saac

The full res image is stunning. The RASA certainly earns its keep. 

Jim 

Lovely, one of my favourite places. 

Jim 

2 hours ago, Nakedgun said:

~

Fits nicely into the space provided. Do you think it's big enough?

 

 

.

You know what it's like, astro kit has an annoying habit of multiplying when you are not looking  

Jim 

Malc I totally agree and more often or not it catches you by surprise what a pupil remembers about a class from years back. For me, the practical work I remember from physics when I was a kid were the Maltase cross with the teltron tube (diffraction of electron beam) ,  the flame test with the alkali metals and while not necessarily enjoyable at the time the ticker tape contraptions we used for speed and acceleration investigations.  The other one is the pearls of water demo which uses a strobe light to freeze the motion of a water jet accelerating under gravity  - it shows the constant horizontal velocity and downward acceleration component of projectile motion. It's an impressive thing to see. I thought I had a video of a recent demo I did but I can only find a still.  Funny how these things stay with you though. 

Jim 

Not your usual astro kit but I was getting so fed up with my various astro related toys scattered around the house, camera battery chargers or usb cables never at hand when needed. So a trip to ScrewFix and here's the solution, quite happy with it ; slowly filling it up but now at least I will know what room I should be looking in  

Jim 

48 minutes ago, malc-c said:

My kids hated science... (hated most lessens really) because it was boring.  Sat there watching a video demonstrating something rather than doing it themselves.  Reasons, probably cost, health and safety, the fear of being sued should little johnny prick his finger or similar.   

I may well be wrong (happily defer to others more knowledgeable) but I belive in England schools will quite often employ science teachers who have no science qualification and hence these are most likely to be hesitant or incapable of running practical work.  In Scotland we were fortunate that we still retain our General Teaching Council which acts as the independent regulatory and professional body .  We retain graduate status for teachers and science teachers must hold an accredited science or relevant engineering degree.  There have been some legal challenges to the graduate status but so far I think we have prevailed. 

Jim 

38 minutes ago, malc-c said:

Not read through the whole thread, but I too came from an era where the children in class could do their own experiments in groups or as individuals.  From simply things like producing hydrogen in chemistry (every kid gets a thrill out of hearing that pop and seeing the flash in the test tube), through to dissecting a rat  in biology.  We also had demonstrations for things that were too risky.  I remember our chemistry teacher demonstrating how a powder such as flour can become explosive using a large tin, length of rubber hose and a candle.  The resulting explosion left the lid embedded in the false ceiling ! - 

Several years ago there was a program where three scientist were challenged with getting 12 of the worst pupils that resided in one of the worst schools in London to pass their GCSE science a year early.  They had one girl who no matter what they did simply played up all the time.  She was removed half way through the allotted time as she was a bad influence on the rest.  The remaining 11 all passed their exams.  How, well the scientist taught them through practical examples, some of which the kids done.  They made science fun and the kids then wanted to learn more.  Granted some of the things were not what every school could do and were done for the program, but these lessons also changed the kids.  They became more respectful, their attitudes to teachers changed and they realized their own potential.

My kids hated science... (hated most lessens really) because it was boring.  Sat there watching a video demonstrating something rather than doing it themselves.  Reasons, probably cost, health and safety, the fear of being sued should little johnny prick his finger or similar.   

Re making and testing hydrogen they currently get to do that in S1 together with testing for oxygen and carbon dioxide and the giggles are very much present. Dissecting I do with S1 and S2 - sheep lungs and hearts but to be honest I prefer leaving it to my Biology colleagues (I hate mess in my lab).  The paint tin with flour is very much still in play and I'll use that throughout the year groups at various stages as it is useful for a variety of concepts (gas laws, energy conservation). Just before splitting for the summer holidays a group of S6 pupils came to see me for an idea for an experiment to use in an RE class where they had to produce a production around a natural/human disaster. They had built a model of Chernobyl and wanted something to emulate the explosion so the paint tin with caster sugar this time was perfect - we had fun practicing that one seeing how high would make the flame plume reach. My personal favourite is the collapsing 50 gallon oil drum set over a burning barbeque  then condensing the steam raised inside - the kids get a hell of a surprise when it suddenly collapses under atmos pressure. Science without practical in school is utterly shameful and simply should not happen - there is absolutely no joy in having somebody stand up and lecture you at that age on some esoteric topic - it has be demonstrated and the pupils need to be active in their engagement. I feel sorry for your daughter sounds like she was short changed. Then again I'm also open to the reality that for many pupils science is utterly dull and without joy or interest for them - for me that was accounting for business class - how I hated that. 

