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foobardog posted:As I've said in another thread, this is not small potatoes. Ordering stuff online is huge. Being able to produce your own media and reach an audience like youtube "stars" is huge. Platforms like Bandcamp are huge. gently caress, we all have GPS units in our pockets and can be reached at any time. That's huge. Yeah, I agree, these things are a pretty big deal in society and earlier posters were kind of downplaying them, but are they really as big of a deal as the automobile, or electrification and plumbing? I don't think they are.
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Jan 27, 2016 04:06
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LogisticEarth posted:The problem with saying "much of the progress since 1950 has been a refinement of old ideas" is that, that's basically been true for every period of human civilization at some point. It's an ongoing process. There used to be way more novel stuff which eventually lead to breakthrough technologies though. If you look at fundamental physics research, they haven't really come up with that much stuff in recent history which could be engineered or which could potentially be relevant to society. In the 19th century we had advances in thermodynamics and electromagnetism which, relatively, pretty quickly gave birth to real technologies like steam engines, the internal combustion engine, electrical power, HVAC, and radio communication. In the early 20th century, we had quantum mechanics, which when applied to the physics of solids, has greatly enabled information technology and lowered the cost and increased the ubiquity of wired and wireless communication. Not much fundamental physics research from the late 20th century onwards has borne much technological fruit. It's not like electromagnetism and thermodynamics where new technology followed physics advances pretty quickly. Today "high physics" focuses on pretty esoteric stuff which requires enormous billion-dollar instruments and sophisticated statistics to detect the weak effects. This sort of decline of useful physics is why people are looking earnestly towards the more emergent sciences like biology for new technologies in medicine. Physics is kind of dying. silence_kit fucked around with this message at 06:34 on Jan 27, 2016 |
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Jan 27, 2016 06:01
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Cantorsdust posted:Fusion power is totally doable. The first experimental reactors producing more power than it costs to run them have been made. ITER in France is supposed to be the first large reactor. My understanding is that that is only true if you do really clever accounting of the energy input and ignore most of it. We are very far from getting net energy generation from fusion. Cantorsdust posted:Nanotechnology is a great example of untapped potential. I don't even know enough to predict what will happen with it, but combining it with advances in molecular biology will be really loving cool. Nanotechnology is mostly a buzzword. We really don't have the ability to engineer things at the nano-meter scale like we do with parts in a machine shop. There is chemistry with molecules, which have always been nano-meter sized, and there is stuff like asbestos and chalk, but these things aren't engineered like designing a macro-scopic piece of metal into a shape. Going from desired result or properties to actual synthesized result isn't as straightforward as that. With molecules and chemistry, it takes many trial and error experiments and at the end you still may not get what you want, and techniques to engineer nano-dust like asbestos are crude and don't give you great control. Maybe the closest thing to nano-technology and nano-engineering is in the most sophisticated silicon integrated circuits, where intricate shapes are engineered in all three dimensions into solid materials truly at the nano-meter scale. The techniques are still not as powerful as engineering macro objects. The tooling is incredibly expensive and very inflexible and the cost can only be justified if amortized over huge volumes of products. silence_kit fucked around with this message at 07:56 on Jan 27, 2016 |
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Jan 27, 2016 07:46
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A Buttery Pastry posted:How do you define discoveries/advances vs. invention? Like, steam engines sorta date back roughly two millennia (though obviously they were basically just toys), but around a thousand years later you began to see slightly more practical versions, though still not useful for real industrial work. Half a millennia later you start to see industrially useful steam engines, and then a century later you have the first commercially viable ones. Depending on whether you count from the more theoretical work being done around 1600, or the commercially viable ones around 1700, steam engines had one or two centuries before they really started to make their mark. Maybe the fundamental physics research from the late 20th century needs a bunch of different fields to get to somewhere they aren't know, before they can produce practical technologies? Just like the steam engine needed improved material sciences to become a proper commercially viable industrial machine. Pointing out cases where the inventors who didn't really know what they were doing discover something, and then later physicists, inspired by the technology, fill in the gaps in understanding only strengthens my point that physics used to be way more useful than it is now. Physicists today don't do that kind of work and instead the premier physicists spend their entire careers looking for esoteric things like the Higgs Boson which nobody outside the world of high-energy physics cares about and requires a billion-dollar apparatus and sophisticated statistical analysis to be able to faintly detect. silence_kit fucked around with this message at 18:01 on Jan 27, 2016 |
