Quantum Mechanic

Content tagged Did You Know That?

Exploring the Hudson Valley

posted on 2015-10-19 00:32:40

Sarah and I took off from work this past week, which I'd been meaning to do for a while now.  You tell yourself you'll take a break when you finish a project and then it goes on for four months and then you say, 'enough.'

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Looking south over the Hudson from the walkway.

We took a  few days to recover and relax at home, in Queens.  Because sometimes it doesn't feel like we get to use our home that much.  We didn't want to just sit around at home for the whole week, though, and Sarah found something that involved the term "vegan brunch," and I was sold.

We spent two nights at the Catskill Animal Sanctuary, which is a nice, vegan BnB that's attached to and supports a rescue sanctuary for farm animals.  I haven't really had the opportunity to spend a lot of time with other people who don't eat animals.  I had a friend in high school, knew one or two people in college, and otherwise haven't really had too many around.  I could do with more people around, period, but the proportion of veg*ans has been historically low.  It was nice to  have someone else asking me not to put anything not vegan in the fridge.  I can do that.  That's the way I live, too.  It was nice not to be the weird one for a few days.

The first night, we had vegan pizza at the Catskill Mountain Pizza Co. in Woodstock.  There were a bunch of people crowded around the bar, watching the baseball game and most were wearing different hats.  It was was open and friendly and felt good to be there.

Me and Jailbird
Me and Jailbird

The next morning, we took a tour of the Sanctuary. Goats are delightfully weird and were easy targets for petting. I also got to hold a rooster.

Jailbird was rescued from a meth lab.  Some of the chickens were boiler chickens -- the kind that are bred for ovens.  They grow so fast and big that they have a fraction of the lifespan of their not-engineered-for-food brethren, and joint problems to boot.  The same goes for the pigs and cows.  Another popular origin story was the pig who was supposed to be a cute little pet and grew to normal pig size.  Some were re-rescued from animal shelters for cats and dogs, where people had left them.

One downside of being around vegans is the popularity of anti-science and, specifically, anti-vaccination.  It seems like people come to it from different directions, but it always saddens me.  It's strange to discuss with people older than me how terrible the old diseases are.  How their unvaccinated children put others at risk; including others who have compromised immune systems and can't be vaccinated, even if they want to be.  I think on some level, I see it as a sort of social pact.  Sort of like how we try to be polite to each other and don't set each others houses on fire.  Putting everyone else at greater risk like that falls into that sort of category in my mind.

These piggles will be 800lbs as adults.  It is not a healthy size for a piggle.
These piggles will be 800lbs as adults. It is not a healthy size for a piggle.

People keep telling me that when I become a parent, my whole viewpoint will change.  I don't imagine becoming a parent will make me so constitutionally different from who I am that I wouldn't vaccinate my children.

Later that night, we explored Saugerties, which was another little town in the area.  We got some yarn for a knitting project I'm going to try and walked out a lighthouse on the Hudson. The lighthouse was also a BnB. It was a little disappointing and the path was soggy.

Saugerties lighthouse.
Saugerties lighthouse.

There were several stores that had vegan options and I was super happy.  I had a vegan ice cream sandwich, which I posted about earlier, and we had tasty soup for lunch and dinner at Rock da Casbah, which was very friendly and provided a tempeh burger and vegan mac 'n cheese.

An animal sanctuary is a place that raises a lot of questions.  Questions like: 'What do you do with the sheep wool, that you have to cut anyway?' and 'Have you seen a rise in goat/chicken/duck rescues as part of the modern homesteader movement?' and 'What sort of relationship can we aspire to with animals?'  They're tough questions, but I missed having real tough questions in my life.  They're things that make it feel more meaningful.  The real hard problems in my day to day life have been dealing with other people for too long, and it filled me with hope and aspirations for what my life could be.

Thanks for reading.

D-Wave's Lightswitch Game

posted on 2012-03-03 18:35:25

Suzanne Gildert is a scientist at D-Wave, which claims[1] to have created the first quantum computer. They currently have sold one to Lockheed Martin, and at least rent time on one to Google, even though the scientific community doesn't know if they're really selling a quantum computer or not.

One of the reasons that all of the scientists have such trouble saying whether what their machine does is quantum computing or not is because their computer could be doing either one of two different things, and getting very similar results.  They are either performing Quantum Annealing or Simulated Annealing which are very similar techniques, and there is certainly no reason their computer shouldn't work regardless of what they're doing, and will be quite good at solving any problem that can be expressed by the equation $$U = \sum_i h_i S_i - \sum_{<i,j>}J_{ij}S_i S_j, \quad (1)$$

which are much more numerous than you might think[2]. The big prize at stake, though, is being able to claim that you made the first reuseable quantum computer, which is naturally a huge claim to fame in the realm of quantum computing research.

Both quantum and simulated annealing work by minimizing Eq. 1, in which all of the $$ S_n$$'s represent what physicists like to call "two-level systems."  That is, something with two main states -- eg. spin, which is up or down or polarization which can be reduced to being horizontal or perpendicular to a plane -- which can form a quantum equivalent to the binary 1 and 0 we're all used to now.