Now all of that said, and while every lesson should have some form of practical, science teaching and science teachers should not be reduced to entertainers for the sake of it or purveyors of pop science (I hate that bloody cat). There has to be a point to the practicals, they have to result in meaningful and relevant learning.  For too many pupils they want the former without the academic rigor that has to follow. 

Jim 

4 hours ago, Macavity said:

"Dreams of New Physics Fade..." - How (un)surprisingly Predictable? 🤣

Cue: "Team Anti-Mainstream (Science)"? With zero actual knowledge
of Science! Yet, I still feel *Slightly Sad* for Experimental Physicists. 😑

As remarked above: "Memories, what memories"... 🙂
 

My spin is all over the place with this one  

Jim 

I must admit I do know a number of science teachers who are nervous about doing practical work in the class. Now this could be for a number of reasons but I couldn't survive without the practical element, take that away and you may as well be in a maths class. Of course we are not doing real science, we are just demonstrating what has been done by other more gifted souls but you still got to have fun   

Jim 

21 hours ago, Xilman said:

I said "qualitive".

The explanation for 10 year olds: many particles, including the electrons in the atoms which make up you, the Earth and everything are called "fermions". Experiments have shown convincingly that two fermions can't be in the same place at the same time (a simplification I gloss over because I do not want to explain spin at this point) so they have to keep a minimum distance apart. Gravity tries to squash them together, this is counteracted by the fermions not wanting to be squidged too close together.

Some other particles, such as photons which are particles of light, are called bosons.  Bosons are different from fermions because they can all be squidged together in some situations. This is the main reason why a laser pointer has a very narrow beam, is a single colour, and looks speckly.  (Again I over simplify).

When the explanation is done face-to-face I draw diagrams and go into slightly more detail. I do, of course, answer the inevitable questions as best I can.

Ok you now have 43 minutes of the remaining 45 minute period left - smoke on go !

Jim

43 minutes ago, VNA said:

Hello, the more one knows, the richer one's life will be.

Education is a life long endeavor.  Besides, curiosity is so much fun!

I cannot honestly think of any alternative way to live a life. 

Jim 

13 minutes ago, Xilman said:

Try asking a secondary school teacher why everything, the Earth included, doesn't fall to the centre of the Earth because of gravity.

Rather hard to explain without a qualitative knowledge of Fermi-Dirac statistics. With that knowledge, easily explicable to kids 10 years old or younger (again, I have practical experience), the answer is obvious.

I think explaining to children age 10 that the consequences of the half integer spin property of fermions prevents Earth's collapse against its gravitational field would be somewhat questionable and the motives rather unclear!

Jim 

52 minutes ago, Macavity said:

Don't worry! I used to find "The Big Bang Theory" (TV prog) slightly funny...
But mostly an irritating stereotype - I now realise it was a Documentary! 😅
The idea they might have benefitted from *practical* experience / reality?

The best line from The Big Bang Theory - from Sheldon "Engineering, the slower younger brother of Physics".  

Jim

39 minutes ago, Xilman said:

To coin a phrase: that is a little local difficulty,

No ${DEITY}-given reason to set an upper limit of class sizes.

It is a long standing practice in Scotland to limit the class size of all practical subjects to 20. Allowing amongst other things for adequate supervision while conducting practical tasks.  It is not seen as any sort of difficulty really, local or otherwise.  Not sure what the situation is elsewhere in the UK but I would be surprised to see that similar arrangements were not in place.  So sure, no God given reason just local Authorities, Unions , and the  Association of Science Education, Royal College of Science and COSLA all working together to form a working agreement.  

Jim 

1 minute ago, Xilman said:

A damning criticism of the current education system.

Really. 

Jim

31 minutes ago, Xilman said:

Define the term "particle" as being an excitation in the relevant field and everything goes away.  Phonons, magnetons, electrons, quarks, gluons, Higgs bosons, etc are all equally particles in this picture.

IMAO, the real problem is with people thinking as particles as being very small billiard balls. Physics has come a very long way beyond that picture, starting about 100 years ago.

We no longer think about combustion as involving phlogiston exchange or chemistry in terms of 4 elements (air, earth, fire and water) so why don't we update our ideas about the nature of particles?

