SFN Blogs

The salmon cannon was all over teh internets on Wednesday, but if you missed it, here's another chance.

I love the company's name, too: Whooshh!

Added bonus of the Kottke link is that there's also a fruit "cannon" video there.

A fish cannon sounds so Pythonesque.

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Cleaning Up Polluting Mines With Plants--Plants That Then Turn Into Precious Metals

Interesting. Though I wonder what happens to animals that eat the plants (or eat the insects that eat the plants), or if the metal content makes them so unpalatable that it isn't an issue. Or do you just have to fence it all off.
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One of the things I was thinking about this past week, in between talks (or possibly during) at ICAP was the connection with the "impossible" drive that was arguably not actually validated by NASA in the news recently. I think the seed of this was planted during a talk about trying to measure the electron's electric dipole moment (EDM), in order to rule out some of the extensions to the Standard Model (SM). There's no connection in the physics, but it's the concept of ruling out certain measurements that struck me.

You might hear the phrase that absence of evidence is not evidence of absence, and that's true, as far as it goes. If scientists have not measured the strength of gravity a million km above the sun's north pole, for example, it would not mean that there is no gravity there. But the aphorism doesn't work when you have done testing and can reasonably expect to get a result if some model is true. Then your absence of evidence really isn't an absence — you've measured something, and gotten a null result or a small result, which rules out a larger value.

Let's say you wanted to make a determination of the existence of mermaids. This being a physics analogy, it wouldn't be enough for a straight up-or-down statement of their existence — you'd have a model of the conditions under which they'd be found. Someone else might have a competing model, saying they existed, but under somewhat different circumstances. Then we could go out and search for the mermaids. We search the right kind of islands at the right time of day, and find nothing. Repeat as necessary, because statistics. That's not going to absolutely rule out the existence of mermaids, but it puts a limit on how many mermaids are statistically likely to be out there. Depending on the conditions under which we searched, it might place stricter limits on one model over another — if another model said that mermaids existed in a somewhat different environment, our search of that "space" might not have been as thorough.

There is (not unsurprisingly) an xkcd cartoon related to this

We rule out phenomena, at increasingly better levels of confidence, the longer we properly observe and don't see anything. ("Properly" because looking with blinders on, or the lens cap in place, doesn't count. e.g. creationists will never find "transitional" fossils because they refuse to look.) Scrutiny in duration and/or in precision, yielding null results, pushes the limits back of where any new discovery might be.

We can also see this if we go back to the days of physics before quantum mechanics, over a hundred years ago. Albert Michelson had remarked, in 1894, "The more important fundamental laws and facts of physical science have all been discovered, and these are now so firmly established that the possibility of their ever being supplanted in consequence of new discoveries is exceedingly remote...Our future discoveries must be looked for in the sixth place of decimals." Lord Kelvin had (supposedly) announced in 1900 that "There is nothing new to be discovered in physics now; All that remains is more and more precise measurement."

The sentiment was wrong, of course: there was new physics lurking. But one part of this was correct: that new physics was lurking in the "sixth place of decimals" or beyond. One or two anomalies aside, the new physics wasn't found where we had already looked — that's physics we still use to this day, in the realm of what we typically observe — it was found as the tools got better.

Which is another reason why the "impossible" drive draws so much scrutiny. We've been down this road before, many times and not seen anything, which is why a claim that something is there (and was there all along) is met with so much skepticism. This doesn't say that there can be new physics. What it says is that any new physics is going exceedingly likely to be found in the uncharted waters. Mermaid sightings were claimed in remote places, not the local beach.
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Microwaving Light Bulbs Is Genuinely Useful (And Entertaining)

Glad to see someone get this explanation right — I've run across far too many that try and invoke electrons hopping between states, as in a Neon light.
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The working rebuilt bombe at Bletchley Park Image courtesy of Wikipeda.

Working with engineers from the AVA Radio Manufacturing Company, they built the "Bomba", which was the first machine to break Enigma codes. By working with a commercially available version of the Enigma machine, they laid down the mathematical foundations that were essential for the British work at Bletchley Park in breaking the German military codes. In particular Alan Turing helped develop the British version of the Bomba and the story from here is well-known.

