IoP Festival of Physics Exeter University 26th November 2016

[Note: Only a grotty phone/camera available so no Periscoping or tweeting and only a couple of photos]

The Science of Fireworks (Matthew Tosh @MatthewTosh f: Matthew Tosh)

Black powder, better known as gunpowder is made from charcoal, sulphur and potassium nitrate.

For low power fireworks PE → KE. For high power just wrap in paper

Flash powder is metal powder plus accelerator. Uses a flashpot which is magnesium based

Uncontained = big flash, little phutt and a mushroom cloud

Partially contained is louder

Fully contained in a bomb tank. Ears covered and feel the shock wave.

Sound effects created by a standing wave. Gallic acid in the bottom of a whistle

Colours: electrons absorb energy  and get excited and release energy as photons

Magnesium → white

Strontium → red

Sodium → yellow

Barium → green

Copper → blue

Potassium → purple


Fountains or gerbs force gases through a small hole

Aerial effects. They don’t use rockets any more. They use an aerial shell in a mortar. Spherical with a burst charge in the centre and stars round the outside of the sphere. A slow fuse leads to a lift charge

How Galaxies Unveil the Secrets of the Universe (Dr Amélie Saintonge UCL)

Start with that funnel diagram showing the history of the universe from the big bang

Then a graph of galaxy colour against mass which shows two dense areas

The Illustrious Collaboration: The James Webb Telescope which will be launched in 2018 and replace the Hubble. Watching the James Webb opening up is amazing.

We saw a picture of the massive 64 telescope array in northern Chile on a high plateau. A brilliant picture of a truck moving one of the telescopes. It has the most powerful supercomputer in the world.

The JW telescope are in Lagrange orbit where the gravity from the earth and the sun cancel.

Which came first; black holes or gravity? THIS IS A BIG QUESTION. We used to think the galaxy came first but now not so sure. We see the black holes through gravitational lensing

Then lunch and my exhibition table. Went well and sold one book



Is there really still “Plenty of room at the bottom and at the top” (Dr Sharon Strawbridge University of Exeter)

Look up Jonty Hurwitz – qunatum artist.

We can now see down to molecule or atomic level using a scanning probe microscope. At the other end we can see 10^26m and see galaxies. But do we use sensible scales. Minute, second, foot, metre are all based on aspects of the earth and people. Although now the metre is based on the speed of light; ie a constant.

The drive for fundamental units. Consider:

Planck units (God units)

Gravitational Constant (G)

Reduced Planck  Constant (h/2π)

Speed of light (c)

Coulomb Constant (kc)

Boltzman constant (kb)

We know all these values very accurately

Note Boltzmann managed to link steam engines to quantum mechanics via thermodynamics

G=(I_p^3)/m_p ×i_p=1

Note Planck time tp = h-G and Planck length

A great quote from Isaac Newton. “I do not know what I may appear to the world; but to myself I seem to have been only like a boy playing on the seashore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.”

How to Build a Time Machine Brian Clegg

St Augustin (400AD) said ” What is time? How can we comprehend it? As long as no one asks me, then I know” And we really haven’t moved on since then. Even Stephen Hawkings doesn’t have an answer.

Einstein created a mash-up of space and time. HG Wells discussed the four dimensions although  physicists  tell us time is not like the other three dimensions because you can’t move through it.

At a time conference they said you cannot move back in time until the time-box has been invented and then you can only move back to that point at which it was invented. It’s easier to go forwards in time. Einstein says if we move quickly we will go forwards in time.

Galileo had his theory of relativity and Maxwell related light to electricity ad magnetism. The speed of light, c, is a constant. So spacemen move into the future. Voyager 1 has  moved 1.1sec into the future. Consider the twin paradox. GPS satellites have to be corrected for this time dilation. If we could travel at just half the speed of light we would create an appreciable amount of time travel. Apollo 10 got up to 0.00375c, but it is just an engineering problem.

Back in time

We are going to need a worm hole or 10 neutron stars spinning around each other. Ronald Mallet tried this with lasers.

