Into the Lair of the Bladder Monster

Warning: this blog post contains pictures of urine, invasive equipment, and the inside of a bladder. It’s probably safe for all audiences, but you might like to put your glass of apple juice down for a minute or two. The short of it all is that I’m probably healthy.

Since my hospitalisation the other month with a renal system infection, I’ve undergone a series of investigations to try to determine if there’s an underlying reason that I fell ill. As my doctor explained to me, it’s quite possible that what I’d experienced was a random opportunistic infection (perhaps aided by a course of unrelated antibiotics I’d been on earlier this year or by certain lifestyle habits), but if that wasn’t the case – if there were some deeper explanation for my health problems – it was important to find out sooner, rather than later.

A sterile pot full of Dan Q's urine.
I’ve peed in so many little pots! If you laid them end-to-end across your kitchen counter, people would think that you were some kind of pervert.

Early on I had several ultrasound scans of my bladder (at a number of different times and at a variety of levels of fullness) and one of my kidneys, the latter of which revealed some “minor scarring” of one of them which apparently isn’t something I should be worried about… although I wish they’d started the two-page letter I got with that rather than opening with, effectively, “Contrary to what we told you at the hospital, we did later see something wrong with you…” But still, good to be reassured that this is probably not an issue.

Ultrasound scan of one of Dan Q's kidneys.
An ultrasound scan of one of my kidneys. Can you tell the sex yet?

More recently, I went to the hospital to have a “flow rate test” and a cystoscopy. The flow rate test involved the most-ghetto looking piece of NHS equipment I’ve ever seen: functionally, it seemed to be little more than a funnel on top of a large measuring beaker, in turn on top of a pressure-sensitive digital scale. The scale was connected up to the only fancy-looking bit of equipment in the room, a graphing printer that output the calculated volume (based on their weight) of the same and, more-importantly, the rate of change: the “flow rate” of the stream of urine.

A stream of urine pours down into a funnel.
I’m right, aren’t I? That’s basically a kitchen funnel, isn’t it?

I suppose one advantage of using equipment like this is that it basically operates itself. Which meant that the nurse was able to give me five seconds worth of instruction and then leave the room, which saved us from our own Britishness forcing us to make small-talk while I urinated in front of her or something. Ultimately, I turned out to be within the range of normalcy here, too, although I was a little disappointed to find that the ward didn’t maintain a daily “score board” of flow rates, as sort-of a science-backed literal pissing contest.

A graphing printer describes Dan Q's urine flow. The 'flow rate' graph shows an initial peak, then a trough, then continues to a higher sustained peak.
Apparently not all men experience that ‘spurt-and-then-full-pressure’ thing you’ll see on the graph on the right, when they start to pee, but some of us do, and it’s perfectly normal. I’m learning so much!

Finally came the cystoscopy, and this was the bit that I’d been most-nervous about. This procedure involves the insertion of a long flexible tube into the urethra at the tip of the penis, under local anasthetic, and pushing it all the way down, through the sphincter, down through the prostate and then back up into the bladder. It’s then used as a channel to pump water into the bladder, filling it to capacity and stretching out the sides, after which the fibreoptic cord (and light) that runs along its length is used to look around inside the bladder to inspect for any of a plethora of different problems.

Cystoscopy equipment, ready for insertion.
You’re going to put that WHERE?

The doctor invited me to watch with him on the monitor, which I initially assumed was because I was clearly interested in everything and kept asking questions, but in hindsight I wonder if it’s just that he – quite rightly – assumed that I might have panicked if I’d have been looking in the direction of the piece of equipment he brought in and jabbed at my penis with. I only looked at it while it was on its way out, and my god its a scary-looking thing: sort of like a cross between a tyre pressure gauge and a blowtorch. The first few inches were painless – the local anasthetic had made me completely numb right up to and including the external sphincter, which is at the base of the penis. However, what I can only assume was the second sphincter complained of the discomfort, and it stung pretty sharply any time the doctor would twist the cystoscope to change the angle of the picture.

