Black Holes and Revelations

I have now finished my superb Futurelearn online course on Gravity, and in the final week the subject of study has been Black Holes.

They are, as you might have expected, completely crazy places. Sadly, unlike the 1979 Disney movie "The Black Hole", they are not filled with lost souls being taken to hell while Maximillian Schell watches from atop a burning rock fused with his robot creation; also called Maximillian and BTW one of cinemas most memorable androids.

They are in actuality far stranger than that. What most folk would consider the "boundary" of a Black Hole, the Event Horizon beyond which light can no longer escape its clutches, is a baffling place where due to relativistic time dilation you can never see something cross the horizon, just see a last frozen image of it before it slowly fades from view. Nothing more can ever be known about anything that crosses this boundary.

Within the Event Horizon, time and space decide they are reversed. Space only points in one direction now, towards the singularity, the infinitely small centre of the black hole where all mass falls, and time can run anyway it wants, so indeed you might perhaps see your own back, and your own past and future, as you fall into the singularity.

Which you wouldn't be able to do, because if you hadn't already been fried by the tremendous amount of X and Gamma rays that are found around black holes, the spaghettification of your body by the intense gravitational field will be your unpleasantly stretched out fate.

Then there is information? Is it preserved in there to be slowly re-emitted by Hawking radiation, or does it imprint on the surface of the event horizon like a hologram? Or is it scrambled, or lost forever?

The concepts are mindblowing.

Si

All text copyright CreamCrackeredNature 03.12.15

Philosophizing at the Death of the Universe

I've just completed the fourth week of my excellent and highly thought provoking Futurelearn course "Gravity", and we've been discussing the supremely headscratchy topics of dark matter - matter that we wouldn't notice if we walked into a room stuffed with it despite the fact there's 5 times more of it than normal matter in the universe - and also dark energy, energy that drives the expansion of the universe, and forms nearly 70% of the Universe despite the fact we've never detected it.

Dark energy in particular is a concept to put your brain through a blender. It corresponds, it is theorised, to the vacuum energy permanently blazing away in space time, an energy produced when a particle and its anti matter equivalent are produced FROM NOTHING and then annihilate each other back into nothingness so fast that we can never possibly detect them.

At the quantum level, creating matter and energy from nothing is allowed. Providing it goes back into nothingness faster than fast can be, this is allowed. Whereas light and gravity act as a brake on the expansion of the universe, vacuum energy does the opposite. It sucks space-time away from itself. And it is doing so at a faster and faster rate.

The expansion of the Universe is accelerating. It will never stop, contract, fall back on itself in a big crunch. The Universe will go on forever.

This sounds fabulous, but it isn't really. It doesn't mean that life will go on forever. Space-time will expand forever, but the Universe will die. Fundamental particles like protons will all decay; the atoms that make up you and me, many of which were around at the time of the big bang, will all splutter out into massless ghosts. As the Universe expands faster and faster, we will see less and less of it as it disappears over a kind of cosmic horizon provided by the speed of light. The longest living stars, red dwarves, will eventually peter out and the universe will be dark and cold, apart from black holes spinning silently in the blackness. And even they too will waft away bit by bit, trillions upon trillions of years hence. No life. No light.

I find it distressing, from a philosophical point of view. In a sense, it means that life is pointless, no matter it does anywhere in the universe to improve itself, it is doomed to fail. There's no point to anything. We cannot defy the laws of particle decay.

Yet I still wonder what hope there could be for life? The only hope that I can see would be to start another universe, a universe with renewed matter and vigour, and leave our ageing protons behind and transfer to a new vessel, within the new universe. Shades of "Being John Malkovich", I realise! Anyone who knows how to start a Universe, your Nobel prize awaits.

Or we could hope that the multiverse theory of everything is correct, that our Universe is merely one of many universes floating around within an 11 dimensional membrane, occasionally triggering new Big Bangs when they brush up against themselves. Here, life could find a way of tunnelling from one universe into an other, or a newly created one, and continue to do so as energy potential runs out in each Universe it colonises on a timescale that makes eternity look like the blink of an eye.

For I do no want life to fizzle out, in a cold sweep of darkness' cloak.

Si

All text copyright CreamCrackeredNature 19.11.15

Evenings with Orion the Hunter

Once again I am at work, and even now my fingers still feel the -4 6am cycle to work this morning. I was wearing two pairs of gloves and thus accidentally changing gear every few metres, but it still isn't preventing the familiar freezing pain from nipping at my fingertips.

