saac

Most likely exhaust from smoky aero engine, likely military. Lights from second aircraft appearing from either above or below plume would be visible. Shame you don't have a photograph may have narrowed it down a bit.  Be worth a look on Flight Radar for activity. 

Jim 

13 minutes ago, Ratlet said:

I've been watching some of the old Sky at Night and Patrick seemed to be a cloud magnet for a lot of major events in the Northern Hemisphere.

There were rumors that the Met Office were considering adding Patrik's back garden to the shipping forecast list:

Rockall, Malin, Hebrides. Southwest gale 8 to storm 10, veering west, severe gale 9 to violent storm. .

Selsey , Clouded Out 

Jim 

1 hour ago, ollypenrice said:

I knew it!  I had a glass of Hospice de Beaune the other day and saw the waiter half drop the bottle on his way to our table.  I couldn't put my finger on what was wrong with the bouquet but now I realize that it was a nasty dose of viscous shear! (It had separated the berry notes from the truffle.)

Olly

Had you enjoyed one too many and entered the quantum realm Olly?

Jim 

Does anybody know what the problem is with new RASA 8  units being released by the company?  I committed funds early on in the year  but ended up withdrawing due to difficulties getting hold of one. FLO are still advising "contact us".  In the end I updated my ED 80 with an Esprit 120 and I'm still itching to put it through its paces.  I guess the RAS8 will just need to wait a while longer. 

Jim 

38 minutes ago, vlaiv said:

In case anyone cares, I have a new favorite interpretation of QM (and I wonder how I did not come across that earlier):

https://en.wikipedia.org/wiki/Transactional_interpretation

 

At any point were you in superposition of favour or was that indeterminate ?

Jim 

1 hour ago, Xilman said:

You don't operate one without special relativity. Things get heavier as they move faster, so they are harder to bend round corners with magnets, the strength of which have to be altered accordingly as the particles are accelerated. The particles travel at essentially the speed of light when they are at high enough energy so to know where they are, the timing of the accelerating pulses of energy requires SR once again.

These are only two examples. Designing and operating the detectors provide more.

True but I was being more general in intention.  For example you build and operate in accordance with Newtonian mechanics because that is the regime in which we function and operate. The electric fields and cryogenic cooling used by our particle accelerator rely on machines constructed and operated under governance of Newtonian mechanics.  Yes, in the final analysis we can reduce every interaction to  a quantum origin but that is not the point I was making. Decoherence removes us from that direct interaction and awareness.  So yes, once we use  quantum theory or SR to calculate the desired speed of our particle and hence energy level of our accelerator - we turn a handle, flick a switch to generate more electricity, greater cooling, higher magnetic flux etc - all produced via Newtonian processes.  But I would argue that the greater part of our operation of the machine is Newtonian by necessity.  I'm not dismissing QM/SR or GR, far from it - I'm just not relegating Newtonian physics.  

Jim 

23 minutes ago, Paul M said:

The late and arguably great, Sir Fred Hoyle, coined the phrase "Big Bang" dismissively^* 

But could "it" have been named any better?

Entries on a postcard... 🤣

 

^* I really liked the Steady State theory as a boy, and at the rate that science was disseminated to the masses by books back then, it was still seriously considered. No scientific evidence on my part, it just upset me less than the idea of a "beginning".

Well the author of the theory called it the Primordial Atom.  Yes Hoyle's term was pejorative, perhaps tinged with a bit of professional jealousy. Lemaitre prevailed  

Unfortunately the term Big Bang stuck even though it was/is wholly misleading and seeds so many misconceptions. 

Jim 

12 minutes ago, billhinge said:

isn't that what I just said?  = "Let go, in free fall the pointer indicates 0 N." I didn't specify a specific height

Yea, but I had previously posted . 

"Mass hanging on a spring balance is easier, use the mobile phone for super slow mo vid.  Makes for a nice theatrical demonstration. "

Maybe cross posted  

Jim

2 minutes ago, billhinge said:

yes provided you drop it from a height and measure the spring extension via video  as it falls, doesn't work if its hanging

Nope, you hang the mass on the hook, hold it and it registers the weight. Let go, in free fall the pointer indicates 0 N.  You only need to drop it from few m as the slow mo vid of an iphone (120 fps) picks it all up quite nicely.  The iphone is great for these type of demos. 

Jim 

18 minutes ago, billhinge said:

or you could just use an accelerometer or your mobile phone 😉 

Mass hanging on a spring balance is easier, use the mobile phone for super slow mo vid.  Makes for a nice theatrical demonstration. 

