour so you can still explore its dizzying glory youtu.be/-5j98wi_M2w

The quantum uncertainty we experience at PBS SpaceTime : Will the cat ruin or not ruin the take?

If you can see the lunar eclipse right now, you're watching all sunrises and sunsets across the world, reflected back to us by the moon. (Images from NASA/GSFC)

Every answer in physics generates more questions. Time to contribute to the exponential growth of questions by trying to answer a few! Please join me for TWO AMAs - today (12/19, 4pm EST) on youtube.com/PBSSpaceTime and tomorrow (12/20) on Reddit.com/r/AskScience

Question time has started for Matt's Reddit AMA. Answers will begin in a little bit, but now's the best time to ask yours (& upvote pls!) reddit.com/r/askscience/c…

Join Matt O'Dowd as he chats with Curt Jaimungal about our quest for a theory of everything, the nature of reality, and obv the obligatory free will question! youtu.be/T6xLFRHW-IY

For a fun conversation between Matt O'Dowd and Neil deGrasse Tyson, check out StarTalk's latest episode! We go from black hole entropy all the way to the solar gravitational lens telescope youtu.be/OcX7xpxOC2U