S3 school pupil - "what's an excitation", "what's a field" "what's and excitation of a field" "how do you know". "Can we do an experiment"  , " minutes later "what is a excitation". 

Ok it's like this, atoms comprise the proton and neutron in a central nucleus with electrons orbiting around them just like the planets orbit the sun.  It's actually a little more complicated than this but this simple model will help us get to where we want to get.  School pupil - "why didn't you say that first".

There is a time for everything and a season for every activity  

Jim 

1 hour ago, andrew s said:

Unfortunately,  it serves the pop science market to keep it mysterious with talk of waves-particles and spooky action at a distance.

I am not sure why educators still stick to the historical approach (via wave particle duality) maybe @saac  can shine some light on that.

Regards Andrew 

 

 

I'm not entirely sure Andrew but I suspect that it is rooted in course design and the sequencing of ideas or concepts. For example, at Higher level we will treat the electron as a particle and apply classical methods to work through calculations of acceleration in electric fields - no mention of the true nature of the electron.  later the first hint that there is something more comes when we introduce the Bohr model but again this is still a classical approach - to widen the discussion we may ask questions of the pupils to consider why the electron is restricted to discrete orbits (we may mention de Broglie wavelength) and tease with where does the electron go  when transiting levels. None of this is within the course spec though and non examinable. Only when we cover the photoelectric effect and interference do we introduce the dual nature but it is very much reduced to a statement and the ability to cite evidence for both natures.  So I think to be honest it may be a time constraint, we simply don't have enough time in the short one year course to develop the ideas or more likely that the classical approach simply opens up a root to traditional calculation problems for exam setting.  At Advance Hire (A level) in S6 (final year) there is a more obvious attempt to introduce properly Quantum physics but again it is a qualitative approach.   The extracts below show the course specification for Advance Hire on Quanta from which you will get a feel for how little we actually cover.   Could we do it earlier, could we abandon the solar system model that we all grew up with and just go for it - tbh I think Chemistry has the lead on Physics in that respect as they introduce the electron clouds (s,p,d,f) at quite and early stage. 

Jim 

5 minutes ago, Ratlet said:

On the theoretical side I've always taken it that science doesn't describe how it is, rather how it behaves.

At the end of the day, a theory is put forward to describe how something behaves.  If it doesn't pan out through experimental evidence then it's kind of just maths I guess?  It doesn't need to have a practical application, but predictions need to be verifiable.

It's often overlooked that whilst most of science is held as being truths, the reality is that they are 'best fits'.  If something more accurate comes along it will (when the old guard dies most likely) replace the existing dogma.  Hell, scientists will sometimes change the model depending on what they are doing.

  Sometimes Newtonian gravity calculations are good enough so why use relativity?

I like the thought that I can look back during my short 40 years on this earth and can rattle off the number of times an existing theory has been overturned or some other major changes has become apparent.  The acceleration of the expansion of the universe, dinosaurs being the ancestors of birds, not reptiles, etc.

When the old has been over written it's not a case of a new truth has been established, rather a better fit has been fitted.

I think a more accurate interpretation is science describes how we think (understand) how nature behaves. That understanding is not perfect (complete) and not fixed and will always evolve. 

Jim 

57 minutes ago, John said:

Meanwhile, 52 years ago:

The Apollo 15 Hammer-Feather Drop - Moon: NASA Science

Yep we use that as well but to be honest I favour Cox's interpretation as it  brings it bang up to date with HD slow mo video and of course the larger drop.  besides the kids know we didn't actually go to the moon  

Jim

6 minutes ago, iantaylor2uk said:

I'm not sure they do think in a different way. If you apply Newton's laws to atoms, you end up with nonsense. If you assume a classical picture of an electron moving in a circle around a nucleus, then electromagnetic theory would say that the electron would lose energy and so spiral in towards the nucleus. It doesn't do this, as atoms are observed to be stable, so you need different physics to describe what goes on in an atom. There is also the fact that objects, such as the electron and photon, sometimes behave as waves and sometimes behave as particles, although they are neither of these, and what they are is not at present understood all that well. These ideas led on to the concept that atoms are stable when the number of wavelengths of an electron around a nucleus was a whole number (this is Bohr's simple model of an atom). These fairly simple ideas then led on to the more complex mathematics of quantum mechanics. For example, if objects behave as waves, then there must be a corresponding "wave equation" which was written down by Schrodinger, although the novel aspect was that his wave equation involved complex numbers, whereas conventional wave equations (for modelling sound waves or waves in the ocean) did not contain complex numbers.  

