You are what you eat, temperamentally
Fecal transplant from humans to rats led to behavioral changes on the rats.
Fecal transplant from humans to rats led to behavioral changes on the rats.
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An extraordinary colonial spider community in Sulfur Cave (Albania/Greece) sustained by chemoautotrophy
We report the discovery and detailed analysis of an extraordinary colonial spider assemblage in Sulfur Cave, a chemoautotrophic sulfidic ecosystem located on the Albania-Greece border. The colony, comprising an estimated 69,000 individuals of Tegenaria domestica (Agelenidae) and more than 42,000...
subtbiol.pensoft.net
We report the discovery and detailed analysis of an extraordinary colonial spider assemblage in Sulfur Cave, a chemoautotrophic sulfidic ecosystem located on the Albania-Greece border. The colony, comprising an estimated 69,000 individuals of Tegenaria domestica (Agelenidae) and more than 42,000 of Prinerigone vagans (Linyphiidae), spans a surface area of over 100 m²—representing the first documented case of colonial web formation in these species.
An extraordinary colonial spider community in Sulfur Cave (Albania/Greece) sustained by chemoautotrophy
We report the discovery and detailed analysis of an extraordinary colonial spider assemblage in Sulfur Cave, a chemoautotrophic sulfidic ecosystem located on the Albania-Greece border. The colony, comprising an estimated 69,000 individuals of Tegenaria domestica (Agelenidae) and more than 42,000...subtbiol.pensoft.net
We report the discovery and detailed analysis of an extraordinary colonial spider assemblage in Sulfur Cave, a chemoautotrophic sulfidic ecosystem located on the Albania-Greece border. The colony, comprising an estimated 69,000 individuals of Tegenaria domestica (Agelenidae) and more than 42,000 of Prinerigone vagans (Linyphiidae), spans a surface area of over 100 m²—representing the first documented case of colonial web formation in these species.
I read this a week or two ago and another interesting finding was that none of the interspecies predation nor cannibalism seen in these species was apparent in the observations. We are all products of our circumstances in some manner.
sringwal
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Voyager 2 May Have Caught Uranus At a Bad Time, Solving a 40-Year Mystery
Voyager 2 May Have Caught Uranus At a Bad Time, Solving a 40-Year Mystery
The "ice giants" of the Solar System – Uranus and Neptune – remain the least explored of any planets orbiting our Sun.
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Don't tell the creationist.
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Do you mean how did the math prove that observation affects behavior?
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I guess that is the question. Just from listening and a little reading today, they discuss how it is like a scattered wave form when not observed and appears to go to either slit, but when observed it is more linear. The way they made it sound was like it could be seen in both states, but I guess it's probably as you mention, the math tells the different states.
I understood the first part of the lecture where it was talking about relativity and time, but quantum mechanics is very over my head. Of course what I was listening to started to get a little new age in the second and third, not sure I'm going to finish it.
superrific
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The particle both has a wavelength and a "particle-like quality." If you put a beam of electrons or photons through a single slit, the resulting scatter pattern (this is the measurement technique -- imagine a giant high-res film that marks when hit by an electron) is like a series of tiny spheres. If you put two slits there, the resulting scatter pattern is that of a wave -- interference and a broad spectrum of film illumination.
This is true even if the choice between one slit and two slits is not known when the particle chooses its path. There's an experiment that goes like this. Take a particle splitter and hook it up so that particles can go one way or another. On one path, the photons have go around a few mirrors or whatever but they always make it to the intersection with the other photons. But those photons don't always make it. They bounce off a mirror that flashes between a reflect state and absorb state extremely rapidly, so basically the mirror is 50% likely to swallow the photon and 50% likely to send it to the intersection. When the photon in the second tube get sent down the pipe, there's an interference pattern. Whey don't, there's a beam pattern. The particle had to "choose" whether to travel as a wave or as an electron before it could possibly know which way it should (this is one of many different versions of a delayed choice experiment. I've simplified a bit).
What that means -- according to the most common interpretation of quantum physics -- is that it's both a wave and a particle at the same time. And if you're asking how that's possible -- well, what is really is just a perturbation of a field. Imagine dropping a few pebbles into a lake. Each ripple would (in this analogy) be a particle. Not the pebbles; those are here for illustration. The electron, neutron, proton, whatever is nothing more than a perturbation in a field.
The reason that particles have mass (most of them) is not because they are made of "stuff" but because they interact with something called the Higgs field. That gives it a certain energy, and in physics, energy and mass are the same -- i.e. directly proportional. And if that seems weird, think about this: when you slap your face, why doesn't your hand just go through your cheek? I mean, the nucleus is a tiny, tiny % of the atom, so when atoms pass by each other, the likelihood of them colliding is very small. Electrons are so small they are hard to hit. Are any of the atoms in your hand hitting any cheek atoms? Maybe, but not enough to make it hurt. At most, from that, you'd get objects that form pasta playdoh whenever they hit something.
