The base-pair sequence of DNA determines its biological function. As you say, this sequence determines what kinds of proteins get made, including their exact shape (and more broadly how they behave).
But TFA is talking about the conformation (shape) of the DNA strand itself, not the protein structures that the DNA strand is used to make.
In living organisms, the long DNA molecule always forms a double-helix, irrespective of the base-pair sequence within the DNA. DNA double helices do actually twist and wrap into larger-scale structures: specifically by wrapping around histones, and then twisting into larger helices that eventually form chromosomes. There are hints that the DNA sequence itself is actually important in controlling how this twisting/packing happens (with ongoing research about how (innapropriately-named) "junk DNA" plays a crucial role). However, despite this influence between sequence and super-structure, DNA strands essentially are just forming double-helices at the lowest level: i.e. two complementary DNA strands are pairing up to make a really-long double-helix.
What TFA is talking about is a field called "DNA nanotechnology", where researchers synthesize non-natural DNA sequences. If cleverly designed, these sequences will, when they do their usual base-pairing, form a structure more complex than the traditional "really-long double-helix". The structures that are designed do not occur naturally. People have created some really complex structures, made entirely using DNA. Again, these are structures made out of DNA (not structures that DNA generates). You can see some examples by searching for "DNA origami". E.g. one of the famous structures was to create a nano-sized smiley face; others have 3D geometric shapes, nano-boxes and bottles, gear-like constructs, and all kinds of other things.
The 'trick' is to violate the assumptions of DNA base-pairing that occur in nature. In living cells, DNA sequences are created as two long complementary strands, which pair up with each other. The idea in DNA nanotechnology is to create an assortment of strands. None of the strands are perfectly complementary to each other, but 'sub-regions' of some strands are complementary to 'sub-regions' on other strands. As they start pairing-up with each other, this creates cross-connections between all the various strands. The end result (if your design is done correctly) is that the strands spontaneously form a ver well-defined 3D structure, with nanoscale precision. The advantage of this "self-assembly" is that you get billions of copies of the intended structure forming spontaneously and rapidly. Very cool stuff.
This kind of thing has been ongoing since 2006 at least. TFA erroneously implies that this most recent publication invented the field. Actually, this most recent publication is some nice work about how the design process can be made more robust (and software-automated). So, it's a fine paper, but certainly not the first demonstration of artificial 3D DNA nano-objects.
Human sorting tends to be rather ad-hoc, and this isn't necessarily a bad thing. Yes, if someone is sorting a large number of objects/papers according to a simple criterion, then they are likely to be implementing a version of some sort of formal searching algorithm... But one of the interesting things about a human sorting things is that they can, and do, leverage some of their intellect to improve the sorting. Examples:
1. Change sorting algorithm partway through, or use different algorithms on different subsets of the task. E.g. if you are sorting documents in a random order and suddenly notice a run that are all roughly in order, you'll intuitively switch to a different algorithm for that bunch. In fact, humans very often sub-divide the problem at large into stacks, and sub-sort each stack using a different algorithm, before finally combining the result. This is also relevant since sometimes you actually need to change your sorting target halfway through a sort (when you discover a new category of document/item; or when you realize that a different sorting order will ultimately be more useful for the high-level purpose you're trying to achieve;...).
2. Pattern matching. Humans are good at discerning patterns. So we may notice that the documents are not really random, but have some inherent order (e.g. the stack is somewhat temporally ordered, but items for each given day are reversed or semi-random). We can exploit this to minimizing the sorting effort.
3. Memory. Even though humans can't juggle too many different items in their head at once, we're smart enough that we encounter an item, we can recall having seen similar items. Our visual memory also allows us to home-in on the right part of a semi-sorted stack in order to group like items.
The end result is a sort that is rather non-deterministic, but ultimately successful. It isn't necessarily optimal for the given problem space, but conversely their human intellect is allowing them to generate lots of shortcuts during the sorting problem. (By which I mean, a machine limited to paper-pushing at human speed, but implementing a single formal algorithm, would take longer to finish the sort... Of course in reality mechanized/computerized sorting is faster because each machine operation is faster than the human equivalent.)
You make good points. However, I think you're somewhat mischaracterizing the modern theories that include parallel universes.