The complex numbers in Schrodinger's equation reflect the complex vibration phase of the wave but, neither the Bhor model or Schrodinger's wave equation describe the separation of the two disciplines (theoretical and practical)   My point being that those with a practical disposition are not necessarily best equipped in exercising their minds to model the world as seen by the theorist. As alien as as a practical task would be to a theorist.  I don't find it surprising that many of the great theoretical physicist such as Oppenheimer were "useless" in a practical setting.; it is a different skill set altogether. 

Jim 

19 minutes ago, iantaylor2uk said:

If you do experiments to try to "prove" Newton's laws of motion you will find it quite difficult. For example, bodies do not experimentally appear to travel at constant speed but instead appear to slow down - this is due to friction. At some point you have to make the jump from complex experimental data to simplify things in a model. Newton realized that in the absence of friction (or other forces) bodies would travel in straight lines at constant speed indefinitely.

Just picking up on your post again Ian as it reminded me of a wonderful video clip from one of Brian Cox's programmes. I show it in class and apart from commenting on the free fall acceleration I make a point of commenting on the joyous expressions shown on the faces of not just Cox but the senior NASA Engineer and his crew. These are professionals in their various fields with many years demonstrable  experience and success. They know intuitively as they know how to breathe that all objects will accelerate at the same rate in a gravitational field irrespective of mass.  But when they physically see both the bowling ball and the feathers behave as Newton predicted they are overcome with emotion.  I love it every time I watch it - it sums up for me what science is really about, that child like  wonder of the world. 

Jim 

18 minutes ago, iantaylor2uk said:

If you do experiments to try to "prove" Newton's laws of motion you will find it quite difficult. For example, bodies do not experimentally appear to travel at constant speed but instead appear to slow down - this is due to friction. At some point you have to make the jump from complex experimental data to simplify things in a model. Newton realized that in the absence of friction (or other forces) bodies would travel in straight lines at constant speed indefinitely.

Agreed but that is where the art/skill of the practical investigator is needed is it not? The skill lies not just in the design and operation of the experimental setup  but also in the processing, presentation and interpretation of data. A simple experiment to show the linear relationship between an unbalanced force, mass and acceleration will produce a scatter graph and a linear fit with good level of confidence, good enough to state F = ma.   At the more complex level say LHC, I would have thought that the practical physicists and engineers are an essential part of the discussions when the theorists consider the data. These are the guys who will know their instrument response, resolutions, sources of error that could pollute or obscure the data.  Or am I being naive, I must admit I have no experience of  this environment. 

As an aside having just watched the Oppenheimer movie the other day - it struck me that people like Oppenheimer and his pals (Einstein, Schrodinger, Heisenberg  etc) they must truly see the world differently, their focus, the catch point that intrigues them. I think when your brain and emotions are tuned to that type of interaction then it is perhaps at the expense of the practical skills that others may excel at. It must be very rare to have both skills present in an individual. 

Jim

(eliminating influences  which remove the setup from the ideal

I don't get the antagonism, theoretical vice practical, they are pretty much dead in the water without each other are they not?  Is it a power play thing about who gets the top jobs in programmes or academia?

Jim 

It can be both or singular surely.  In education (secondary school) it is the practical element of science that places the cap on class size. A non practical subject such as Maths, English Languages etc can have a maximum of 30 pupils while a science class (single subject or composite) is capped at 20.  As an engineer I've always seen Physics having a strong practical association.  I think in the profession world of science though the association is less important. There are aspects of science in any displinces where the theoretical task provides a sufficient workload.  I think the spilt or theoretical and practical works quite well allowing people to play to their strengths. 

Jim  

On 30/07/2023 at 20:23, Marvin Jenkins said:

Different people see pain and pleasure in different ways. I for one get great pleasure from observing DSOs through my eyeball.

some people like to do a similar thing with a computer and camera. I personally love the EP, like the camera, hate the computer.

Marv

That's the key, do what gives you satisfaction.  I love the opportunity that AP and digital sensors give for doing some practical astronomy. Once my imaging plan is up and running I'll move on to visual and go for a wander around the sky. 

Jim