Stopping force, though "physical", is actually a property of electromagnetics. It's the electro-static repulsion between atomic states that causes the atoms not to pass through each other -- which is to say, you already know that objects are all about fields. Now it's thought that the mass is also about fields. But it's all the same.
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stankeylegjones
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The double slit experiment requires the language used to describe it to be based in the principles of linear algebra. This is very much different from the language required to describe classical (Newtonian) mechanics, calculus.
I hope that this brief comment will draw out more questions from you so that we can keep the discussion going, as I enjoy discussing things of this nature.
superrific
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You can think of it as observation affects behavior, but it's more subtle than that. First, when we say observation, we don't mean whether we see it. We mean, does something interact with it. Things happen in the center of stars even though there's no observation. The interaction of quantum states can count as observation (though not under all circumstances).
Second, I'll give you the Feynman account of how things work. If you shine a particle across the room, it "takes all possible paths." Like, every single possible path is in the particle's probability distribution. Going straight there is one path. Bouncing around the room eight times is another path. so is going out a bit, then curving around a few times, spelling out "Dook Sux" and then hitting the wall. Every possible path -- an infinite number, all with at least infinitesimal probability. But most of those paths cancel each other out. The wacky one just described is canceled out by a different wacky one.
But the cancelling out doesn't actually happen until the system is observed -- i.e. the system interacts with something. If you have a photon emitter in a vacuum, the photons are still taking all possible paths. That is, the photon in theory could be anywhere. But when something interacts with it -- i.e. a measurement device, or another object or anything that would disturb it -- then the superposition is broken: the photon can't take all possible paths. It takes a path, the choice of which is given by the probability distribution. In a two slit experiment, the probability distribution looks wave-like. In a charged particle approaching a coloumb barrier (i.e. a voltage), the particle occasionally takes a path that requires more energy than it has -- this is called tunneling and it is extremely counter-intuitive, like a ball that sometimes rolls through a hill instead of rolling over it (which it couldn't do because it had too little energy). All sorts of non-intuitive path patterns can be taken depending on the circumstances.
On a macro scale, like ordinary life, the probability distributions are so tight because statistics. You are seeing huge, huge numbers of photons in even the faintest light. When you have very, very, very many objects, the likelihood of them collectively reaching their overall average is very, very, very high.
superrific
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It's taken me a while over the last month, but I finally figured out what symmetries do in QFT -- figured out as in really understanding how the Lie groups interact with the whole theory. I don't know why -- probably very rusty linear algebra -- but SU(2) just didn't make sense to me. I knew all the representations and the algebras but I just didn't get why it mattered, or how it mattered. The other day, I finally got to a point where I get it. Pretty cool. I'm certain I don't get it like a mathematician, not close, but good enough for my purposes.
I also learned that Lie is pronounced, Lee. I thought it was Li-ay or Li-uh.
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This comment reminds me that I took linear algebra, calculus 1, 2, 3 and differential equations in college and I can barely add now.
I recall from linear algebra learning the transforms needed for graphical displays but little else.
I did find the relativity and how time and relativity are needed for your GPS systems to be interesting, I recall that from before but it was a good listen and I actually understood.
For quantum physics I have a slight understanding of entanglement or the theory, I guess, but not much more. I'm probably not well versed enough to ask an educated question. Though I did read An Elegant Universe by Brian Greene a few years back, but that's more string theory, if I recall correctly.
stankeylegjones
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Super, that is cool to hear! I remember us chatting a while back and you were saying that you felt like you were too old to make much headway with advanced mathematics. Clearly you were wrong! When you have some time, I'd love to hear more about what you've learned in this area!
Yes, Lie and Euler are two very commonly mispronounced names. Everyone does it...until they're told hold to say them.
stankeylegjones
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Students usually think that relativity (both special and general) has no "day-to-day" applications in their lives....until the see that relativistic corrections are needed for GPS systems.
Lenny Susskind has his "Theoretical Minimum" series, in which his quantum mechanics book is enjoyable. His series doesn't assume much fluency in mathematics, and he's such a great story teller. You might want to check it out.
superrific
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Well, I'm not making much headway with the math. I'm not really trying. I'm accepting the math and just figuring out what it means. I suppose that's not nothing, but it's also not studying differentiable groups.
Ddseddse
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stankeylegjones
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It's definitely not nothing! I think you'll be surprised how easy it will be to "learn" the math once you start back.