View up a urethra, from a cystoscope.
The view as you ‘travel’ up the urethra looks pretty much like I expected. With a motion simulator, it would make a pretty cool ride!

Seeing the inside of your own body is an amazing experience. I mean: it’s not amazing enough to even be worth the experience of a cystoscopy, never mind the illness that in my case preceeded it… but it’s still pretty cool. The ultrasounds were interesting, but there’s nothing quite so immersive as seeing a picture of the inside of your own bladder, gritting your teeth while the doctor points to an indentation and explains that it’s the opening to the ureter that connects to your own left kidney!

Unfortunately I neglected to take my phone into the operating room, having put it into a locker when I changed into a gown, and so I wasn’t able to (as I’d hoped) take photos of the inside of my own bladder. So you’ll have to make do with this video I found, which approximates the experience pretty well. The good news is that there’s probably nothing wrong with me, now that the infection from earlier this year has passed: nothing to suggest that there’s any deeper underlying issue that caused me to get sick, anyway!

The bad news is that while the procedure itself was shorter and more-bearable than I’d expected, the recovery’s been a real drag. A week later, it still hurts a lot to urinate (although I’ve stopped yelping out loud when I do so) and my crotch is still too sore for me to be able to cycle. I’ve also discovered that an errection can be painful enough to wake me up, which is definitely not the most-pleasant way I’ve been roused by a penis. But it’s getting better, day by day, and at least I know for sure that I’m more-or-less “right” in the renal system, now.

The Bladder Monster

As I mentioned last week, I’ve been ill. For those who wanted the grisly details, well: here you go.

Warning: this blog post contains frank subjective descriptions of the symptoms of slightly-icky medical conditions including photographs. It’s probably safe for all audiences, but you might not want to be drinking anything while you read it.

The trouble began, I suppose, about a month and a half ago, when a contracted what seemed to be a minor urinary tract infection. If you’re a woman then, statistically-speaking, I probably don’t need to tell you what that is, but for the benefit of the men: it’s what happens when bacteria (or, sometimes, a fungus or virus) infects the renal system: the kidneys, bladder, ureters, and especially the urethra. It’s not pleasant: it gives you the feeling of needing to pee the whole time, makes it harder to pee, and – when you do – it feels a little bit like you’re piss is made of lava.

Microscope view of infected urine.
This urine contains white blood cells (the big circles) and bacteria (the tiny ‘wormlike’ things). Healthy urine contains little to none of these. Anybody else feel like they’re playing Spore?

Despite it not being common for men (more on that later), I’ve had mild UTIs on a couple of occasions in my life, and I’d always found that ensuring that I got plenty of water and a full RDA of vitamin C was more than enough to make it clear up all by itself within a couple of days. So that’s what I started doing. But then things took a turn for the worse: I started getting a stabbing pain in my left kidney. Recognising this as being pyelonephritis, I went to the doctor who prescribed me a course of the antibiotic ciprofloxacin. Within a couple of days I was feeling right as rain (of course I continued to finish the course of drugs, although I was interested to see that that advice is starting to become controversial).

Dan and Annabel have a picnic in the park.
Happy, healthy, and out for a picnic.

Naturally I was a little disappointed when, the week before last, I started getting UTI-like pain again, followed very swiftly this time by pain in my bladder that constantly felt a little like I was recovering from being punched. Back to the doctor I went, where (after the usual tests to work out what the most-likely best-antibiotic to use was) I was prescribed a course of nitrofurantoin. I’d never had this particular drug before, and it wasn’t initially clear which of the escalating ill-effects I was experiencing were symptoms of the infection and which were side-effects of the medication: it started with joint pain, then nausea, then diarrhoea, then a full-on fever. It was at the point that I was fully-clothed in bed, running a temperature and soaked in sweat but still feeling cold and shivering that Ruth called 111, who told her to take me to A&E.

(Which, like her care for me in general, she did fabulously well, except for a little bit where she sort-of ran me over in the car park of the hospital: thankfully some friendly paramedics were standing around and were able to drag me into the building. Anyway, I don’t have much memory of that bit and I certainly don’t have any amusing photos, so I’ll skip over it.)