The efforts of Rejewski, Ró?ycki and Zygalski are far less well-known and were never really appreciated in their lifetimes. There is a small memorial at Bletchley Park in honour of these three.

In August 2014 the Institute of Electrical and Electronics Engineers (IEEE), as part of their Milestones commemorations have honoured Rejewski, Ró?ycki and Zygalski with a plaque outside the Institute of Mathematics of the Polish Academy of sciences. I was lucky enough to be present at the unavailing ceremony which was hosted by IEEE President Prof. J. Roberto B. de Marca. There were several diplomats and representatives from the Polish military. Janina Sylwestrzak, the daughter of Marian Rejewski, was also present and gave a short speech (in Polish of course).

The Rejewski, Ró?ycki and Zygalski memorial stone.

The plaque reads as follows;

You can find out more about the Polish work on breaking the Enigma codes by following the links below.

Links

Milestones:First Breaking of Enigma Code by the Team of Polish Cipher Bureau, 1932-1939 IEEE website.

The Breaking of Enigma by the Polish Mathematicians, Virtual Bletchley Park.

Poland's overlooked Enigma codebreakers, BBC News.

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The material is produces via the heat treatment of used cigarette butts in a nitrogen rich environment.

The article states that the processed cigarette filter material stored a higher amount of electrical energy than commercially available carbon. Also the material stored more energy than the more experimental materials graphene and carbon nanotubes.

If the process can be made economically viable then this process could be used to ecologically recycle cigarette butts.

Reference

[1] Minzae Lee, Gil-Pyo Kim, Hyeon Don Song, Soomin Park and Jongheop Yi, Preparation of energy storage material derived from a used cigarette filter for a supercapacitor electrode, 2014 Nanotechnology 25 345601.

Link

Cigarette butts offer energy storage solution IOP News
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Talking to someone who is not a scientist, but has lots of experience of working with horses, said that the horse riding community knew this already. However, a scientific study was needed as anecdotal evidence is not enough.

That said, this was known about for donkey's years*!

*Non-native speakers may find this link useful.

Link

Horses' mobile ears are 'communication tool' BBC News

Reference

Jennifer Wathan & Karen McComb, The eyes and ears are visual indicators of attention in domestic horses, Current Biology , Volume 24, Issue 15, 4 August 2014, Pages R677–R679.

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I'm attending ICAP (International Conference on Atomic Physics) this week. I would say I'm at the conference, but it's in DC, so I didn't have any travel to get (t)here, but it means commuting to the conference site and that makes for a long day. An added bonus is no wifi at the site, so my contact with the digital world while I'm there is more or less limited to a few tweets on my phone.

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As you can imagine as a mathematician, the bigger and harder the equations the happier I am. Not really, we look for pattens and elegance rather than just difficult equations, though of course difficult equations can be elegant and contain a lot of interesting structure.

Anyway, scientists now have an equation for happiness and here it is

Taken from [1].

Now we just need to apply some calculus to find the maxima (local or global I'm not fussy) and find out just how happy a mathematician can be!

Reference

[1] Robb B. Rutledge, Nikolina Skandali, Peter Dayan, and Raymond J. Dolan, A computational and neural model of momentary subjective well-being, PNAS 2014 : 1407535111v1-201407535.

Link

Equation 'can predict momentary happiness' BBC News
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While I was on vacation there were some ripples in twitter-land about NASA announcing a rocket propulsion system that didn't need fuel. Here's a representative sample: 'Impossible' Space Engine May Actually Work, NASA Test Suggests

Sadly, no. And I say sadly not because of disappointment that gizmos that can't possibly work don't end up working, it's that NASA was involved and gave this two thumbs up. They need to be better than this.

This being the internet, rebuttals to the NASA report already exist. The one from John Baez is pretty good

The tl;dr version. Lots more detail in the link.

That first one is mind-boggling. It's as if you weighed something at two pounds, and when the scale was empty, it read two pounds, so you conclude the test object weighs two pounds. (Insert joke about not having to be a rocket scientist to understand calibration runs. But … apparently it helps to not be a rocket scientist, in this case) That's some sloppy science.

