What is the Universe expanding into..

[Galu]

I meant the density of space rather than matter. Space density is not material density but the reduction in plank length so that propogation of EM is slowed and material length is contracted.

Let's get the name right - it's Planck, not plank!

You mentioned the Planck length matrix earlier, and I've found out that the Planck length, time and mass follow the Lorentz contraction and are specified by a group of diagonal (or is it non-diagonal?) matrices with complex units - something to do with the quantum structure of spacetime it seems.

All new to me, so you'll have to educate me. Got any good references I can study?

 

[Galu]

Nothing passes the event horizon as time is slowed down to a stop.

From your perspective, as you fall into a black hole time would pass at the same rate as it always has been, so that you would fall towards the black hole, pass the event horizon, and hit the singularity in almost no time at all.

Only to an outside observer would time appear to stop at the event horizon and they would never see you pass it.

 

[Disco-Pete]

Nothing passes the event horizon as time is slowed down to a stop.

Do you mean on the way in or on the way out? Either way you mean it, what happens to light that enters, never to escape?

 

[Galu]

...what happens to light that enters, never to escape?

I don't think that pde2000 can answer that question any better than I can!

A photon of light will be rapidly pulled towards the singularity. What happens to the photon in the extreme conditions of the singularity, however, is one of physics’ big unanswered questions.

 

[pde2000]

I'm only pulling thoughts out of my old brain and it's getting late. There was a series of articles many years ago with the title 'quantum foam' i think. The other nice thing about the Planck (oops sorry) length matrix is that probability distribution of an electron makes abundant sense within it as an electron simultaneously exist as a cloud of virtual particles with a sum of one real. This is how it is possible for a single electron to diffract (passing simultaneously through two slits). As an electron is accelerated it spends less time along its path through the matrix and so the probability distribution is narrower (takes time to build up a cloud), hence the shroedinger wave function. I cant quite get my head around how big objects do the same thing, like molecules, but apparently experiments have demonstrated wave function by diffraction.

 

[Galu]

I saw reference to "quantum foam" and "Planck length" while I was searching for information earlier. Quantum foam - Wikipedia

There was a lot of discussion earlier in the thread regarding the interference of electrons (and even molecules) in terms of the wave function and the probability of being detected.

 

[Galu]

The other nice thing about the Planck length matrix is that probability distribution of an electron makes abundant sense within it as an electron simultaneously exist as a cloud of virtual particles...

I've found numerous references (which are all mathematically opaque to me!) to the density matrix - which is used an alternative representation of the state of a quantum system instead of the wavefunction.

4.1 The density-matrix

It appears to be a tool used when dealing with a quantum system comprising of mixed states rather than a pure state - which is characterised by a simple waveform.

So, is an electron a mixed state, or would that be a molecule?

That's all, my head's about to explode!

To resume normal service, here is an update on the Arecibo Observatory a year on from its collapse: Arecibo Observatory: A year after telescope's collapse, an icon gets continuing cleanup and a new documentary | Space

There's a movie in the making - The Biggest Dream: Arecibo Observatory Movie - The Biggest Dream TRAILER - YouTube

 

[Bonsai]

Since we have been talking about time, I thought this might be an interesting diversion. Conrad Heyer was born in 1749, fought in the American revolution and lived to 106, dying in 1856.

He is possibly the earliest born person to have ever been photographed.

Think about that - a guy born ~35 yrs before the American revolution, before the French revolution and there's a photo of him (as an old man of course).

Conrad Heyer - Wikipedia

 

[Galu]

Not bad for a time when the average life expectancy was around 40 years!

Furthermore, Conrad apparently reached the biological maximum for human life expectancy!

Life expectancy - Wikipedia

"A theoretical study shows that the maximum life expectancy at birth is limited by the human life characteristic value δ, which is around 104 years."

 

[system7]

Great disappointment today at Wetherspoons Pub as I got my 99p coffee, after a significant £2 15/8 investment in the People's Racehorse Pyledriver in the Hong Kong Vase at the friendly Betfred bookies. Once we figured out the time zones. We think the Race is on Sunday at an unearthly 6 AM. But not sure. But Betfred think they can cope with a near £4 loss.

Wetherspoons have removed table numbers!

Now you scan the phone app or something? Whatever is going on? Will Taxis no longer have interesting numbers like 1729?

Ah well, I spotted an interesting bright Star in the Sky. Got the useless Canon camera and tripod out.