Dan, shortly before inpatient admission but already recovering from the worst parts of his hospital visit, last week.
Feverish to the point of delirium, I don’t have much recollection of the first few hours(?) in the hospital. But I was alert enough to request that a photo was taken for the inevitable blog post. Ruth, however, insisted upon waiting until I apparently looked a lot less like I was about to die: so here it is!

A few tests later, the medical staff seemed confident that what I was experiencing was not an allergic reaction to the antibiotic (however, I see that they still made a note of it as a risk on my notes!) but was a progression of the infection, which seemed to have crossed over from the tissues of my renal system and into my bloodstream and was now generally causing havoc by attacking the rest of my body. They hooked me up to a drip of an intravenous antibiotic and kept me stocked with painkillers, then sent me up to the urology ward and set me up with a “bed” (urology mostly deals with outpatients, and so my ‘bed’ was actually a trolley, but they wanted to keep me close to the urologists in case of any complications).

The view from my hospital ward window: Oxford city is visible in the distance.
It was only the following morning, with the delirium passed, that I realised that I was on the sixth floor. Looking out of my window, I could just make out the spires of the Bodleian Library in the distance, so I dropped my coworkers an email to apologise for not being on my way there.

A consultant switched me to a week’s course of yet-another different antibiotic – co-amoxiclav – and recommended keeping me in for another night. Now, I think that co-amoxiclav is a really interesting drug, so I’m going to be a bit of a nerd and tell you about that for a bit (I promise we’ll get back to my health in a moment: if you don’t want the science bit, just scroll past the diagrams to the next photo).

Amoxicillin, with lactam ring highlighted.
This is amoxicillin. I’ve highlighted in blue the lactam ring, which is the important bit.

Co-amoxiclav is a mixture of two drugs. The first is the antibiotic amoxicillin. Amoxicillin belongs to a class of antibiotics (which includes penicillin) called β-lactams, which is the most-commonly used family of antibiotics. These antibiotics contain a four-point lactam ‘ring’ (highlighted in blue above), and the way that they work is that this part of the molecule bonds with a particular protein common to all gram-positive bacteria. Normally this protein is responsible for producing peptidoglycan, which is an essential ingredient in the cell walls of these kinds of bacteria, but when it gets locked to a β-lactam ring it stops working. As a result, when the bacterium reproduces the new child doesn’t have a proper cell wall, and can’t survive long in even the least-hostile environments.

Of course, we’re in a medical arms race right now because some of the bacteria which we’re targetting with antibiotics are becoming resistant. And here’s one what that they’re doing so: some of these bacteria have evolved to produce beta-lactamase, also bonds with beta-lactam rings, adding an OH to them and making them useless. Bummer, eh?

Clavulanic acid, with beta-lactam ring highlighted in blue.
And this is clavulanic acid. Recognise that shape on the left-hand side of the molecule (highlighted in blue)? Yup: it’s another lactam ring.

The second drug in co-amoxiclav, then, is clavulanic acid, which was discovered in the 1970s and started being added to drugs in the 1980s. Despite having a β-lactam ring (as you’ll see in blue above), clavulanic acid by itself it isn’t an effective antibiotic (for reasons I can’t quite get my head around – anyone want to help me?). But what it’s great at is bonding that lactam ring to beta-lactamase, thereby deactivating the bacterial counter-offensive and allowing the amoxicillin to carry on working, combating resistance.

So what you’ve got in co-amoxiclav is a an antibiotic and a chemical that counteracts the effects of a chemical that deactivates that antibiotic. Wow! It’s things like this that really make me wish I had a brain for biology!

A cannula in the back of Dan's hand.
These things aren’t terribly comfortable when you’re trying to sleep.

I was eventually discharged from hospital and released to go home for lots of bed rest and water, along with a further week’s course of co-amoxiclav. Unfortunately it turns out that I’m one of the unlucky folks for whom amoxicillin makes me dizzy, so I spent most of that week lying down in-between wobbly vertigo-filled trips to and from the bathroom. But it worked! Within a few days I was feeling much better and by the end of last week I was able to work from home (and actually feel like I was useful again!).

