Go Ballistic! winners at Big Bang North East

/0 Comments/in , /by

Phew! We’re slowly recovering from a couple of crazy days at the Big Bang North East. We spun patterns and collected hopes and dreams for future tech with the Technology Wishing Well; explored the universe with our space-themed show; and launched ping pong balls with hundreds of catapults in our Go Ballistic! workshop.

We had about 18 booked groups through the workshop, and managed to squeeze in a few more schools too. We’re sorry if we had to turn you away, we were crazily popular. Apart from anything else, there are no more decent plastic spoons to be had anywhere in central Newcastle. We bought (and used) them all!

So here’s the moment you’ve all been waiting for, the grand reveal of the final standings on the leaderboard:

Click the image to see it larger, but here’s the leading portion of results of 4m and above:

  • Longest distance achieved: Royal Institution, 5.80m. However, see below!
  • Gosforth East Middle School (yr. 7): 5.00m (secondary winner!)
  • Academy 360 (yr. 8): 4.80m
  • Monkwearmouth (yr. 7), Washington (yr. 8): both 4.65m
  • Monkseaton Middle School (yr. 6), Bede Academy (6JRA): 4.40m (joint primary winners!)
  • Farringdon: 4.40m
  • Gosforth East Middle School (yr. 6): 4.30m
  • Heworth Grange: 4.10m
  • Southlands A: 4.00m
Emma King RI catapult

Dr. Emma J King of the Royal Institution with her redesigned catapult, which achieved a throw of 5.80m from a single elastic band.

Congratulations to the entrant from the Royal Institution in London, Emma J King, pictured left. Emma’s throw of 5.80m was the longest we saw on the day. The eagle-eyed amongst you will notice that her catapult design was dramatically different to anyone else’s, but you’ll also notice that Emma isn’t quite a school student. In fact she has a PhD in physics, and neither we nor she thought it was entirely fair to count her remarkable score against everyone else’s. Hence: she’s disqualified.

Our Secondary winners therefore remain Gosforth East Middle School (yr. 7), who landed a remarkable 5.00m to huge jubilation around the launching table. Academy 360 (yr. 8) were worthy runners-up, spending over an hour trying all manner of different approaches to eek out the next twenty centimetres they needed. Valiant determination!

Sterling performances also from Monkwearmouth yr. 7s and Washington yr. 8s, both groups with impressive bests of 4.65m.

Snapping at their heels were our joint Primary winners Monkseaton Middle School (yr. 6) and Bede Academy (class 6JRA), both at 4.40m.

We’ll be sending both primary and secondary winners suitable trophies, just as soon as they’ve emerged from our 3D printers.

Well done all, and our thanks for your enthusiasm and ideas. We had a blast running the workshop, and we hope you enjoyed it as much as we did. One of my favourite moments was when a chap from the Army was standing nearby for a good half hour, watching a couple of groups develop, test, and iterate. I wandered over and invited him to make his own catapult. “Not a chance,” he said, “I wouldn’t get close to what this lot are doing, and I’d never live that down: I’m Royal Artillery.”

Wise man.

Study with us! PhD Studentship available

/0 Comments/in /by

Think Physics’ host institution Northumbria University has a PhD studentship available. Here’s the title:

Impact of Academic Research through Northumbria’s STEM outreach activities on the uptake of STEM disciplines by young people

I know, right? Snappy.

Importantly: there’s a full stipend available for this PhD, for three years at RCUK rates and fees.

There’s a full description of the project on offer at Find a PhD.com, and you can apply through that site too. At the time of writing this post the application deadline appears to be rather soon; that will be extended to later in July, so you’ve time to think it through.

Brain exercise for half term: P vs. NP

/0 Comments/in /by

If you’ve reached the stage of half-term where binge-watching iZombie, staring out of the window at the miserable weather, or playing yet another round of Overwatch just aren’t doing it for you, try this minor intellectual stimulation.

P vs. NP is one of the foundational problems in computer science, with a $1m bounty attached to the first correct solution. This film does a great job of setting out the problem in an understandable way, and exploring its implications.

P vs. NP is about whether every problem with a quickly verifiable solution can itself be solved quickly, which sounds like the sort of abstraction beloved only by mathematicians. But P vs. NP is related to a whole host of problems that would have very real implications if they turned out to be easier than we currently think. Encryption, for example. Or computational protein folding. And the film argues that this world of complexity problems describes not just problems in computing and mathematics, but complex problems throughout human experience.

Watch the film. Maybe get sucked into the rabbit hole of Wikipedia. But make sure you have something not too taxing to soothe your brain afterwards. Another round of Overwatch, perhaps?

How long would it take to fall through the Earth?

/0 Comments/in /by

This is a classic calculation, and one that’s surprisingly tricky: suppose you could bore a hole all the way through the Earth. If you jumped in, how long would it take you to fall through and come out of the other side?