Implications of backwards  time travel,

Grandfather paradox; physicists say it wouldn’t work because of this.

But we lie in a quantum universe and it might split in two to make up the multiverse..

Is time continuous. Probably  not. It might be split into periods of 10^-44 sec


Annual South West Physics Day 24th June 2016

A conference intended primarily for physics teachers I gatecrashed and enjoyed all the activities. There seemed to be some major building works going on at St Lukes but a really helpful builder pointed me in the right direction for registration.

First a traditional academic lecturer on planet formation by Dr Zoe Leinhardt.

Then a workshop on particle accelerators making both a linear one out of a piece of drain pipe and  a circular one in a salad bowl. Little did I know I would be walking home through Exeter carrying a great big salad bowl.

Lunch was excellent and then a second workshop on photonics.

There followed a sort of speed-dating arrangement with 10mins at about 8 stations.

  1. Optics
    2016-06-24 15.05.17
  2. Lycra sheet gravitational field
  3. pushing a straw through potato
  4. A sort of tricks with match boxes
  5. Longitudinal fields
  6. An incredible demonstration of hardened steel balls which could burn through paper when they collide or not if they were mild steel (boules)

A great day. A long walk home!

Saw this which added to my depression following our exit from Europe

2016-06-24 13.55.13



Festival of Physics Exeter 21/11/15


Whatever happened to lecture theatres during my five and a half year’s hiatus? This is the first time I’ve been in the Alumni Theatre in the Forum of Exeter University. Look at those gaps between the chairs. That’s so that

2015-11-21 11.19.17

You should be able to click on any of these pictures to expand them

the audience can look between the seats of the lower tiers with an uninterrupted view down to the presenter. The screen image is both larger and more razor sharp than I remember. As you can see each chair swivels so they can be arranged into discussion groups (I think). Mains charging sockets and data connections provided  to the side of each chair (obviously). In my day, we had to enter with our equipment fully charged!

I’m pleased I attended this festival today, if for no other reason than I now know I’ve got to up my game in readiness for my presentation at Bristol’s Festival of Physics in early March. You see, most of the presentations I saw today seemed to use Powerpoint, and on a Mac. I don’t possess either; retirement does that to you. The main problem is that, in the main, today’s presentations had natty animated gifs. In my day I’d resort to something called Toolbook, but I’ve an uncomfortable feeling we’ve moved on a bit since those days. So [note to self], redo my presentation slides and generally make them more professional (probably by losing the photocopied images from books inserted as bitmaps).

The President of the Institute of Physics, Professor Roy Sambles, opened the proceedings with some basic light theory; this apparently being the Year of Light. He used some fairly basic demonstrations to good effect. He actually resorted to one of those good old-fashioned overhead projectors; you know, the ones that stank of ozone. I used to play tricks with those for pedagogic effect myself: things you could never do these days with a visualiser or Powerpoint and a laptop. Models to illustrate longitudinal and transverse waves, which, no doubt, are now lost in the mists of time.

Professor Sambles also managed to weave in some choice statements extolling the importance of women in science, as well as some pointed comments regarding the lack of funding for science under this government.

Continuing on the Year of Light theme, Professor Nick Stone was next up, describing how laser light can be used in both the detection and treatment of cancers, especially oesophageal cancer, but also breast cancer. He highlighted how important colour is in diagnosis by considering yellow eyes  (evidence of jaundice), blue lips (oxygen deprivation) etc.

The statistics say that 1 in 3 of us will get cancer in our lifetime, while 1 in 4 will die. With regard to oesophagus cancer, there is a 1 in 10 chance of survival after 5 years.

This is Dr Zoe Leinhardt who works in the area of locating planets that are orbiting bright suns. She eloquently described the several techniques that are used to mask out the sun’s energy so that the planets can be observed. That top right scatter plot illustrates the clusters of planets that have been discovered and plots the planet’s mass against its individual distance from its sun. The picture isn’t clear enough to study, but the relationship between these two parameters as it is measured across the universe is most interesting. It seems our own solar system is most untypical of the wider cosmos in this regard.