Winter thrushes are appearing in numbers on the farmer's field next to the showground; impossible to confirm at this distance but they would appear to have very pale breasts and thus most likely be fieldfares. Above them gulls squabble, and occasionally a kestrel makes its way to find a favoured hunting spot around the margins, looking for any mouse not frozen into the semblance of concrete.

At least there are benefits to these freezing nights. Like two nights ago, the clearest, darkest night I have seen for a long while. The stars were glittering diamonds on their velvet display case; the Milky Way was overhead in Cassiopeia, flowing like Cleopatra's bathwater. Straddling the southern aspect, most prominent of all winter constellations, was the mighty hunter himself, Orion.

Orion from wikimedia, uploaded by Mouser

From my garden as midnight approaches, he appears to have suddenly leapt out from behind a tree in order to shoot a terrible creature of myth, or perhaps even me. To his upper right his bow is raised, and if that isn't enough, he is wielding a club with his other hand.

Confusing overkill? Some representations have the bow as a shield, but I can't stop my brain convincing me it's a bow. After all, who hunts with a club?

However he hunts, it has certainly been successful, because in clear skies you can see the body of Lepus, the celestial hare, at his feet. The hare was present the other night, and to see it from my urban garden is all but miraculous, thus illustrating how clear the sky was.

I didn't use my binoculars; when you do, the starfields are magnificent, probably the finest you will see from the UK. There are stars everywhere, and not the faint ones associated with Cygnus and the Milky Way within; these are genuine jewels of the sky. The great nebula sits ghostlike, illuminated by the light of the searing hot iota orionis "trapezium" and the new stars forming within.

It is a beautiful view.

However, even without the binoculars there is still plenty to see and think about. The hot coal of Betelgeuse glows firey at the top left, big as 20 suns, monstrously unstable and thus variable in brightness. It is reckoned to be candidate for going supernova within a few million years, and it will be as bright as the full moon when it does.

At the opposite corner sits Rigel, a hot, blue white star that is a single to our eyes, but is actually a triple star system adding up to a whole 120,000 times more luminous than the sun. There is, of course, the nebula, still plain to the naked eye - and then the belt, the central star of which, Alnilam, is a blue-white supergiant also doomed for a supernovic ending.

It is 350,000 times more luminous than the sun, and all in all is the intrinsically brightest star you can see easily in the night sky.

After Christmas, Futurelearn are running a course on this constellation. So, why not familiarise yourself with it now, as the great hunter bestrides the night sky.

Spring Observations Under a Freezing Sky; The Northern Globulars

This is the first really clear sky without any hint of a moon I've had a for a fair old while, or so it seems, and I was really looking to take advantage of this. Despite a frost in the air that was making my hands glow purpley-blue in the darkness or so it felt.

I took a tiny tot of rum with me for warming purposes - those heating vapours, you know - and got my binoculars out, starting out with M44 the Beehive, already low down by midnight in March, but barely seen all year with all the bad weather. It wasn't the best view, but there, I'd seen it. I also took time to observe the beautiful constellation of Coma Berenices, a glittering waterfall of faint stars filling the field of view in my 10x50s. I can't spot any of the galaxies, but I really don't care.

I then turned my attention to my main targets; the great globular clusters of spring. There's more on them here:

http://www.astronomynow.com/news/n1305/14globulars/#.UzC4mMxIWOg

I've never seen M10 or 12, and Ophiuchus is not really a March constellation at this time in my garden, so I headed further North and picked out all my targets very quickly. It is interesting that to me, Messier 5 is almost equal with Messier 13, while the more diffuse (to my eyes) Messier 3 is rated as superior. I like finding Messier 5, as to navigate to it, you start at the bright orange and fascintatingly named star Unakalhaut, Alpha Serpentis.

Good name for a star that, almost as good as Zubenelgenubi in Libra.

The fourth on the list is the other, overshadowed globular in Hercules, Messier 92. I've found it easily before, but last night, the reduced observing schedule of the winter had put my eyes out of practice so badly, they were squinting shut! My poor eyes!

So, it was with disappointment in my heart that I headed for bed without craning my neck (and probably straining it again) to look for the Ursa Major galaxies.