So, no. You can't get from

to

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I have again been playing with some random walks, using the same method as here. This time I used 1000000 iterations and added some colour.

Once again, these images are rather for artistic purposes than scientific purposes.

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Sorry, I've been traveling. <ref blows whistle, lose possession of ball>

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Dalek-like robots are being employed to clean the wards of a North Wales hospital.

Robomen being lead by a Dalek. Image by the BBC.

One of my friends (who shall remain nameless) was worried about robots taking over the world. His nightmares will only get worse!

A member of the cleaning staff at Glan Clwyd hospital in Bodelwyddan. Image by the BBC.

Link

Robot cleaners used cut hospital infection in north Wales
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Having Fun with the Equation of Time

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I wrote an Abstract for the work I shall do on Coding Process Improvements. I hope others will make critical comments, which will help me improve this work. Additionally, I hope to convince others that this project can significantly reduce design and development times for software systems and simultaneously increase quality.
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Below are random walks on the plane (not a lattice) for which step size gets (on average) smaller and smaller with each step. I pick the step size using the Maxwell-Boltzman distribution (with a =1) and a suitable scaling which depends on the iteration parameter. I the add a opacity depending on how many times the points are visited: bright white means a lot, while grey means not many and black never.

I may play with these further, but they make some interesting pattens. We have approximate self-similarity and so these patterns have fractal-like properties. Anyway, enjoy....

These images were created for artistic rather than scientific reasons. That said, random walks are have been applied to many fields including ecology, economics, psychology, computer science, physics, chemistry, and biology.

Probably the most famous application of a random walk is to Brownian motion, which describes the trajectory of a tiny particle diffusing in a fluid. I have no idea if there is anything scientific in these images, but I would not be surprised if for small step sizes we have approximately Brownian motion. However, I would need to think a lot more about this before making concrete statements.
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Making Optical Waveguides Out of Thin Air

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[youtube:https://www.youtube.com/watch?v=pNe6fsaCVtI]

Analysis of this and more over at Bad Astronomy.
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I saw, via twitter, so links to a story that seems to be a repeat from a few months ago: about a bra (dubbed SHE) that delivers a jolt to would-be attackers.

The problem with a majority of them: they claim the shock is 3,800 kV (kilovolts). That's curious jargon, to use that number and that prefix — why not just say 3.8 MV (megavolts)? I suspect from that alone that this is a transcription error somewhere, and the original was 3,800 Volts, which is 3.8 kV, and someone combined them. It's even possibly an error of notation, because some folks use commas and periods in the opposite sense in their display of numbers. Maybe someone got confused.

But really, the true clue that this is wrong is the physics. The dielectric constant of a material tells you how much of a potential difference you can apply before it fails as an insulator. For things like neoprene or polyethylene, i.e. rubber or plastic, which are good insulators, the value is around 20 MV/m and we have almost 1/5 of that. In other words, you'd need about 20 cm of the material at an absolute minimum, which gives new meaning to the term "padded bra". Since nobody with engineering sense would fail to have a safety margin — conditions will be less than ideal, materials wear and crack, etc. — it's larger, perhaps double (or more). So, in a word, no.

But scale that down to 3.8 kV and the thickness is now of order a millimeter, which is reasonable. Within the context of the discussion.
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11 Ways Women See STEM as a 4-Letter Word

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The Cornish beaches where Lego keeps washing up

Reminiscent of the Friendly Floatees rubber ducks, turtles and frogs.
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Harvard students’ invention puts cake in a can

Arbitrary serving size, too — if you want one cupcake, you make one cupcake. Microwave in 30 sec. With that ease, though, I'm not sure "portion control" is as much of a feature as they tout.

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Every now and then there's a kerfuffle about people treating other people badly. These things need to be talked about, but I wish we could do a better job of it. You might guess that this is prompted by the recent Feynman posts and responses/comments, and you'd be right. Before that it was "not all men", and before that, Bora. But I'm not going to go into specifics about any of those, I'm going to tell you why such discussion is off the table for me. Even (perhaps especially) in the light of declarations that others must speak up — that silence is assent, and similar assertions.