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Jan 27, 2016 17:31
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A Buttery Pastry posted:Well, that probably has something to do with it being much easier to create the very basics of a steam engine than a fusion reactor. After the low-hanging fruits have been picked by random people, and then studied by physicists, physicists now have to develop the tools to pick those fruits themselves because we're now operating on a level of complexity and a scale which simply can't be compared to a machine that could probably be fixed by whacking it with a hammer. In that sense, physics is more useful because it's the only tool we have. I think that it is more due to physicists retreating into studying more and more oddball stuff which is further and further away from normal conditions on earth. Physics actually abhors complexity and a lot of physicists bend over backwards to study the simplest physical systems so they can approach problems from a bottom-up perspective. This explains physicists' fascination with stuff like the Higgs Boson, a supposedly very important fundamental particle which governs everything but 99.99% of science doesn't really need to explain how things work. It's navel-gazing. A Buttery Pastry posted:Also, as I pointed out, there was a full century from theory to commercially viable machine. I'm not intimately familiar with the history of the steam engine, but from reading wikipedia, the first commercially sucessful steam engine predates the development of the systematic theory of thermodynamics which explains how it works. This is not the example you want to trot out when trying to point out the lag between fundamental physics advances and technology. A Buttery Pastry posted:And along the way develop a bunch of new or improved poo poo because the old poo poo isn't good enough, which might then have applications in other fields. From what I gather, that is precisely what happens when people try to expand our knowledge, they're forced to create practical poo poo too because that's the only way they can actually measure anything, or make particles do what they want them to do. Yeah, this is true, but the benefits of this I think is often overstated. A lot of the specialized instrumentation isn't developed because it really isn't needed by society. Some physicists spend their entire careers building refrigerators to cool things down to temperatures which are small fractions of a Kelvin so that they can study what happens at such low temperatures. Turns out that normal people on Earth at about room temperature don't really care about what happens at milli-Kelvin temperatures, and they don't want to pay for the cost of the refrigeration. Potential BFF posted:Significant discoveries in fields like cosmology, astronomy, and physics don't necessarily positively impact Joe Sixpack in the short term so they aren't as noticeable to the public at large but there's huge progress being made in those fields. I doubt very many people outside of physicists cared about relativity in 1916 but in 2016 your car GPS has to adjust for its effects to function. Providing like a one part in a million correction or whatever (I've heard that the correction due to special relativity and the correction due to general relativity have opposite signs and thus partially cancel lol) to GPS calculations of position is the only real application of relativity that I have ever heard trotted out. silence_kit fucked around with this message at 05:46 on Jan 28, 2016 |
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Jan 28, 2016 05:38
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Lucy Heartfilia posted:Only a retard thinks that physicists are only doing particle physics and astrophysics. Particle physics and astrophysics are "high physics" though, and are more prestigious than the more practical fields like condensed matter physics.
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Jan 28, 2016 06:28
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Doctor Spaceman posted:So much so that the Nobel Prizes in 2007, 2009, 2010, 2012 and 2014 all went to discoveries like graphene, CCD cameras, and blue LEDs. Most of the time discoveries in condensed matter physics have to actually matter to society to earn a Nobel. And in a lot of those cases, those contributions weren't fundamental physics advances, they were more like chemistry/material science advances, like with Charles Kao proposing the idea for fiber optics by recognizing that if you were to make glass very pure, it could be very transparent to infrared light. Or Shuji Nakamura perfecting the metamorphic epitaxial crystal growth of gallium nitride to enable efficient blue light-emitting diodes. I'm sure those in high physics scoffed and said that those scientists discovered no new physics when those awards were announced.
