FourPacketsOfPeanuts

I like to binge read and self educate. When coming to a new topic (let's say History of Western Art or Pharmacology) I've never found a single place where I could look up the key texts that a university student would be reading to get into the subject. Usually I search around and find an actual university's reading list or something equally well put together but it's hit and miss.

Had anyone ever come across a single place that holds this kind of info over a wide range of subjects? (Books specifically)

Am looking for a compact paperback encyclopedia but am struggling to find one available in the UK. I used to have the Hutchison compact, but believe that was last printed in the 90s..

You know, "hatch". But it's funnier saying door. Could a ship just dock with it, equalise pressure, and open the hatch? Or is there some sort of security? I tend to think there's no lock because of a macabre situation where the crew are dead and the station is being recovered. But it's amusing to think in space they don't need to keep the doors locked.

I was listening to the New Year's Day concert by the Vienna philharmonic and wondered who one of the composers was so used a popular song recognition app. (I expected it would make some fuzzy match on the piece and give me the name + composer). To my amazement it did give the name and composer but as played by the Vienna philharmonic in 2005 in the same location. The orchestra does not have the same members as 19 years ago, nor was it the same conductor, so it seemed the piece was matched on the acoustics of the Musikverein where they were playing, which I found astonishing.

For the regulars this ought to be easier than your usual broadsheet cryptic, and I believe I've completed it, am just mystified as to how some of the clues are supposed to work..

34a A posh car taking carriers outside department store

_ A _ R _ D _

So for this I had "Harrods". So "department store". The "posh car" is rolls royce giving the RR. But I'm lost as to how the remaining letters on the poster (HAODS) are "carriers". It almost seems like a typo for HANDS, which would make sense, but obviously doesn't give Harrods, or anything else that makes sense

Help? An I missing something or is this a mistake by the setter?

It was very satisfying

I was in town to set up a new banking account but wanted to check the deals on my existing ones first. I would have used my phone for this but I have recently got a new phone and would need to join a public WiFi to reinstall my previous apps (if it was possible to do this over my unlimited 5G connection, the way to do this wasn't apparent). I attempted to join the library's public WiFi but needed to supply my membership number which I had not brought with me. No problem I thought as I happened to have my passport and I could surely show this to the customer service desk to prove who I was. The person there was helpful, but said I would need to also show proof of address in order to release my membership number. They suggested I access one of my banking apps on my phone which would show my home address on a statement. But getting my banking apps working was the very reason I needed to join the WiFi in the first place! I asked why proving my address was relevant to getting my membership number when I had already proven who I was, and they admitted they didn't know. We both mused at how things like this highlighted the futility of life. I returned home having not accomplished any of the things I set out to do.

A family member put on a game show that included Brian Blessed and I commented it 'must be old as he's been dead for a while'?

Nope. 88 and going strong.

Who else has surprised you?

I feel the obvious answer should be "no" but help me think this through. It came from the previous Q on blackholes and am posting here for more visibility.

So considering two blackholes rotating about each other and eventually combining. It's in this situation that we get gravitational waves which we can detect (LIGO experiments). But what happens in the closing moments when the blackholes are within each others event horizon but not yet combined (and so still rotating rapidly about each other). Do the gravitational waves abruptly stop? Or are we privy to this "information" about what's going on inside an event horizon.

Thinking more generally, if the distribution of mass inside an event horizon can affect spacetime outside of the horizon then what happens in the following situation:

imagine a gigantic blackhole, one that allows a long time between passing the horizon and being crushed. You approach the horizon in a giant spacecraft and hover at a safe distance. You release a supermassive probe to descend past the horizon. The probe is supermassive in the way a mountain is supermassive. The intention is to be able to detect it's location via perturbation in the gravity field alone. Similar to how an actual mountain causes a pendulum to hang a miniscule yet measurable distance off the vertical.

Say the probe now descends down past the horizon, at some distance off the normal. Say a quarter mile to the 'left' if you consider the direction of the blackholes gravitational pull.

Let's say you had set the probes computer to perform some experiment, and a simple "yay/nay" indicated by it either staying on its current course down (yay) or it firing it's rockets laterally so that it approaches the direct line been you and the singularity and ends up about a quarter mile 'right' (to indicate nay).

The question is, is the relative position of the mass of this probe detectable by examining the resultant gravitational force exerted on your spaceship? Had it remained just off of centre minutely to the 'left' where it started to indicate the probe communicating 'yay' to you, or has it now deflected minutely to the right indicating 'nay'?

Whether the answer to this is yes or no, I'm confused what would happen in real life?

If the probes relative location is not detectable via gravity once it crosses the horizon, what happens as it approaches? Your very sensitive gravity equipment originally had a slight deviation to the left when both you and probe were outside the horizon. Does it abruptly disappear when it crosses the horizon? If so where does it go? The mass of the probe will eventually join with the mass of the singularity to make the blackhole slightly more massive. But does the gravitational pull of its mass instantly change from the location in the horizon where it crossed (about a quarter mile to the 'left') to now being at the singularity directly below. Anything "instant" doesn't seem right.

Or.. it's relative position within the horizon is detectable based on you examining the very slight deviations of your super sensitive pendulum equipment on board your space craft. And you're able to track it's relative position as it descends, until it's minute contribution to gravity has coalesced with the main blackhole.

But if this is the case then aren't we now getting information from within the horizon? Couldn't you set your probe to do experiments and then pass information back to you by it performing some rudimentary dance of manoeuvres? Which also seems crazy?

So both options seem crazy? Which is it?

(Note, this is a thought experiment. The probe is supermassive using some sort of future tech that's imaginable but far from possible by today's standards. Think a small planet with fusion powered engines or whatever. The point is, in principle, mass is detectable, and mass is moveable. Is this a way to peek inside a blackhole??)