Next we had Dr Stijn Wuyts (Bath Uni) who described the importance and methods of creating 3D planetary images.

2015-11-21 12.15.26

This is an interesting infographic of the range and types of reflector telescopes  over time. Not unreasonably, the larger ones are the newest. Many are located in Chile where the night is dark and humidity is low. It was good to see some of the equations for telescope dish resolution that I kind of grew up with, as well as mentions of the interferometry techniques. It took me back to my days of playing with microwave reflector antennas. The principles and equations are the same; only the wavelength is different

Lunch was a chicken caesar wrap and a cup of AMT coffee. That’s how to live! I saw some delegates had brought their own packed lunches. Such planning!

After lunch was the climate and weather sessions. Firstly was Dr Colin Jones from the Met Office who lucidly described climate change and the greenhouse effect.  He explained that the more recent models include the biological effects of climate change. In particular there is excellent correlation across all the models (about 40 of them?). I’ve included all the plots he displayed. Some are temperature over time, others are variations in CO2 etc. The only thing to notice is that they are all heading  exponentially upwards except for the one which is dropping. That’s the most terrifying plot. It represents the hottest years ranked in reverse order. It shows that all the hottest years are the more recent; the colder the temperature, the longer ago it was. He also explained the so-called warming hiatus. Apparently it doesn’t exist. He spent some time discussing the El Nino and the La Nino effects.   (Don’t forget you can click on any image to magnify it). I wish  there had been time to discuss those pesky climate change deniers.

Finally, also from the Met office was Professor Dale Barker who discussed methods of predicting the weather and the modern techniques of collecting data. Although they still use weather balloons and meteorological aircraft today, increasingly they rely on data collected from passenger planes, ships and are even beginning to collect data from peoples car’s thermometers. He referred to this as opportunistic data.

He didn’t mention the loss of the BBC contract but it sounds as if they have much  more important clients than the BBC, such as oil companies (for rigs), disaster teams, rescue groups, shipping and airlines etc.  where accurate weather predicting is more important than us preparing for our barbecue.

So all in all, an excellent day. I’m afraid I gave the ‘3-Minute Wonder’session a miss; the weather man warned us of imminent rain so I headed home before it arrived. Met lots of interesting people, some old friends, some new acquaintances.

Looking forward to the next one.

Lerryn Creek

Image result for images of LerrynIt started off such a nice day. Warm, gentle, up-river summer wind, fluffy clouds scudding across…well, you get the idea.

Pete and I loved Lerryn cream teas. Back then, before they invented cholesterol, the mark of a quality cream tea was when a great dish of butter was served together with the clotted cream and jam. We arrived, as usual by inflatable. Not our own of course, but one hired from one of the prominent Fowey ’emmet’ boat hire companies; Bert’s Boats. We were on school holidays and camping in Polruan, pretending to be adults and, since we came down to Fowey so regularly, also pretending to be locals. We thought we knew everyone of import in Fowey, and they knew us. But we weren’t locals, and where we came from they didn’t have much in the way of tides, there not actually being any sea nearby.

As soon as we left the Lerryn tea shoppe and looked at the river (or lack thereof) we knew it was going to be a close-run thing. And when a river looks like a ‘close-run thing’, you stand no chance. Still, with our sense of hope only surpassing our naivety, we dived into the inflatable and pulled the Seagull ignition rope. As ever, it started first pull and we putt-putted all the way out until we grounded … about one and a half metres from the bank, and about fifty metres from the only remaining deep channel. We raised the outboard and rowed earnestly and just about made it all the way out to the remaining channel…which, in the mean time had dried to a trickle. We were stuck, more or less in the middle of the hundred-metre wide river watching the water rapidly receding.

Luckily we had a basic knowledge of oceanography and calculated that the water would return to collect us in – well, either four hours or six..or, indeed, anything in between (I did say ‘basic knowledge’). It was 3 pm and we were on holiday. No problem. We could easily kill that time in talking; planning the rest of our holidays, what we thought of the latest C,S,N and Y album, the best beer in The Lugger (I’m not sure if we were actually even 16 years old. Ah, those halcyon days!), how, if we were going to score, it would have to be with local girls, and certainly not with emmets.

