We're here at the Nordic Institute for Theoretical Physics (NORDITA) ready to take your questions.

We spent this past week working on some of the most challenging questions in theoretical physics. Last Tuesday, our colleague Stephen Hawking presented to us his latest idea to solve the growing paradoxes of black hole physics. We discussed this, and many other ideas, that may light the path towards a deeper understanding of black holes... and perhaps even point us towards the holy grail of physics. The so-called, "Theory of Everything"!

Could black hole Hawking Radiation be a "super-translation" of in-falling matter? Why does the Universe conserve information? Is "information" a physical object or just an idea? Do collapsing black holes bounce and become a super slow-motion white holes? Can black holes have an infinite amount of charge on their surfaces? Or, could black holes not exist and really be “GravaStars” in disguise? We’re trying to find out! Ask us anything!

Special thanks to conference organizers Nordita, UNC-Chapel Hill, The University of Stockholm, and facilitation by KTH Royal Institute of Technology.

AMA Participants so-far:

  • Malcolm J. Perry
    String Theorist
    Professor of Theoretical Physics, Cambridge University
    Chief Collaborator with Stephen Hawking and Andy Strominger on new idea involving super-translations in Black Hole physics.

  • Katie Freese
    Director of The Nordic Institute of Theoretical Physics
    George Eugene Uhlenbeck Professor of Physics at University of Michigan
    Founder of the theory of “Natural Inflation."
    Author of first scientific paper on Dark Stars.
    Author of “The Cosmic Cocktail: Three Parts Dark Matter.”

  • Sabine Hossenfelder
    Assistant professor for high energy physics and freelance science writer
    The Nordic Institute for Theoretical Physics (Nordita)
    Blogs at backreaction.blogspot.com

  • Paulo Vargas Moniz
    Chair of department of Gravitation and Physics
    University of Beira Interior, Portugal
    Author "Quantum Cosmology" Vol I, Vol II.
    Author of "Classical and Quantum Gravity"

  • Carlo Rovelli
    Theoretical Physicist
    AIX-Marseille University
    Author "7 Brief Lectures in Physics"
    Co-founder of Loop Quantum Gravity.

  • Leo Stodolsky
    Emeritus Director
    The Max Planck Institute
    Originator of methods for detecting dark matter in Earth-based laboratories

  • Francesca Vidotto
    NWO Veni Fellow
    Radboud University Nijmegen
    Author of “Covariant Loop Quantum Gravity.”
    Author of the first scientific paper proposing Planck Stars

  • Kelly Stelle
    Professor of physics
    Imperial College of London

  • Bernard Whiting
    Professor of Gravitational and Quantum Physics
    University of Florida

  • Doug Spolyar
    Oskar Kelin center fellow of cosmology
    Co-author of first paper on Dark Stars

  • Emil Mottola, particle cosmologist
    Los Alamos National Laboratory
    Author of first paper on GravaStars

  • Ulf Danielsson
    Professor of Physics
    Uppsala University
    Leading expert of String Cosmology
    Recipient of the Göran Gustafsson Prize
    Recipient of the Thuréus Prize

  • Yen Chin Ong
    Theoretical Physicist
    Nordita Fellow

  • Celine Weimer
    The Un-firewalled
    Queen of the Quark-Gluon Plasma, the CMB Anisotropies, and of the First Baryons
    Queen of Neutrinos
    Khaleesi of the Great Universal Wave Function
    Breaker of Entanglement
    Mother of Dragons
    KTH Royal Institute of Technology

  • Tony Lund
    “Through the Wormhole: With Morgan Freeman”

Proof: http://www.nordita.org http://i.imgur.com/Ka3MDKr.jpg Director and Conference Organizer Katie Freese: http://i.imgur.com/7xIGeGh.jpg Science Writer Tony Lund: http://i.imgur.com/mux9L5x.jpg

UPDATE: we had such a blast hanging out with you all tonight, so much so, that we are going to continue the conversation into the weekend. We may even bring along some more friends!

8/31/15 UPDATE: Please welcome Sabine and Paulo to the conversation!

Comments: 1674 • Responses: 6  • Date: 

theduckfliesagain487 karma

If you could rename "black holes" based on what we currently know about them what would you call them? And why?

TonyLund506 karma

Based on what I've heard this week...