Free of symptoms and off the drugs, I returned to work properly on Monday morning and everything seemed fine. Until, late in the morning, I went to the bathroom and started pissing blood.

A kitten lying on its side.
I took a picture, but it’s too grim even for this blog post. Here, have a kitten instead. Do an image search for ‘gross haematuria’ if you want a clue: the kitten will still be waiting here when you need it.

Now apparently blood in your urine, while horrifying when it happens to you unexpectedly, isn’t actually a sign of a medical emergency. I was starting to get bladder pain again, quite intensely, so I excused myself from work and called the urology ward, who decided that I wasn’t in bad enough a condition to go and see them but sent me straight to my GP, who gave me another fortnight’s worth of co-amoxiclav. They’re monitoring my progress with urine and blood samples and if by Friday it’s not having an impact, they’re going to want to send me back to hospital (hopefully only as an outpatient) and pump me full of the intravenous stuff again. So… fingers crossed for a good result out of these drugs.

Co-amoxiclav tablet in packaging.
My co-amoxiclav tablets each come individually wrapped in a nitrogen-filled foil bag. I’ve no idea what it is that they’re concerned that they’ll react with, but I’m eating three of them a day anyway.

I was hoping that by this point I’d be writing this blog post and telling you all about how I’d fought the bladder monster and won. But it looks like I won’t be able to claim that victory for another week or two, yet. All I know is that I searched for “bladder monster” and found this. Yeah: that feels about right.

Is it possible to ‘blow’ a whistle or other wind/brass instrument underwater? How?

This self-post was originally posted to /r/askscience. See more things from Dan's Reddit account.

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Wind and brass instruments (which I’ve just learned are collectively ‘aerophones’) work because since characteristic of their shape causes the air that is pushed or drawn through them to vibrate at particular frequencies. They work in air whether you’re down a mine or at the top of a mountain, so there’s clearly some tolerance to pressure variation. I presume, therefore, that you could play them using other gases too (e.g. by connecting a whistle to a pump in a nitrogen atmosphere, for example), albeit presumably with a change in pitch (we have whistles driven by an air/steam mixture on steam locomotives, for example).

But I wonder: can such an instrument be used with other fluids? How about a liquid, like water? Can I pump water through an underwater whistle in order to make a whistle-like noise? What are the physical constraints on doing so (e.g do I need a higher pressure difference in water)?

If it’s not possible, why not? What could be done, hypothetically, to construct an aerophone-style (“hydrophone”?) instrument that would work underwater?

tl;dr: Could I pump water through an underwater whistle to ‘blow’ it? If not, how can I ‘fix’ that?

Why are ice cubes white towards the centre but transparent towards the edges?

This self-post was originally posted to /r/askscience. See more things from Dan's Reddit account.

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I’ve just finished a long work week, got home, and made a gin and tonic, and I’m looking at the ice cubes bobbing in it and noticed something I’d not paid attention to before: the cubes seem to be opaque in their core but more-transparent towards their crust. You can see what I mean in this photo.

Now other photos, like this one, show that the effect isn’t universal (and I’m pretty sure I’ve seen perfectly clear ice cubes before, too). So… why are mine opaque?

If it helps:

  • Mine were made in a conventional food freezer at -20°C
  • I’m in a hard water area
  • I’m using an ice cube tray which makes “cubes” that are actually trapezoidal prisms

Thanks!

Why are different kinds of stars found ‘between’ the spiral arms of our galaxy than in them?

This self-post was originally posted to /r/askscience. See more things from Dan's Reddit account.

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I was elsewhere in Reddit when somebody made the claim that the space between the spiral arms of our galaxy aren’t empty, but are simply filled with different kinds of stars (different luminoscities, etc.). I was skeptical, but other sources claim that this is true, too. However, I can’t find any explanation as to why this might be the case.