And so we sat on our individual wooden planks as the Mississippi quickly turned into what could only be described as a salt-lake bed, but with a two-metre quicksand base. Not a soul in sight on either bank and no other boats. Well, there wouldn’t be, would there? Our acute embarrassment in being such ’emmets’ remained unstated by either of us, although we were considering the consequences of such foolishness. If the boatmen thought there was any chance we had actually headed in the opposite direction and seaward, the RNLI might be involved. We listened for the sound of the double rockets. We awaited the sound of a helicopter.

It was about 5 pm when we realised what truly unmitigated embarrassment felt like. We heard a vehicle. It was a flatback car and had driven down an, as yet, unnoticed small concrete slipway on the far side of the riverbed. A guy got out. I know it sounds stupid but some ridiculous notion of rescue came into our heads. He donned waders and recovered a spade and bucket from the back. He waded out into the muddy riverbed. He dug into the pliant sand and occasionally extricated a lugworm and dropped it into his bucket. He was shortly joined by more cars on the slipway, and what were, presumably, his colleagues from  some sea angling club. They too were bait-diggers. They fanned out from the slipway. We could do nothing but watch.

Incidentally, two other facts you should know about our predicament; both will come more relevant later in the tale. Firstly we were wearing only shorts and a tee shirt. Secondly, we had a tin of baked beans. Don’t ask me how this came into our possession. There must have been a little shop in Lerryn, or maybe the tea shoppe sold simple comestibles. I really don’t know, and how it was acquired isn’t central to the plot anyway.

Meanwhile, those bait collecting characters continued to fan out from the river bank and, as they did so, they progressed across the riverbed getting ever closer to our vessel. Well, I say ‘closer’ but, as stated, they were utilising this fanning arrangement, so they weren’t so much approaching us, as surrounding us,

Now comes the real dilemma. AT WHICH POINT, IF SUCH A POINT EXISTS, DO YOU BREAK INTO CONVERSATION?  When you are at shouting distance perhaps? Or may be at normal conversation volume distance? How about when one or more of them are actually alongside you and scrutinizing your bilge?

And, once  that decision has been taken, what do you actually say?

“Do you come here often” is just absurdly inane.

How about “The tide caught us out.” Nope; they just may have worked that one out for themselves.

“Do you see many boats stuck in the middle of this creek?” Hell no! That would really make us sound like imbecilic emmets.

I opted for a, ‘Hi.’ It was meant to come out all cool and laid-back like sixteen-year-olds think is appropriate, It came out sounding like a cross between Frank Spencer and Kenneth Williams. Attempting to communicate was an error of judgement.They had totally ignored us before my welcoming salutation. That, in hindsight, should have been a sign. They certainly continued to ignore us after it. By ignore, I mean, we were actually invisible. Not so much as a side-ways glance, let alone some facial expression suggesting that we were moronic idiots, which, under the circumstances, would have been both appropriate and deserving. As they continued around the boat on their way to the opposite bank, digging trenches that formed ephemeral patterned channels in the mud bed, we learnt another valuable lesson. No, we could not have got out of the boat and lifted it back to the bank; at least not without a military ‘Cumberland’ pontoon. We had no option but to sit it out. The bait diggers had special boots and they still sank down to waist-level. We chose to ignore their presence as they made their way back to their slipway and passed us, the unseeable emmets again.

The way the brain operates is weird. Maybe a qualified psychiatrist could explain why Pete and I felt it necessary not to talk to each other while the diggers were within hearing range. We just starred at each other; not at the baiters, not even beyond our gunnels. I’m sure our self-imposed silence did nothing to ameliorate our embarrassment.