After last years' Triumph on interesting Double Jupiter/Saturn Astronomical Conjunctions,

I can now modestly claim to have DONE IT AGAIN! But this time a TRIPLE. There is a slim chance I might get Mercury and the new Moon in too this week, weather permitting.

 

[Galu]

But this time a TRIPLE.

I'm not so sure it's a TRIPLE!

I think you've captured the bright Jupiter on the upper left and the faint Saturn on the lower right.

Venus will presently be much lower in the sky and to the right of Saturn.

I base this on the attachment which shows the situation as it will be on December 7th 2021.

EDIT: I opened your attachment which I now see is different from your main picture. That must be the bright Venus on the lower right.

So a TRIPLE, but in the attached photo - not the main one.

 

[system7]

I must Thank you, Galu. I missed a trick here...

How could I miss Fomelhaut? One of my favourite Stars at 22 LY. But the Planets remain.

We must watch the skies.

 

[Galu]

We must watch the skies.

Budget refracting telescopes now come with integrated smartphone adaptors - so you can mount your phone to the eyepiece and take images.

It's not too late to ask Santa!

 

[system7]

That camera is a nightmare to operate in the dark! I think I did alright last night. I had this notion that Mercury was about too, but that will be later in the month after Christmas. And very low indeed, so I am not getting my hopes up. I did see Mercury in Spring a few years back. It's quite bright.

We might look out for Comet Leonard over the next few mornings, about an hour and a half before sunrise. Sunrise is about 7.45 AM in the UK currently.

Comet Leonard on course for a good showing – Astronomy Now

Sunday's weather looks best for the South-West, Wales and Scotland:

Ventusky - Wind, Rain and Temperature Maps

It's going to be near Bright Orange Arcturus which is on an arc round from the tail of the Plough. Binoculars job I think, but who knows? Skies can be good before sunrise. Tail points away from the Sun, doesn't it. I did manage to see Comet Neowise last year. Rest of you missed it, didn't you! It wasn't much to look at in Portsmouth, but we get a good view of sunrise at Southsea beach. Over the sea.

 

[Bonsai]

For @steve

https://twitter.com/spacehub_sl/status/1466394858826829832?s=21

 

[Galu]

Sunrise is about 7.45 AM in the UK currently.

Not much chance of me seeing Comet Leonard then - Galurise is an hour and a half later!

 

[system7]

I spared you this, but apparently Elon Musk is in a complete PANIC about his Dreams of US Conquering the UNIVERSE. Claims to be facing Bankruptcy.

Elon Musk: SpaceX could 'face genuine risk of bankruptcy' from Starship

I was struck by this image of Sidney Coleman recently. The People's Physicist. Are we, by any chance related?

Anywhoo, old system7 has already borrowed a pair of 10x50 Binoculars. Ready for Sunday. All will be revealed. Can't wait!

Expect Spectacular Results. Taking that rotten Canon Coolpix A100 Camera too. And my old HP camera which I far more trust.

 

[Galu]

How could I miss Fomelhaut? One of my favourite Stars at 22 LY.

I looked up Fomalhaut and it is, indeed, an interesting star - as the link below reveals.

EarthSky | Fomalhaut, loneliest star, near Jupiter and Saturn in 2021

Sometimes called the Loneliest Star, bright Fomalhaut is used in navigation because of its conspicuous place in a region of the sky otherwise lacking in bright stars.

Fomalhaut is of special interest to astronomers because it has several rings of dust and gas around it, early indications of planets in the process of formation around this star.

 

[Galu]

Anywhoo, old system7 has already borrowed a pair of 10x50 Binoculars.

I have a pair of 10 x 50 binos, but my World War 2 military binos are far superior for casual planet gazing.

They have the advantage of larger objective lenses (giving superior light gathering ability), fixed focus (so you don't have to fiddle around with the focusing control) and a wide field of view (so you can easily locate the object of interest).

 

[system7]

My neighbour, Paul, came up with the goods tonight! A pair of what looks like 1960's Soviet Union 7x50 binoculars!

Perfect for my purposes. Carl Zeiss optics. He has apparently learned (from Facebook, I suppose...) there is a slim chance Comet Leonard will hit the Earth.

Not a chance, IMO. Miss us by 60 million miles.

Weather forecast seriously downgraded in Portsmouth. Usual grey murk in prospect.

Ventusky - Wind, Rain and Temperature Maps

Looks like the Scots need to get up early for this one. I think I'll stay in bed.