Showing posts with label primordial black holes. Show all posts
Showing posts with label primordial black holes. Show all posts

Saturday, August 13, 2016

Gazing into the cosmos -- Galaxies and Black Holes and SETI and METI (again)

Yes, events in our tiny corner of space and time... the Olympics and spreading viruses and momentous elections... transfix us.  So it's even more important to lift our heads! And thus to recall that we are members of a truly wonderful human civilization.  As you ponder the miracles below - just a sampler out of so many - remember that your people are doing this right now.  You, your neighbors and fellow taxpayers.

We aren't at War with Science.  We are the scientific civilization, and any truly worthy Father (or Mother) would be proud. And nothing is beyond us.

== Cool overhead! ==

Having arrived at Jupiter, NASA's Juno spacecraft has sent its first in-orbit images! 

Astronomers have discovered a new dwarf planet orbiting beyond Neptune; this icy world 2015RR245 is about 700 km in size, and has a hugely elliptical orbit, which takes it far beyond the Kuiper Belt.

This is boss... The largest three dimensional map of the universe, to date: a new 3D map plots the locations of 1.2  million galaxies -- a quarter of the sky. Created by scientists at the Baryon Oscillation Spectroscopic Survey (BOSS), part of the Sloan Digital Sky Survey, the data will help scientists understand the nature of dark energy and dark matter in shaping the cosmos, and driving cosmic expansion. The image shows just a slice through the 3D map; each point not a star, but a galaxy.  And we've only just begun...

1300 new galaxies were just discovered by South African astronomers, in the first phase of the Square Kilometer Array (SKA) -- which will be the largest telescope ever built, consisting of thousands of radio antennas covering over a square kilometer in South Africa and Australia. The image resolution is expected to exceed that of the Hubble Space Telescope by a factor of fifty. Besides galaxies, it will survey for dark energy, dark matter and perform tests of general relativity.


For big perspectives on the nature of the cosmos, see Caltech professor and science popularizer Sean Carroll’s latest book, The Big Picture: On the Origins of Life, Meaning, and the Universe Itself -- a title grandiose enough to hint at the scale he is tackling, weaving together diverse concepts from physics, evolution, neuroscience and philosophy to get at the essence of the cosmos itself. 

Carroll writes,What we believe about the fundamental nature of reality affects how we look at the world and how we choose to live our lives. We should work to get it right.” 

== The Goldilocks zone ==


An abrupt outburst from the young star V883 Orionis gave astronomers their first view of a water 'snowline' in a protoplanetary disk -- the region around a star where temperature and pressure allow the formation of water ice -- a key feature in the development of life.


It appears that crowded stellar neighborhoods affect planet formation in interesting ways.  The denser environment in a cluster causes more frequent interactions between planets and nearby stars, which may explain the excess of hot Jupiters observed.  

Michaël Gillon, of the University of Liège, says “I’ve always been focused on extraterrestrial life.”  His TRAPPIST transit planet-finding scope focuses on ultra small “ultracool” dwarf stars and has found planets orbiting one of them in its goldilocks zone, though tidally locked so water could only settle as liquid along the Twilight Zone. Also that region would have some shelter from frequent red-dwarf flares. Even the too-hot sun-facing hemisphere would be dim… life could only subsist on infrared.


== Primordial Black Holes ==


Science fiction and adventure novelist John Ringo (most recently author of Black Tide Rising) and I recently shared thoughts on “Primordial Black Holes” or PBH – massive singularities that might have been created in the very process of the Big Bang and most of which might be with us still, today.  Indeed, some believe these might explain some of the mysterious Dark Matter. A potential resurrection of the MACHO alternative explanation for dark matter - now currently favoring WIMPS.

Getting a bit technical here: Various approaches to detecting PBH are on the table.  For example, small ones in the mass range of E11 grams may be expiring to Hawking Radiation about now and thus possibly detectable as bright explosions. At a larger scale, the fact that LIGO detected two mergings of intermediate size BH (in the range of 20-100 solar masses, we think) within just a few months of each other suggests that this is happening all over the cosmos pretty regularly!  If that bears out, then it really puts the PBH scenario in play!

Moreover, if we detect these things in scads, then it will let us derive a rough power law for their size range.  Once you have such a power law, then it's traditional to extend it beyond what you can observe, giving us a hint whether there are mega-scads of much smaller BH. (Which of course leads one to ponder the initial scenario in EARTH.)