One at a time, the cars left. We were on our own again. But we knew the tide had turned and the sea was on its way to rescue us. And just how did we know this? The wind velocity abruptly increased to about Beaufort Number 3 or 4. Not in itself a problem, but accompanying it was a significant temperature drop. It was now cold. But we were okay; we were sixteen…ish. An hour later as the sun was visibly dropping behind the curving river bank, we weren’t okay. We were really quite, quite cold.

Pete and I never argued. That’s why we would always go on holiday together. But we must have argued then. Don’t ask me what about. All I remember is him threatening to wallop me over the head with what he thought was the only weapon on board; an oar. Now if I had taken up the other oar, I’m sure nothing good would have come of the conflict. But he had forgotten the can of baked beans. And by now, and being sixteen (did I mention that?), we were hungry. We forgot our hostility and returned to the possibility that we might be able to crack the tin open with something. We tried smashing it on one of the sharper protrusions on the Seagull. We gave up on that or, indeed, any actions involving the oars for the same reason: we had no plasters or bandages on board. Those old iron rowlocks would have done the trick. Our rowlocks, of course, were cutting edge reinforced composite rubber ones

We sat.

By the time we saw the tidal bore heading our way we were shivering and probably hyperthermic. Still, just as the moon is wont to obey the rules of its synodic orbit, so our path home reappeared. Driving into the wind, we arrived back at the Fowey jetty just around dusk. No welcoming party; no one to throw a foil blanket over us and give us a mug of steaming cocoa. Equally, no one to express concern as to where we had been all this time. ‘Bert the Boat’ had long since abandoned his post and returned to his cottage, oblivious to our absence. We would return in the morning to pay him his hire fees. Neither he, nor anyone else seemed at all concerned about our absence. Did they know what happened? Did they care. What about those furtive glances from the remaining Quayside traders? Were they thinking, “Bloody idiot emmets”? Nooo,. Surely that was just our frozen imagination playing tricks; clearly no one either knew or cared where we had been, or how long we were out there. Under the circumstances, best we just fade away..

We decided not to stop off for a drink but to head directly along the Esplanade back on the passenger ferry for Polruan. We would pick up some pollock and chips from the chippy there just up from the Quay, and then get back up the hill to the campsite. It was only 9pm and two hours before the last ferry. But the way we felt, we just wanted to be on the same side of the river as our sleeping bags, and as soon as possible

We walked the half mile trek from The Fowey Quay to the Polruan Ferry jetty and wandered into the blockhouse shelter while we waited for the water taxi. In there were two girls who we had noticed only the day before loitering outside The King of Prussia. Not what you might call pretty in a cute sense, yet they possessed a certain worldliness (they may have been eighteen). That free-spirited mysticism so commonly found among the daughters of boatmen (Yea, right!). But more importantly, they were definitely local, and so were, in our minds,highly eligible. Pete and I had well-practised chat-up lines just for such occasions as these. We looked at each other; the signal to start. One of the girls beat us to our routine and cut us dead with five short words “You got back OK then”.

We both just about managed a one word response: “Yep”

Sidmouth Science Festival

Over the years I’ve done a handful of these types of outreach activities, but nothing quite matches the Sidmouth Science Festival for its eclectic mix of activities housed in such a range of venues. These included; churches (note the plural), a museum and art gallery, marquees and the fabulous Norman Lockyer Observatory
This was the second year I was invited to demonstrate my balls…and javelins, and discuses, and shuttlecocks to the population of Sidmouth and, as I discovered, the wider; indeed much wider, environs.
So last Saturday I could be found in the Parish Church of St Giles in the auspicious company of the Met Office (with their 6 tables and 5 demonstrators)


and The Institute of Physics (another 6 tables and maybe 6 helpers to their name).


And that guy with the space shuttle on his back? That’s Rolf. More of him later

Oh yes, and me (with my one table and…guess how many helpers)


From a practical perspective, the venue chosen for me was perfect.