If you’re taking A-level physics you know pretty much everything you need to do the calculation for yourself, but there are a few fiddly little problems you need to deal with along the way. Most importantly: if you’re falling through the Earth, only some of it is below your feet. The rest of it is above your head, and the force of gravity from that part is pulling you not downwards but upwards. So working out the forces isn’t as simple as you might hope, but you do get something back: when you start picking away at the maths, you’ll find that what happens when you reach the centre of the planet is pretty important.

Have a think about how you’d tackle the problem yourself, then take a look at this video from MinutePhysics.

Tip of the hat to Alom Shaha for pointing us to this.

Engineering principles: keep it simple

/0 Comments/in /by

We’re developing a neat little workshop based around catapults, bits of which have sneaked out into the world in test events over the last couple of months. The core of the challenge is the simplest possible catapult we could dream up, which uses a paper cup, elastic band and a plastic spoon to fire a table tennis ball at least five metres. It’s tremendously satisfying, but it’s not quite enough on its own for the workshop.

My Mark II Catapult uses the same basic ingredients, but pivots the spoon on a kebab stick bearing. It’s even more satisfying, but a little more fiddly to make and – annoyingly – slightly less effective in range.

This morning: the Mark III Catapult, which uses the elastic band as a torsion spring. It’s fiddly to make, pushes the limits of cardboard cup rigidity even more than the other designs, and…

…is almost completely ineffective.

Back to the drawing board, with one key engineering principle ringing in our ears: keep it simple.

Turns out motor racing might be useful after all

/0 Comments/in /by

The Formula 1 Championship is a strange beast. I’m not alone in having become thoroughly bored with the political wranglings around it, and I’ve drifted far enough away that I no longer even recognise most of the team names. So it’s something of a surprise to learn that the engineering work going on behind the scenes might still be – whisper it – relevant and useful.

Animagraffs car engine

Click for animated diagram of an internal combustion engine, from the excellent Animagraffs.com.

Burning petrol in a car engine is fairly mad in the grand scheme of things, partly because internal combustion engines are horribly inefficient. They typically bumble along around the 20 or 25 per cent thermal efficiency mark: only one fifth or so of the energy input (in the form of petrol) is turned into useful work. That’s not necessarily a great surprise if you look at everything that’s going on inside an engine –  click the picture for a brilliant Animagraffe page illustrating the four-stroke engine cycle. Car engines get hot, and that heat isn’t doing anything to propel you down the road.

Diesel engines can head up towards 40% efficiency, but even as recently as 2014 it was big news when Toyota managed to hit 38% for a petrol engine, which I think is the one currently in their latest Prius hybrid.

So a rumour that the Mercedes and Ferrari F1 teams have petrol engines that achieve somewhere around 47% efficiency is eye-catching. They’re managing this thanks to German engine component supplier Mahle, whose design adds a secondary combustion chamber linked to the main cylinder head. The spark plug ignites a fuel-rich mixture in that secondary chamber, blasting a turbulent jet of burning gases into the leaner mixture in the cylinder. That leads to more complete combustion, and hence a more efficient engine overall.

Now, internal combustion engines are at their most efficient when they’re operating under load (ie. accelerating) and with the throttle full open (ie. accelerating hard). Which is more like the typical situation for Formula 1 engines than a daily commute, bumbling along in nose-to-tail traffic. So gains at the racing circuit don’t necessarily mean as much on the public road. Nevertheless, the thought that there are still major gains to be wrung out of old engine technology is surprising, and encouraging. Maybe we’ll see some of these ideas in road cars in the not-too-distant future?

Read more about the ‘Turbulent Jet Ignition” technology in this excellent Ars Technica article.

In fact, engine technology remains a huge field of research. Here’s engineer Hannah Petto giving a behind-the-scenes peek of the engine test facilities at Caterpillar’s engine research site, here in the UK, outside Peterborough:

The racing teams may have all the showy glamour, but there’s similar sorts of work going on for construction and agricultural machinery.

Not-so-coincidentally, the Think Physics office is currently reverberating to the sound of power tools and hydraulic hammers, as the building here at Northumbria University is being partially rebuilt to accommodate – amongst other things – a new engine test facility similar to the one Hannah shows in the film. It’ll be used to help deliver the new Automotive Engineering degree course we have starting up here from September this year.

The future may rest in electric vehicles, but we’re a long way from done with internal combustion.

A-Level Physics teachers: your thoughts welcome

/6 Comments/in /by

A few months ago, we made a film of an A-level core practical: measuring g via the free-fall method. Many teachers responded to our invitation to comment, and to our shameless request for recommendations for funders. Well… that worked. Thanks for your kind words, and thanks to your kind words we’re making more of these films. We’re not yet revealing the funder, but we can reveal the first three (or four) practicals we’re filming. We’d also like your help again.