It does appear obvious that if there were scads of PBH - after the Big Bang - then those at the larger end of the power law distribution in size would act as nucleation sites for galaxies.

The mind wanders to macro cosmological maunderings, like the way some guys like Lee Smolin envisioned that big BH in our universe may seed Bangs elsewhere and elsewhen. Indeed a medium sized BH might engender a new universe vastly larger than the mass it contains. I have a short story "What Continues..." about Smolin's implication... that Our cosmos was born from a BH in a mother universe and our BH engenders daughters... and that the traits of such descendants might "evolve" in ways to maximize BH (or egg) production, and that might explain why our universe seems "fine-tuned" for life.... Phew!

For more about black holes and big picture thinking: Mapping the Heavens: The Radical Scientific Ideas that Reveal the Cosmos. Yale astronomy professor Priyamvada Natarajan provides historical perspective and an insider's insight into the revolutionary research that has shaped our understanding of the universe, from dark matter to dark energy, from black holes to quasars and an ever-growing list of exoplanets.   

== Again with the yoohoo screamers? ==

The METI - SETI debate develops.  Dr. Doug Vakoch held up the let’s-shout-yoohoo side amiably at Toronto’s terrific IdeaCity conference (much better than TED)… while I skyped in to represent the let’s-learn-more-before-hollering position. 


I like Doug and he fights fair. And a fair debate over this matter is all that most of us METI-dissenters have been demanding. Some true due-diligence and extended-ecumenical, broad exposure of the ideas to critical peer review and public comment, outside a narrow clique of peremptory zealots. You can watch the brief debate here, odownload the mp4 file.

The IdeaCity audience was buzzing about it afterwards. They took a poll - who do you think had the edge? immediately following my debate with Doug – the caution approach won with 64%.  Note that this always happens


Modern, liberal audiences always poll way in favor of METI at first. 
Only then, once they learn more, they lean the other way, toward wanting to engage the complex issue and share open argument, first.  Which is why The SETI Institute's top METI zealot, Dr. Seth Shostak tries always (inexplicably) to control which ideas his audiences are exposed to.

== They do keep trying ==

One more silly METI stunt - (Message to ET) - by arrogant twits who declare "we know exactly what the cosmic situation is, and anyone who disagrees can be dismissed out of hand. We assume there's nothing to discuss with anyone, so we'll just alter our planet's observable parameters (a kind of pollution) without bothering to consult anyone else, do an environmental impact report or address the concerns of colleagues." 

Of course we understand the attention-seeking value of such stunts. But if any of you are actually interested in what actual astronomers have to say about the argument, I posted my own paper objecting to METI. Most of the widely held assumptions - like "aliens can already watch our TV" are simply flat out and extremely wrong.


Oh... as we are about to post... and now the METI zealots are at it again!  With a new kickstarter campaign now they want YOUR money in order to find stunts that will not advance science an iota, or achieve first contact, but that might have a slim but real chance of endangering our world.  (See the flaws in this mindset illustrated by Liu Cixin's fantastic novel - winner of last year's Hugo Award - The Three Body Problem.)

meti, seti

Sure, by posting this link I just drew some folks to look at the METI guy's sales pitch and maybe give them a buck or two.  


A far better kickstarter would be to fund a new science show getting many of the world's top minds on-camera discussing SETI and METI, exploring implications that you never imagined! And figuring out how to get past cliches... perhaps polling the people of this planet whether or not they want a small team of zealots precipitately screaming into the cosmos on our behalf, without so much as an impact report in advance. 


Now that would be a worthy kickstarter! Get the whole planet discussing the parameters of the Drake Equation and the Fermi Paradox and real science! A fascinating exploration and discussion that might even lead to a win-win compromise - as often happens when scientists and the public argue like grownups - and possibly even find a middle ground! Maybe charting a way to do this responsibly and well.


Again, my own response on METI is here


== The real lesson? ==

Let's do most things in the open. Argue fairly. And stay scientific! (Remember this, during the elections!)

But above all, pause every now and then to wade through the hip-deep river of wonders that are pouring forth from curious and disciplined minds... assisted by folks like you who eagerly ask questions and willingly help to pay for it all!  

And as you pause, ponder this too:

I am a member of a civilization that does stuff like this!