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Jan 28, 2016 17:12
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QuarkJets posted:Everyone else in the thread brought up GPS several times but what a lot of people don't realize is that you need relativity for an absolutely insane number of things. We'd be hilariously less advanced without an understanding of it. Goodbye medical imaging, nuclear power, everything that uses a laser, etc. Why do you need relativity to understand imaging and how lasers work? I realize that the following thing I'm about to point out is not totally relevant evidence, but Shuji Nakamura, the Nobel Prize winner I mentioned before, is often credited for demonstrating the first blue semiconductor laser. He has a Masters-level electrical engineering education and probably was never taught special relativity. silence_kit fucked around with this message at 15:09 on Jan 29, 2016 |
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Jan 29, 2016 14:51
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McDowell posted:Part of the discovery of relativity is that the difference between a magnetic field and an electric field is the frame of reference. I don't think that this is fundamental to how a laser works though. When Einstein proposed the process of stimulated emission (this is the physical process which allows light to be amplified inside of a laser), I don't think that he appealed to relativity. Certainly people who design and engineer lasers don't need relativity to be able to do their job. Shuji Nakamura, who is credited with demonstrating the first blue semi-conductor laser, having only a Masters degree in electrical engineering, was probably not taught special relativity. silence_kit fucked around with this message at 15:22 on Jan 29, 2016 |
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Jan 29, 2016 15:16
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McDowell posted:I was refering to medical imaging - particularly MRI. Relativity uses laplace transforms which are very common math in advanced engineering. I don't understand the physics of nuclear magnetic resonance well enough to say whether or not special relativity is relevant. I also think that you might be conflating the Lorentz and the Laplace transform. A quick Wikipedia search shows me that the Laplace transform was developed in the 19th century for probability theory. We didn't need relativity for there to be the Laplace transform. silence_kit fucked around with this message at 16:36 on Jan 29, 2016 |
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Jan 29, 2016 16:30
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McDowell posted:Early morning phone posting, sorry - MRI requires both Lorentz and Laplace equations so you can create an image based the the spin/alignment of hydrogen atoms in the body. I still suspect that you are conflating things here. The mathematical problem of readout of the nuclear magnetic resonance signals and construction of the MRI image I'm sure relies on the Laplace transform or something mathematically like that. Laplace equation is just the name of a type of differential equation which pops up in different areas of physics, it's a different thing. But the mathematical problem of constructing the image from the nuclear magnetic resonance signals is different from the fundamental physics which creates the nuclear magnetic resonance signal. Edit: Are you conflating Lorentz line shape with Lorentz transform?
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Jan 29, 2016 18:08
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You never actually answered the question. Why is special relativity relevant for lasers? OK, let me namedrop science terms now in an attempt to gain some credibility. I have studied the theory behind how a semiconductor laser works (I took a class where I was presented a ~microscopic theory of optical gain and absorption in semiconductors) , and IIRC not once was special relativity invoked. What am I missing? IIRC, when Einstein proposed the process of stimulated emission, he didn't invoke special relativity either. Why is it so important for lasers then? Phyzzle posted:There may have been some grumbling among . . . "high" physicists about the graphene Nobel Prize. Most of the novel physics was figured out by other people, but the prize was given to Andre Geim after he figured out a practical way to produce it reliably. (By sticking scotch tape to pencil lead and peeling it off over and over.) Still, the physics behind graphene is about as novel as tau neutrinos. I think everybody outside of the graphene research community grumbled about that one. There was a lot of hysteria surrounding graphene and many technological applications were promised. People were saying that the material was going to replace normal transistors in computer chips, overlooking the fact that graphene wasn't a real semi-conductor, and thus didn't come with the major benefit of semiconductors used in making electrical switches which is strong electrical control/modulation of conductivity. They fundamentally stood no chance of electrically modulating the conductivity by 1000x or greater, which is one of the technical requirements of transistors in computer chips. It's like trying to make a solar cell out of black paint. silence_kit fucked around with this message at 21:57 on Jan 29, 2016 |
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Jan 29, 2016 20:58