Is our galaxy unusual in this regard? Is it that stars form throughout our galaxy, but matter ejected from the bar into the arms affects the type of stars seen there? Is this a question of what forms where, or is it a clustering question? I honestly haven’t a clue, and I couldn’t find where this question had been asked before so I’m still “in the dark”… unlike the ‘dark’ places in our galaxy!

I can see (MegaLounge)Earth from here!

This link was originally posted to /r/MegaLoungeMars. See more things from Dan's Reddit account.

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[this was originally posted to a private subreddit]

"You are here" pointing to Earth as seen by Spirit rover
This is the first image ever taken of Earth from the surface of a planet beyond the Moon. It was taken by the Mars Exploration Rover Spirit one hour before sunrise on the 63rd Martian day, or sol, of its mission. (March 8, 2004) The image is a mosaic of images taken by the rover’s navigation camera showing a broad view of the sky, and an image taken by the rover’s panoramic camera of Earth. The contrast in the panoramic camera image was increased two times to make Earth easier to see.The inset shows a combination of four panoramic camera images zoomed in on Earth. The arrow points to Earth. Earth was too faint to be detected in images taken with the panoramic camera’s colour filters.

ISEE-3

This article is a repost promoting content originally published elsewhere. See more things Dan's reposted.

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Back in early March, I posted comic #1337, Hack, about a wayward spacecraft. ISEE-3/ICE was returning to fly past Earth after many decades of wandering through space. It was still operational, and could potentially be sent on a new mission, but NASA no longer had the equipment to talk to it—and announced that reconstructing the equipment…

Pen testing

This is not a blog post about pentesting, or any other kind of software-engineering inspired testing of pens. Nor is it a blog post about the kind of fascination some people have with pens and ink. Instead, this is a blog post about history and psychology.

Recently, JTA asked me what I do when I want to test a pen, and he was surprised with the answer. Before I tell you how I answered, I’ll tell you about what I learned from the conversation. And before that, I’ll tell you about the history of pen testing. And then, finally, I’ll tell you why I think it’s important from a psychological perspective.

Fragment of the Hebban Olla Uogala document, the oldest surviving Probatio Pennae.
The oldest surviving Probatio Pennae, or “pen test”, is of the Old Dutch words “hebban olla uogala”, and is stored in the Bodleian Library.

Historically, the “breaking in” of a new pen was called a probatio pennae, literally “pen test”, and would typically be a few lines of text or a short proverb: something that demonstrated the pen’s ability to write. For the entire mediaeval period, plus several centuries besides, the principle instrument for writing would be the quill pen: the primary wing feathers of a large bird such as a goose, often hardened in hot ashes, stripped of barbs, and cut down to size with an blade whose purpose lends its name to what we now call a “pen knife”. With such a tool, a scribe would want to be sure that the pen could hold an adequate nibful of ink without splashing or spraying, and – despite the high value of paper – it was clearly essential to write a whole sentence or two to be sure.

De Klerk, by Philip van Djik.
De Klerk, by Philip van Djik, contemporaneously shows a scribe cutting the nib of his quill pen.

A modern ballpoint pen has no such issues, but instead introduces some of its own: a plastic-lined inkwell can be gradually penetrated by the air, causing the ink to dry up; the ball can become stuck and will not turn freely; air bubble can develop within the tube (especially if the pen is stored, or worse-still used, the wrong way up); and, of course, the pen can run out of ink. This typically precipitates its disposal: your biro isn’t built to be re-used for anything except perhaps to perform an emergency tracheotomy, and it’s cheap enough that you don’t want to waste your time repairing it. As a result, our pen tests have become fast, designed to determine within a few seconds whether the pen we’ve got is working or, in the case of a stuck ball, can be made to start working with a sufficiency of scribbling. Our culture of disposal can’t spare the time for any more than a cursory test before we give up and grab the next one.

Comic: A customer stands confused, holding a toaster, outside Melvin's Throw-It-Away-And-Buy-A-New-One-Shop (formerly Melvin's Fix-It Shop)
Why keep a pen? Why keep a toaster? Why keep a computer?