An example set of states and energies for annealing runs.

In annealing, the overall group of two-state systems will have different amounts of energy when some of the parts are in different states. So the equation will be minimized when the parts are in the correct combination of 1's or 0's.  Suzanne wrote up a nice blog post about that for D-Wave, so I'll just send you off to that.

The important difference between quantum and simulated annealing lies in how the group of objects goes from a starting state, say all spins pointing down (we'll call it 111 in binary) to whatever the lowest energy state is.  In the picture, I made up a system where the x-axis shows three two-state systems and what state they are in (i.e. '010' means particle one is up, particle two is down, and particle three is up) and the y-axis is the energy of the group of three in that state.  As is common, we start in state 111, at the very rightmost point of the graph.  In both cases we hope the system will end in 100, the lowest energy state (See? It's the lowest point on the graph).

Quantum Annealing


In quantum annealing, we use the phenomenon called quantum tunnelling. Tunnelling is the quantum property by which a system can move from a low energy state to a lower energy state by skipping over an intermediate, higher-energy state.  In macroscopic terms, it would be like a ball on the ground next to a well suddenly being inside the well.  We don't expect it to end up in the well because it would need to raise itself up the side of the well first, something which would take energy to do, and since the ball was just sitting there, nicely, we wouldn't expect that at all.  Quantum objects do this all the time and the effects just don't add up to much on the scale of our ball.  Nevertheless, there's a calculable probability that all of the atoms in the sun will jump simultaneously to right where Earth is, but it's so small that its chances of happening before the universe ceases to exist are on the order of you winning the lottery a few times while getting hit by lightning and dying in plane crash simultaneously (please don't check that statement mathematically).

In the quantum world, we can take that graph and turn it upside down in our heads.  Now we're imagining a sort of probability distribution representation of the system.  The quantum way of thinking about it is that if we measure the state of the three particles over and over, we'll find them in state 100 most of the time, because that is the loest energy state, but then we'll also find it in states 011 and 111 sometimes, since they're more energetic than 100, but not by much and so are the next most likely states.

This method is dependent on maintaining coherence among the particles -- a special quantum property where the properties of the particles are interrelated.  One of the hallmark measurements of quantum computing is the coherence time of the qubits, which determines how long you have to do quantum-style work with them before they turn back into regular old pumpkin particles.  This is one of the big criticisms of D-Wave -- they haven't published these numbers, and so nobody can say for certain that they're doing quantum annealing as opposed to, say...

Simulated Annealing


Which is not quantum at all!  Simulated annealing serves the same purpose, though, and, by analogy, uses a balloon instead of a ball, and hopes it deflates over the well and falls in.  In this case, the system is exposed to some energy, so it can travel up and down the slopes of the graph as it likes, and is slowly cooled (or some equivalent, energy-removing operation) in the hope that, as it cools, it will fall into that low energy state.

Behind Closed Doors Does Not a Community Make


While I certainly don't like the method of keeping all of your cool research to yourself, I do think that D-Wave is doing cool research.  That said, I think their marketing department is probably stretching the truth if not outright lying about what they actually are selling.  As I was attempting to say, though, simulated annealing will get the job done in any event, I think most academics are just upset they're building something even remotely quantum while most of the rest of us are spending hours adjust delicate equipment in labs, trying to get a handful of qubits to do anything while they're claiming hundreds.  If you're interested in some of the controversy, you can spend a while reading Scott Aaronson's very interesting blog.

[1] D-Wave only publishes select information to the scientific community at large, and, as of the last time I really looked into it (a few months ago), they hadn't published anything that anyone had taken as definite results.
[2] Google seems to be using this for training image recognition software.

The Same Man Who Helped Stop Europe From Starving Invented Gas Warfare

posted on 2012-01-20 16:59:54

Frtiz Haber was a German chemist who invented both a process for nitrogen fixation, which kept many people in Europe from starving, and pioneered the use of chlorine gas in trench warfare.

Brought to you by a Radiolab episode I listened to yesterday.

The Conjunction Fallacy

posted on 2011-11-02 15:14:47

I was just reading through the wonderful debriefing that is Skepchick quickies, and came across this Scientific American piece about Sherlock Holmes and logical fallacy.The gist of it all is, that we are more likely to choose two things to describe something than one.  The article cites a scholarly article where people were described with various attributes and then choices were given for the subject to guess which phrase best described them.  When told the character was good at math, the subjects were far more likely to guess that they were an accountant and something else -- even when the choice 'accountant' by itself was available.

The logicallly fallacious part of this all, is that a subset (i.e. accountant and something) is smaller than the set it's a subset of (i.e. accountants).  Because of that, it's much less likely that the conjuction of the two sets (accountants and gymnasts, say) is the correct answer.

I may have to go back and read some Holmes to see if I can notice this quality of his.  I think I read most of it on a flight from Japan to Germany by way of China, and I'm pretty sure my brain blocked most of that to keep me sane.