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QuarkJets posted:The Dirac equation is a relativistic wave equation. The Feynman path integral is the result of a relativistic description of quantum mechanics. Both of these tools are fundamental to a modern understanding of condensed matter physics. You don't need them for industrial semiconductor research, but that kind of research wouldn't even exist without relativity (basically you use relativity every time that you work in this field, you just might not realize it) Does this level of description actually benefit you when trying to describe how a laser works? This is what I'm asking. What feature of lasers requires relativity to exist? Of course, I'm sure that there are things in solid state physics that require relativity to be explained. Are lasers one of them? I will not accept an answer like: stimulated emission/lasing is just a limiting case of the a more general theory which involves sophisticated relativistic physics blah blah blah etc. etc. because sometimes generalizing doesn't really give you extra insight on how something works or doesn't add anything substantial to the explanation. It's like telling a structural engineer that he really needs to know quantum mechanics to be able to do his job well. Quantum mechanics doesn't inform him on how to design a bridge. If QM had never existed, it wouldn't have changed how the structural engineer designs bridges. Or for a more extreme example, it's like telling biologists that all of their work hinges on the existence of the Higgs Boson or some other fundamental particle that physicists spend their entire careers trying to find. But that's totally absurd. If no one had ever worried about the Higgs Boson, our understanding of biology would not have been any different. QuarkJets posted:Have you actually read Einstein's theory for stimulated emission? He invokes relativity explicitly, in both name and function. Here, go read it: http://cua.mit.edu/8.421/Papers/Einstein%201917.pdf Huh, I actually had read that before but only to section 3. The most famous part of the paper is when he postulates stimulated emission and the A and B coefficients and shows that they allow you to get the blackbody spectrum when you treat the electromagnetic field and the ideal gas with those A and B coefficients as being in thermal equilibrium. It looks like later in the paper he checks whether the gas with the A and B coefficients in thermal equilibrium with the electromagnetic field follows the Maxwell Boltzmann velocity distribution. He uses a coordinate transformation to a moving reference frame of a gas molecule in the argument and does name-drop relativity, but does the transformation in the limit of non-relativistic molecular speeds, or basically, where the theory of relativity isn't very important. Sorry, I'm not convinced that relativity is that important to stimulated emission or to the basic physics of a laser. silence_kit fucked around with this message at 06:06 on Jan 31, 2016 |
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Jan 31, 2016 05:49
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Bip Roberts posted:No, you really don't need relativity to describe a laser. You need a quantum mechanical representation of electrons and light matter interactions but none of the systems need the relativistic Schrodinger equation to be represented. You can derive the phase matching geometry, the population inversion and stimulated emission with non-relativeistic theory. Yeah, what I'm asking QuarkJets is whether there are some features of lasers which require relativity to be explained. He is just obfuscating things by bringing up extra formalisms which are required in modern solid state physics to explain more unusual things. He has not answered my pretty direct question after many posts in this exchange. Dirk the Average posted:This is a bit disingenuous - of course a structural engineer doesn't need to know about quantum mechanics. He or she is working with macro-scale objects that are described perfectly well by Newtonian physics because the wrinkles that QM adds to those equations are effectively nil at those scales. Look, I'm not accepting this kind of reasoning. Structural engineers do not design bridges for Rick Moranis in Honey I shrunk the Kids. The fact that QM is a generalization isn't interesting to the structural engineer because it doesn't really inform him on how to design bridges. Before you bring it up, I am not questioning whether the theory of quantum mechanics has borne technological fruit. What I am asking is whether relativistic physics is essential to certain technologies. Relativity providing a one part in a million or whatever correction to GPS calculations is not very impressive, sorry. That's kind of embarrassing if that is the killer app of the theory of relativity. QuarkJets posted:It's not important for a layman's understanding of how a laser works, if that's what you're asking. But special relativity is fundamental to condensed matter physics, which allowed us to actually build the semiconductor lasers that you brought up. How? What about semiconductor lasers could not have been done without special relativity? Edit: I found this quote from Sheldon Glashow: ”Modern elementary–particle physics is founded upon the two pillars of quantum mechanics and relativity. I have made little mention of relativity so far because, while the atom is very much a quantum system, it is not very relativistic at all. Relativity becomes important only when velocities become comparable to the speed of light. Electrons in atoms move rather slowly, at a mere of one percent of light speed. Thus it is that a satisfactory description of the atom can be obtained without Einstein’s revolutionary theory.” Basically, what I am asking here is why is he wrong here in the case of lasers? silence_kit fucked around with this message at 20:08 on Jan 31, 2016 |
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Jan 31, 2016 19:39
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Dirk the Average posted:We're more or less in agreement on that - QM has very little impact on structural engineering. It is, however, about as relevant as stating that evolution has no impact on structural engineering though. Oh, I put in an edit: silence_kit posted:Before you bring it up, I am not questioning whether the theory of quantum mechanics has borne technological fruit. What I am asking is whether relativistic physics is essential to certain technologies. Relativity providing a one part in a million or whatever correction to GPS calculations is not very impressive, sorry. That's kind of embarrassing if that is the killer app of the theory of relativity.