I used to be active on various discussion boards other than the one that hosts this blog, and I'd go and visit when physics discussions at SFN were slow. I was reading a thread where someone (a crackpot, if I may) was proposing an alternative to relativity, which was almost certainly wrong, and there were posters making note of that in no uncertain terms. I noticed a problem, though — one of the equations the crackpot was using was actually correct — I think it was the gravitational time dilation formula gh/c^2, which is the approximation you get when you can assume g is constant — and I made a post pointing this out: I said that there were a lot of questionable claims being made, but this equation was not one of them. Adjust criticism accordingly. No problem, right?

Not so much. At that point, a number of other posters set upon me, accusing me of defending the crackpot, and concluding that I must therefore be a crackpot. There was one who went so far as to say that no real physicist would ever use an approximate formula (!), because we had computers and could run code using an exact formula. Actual examples, including physics papers using similar approximations were not enough to dissuade these folks from their positions. I had been branded a crackpot and once that had happened, no facts mattered. At that point I was was wrong by fiat so anything I had to say was dismissed, and my support for the entirety of the crackpot's position was assumed. After that, the only dialog directed at me was sarcastic. I was a leper.

It was not a pleasant experience, and this in a relatively mild atmosphere. It gave me some perspective in moderating discussions involving those who are not enamored of the scientific mainstream — look at the facts, and do not assume more is there than is written, and don't attack the person. Snark is a signal that any serious consideration is over, so one has to be sure all reasonable discourse has been exhausted. It can happen, and I'm guilty of that from time to time, but it's after going over the same ground three or four times and making no progress. (Sometimes a claim is so outlandish that ridicule is the only response — but those are exceptions, not the norm.)

I'll use, as an example, the use of the term I'm not particularly fond of: "fanboy" (or worse, fanboi). I usually see these in discussions about Apple products (as an observer — I rarely participate), aimed at someone who likes Apple products. A: I like X about my iPhone. B: Fanboi! To me, it's a signal that the party isn't willing to discuss any merits of the argument. It's dismissive and no better or more productive than an eight-year-old engaging in name-calling. In the Feynman discussions, I have not checked to see if it was deserved or not (probably yes, but I don't know), but to my mind any useful conversation is over once someone has dropped the fanboy flag or other blatant sarcasm on the pitch. It's a big Do Not Enter sign.

Another danger about snark is it's an invitation for others to jump in. It's a sort of mob mentality, I think. Scientists having discussions generally keep to the issues and don't typically degenerate into mockery, but something happens once that first window gets broken. People in the mob probably don't recognize they are in one, at least at the time.

Pointing out an error in an evolution paper does not make you a creationist, pointing out a mistake in a global warming paper does not make you a denialist, just as pointing out an error in a critique of crackpottery did not make me a crackpot. Correcting the facts is what we should be expecting in discussions, so the "if you're not with us you're against us" mentality absolutely does not fit. We, as scientists, recognize the dangers of that in formal science, and go to great lengths to point out to science detractors that we are not promoting dogma. That attitude needs to be more pervasive in discussions about the culture that surrounds science.

I have opinions on matters, and perhaps something to add to a discussion. But the entirely predictable response that gets played out gives me pause about participating. Perhaps that's an unfixable part of the internet. But it may also be true that some of what many agree are social issues in STEM that don't seem to be getting better very quickly are being hampered because some people feel shut out of the discussions as they become polarized so quickly. Think about that: people you want to reach are possibly being shut out of the conversation because of the fear that they will be verbally pummeled and shunned at the slightest inkling that they don't agree with you, because they see how others are treated. You will not hear their voice, and if they feel that they are being attacked, they will not listen to yours.

I want the broader social situation to improve. These conversations need to happen, so we must do a better job of encouraging the conversations. I can disagree with details of something you say without disagreeing with your conclusion. Finding fault with some fact you've quoted does not automatically mean I agree with your opponent — I want you argument to be stronger, unassailable, and I've found a chink in it. I'm trying to help you. But having been burned by this before, under milder circumstances, I have no wish to jump in to a much hotter fire.

These conversations need to happen. We must do a better job of encouraging the conversations.
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