So what do we write? What is the probatio pennae of our times? It’s been widely-reported (although I can’t find any decent citations) that, upon being offered a new pen to try out, 97% of people will write their own name. Now that statistic smells fishy to me (no good citations anywhere, and 97% of people use 97% as their “virtually all” number, for made-up statistics), but I’ve been testing the hypothesis among friends these last few days, and I’ve gathered enough evidence to convince me that it’s probably the case that many or most people will write their own name to test a pen.

Signing a cheque.
That’s not so surprising: in this computerised age, most times we’re given a pen it’s to sign our name. About 97% of the time, anyway. ;-)

Somebody had presumably asked JTA what he wrote, earlier in the day, because he took the time to tell me that when he tests a new pen, he typically writes the word “hello”.

Now I find that pretty weird. Maybe it’s the software engineer in me, but to me the mark of a good test is that it covers all of the possible cases, in the minimal possible effort. Writing your name is easy because it’s managed by what is popularly-called “muscle memory”: a second-season episode of Castle (correctly) used this as a plot point, when a man suffering from retrograde amnesia was unable to remember his name, but was still able to sign his name because the act of signing it had been rendered, by years of practice, into his procedural memory, which was unaffected by his condition. But writing a word, like “hello”… requires a comprehension of language. Unless he’s tested enough pens to have built a procedural memory of writing “hello” to test pens, JTA’s test has a greater number of neural dependencies, which – with apologies to those of you who aren’t interested in automated software testing – produces what we’d call an unnecessarily “brittle” test.

Animation of a hand using a pen to write a name, "hello", and a scribble.
A demonstration of a handful of ways in which people test pens, in Animated GIF format.

Me? I just scribble, which my quick survey (and several comparable ones online) show to be probably the second-most popular action to test a pen. Scribbling, to me, simply seems like the minimal test path: the single simplest thing that can be done with a pen that will demonstrate that it’s fit for purpose. I don’t need to test that a new pen can write words, because – to me – writing words in particular is not a function of the pen, but a function of my brain! To me, the pen’s function is simply one of transferring ink to the paper, and any semantic meaning coming from the ink is a product of my intellect, not of the writing implement.

So why is this important? Well: I have a half-baked hypothesis that the choice of what to write with a new pen might be linked to other aspects of our psychology. When I’m developing a new template for a website, for example, I use lorem ipsum text and dummy placeholder images as filler (just occasionally, I’ll use kittens, because kittens are adorable). That’s because the absence of meaning to the words that appear (I don’t read Latin, and even if I did, lorem ipsum is frequently mangled) has no bearing on my comprehension of the design: and, in fact, it can sometimes be a benefit to be deprived of the distraction of legible content.

A kitten by a mirror.
At last, a legitimate use in an otherwise un-kitten-related blog post to use a PlaceKitten.com image!

But I’d hypothesise that people who write words as a probatio pennae would be less-comfortable with illegible placeholder-text in a design than those who drew scribbles or signed their name. I have a notion, from my own experience, that the same parts of the brain that is responsible for judging the quality of a writing implement are used in the judgement of a piece of design work. Hey: maybe if that’s true, graphic designers should have their clients test pens out, in their presence, before they decide whether to use believable filler or lorem ipsum text in the designs they’d like approved.

Or maybe I’m way off base. What do you write when you test a pen?

Proxima Centauri is 4.3 light years way: too far to travel. Why don’t we just use Mercury (which has an 88 day year) as a staging ground, and launch from there?

This self-post was originally posted to /r/shittyaskscience. See more things from Dan's Reddit account.

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Mercury’s year is only 88 days, so if we launch a rocket from there, we only have to travel for just over 1 light year, saving time and fuel.

Edinburgh 2012 – Day Three

On the third day of our Edinburgh Fringe Festival Holiday, Ruth, JTA and I… saw more Free Fringe comedy. Are you spotting a theme, here?

Matt R with Helen Arney of Domestic Science, explaining why he's drawn a silicon lattice onto an iced bun.
Matt R with Helen Arney of Domestic Science, explaining why he’s drawn a silicon lattice onto an iced bun.