We’re filming next weekend, 21st/22nd May, and we’d be delighted if these films could reflect your experience with practicals you’ve completed, your thoughts about ones you’ve yet to teach, and so on. We’ve a crack team of advisors and supporters already involved, but nothing beats the broad experience of teachers across the UK (and internationally).

So: here are the outlines of the films we’re planning to make. Please leave a comment below if you’ve any pertinent thoughts. It’s extremely helpful if you sign your comments with your real name, and note your affiliations (ie. school, that you’re a teacher / head of department / examiner etc) if appropriate. As before, the films are intended primarily to support teachers, but may be of use to students for revision purposes.

Laser diffraction

  • Introduction to traditional two-slit diffraction apparatus, with recap of explanation.
  • Plotting slit/screen distance vs. slit spacing.
  • Discussion of laser safety issues and suppliers.
  • Suggestions around practicalities, and the value of the practical for exploring issues of experiment design.
  • Alternative arrangement using a wire rather than traditional double slit.
  • Second alternative using diffraction gratings and vertical arrangement.
  • (possibly – this film’s already getting quite long!) third alternative using diffraction from a CD, as suggested by OCR.
  • Discussion of historical context and significance.

Finding the EMF and internal resistance of a battery

  • Conceptual basis of internal resistance; review of relationship between EMF, terminal potential difference, current and internal resistance.
  • Apparatus, using multimeters, variable resistor, bare wire contacts.
  • Variations, including array of known resistors; switched contact; analogue meters.
  • Comparison of internal resistance of different battery types.
  • Discussion of value of this practical for exploring key lab skills, including careful but quick working.

Discharging a capacitor through a resistor

  • Using a data logger to explore capacitor behaviour.
  • Initial verification of \(V = V_0 e^{-t/RC}\); demonstrating that voltage decay half-life is constant, and the time taken to decay to \(1/e\) of the original value.
  • Manipulation of \(V = V_0 e^{-t/RC}\) to a form comparable with \(y = mx + c\); processing and plotting data accordingly.
  • Low-budget version of practical using voltmeter and stopclock, and with hand-processing of data.
  • Extend the practical to finding the value of an unknown capacitor.
  • Discussion of error.

Force on a current-carrying conductor in a magnetic field

  • The standard ammeter and balance arrangement.
  • Sequence of
  • Determining magnetic field strength.
  • Alternative arrangement with U-shaped wire segment.

Thanks in advance for all your comments and suggestions. Inevitably, we won’t be able to incorporate everything everybody suggests, but if you’ve come across a brilliant way of covering one of these practicals which we’ve not mentioned above, or have thoughts on aspects your students find particularly challenging – we’ll do our best to incorporate your ideas.

Final note: this post was written by Jonathan. Hello. I’m the film-maker behind all these videos, and while I am technically a physicist, I last saw most of these practicals in my own A-level studies more than 25 years ago. Any glaring howlers in the above are due to my misunderstanding of the scripts, and you can be reasonably confident that the many teachers involved in the filming will politely roll their eyes before we commit film-based crimes against physics.

Watch this marble run with magnets

/0 Comments/in /by

Brilliantly inventive. See if you can work out how all the different mechanisms work – there are some amazing and subtle ideas in here. Great stuff.

Tip of the hat to Joe for spotting this as it hit Digg this afternoon.

View the transit of Mercury on 9th May

/0 Comments/in /by

This May will provide us with a fantastic opportunity to observe a transit of Mercury. It should be possible to view the eclipse from your school or home, but we will need to keep our fingers crossed for good weather.

What’s a transit of Mercury?

Like a solar eclipse, when the Moon obscures the Sun, a transit occurs when Mercury or Mars (the only planets between us and the Sun) partially block the view of the Sun from the Earth. A transit is much rarer than a solar eclipse. A solar eclipse may occur a few times a year, while transits of Mercury occur between 3.5 and 13 years apart, and transits of Venus come along only every century or so.

The next transit of Mercury will start just after midday on 9th May and will finish at around 7:40pm

How to observe the transit safely

The best way to observe in a group is to project an image of the Sun onto a shaded white surface using a telescope. CLEAPPS Guidance leaflet provides excellent information about how you can set this up: www.cleapss.org.uk.

However if you do not have a telescope, or the weather is poor on the day, live streams of the transit will be available on the internet.  ESA will be providing one and the link will be provided on their website closer to the event.

 

Never look directly at the sun!

You could permanently damage your eyesight

 

Activities

The Royal Astronomical Society have produced a teachers activity pack (PDF link) which contains a range of different worksheets and activity suggestions for use with primary and secondary students. The pack also supports literacy and numeracy, and features Mercury-themed cupcake investigations.

You could ask pupils to compare the size of Mercury and the Sun. They could do this by looking at the diameter of the two objects, the area of the disc, or their volume. Which approach gives the best idea of the relative scale of the two? NASA has created a solar system explorer website that will help students investigate further.