One of the questions I get most often is “Do you really think there are singularities at the centers of black holes?”
No. I don’t. I think we still don’t understand how gravity works on quantum scales. Last week my own thoughts where brought back to the surface as I listened to a talk given by Sean Carroll that was eloquently summarized by Chris Lintott. This post isn’t a summary of Sean’s talk, but it dovetails it.
Ancient maps labeled the unexplored corners of the world with the warning, “Here be dragons.” As cosmologists look back in time to the first moments of our own universe we find ourselves journeying with our minds beyond the safe boundaries of charted land. As time winds back toward zero and densities and temperatures reach the extraordinary levels of 10^93 gm/cm^3 and 10^32 Kelvin, we go beyond the boundaries of where physics functions and into our own world of dragons.
These numbers describe a time called the Planck time. This briefest of moments, 10^-43 seconds after what we call the Big Bang, is the point in time when quantum mechanics takes over. At intervals of time smaller than this Planck time, we can only use statistics to say what might have been, and what was is lost into the soup of what ifs.
At this moment run by probabilities, all the mass in the Virgo Supercluster was compressed into far less space than a common lead atom. At these densities mass could not exist in any normal form, but rather existed as pure energy. Just as mass couldn’t exist as normal matter like electrons and protons, the basic forces also couldn’t exist as normal forces like gravity and magnetism. Instead, according to theorists, the forces tangled together to form a single force.
And here is where things break.
As we work to understand the blending of forces, gravity refuses to play. Just 150 years ago we had 3 well recognized forces: Gravity, Electical Force and Magnetism. Under Maxwell, Electricity and Magnetism became the Electromagnetic Force, and later the Strong and the Weak forces stepped forward to explain how nuclei stay together and decay apart. Through the standard model of particle physics, these forces can be drawn together and explained through their interactions with atomic and sub-atomic particles.
But, 150 years and 2 new forces later, gravity still doesn’t fit in. It breaks at atomic scales and defies the mold of quantum mechanics. It won’t play with the Big Bang mathematical models.
It simply defies our current understanding.
And this is the beauty of physics; we, its practitioners, don’t try to cover its flaws. As a community we know gravity is broken, and we know to tip toe around the topic of quantum singularities. We can play at the math, and work at working out the geometry of the centers of black holes, but in its broken beauty, gravity can only respond with twisted infinities that poke through the fabric of space and time.
But this isn’t a new experience for us. The forces have played hard to get before. Before we understood quantum mechanics, we also predicted light bulbs should give off near limitless amounts of ultraviolet light. This was called the Ultraviolet catastrophe, and it was fixed by quantifying atomic transistions.
It is generally hoped that today’s gravitational singularities – both in black holes and at the first moment of the big bang, will go away once we draw out gravity’s quantum personality. In that moment of mathematical discovery, we may find that the Big Bang is a smooth wave function that flows into a well-defined source; we may find that black holes are simply the homes of free quarks, liberated from their normal nuclei bonds. We don’t know. But we know what we don’t know, and this is powerful. Without fear, I can say, here be the next big mystery, here be the dragon’s treasure waiting for the taking.
Thanks for making it clear for us readers!
(I wonder what black holes would really “look like” on the inside…)
One more thing…
Is it a coincidence that there is also a “Here Be Dragons” post at Bad Astronomy? (Different topic, though)
Total coincidence – great minds just think a like 😉
Great post, very well put.
One minor quibble – on the subject of unification, it could be argued that ‘gravity’ isn’t the only problem. Ever since the success of electro-weak unification, there have been furious attempts worldwide to include the strong nuclear force in a grander scheme (GUT. However, this has proved to be far harder than expected, and it now seems the only way even the three non-gravitational forces can be unified is through supersymmetry, or equivalent exoctic mechanisms…so although gravity really is the black sheep it’s not the only hiccup in unified field theory…Cormac
I know a lot of people don’t have any problems with singularities, but I find it easier to grasp a black than a singularity. Singularities are right up there with Branes, strings and Calabi-Yau manifold. And just to prove how little I know about these things I just wikipedia’ed them and confirmed that I don’t know anything after reading the articles.
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dww
Thank You for that great explanation.
What is it about gravity that breaks down? Isn’t gravity holding it all together?
Wow nice post, thanks for simplifing it for us lay people, and hey you are quite good with words, nay i would say eloquent.
11.30 am
Calcutta, India
On a friend’s computer and playing. Which is real time and metaphor(and hilarious because I know next to nothing and everything about computers). If you add Quantum resonance theory to the recipe of parallel universe romance-you get a butterfly effect of possibilities, that is to say, infinite in a way in which one or the many can only understand as a (sh)ape. An amorphous love affair of candy for the movies in the image nations (al)one can travel-a baklava of harlequin layers…each human body adds to the resonance gravitus of the situational comedy. Who I hold hands with today could lead to all of the angels dancing on the head of a pin yesterday(my family of quarks loves lee press on nails-hee hee) and this universal human condition would be, could be, starting anew.
Listen to the mitochondria. They are the God’s within.
Anchorage, Alaska. Read and watch the Golden Compass….Lyra and the alethiometer resonates through my mass. Think. Friends in three dimensions shall hold me truly.
COMMENT on Heather Soots comment-
is it mysticism ? is it science? is it poetry? is it crap?
whatever you have written its …well its STRANGELY beautiful.
what is it though?
have read all three of the lyra/northern light trilogy , but still cant figure out what you mean.
2.05 a.m
Calcutta, India.
Dear Syed Moin Doja-
Amorphous ego or not…I still loved hearing you call my words STRANGELY beautiful. I’m all but not completely lost. For about 3/4 of a year I’ve been trying to find the clan(s) that know my changeling self.
My belief receptors are almost always open to new information. My systems build and re-build. Time spent constructing an altar, or even a soapbox, is bought with an ambition that can best be described as borrowed by others.
I’m me. Beautiful Mind White Trash Trailer Style. But what am I also? Crookedly Buttoned Professor? Vampyre? Werebeast? Wyvern’s bride? Geometric Princess of the Time Space Continuum? Have I, like an electron, forged different paths because of my audience? There is more here than my Electrolux can explain to me…even absent-mindedly.
I’m a Prodigal daughter knocking on lintels painted with blood that smells like mine. Sometimes I’m pinched by a crown and duct-taped into a throne in castles I’ve never been invited to.
I’ve romanced the stone-templates with laughter. Quantum origamis pinwheel through my wyrmholes and other’s lips are inside my own speech. But where does one live when more than one reality is layered in perceptions? Family, I am alone.
Living off the grid is more about circumstances and moneterial allocations than choice. The High-falutin’ language is less about being coy than it is about stroking the words quickly. Break the metaphors and equations into blocks and the bullshit will be shinier. Brother Crow please turn your head and wink.
The Vistas and the art and the beauty in my head are most certainly not all mine. My awareness keeps climbing sideways stairs. But I’m older, and uncertain of who to whisper to in person.
I yearn for asylum.
I’m rather more simple in person. Look closely.