First up was Domestic Science, with “real life – for now – partners” Helen Arney and Rob Wells. This pair brought science to life, opening by re-enacting an event from one of their first dates when they discovered that turmeric contains curcumin, a pH indicator, and demonstrating how this can be used (by first dying noodles with turmeric, and then dipping them into acidic and alkaline solutions to observe their colour change). Later, they’d go on to perform audience-participation demonstrations of gravitational wobbles (as a mechanism to detect extrasolar planets), AM radiowave reflection off the ionosphere, and more. They also used us as a live experiment, having us listen to jokes written by comedians of different genders (but recorded in both male and female voices) and rate them, in order to see if the gender can be determined by the listener. All in all, a really enjoyable first show for the day.

Helen Arney retweets my message "New day, new #EdFringe shows. Starting with @DomesticScience. Looks like there'll be a test at the end", adding "Congrats! You passed!"
Helen’s response to my tweet that there must be going to be a test, after finding a sheet of paper with numbers on it, on my seat (it later turned out to be for the engendered-joke study).

Ruth and I took our lunch in David Bann’s vegetarian restaurant, here in Edinburgh, which was delicious, although I probably should have stopped at two courses and not also had desert, as I then spent most of the afternoon waddling around like a fat penguin. I can particularly recommend the aubergine, chick pea and cashew koftas.

David Bann, Edinburgh.
David Bann, Edinburgh.

Next up, we went to see Yianni‘s new show, Numb and Number. We’d first seen Yianni in 2006 (we had him take a photo of us with Peter Buckley Hill), and he was even more brilliant now than he  was back then. In this new show, he talks about autism, numbers, and rainbows, in exactly the right order (any other order would be wrong, right?). Poor JTA was picked on and tricked into coming across as racist, but in the most hilarious possible way.

Matt R and JTA enjoy a quick after-dinner whisky, before it's time to go out for more comedy.
Matt R and JTA enjoy a quick after-dinner whisky, before it’s time to go out for more comedy.

You might remember that yesterday, Matt was invited on stage to separate currency for magicians Young & Strange? Well: coincidentally, Yianni asked Matt what was significant about the sum £88.88, and quick as a flash Matt responded that it was the sum of all of the denominations of currency (1p, 2p, 5p, 10p, 20p, 50p, £1, £2, £5, £10, £20, £50). He denies it, but I’m pretty sure that he wouldn’t have been able to pull off this trick if he hadn’t have been reminded of this just the previous day.

We retreated to the flat for a haggis dinner and a round of whisky before heading out again. My stomach was already bloated from my huge lunch, and I’m not sure that a large dinner really agreed with it: I almost required help to roll me up the street to the next show.

Phill Jupitus leaps around in front of JTA.
Phill Jupitus leaps around in front of JTA. Unfortunately, my camera wasn’t quick enough to catch him in the dim light of the Canon’s Gait basement, so you’ll probably have to take my word for it that it’s him.

We finished our day with Peter Buckley Hill And Some Comedians, still probably our go-to Free Fringe show. This evening, his line-up featured Phill Jupitus of Never Mind The Buzzcocks fame, who talked about the week that he met a Beatle and two Rolling Stones, leaving the audience laughing themselves to tears. Also in the line-up was Wil Hodgson, a heavily-tattooed former wrestler with a shaved head, who talked mostly about his hobbies of collecting My Little Pony toys. He won JTA over, I think, when he finished his set shouting “Fuck Laughing Horse!”

And then, at last, it was time for bed.

If I put a pair of telescopes in parallel, will the effect be multiplicative or additive?

This self-post was originally posted to /r/askscience. See more things from Dan's Reddit account.

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Suppose I have a pair of 15x zoom telescopes (for example, I separated a pair of 15x zoom binoculars) and laid them end-to-end. Naturally there’d be some loss of field-of-vision when looking through them both. But would the resulting zoom level be 152 (i.e. 225x)? Or 15*2 (i.e. 30x)? Or something else entirely? Or am I oversimplifying?

Update: clearly I mean in series, not in parallel. With thanks to mynameistux.