  1. The flagstone floor was hard enough to allow my bouncing and spinning skills to be exhibited to their best/worst* advantage (*delete as appropriate).
  2. The table had a raised rim which discouraged the more sprightly projectiles from attempting to lower their potential energy (i.e. from falling to the floor)
  3. Tea/coffee and cakes were available just four metres away
  4. Spiritual support from the Parish rector was on hand following the arrival of a crate-load of ten-year olds

Stand-out memories include:

  1. A lovely lady who brought her equally lovely young daughter all the way from Teignmouth by public transport. It took a few moments for me to register that Teignmouth is actually on the other side of The Exe. I know they left at 7:30am to be there. I wish I had asked her how she came to hear about the Festival.
  2. Someone decided to came to the Festival because they heard my interview with Vic Morgan on Radio Devon’s Late Show (1hr 11m in). I must confess that hearing that gave me a bit of an egoistic thrill. There were two further ‘customers’ who said they had heard about the Festival from Radio Devon.
  3. This point applies to both days. The greater majority of my customers were under ten years of age. Now, I’m fine dealing with teenagers and older. But these young-uns struggled to even grasp the concept of a ball actually having a flight path, let alone that it may vary from projectile to projectile. We usually connected at the level of;
    “What sport is this ball used for?”
    “Correct. Now which country do they play baseball in?”
  4. They were also universally besotted by anything that moved such as; my Newton’s Cradle which had to be untangled several times, my gyroscope (still awaiting repair) and my mini-pool table which, miraculously, still possesses all sixteen balls even though we had to recover at least two from behind the alter and one from the rood screen.

Day Two. Norman Lockyer Observatory

Soft earth ground rather precluded any tricks with the Bouncyball (or as we old-uns knew it, the Superball). The indoor boomerang was very popular, some of the children quickly mastered the trick of ensuring its return and some even seemed to grasp the idea of the turning action being created by the gyroscopic force.

Here’s my table.

2015-10-18 13.45.03  2015-10-18 13.46.09

At this point I’ll introduce you to the little guy in the blue jumper experimenting with the Newton’s Cradle. He was totally besotted with it. Once he set the balls in motion and worked out what was going on, he reached into his pocket, pulled out his smartphone and, with my help, created a series of videos illustrating the various ball-interactions. That’s right, that will be the very same smartphones that Sir Michael Gove and his ilk want to see banned from scholarly institutions.

Now the cradle’s ball interactions were not new to our little man. Apparently there’s some quiz show he’s seen allied to the Lottery programme which utilises something like the cradle to create some game show. I have not seen this, but he proceeded to construct a whole game scenario using this cradle and other items he found on the table and began running the game with any clients who happened to wander close to the table. This went on for well over half an hour. He never tired. When I suggested that I needed to divert my attention from him to show certain items to our assembled audience and teach them, he simply added that concept to his game strategy. Pedagogically, this was game-based learning at its best.

So for that reason, here’s our cradle wizard again.

2015-10-18 13.45.11

One other little scientific connection was made by a little girl. She picked up some sort of air-blaster toy that had been left by my table and removed the sixteen balls off the pool table. She then picked up two of my table tennis balls, placed them on the pool table and commenced playing pool with them, remotely from a distance using the blast of air from the gun in place of the cue. Again, those all-important connections had been made; the prospective mark of a great scientist in the making.

Here’s some guy with some Lego and electronics and stuff. I saw him last year but still haven’t had chance to pop over and see what he was up to.

2015-10-18 15.55.40

And lastly, here’s Rolf again. It’s fitting that he’s my last picture because, long after the rest of us had weakened and lost our voices and packed everything away. And while the marquee people were itching to dismantle the tent, he still had groups of children around him, hanging on his every word as he excited their imaginations with space stories. He was truly the Duracell battery of the day.

2015-10-18 16.36.54

So there we have it. That was my personal, and necessarily limited perspective of the Sidmouth Science Festival. Although I was only there for two days and clung to my stall for the duration, the range of activities across almost two weeks is amazing. They ranged from scientific story telling for the little-uns, to Raspberry Pi jams for the older children and adults, to lectures by acclaimed scientists on a range of subjects; some controversial.

Looking forward to next year when I will add a dart board  to my repertoire (don’t worry, it’s magnetic), as well as, maybe, a basketball or netball net.