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Jan 31, 2016 20:13
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McDowell posted:Are you Andy Schlafly? I'm not questioning whether it is true. I am questioning whether it is as important to technology as Quarkjets claims. All I want is a non-inflated evaluation of the technological applications.
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Jan 31, 2016 20:31
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QuarkJets posted:Thanks to SR, we know that a static electric field looks like an electric field plus a magnetic field when you're moving through it. Without SR, you wouldn't be able to accurately predict the behavior of electrons in a semiconductor. Even when they attempt to capture this effect they can't accurately predict the energy spectrum of electrons in a semiconductor. It's also a pretty weak effect in the semiconductors used in making lasers. Magnetism is weak in most materials. I think you are overstating the importance of this. I just learned a couple of days ago that tantalum nitride, a material sometimes used in integrated circuits to make resistors, has a negative temperature coefficient of resistivity. I thought hmmm, that's interesting, TaN must not be a metal and must be an unintentionally doped semi-conductor. I checked a paper where they did ab-initio calculations of the band structure, and they didn't really even know what the band gap was. Different techniques gave different results and both were 1 eV off from experiment. That's a huge error in the calculation of a pretty basic property of a material. They have bigger problems to worry about than to fiddle with small relativistic corrections. It doesn't really inform people very much. Now sometimes the relativistic physics leads to qualitatively new phenomena and I'm sure the solid state physicists are all over that. I'm not questioning that. Phyzzle posted:Would the invention and development of lasers have been seriously delayed by not having the theory of relativity? That's actually a difficult, technical question. Yeah, I totally agree and this is what I'm saying. It's totally misleading to call lasers a triumph of special relativity. If you are saying stuff like that then you may as well list every technology ever as being a triumph of theorizing/finding the Higgs Boson, which is ludicrous. silence_kit fucked around with this message at 22:41 on Jan 31, 2016 |
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Jan 31, 2016 22:31
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QuarkJets posted:I disagree for the reasons that I've already laid out. While you have pointed out that sometimes in condensed matter physics people worry about relativity, you haven't closed the loop by pointing out where in laser science relativity actually matters. Your earlier claim that lasers are a technological fruit of the theory of relativity is very misleading. Edit: Not worth adding to a new post. QuarkJets posted:I've done this, you just keep handwaving away all of my posts and creating strawman arguments in their place. If you want to continue believing that special relativity is useless to the physics of lasers and MRI machines then I no longer feel compelled to stop you I'm ignoring a lot of the words of your posts because they aren't logical arguments and are mostly personal attacks on me in an attempt to discredit my opinion. Not really having a systematic understanding of how MRI works, I never claimed that relativity was irrelevant to MRI. I'd suggest you do the same when you are out of your element. That's why I asked you. You never actually concretely explained why special relativity is relevant to MRI. silence_kit fucked around with this message at 02:51 on Feb 1, 2016 |
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Feb 1, 2016 02:21
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SHISHKABOB posted:I think you're just looking at specific things and drawing a conclusion while ignoring selection effects. You aren't aware of all fields of study at all times, that's impossible, it's the reason why people have specialties in the first place. You sound like those people in the 19th century who were like "Everything that can be invented has been invented." Blue Star is right in that integrated circuit technology is running out of steam. We are now at the point (and have been for a while, I think) where making the transistors and wires smaller doesn't greatly improve the performance of the circuits on the computer chip, it mostly allows the chip designers to add more and alternate functionality to the chip for the same cost. The technology has had a pretty good run since the 60's/70's. And he is right in that it would be nice if the computer chips were to keep on getting faster, since faster computer chips would aid in technological development in many areas. Certainly it would make computer programmers' jobs easier. But the mistake he is making is that computer chips are not all of technology. Arguably they aren't as socially important as stuff like energy or medicine.
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Feb 1, 2016 17:51
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Fojar38 posted:Even with the limits of miniaturizing the computing technology we have now we are still pushing new boundaries in computing power. The Summit supercomputer at Oak Ridge is going to come online in 2018 or so and is expected to be capable of calculating in exabytes (a billion billion calculations per second) and that isn't even accounting for things like quantum computing which we've still barely scratched the surface of. My understanding is that they are struggling to find applications for quantum computers. I have heard that there is supposed to be a huge benefit for them over normal computers when solving the problem of factoring large numbers, but it is unclear if that benefit translates to other problems.
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Feb 1, 2016 22:36
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