Jim

50 minutes ago, Mr Spock said:

I have a BSc 

(bronze swimming certificate)

 

Too my undying shame I don't have one of those.  I can do a couple of lengths and that is it  

Jim 

34 minutes ago, billhinge said:

Is there a Newtonian gravitational force on the bottle & water or is it weightless in free fall ? 

 

 

 

 

 

Yes there is, Newtonian at least. The water is a viscous liquid, a Newtonian liquid indeed. As the bottle falls (follows a straight path (geodesic) through the curvature of spacetime) the currents in the water will experience and exert viscous shear forces. Impart a spin on the bottle before you let go and these shear forces will present a delightful vortex in the water. Now how about we replace the water with supercooled liquid Helium! 
Jim 

2 minutes ago, andrew s said:

Sadly, I spent years trying to understand how our classical reality emerged from the quantum world. Eventually, I came across environmental dechoherence but even this did not solve the measurement problem. 

I feel it's more subtle than @vlaiv characterisation but I may be wrong.

I am now content with my ignorance in many areas.

Regards Andrew 

I have become all too comfortable with that feeling too Andrew. I'm content, why fight the reality of experience  

Jim 

2 minutes ago, Xilman said:

We have been manipulating individual atoms for rather a long time.  A famous example is IBM spelling their company's name dates from 1989.

See https://en.wikipedia.org/wiki/IBM_(atoms) for more detail.

I remember that one, it was a precursor to Atom Boy. I was wondering if the manipulation had gone beyond that with more meaningful intent - beyond a demonstration of capability

Jim 

2 minutes ago, Xilman said:

Lasers, superconductors are good examples. Bose-Einstein statistics are profoundly non-Newtonian.

Drug design is another one. QM calculations of molecules. their structure, their energy levels and their binding to biologically important molecules started about 1985. These days all serious pharmaceutical companies employ quantum chemistry specialists. Relativistic QM is becoming ever more important in that field.

Disclaimer: I almost joined a quantum chemistry research group back in the mid-80's.

 

2 minutes ago, vlaiv said:

Last that I've head about in that field is using electron spin to record the data. It was hot research area some time ago, it has a catchy name as well - let me see if I can find it.

https://en.wikipedia.org/wiki/Spintronics

yep, spintronics it is

 

16 minutes ago, andrew s said:

@saac the hot topic area would be quantum computing. Also solid state chip design is hitting the limits set by QM. Regards Andrew 

Thanks for these.  It's really good to be able to point to current uses/direction of research when talking about this area with pupils, it gives it all relevance. 

Jim 

4 minutes ago, andrew s said:

If you want to frighten a quantum physicist ask them about the measurement problem.  🤫😉😊

Regards Andrew 

I've not came across that , ok I'm having a chat with Chat GPT later on  

Jim  

4 minutes ago, vlaiv said:

Computing heavily depends on QM effects now.

Storage for example - look at video titled Boy and his atom to get the idea of how "deep down" electronic device companies go in search for more computing power and storage.

No way to develop new microprocessor process without QM for example - https://en.wikipedia.org/wiki/3_nm_process

 

I love the "Boy And And His Atom" video . I remember my physics teacher saying "we will never see the atom". Ok so we are technically still not seeing it rather visualizing it but that video is mesmerising - it raises so many questions when you realise what you are watching. It's about 10 years old now I think;  I wonder how further they have progressed.  Are we manipulating individual atoms yet ?

Jim  

3 minutes ago, Xilman said:

Err...

CERN, and absolutely every particle accelerator working at more than 100keV or so, absolutely requires non-Newtonian mechanics. The rest mass of an electron is only 511 keV.

I guess you have heard of GPS. It absolutely requires GR to be useful.

Sending anything to another planet also require GR to get there with any degree of precision.

Relativisitic QM is essential to understand almost anything at a small scale, including electron spin and antimatter. At large scales, why don't we fall to the centre of the Earth under gravity? Answer: Fermi-Dirac statistics.

QM itself is profoundly non-Newtonia. Try explaining lasers and superconductivity  in a Netwonian universe.

I know you are trying to be funny, but still ...

 

 

Yes they do but you don't build and operate a particle collider without Newtonian mechanics  - stress, strain, acceleration, momentum, compression, expansion, cooling, fabrication of steel , concrete, generation of electricity etc.  That is the point I was making - we live and function in a Newtonian realm and we have discovered the quantum through that. 

Jim 

11 minutes ago, andrew s said:

Absolutely,  the classical world is our domain. It is the bumps and bruises of our experience with Newton's insights that forged our world.