  • If Malcolm is correct: "Confounding Sasquatch Spheres."
  • If Emil is correct: "Super Heavy GraviStars"
  • If Francesca is correct: "Quirky Flippy Bouncy Whitey Blacky Ball"
  • If Jim is correct: "Cosmic Oreo."
  • If Stephan is correct: "Black Holes -- stop worrying about it."
  • If Joe is correct: "Fiery Death Ball"
  • If Samir is correct: "Deadly Fuzz Ball."

There are more... I'll try to think of them!

Someday, I hope each of these will get their own movie poster!

(EDIT -- bad grammar)

TonyLund327 karma

Thanks, Reddit!! We just hit the front page, so we opened up a bottle of Benromach 10 Year Old Speyside Scotch, and we toast to you all for the great questions! http://imgur.com/eGWwAMK

Dave9557242 karma

Can you explain some of what you're doing in laymen's terms?

BernardWhiting355 karma

Gravity explains how heavenly bodies, such as stars and planets, hold together, while quantum mechanics explains what are the properties of ordinary matter. We are trying to understand how these two theories can work together when stars become very compact and collapse to form a black hole. So far, our understanding suggests that black holes should not remain black, but should eventually evaporate. This leaves us with a puzzle about how information of what formed the black hole can still be preserved after the end of the evaporation. That is the puzzling problem we have been discussing all week.

Fumblesz15 karma

So what are some theories - once again in layman's terms (as much as possible) that you've been discussing, if you're allowed to share?

TonyLund63 karma

One of the ideas presented that I quite enjoyed was Carlo and Francesca's theory that when a star collapses, it does not form a black hole. It actually 'bounces' over a VEEEEEERRRRYY long period of time (we're talking 10 followed by 50 zeroes or higher, depending on the mass of the initial star. It's a very speculative theory, and based primarily on ideas found in "Loop Quantum Gravity" which is also speculative) However, I found this idea compelling because it challenges us to consider the possibility that the Universe is playing a trick on us! What we think is one thing, may actually turn out to be another in disguise.

Another excellent talk argued that Black Holes are actually "GravaStars" -- in essence, an EXTREMELY dense star.
(I may also be biased because Emil's math was entirely classical and I didn't have to pretend to understand it ;))

metaranha52 karma


As someone working to get the word out about scientific discovery, what are the biggest challenges you see of reconciling complex science and the understanding of the common person?

TonyLund108 karma

Ah, yes. It can be quite hard sometimes because some of the most beautiful ideas in cutting physics are difficult to explain in less than 20 minutes.

I tried once to explain the Anti-De Sitter Conformal Field Theory Duality ("Ads/CFT") to my Mother's kindergarten class. I think one of them got it, but she may been just been eagerly staring at the cookie jar.

What's so pleasurable about attending conferences like these, is that Physicists use the same neurological tools as laymen to try to understand the mysteries of the Universe... our brains are very good at understanding concepts related to motion, so Physicists often discuss new ideas by describing how imaginary particles, or mathematical objects, or even calculations themselves, "move" in an abstract space. For example, its useful to think about equations "going to infinity" rather than resulting in infinity.

So, the layperson uses the same regions in their brain to understand complex processes, they just don't have the massive lexicon of terms and concepts that these cats do.

So, when I've only got 2 minutes to explain"Ads/CFT" on TV, I always try to think about what's literally moving in that space, and how to visualize it.

TexasStarForever26 karma

Pretty cool ! How is the chick action ?

KatieFreese93 karma

I'm a gorgeous babe myself, dude.

LeoStodolsky45 karma

Can testify to that. But are you invariant?

Dave955743 karma

We should measure her gorgeousness over time. I'll apply for a grant.

TonyLund63 karma

Katie's beauty seems to be fixed and not time-dependent. It therefore follows that her beauty extends to the null infinity boundary of the Universe.

AtopiaUtopia0 karma

Does Tony know that 'Lund' means penis in Hindi? I'm sorry, it's a very immature question and I'll probably be downvoted.

TonyLund2 karma

I live with an Indian roomate my first two years in University....

Apparently "Tony" also sounds very similar to the word "Pensive."

So, one can only hope my obituary in India will read "Americans Mourn the Loss of Pensive Penis."