It is the lack of connection to our experience that make relativity and QM strange and mysterious. Open to our prejudice and fantasies. 

Regards Andrew 

That is it Andrew, that is spot on actually. 

I remember Prof Jim Al Khalili in one of his videos pointed to quantum effects which were tangible in biological systems - navigation in robins, photosynthesis, and I think something to do with the sensory perception of fruit flies. Are there any examples of where we have used the rules and theories of quantum mechanics, GR to build or operate in the macro world?  I know GR calculations influence corrections I think to the GPS signal to counter time dilation arising from gravitational effects. But are there any situations where we start the design process off with QM or GR as the tools. Design, specification of particle colliders I guess?  Are there any quantum engineers out there - that sounds a cool job title  

ps - I just thought, I guess semi conductors would fall into the QM design realm  - but they don't count that's not real engineering  

Jim 

The OP has a lot in common with the BIg Bang - came from nowhere, caused inflation, followed by expansion and nobody knows why!

Come on OP,  send out an echo from the big bang  

Jim 

12 minutes ago, Xilman said:

Agreed. Newtonian dynamics and Euclidean geometry is so brain-washed into us from childhood that truly grokking that they are only special cases can be extremely difficult.

Even after you achieve that level of enlightenment, the concept of a (-,+,+,+) metric can cause difficulty. The idea that a vector can be non-zero and yet have zero length is profoundly non-intuitive until you recalibrate your intuition.

I am an immense fan of Misner, Thorne and Wheeler's Gravitation, very widely referred to as MTW. Fully understanding it takes a mathematics level somewhat above A-leverl standard but does not require a physics degree. I have a degree in chemiastry, for instance.

Hang on don't go dissing Newtonian dynamics here     Can you tell I am a fan boi - stands up and mutters to the group  "I'm Jim and I'm an engineer.  It's been 32 days since picked up a slide rule " 

We came a long way on the back of Newtonian mechanics - heavier than air flight, split the atom, left the planet, built CERN and found more quantum stuff, put JWST in space to see the beginning.   Not so bad for "special cases" - we inhabit that realm.  Let's hear it for Newton.   

Jim 

18 minutes ago, andrew s said:

In the end I am left with what Einstein's I said "time is what a clock measures "

Regards Andrew 

also what we will never have enough of!

Jim

25 minutes ago, teoria_del_big_bang said:

Well considering it is the one and only post from the OP it has certainly stirred everybody up 🤣

Steve

It's still cloudy here, we can be grateful to the OP for something to occupy the time. 

Jim

Our principal theories do seem to attract tall poppy syndrome style critiques.  I think that comes from a fundamental misunderstanding and a lot of misconceptions popularised by pop science. I've never applied GR in anger (would not know how), but I have applied other theories. I've used Euler's theory on stress loading of beams, Prandtl's theory describing laminar flow, both in practical engineering settings. Before you apply a theory you first set about to understand the limits of the theory, the regimes in which the theory provides a reliable description. You also need to define what you mean by reliable - what level of reliability or confidence are you looking for.  There's the rub, chase 100% confidence then you are chasing a will-o-the-wisp where you will waste money, time and effort. You will also, and without good reason, discard a perfectly adequate description of nature. So GR , does it have limitations, it goes without saying of course it does. Does it work, is it any good ? Without question of course it is, as has been said already, it has made perfectly sound and verifiable predictions - not only does this thing work it works exceedingly well.  If you are trying to apply it outside of its limitation then you don't know what you are doing and your criticism is unfounded.  I don't think that is what is happening with modern cosmology with respect to considerations of dark energy/dark matter as examples.  Our well tested theories, applied within known limits, are pointing to something we need to better define; this is not blind adherence, this is science at its best, this is how we advance. 

Jim 

5 minutes ago, wesdon1 said:

@michael8554 Hi again Mike. Yes the dark matter and dark energy theories are basically scientists admitting " we literally have no clue what it all is!?" Tbh Mike, I have have always wondered about whether the reason scientists can't explain what dark matter and energy is, is because the fundamental Einstein theory of general relativity, which beautifully explains a lot, very precisely, is actually totally wrong, and if scientists worked out a new "Einsteinian type theory of general relativity" that accounted for all the so called unknown mass and energy, then there would be no need for dark matter and energy theories? I feel scientists have stay blindly loyal to Einstein's theories, instead of ripping up the book and starting from scratch, so to speak. 

As you rightly say Mike, given time, all will be revealed.

From gravitational lensing to time dilation if I recall it has held up fairly well to testing. What areas about GR do you think need re thinking?

Jim