So long as we use the real physicists definitions and not something out of Stargate SG1, those parallels will always remain undetectable. SF writers tell stories about interacting with other universes - physicists define them in ways that show they can't be interacted with to be verified.
(emphasis added) Your implication is that physicists have invented parallel universes, adding them to their theories. In actuality, parallel realities are predictions of certain modern theories. They are not axioms, they are results. Max Tegmark explains this nicely in a commentary (here or here). Briefly: if unitary quantum mechanics is right (and all available data suggests that it is), then this implies that the other branches of the wavefunction are just as real as the one we experience. Hence, quantum mechanics predicts that these other branches exist. Now, you can frame a philosophical question about whether entities in a theory 'exist' or whether they are just abstractions. But it's worth noting that there are plenty of theoretical entities that we now accept as being real (atoms, quarks, spacetime, etc.). Moreover, there are many times in physics where, once we accept a theory as being right, we accept its predictions about things we can't directly observe. Two examples would be: to the extent that we accept general relativity as correct, we make predictions about the insides of black holes, even though we can't ever observe those areas. To the extent that we accept astrophysics and big-bang models, we make predictions about parts of the universe we cannot ever observe (e.g. beyond the cosmic horizon).
An untestable idea isn't part of science.
Indeed. But while we can't directly observe other branches of the wavefunction, we can, through experiments, theory, and modeling, indirectly learn much about them. We can have a lively philosophical debate about to what extent we are justified in using predictions of theories to say indirect things are 'real' vs. 'abstract only'... but my point is that parallel realities are not alone here. Every measurement we make is an indirect inference based on limited data, extrapolated using a model we have some measure of confidence in.
Occam's Razor...
Occam's Razor is frequently invoked but is not always as useful as people make it out to be. If you have a theory X and a theory X+Y that both describe the data equally well, then X is better via Occam's Razor. But if you're comparing theories X+Y and X+Z, it's not clear which is "simpler". You're begging the question if you say "Clearly X+Y is simpler than X+Z! Just look at how crazy Z is!" More specifically: unitary quantum mechanics is arguably simpler than quantum mechanics + collapse. The latter involves adding an ad-hoc, unmeasured, non-linear process that has never actually been observed. The former is simpler at least in description (it's just QM without the extra axiom), but as a consequence predicts many parallel branches (it's actually not an infinite number of branches: for a finite volume like our observable universe, the possible quantum states is large but finite). Whether an ad-hoc axiom or a parallal-branch-prediction is 'simpler' is debatable.
Just about any other idea looks preferrable to an idea that postulates an infinite number of unverifiable consequents.
Again, the parallel branches are not a postulate, but a prediction. They are a prediction that bother many people. Yet attempts to find inconsistencies in unitary quantum mechanics so far have failed. Attempts to observe the wavefunction collapse process have also failed (there appears to be no
I disagree. Yes, there are tensions between openness/hackability/configurability/variability and stability/manageability/simplicity. However, the existence of certain tradeoffs doesn't mean that Apple couldn't make a more open product in some ways without hampering their much-vaunted quality.
One way to think about this question to analyze whether a given open/non-open decision is motivated by quality or by money. A great many of the design decisions that are being made are not in the pursuit of a perfect product, but are part of a business strategy (lock-in, planned obsolescence, upselling of other products, DRM, etc.). I'm not just talking about Apple, this is true very generally. Examples:
- Having a single set of hardware to support does indeed make software less bloated and more reliable. That's fair. Preventing users from installing new hardware (at their own risk) would not be fair.
- Similarly, having a restricted set of software that will be officially supported is fine. Preventing any 'unauthorized' software from running on a device a user has purchased is not okay. The solution is to simply provide a checkbox that says "Allow 3rd party sources (I understand this comes with risks)" which is what Android does but iOS does not.
- Removing seldom-used and complex configuration options from a product is a good way to make it simpler and more user-friendly. But you can easily promote openness without making the product worse by leaving configuration options available but less obvious (e.g. accessed via commandline flags or a text config file).
- Building a product in a non-user-servicable way (no screws, only adhesives, etc.) might be necessary if you're trying to make a product extremely thin and slick.
- Conversely, using non-standard screws, or using adhesives/etc. where screws would have been just as good, is merely a way to extract money from customers (forcing them to pay for servicing or buy new devices rather than fix old hardware).
- Using bizarre, non-standard, and obfuscated file formats or directory/data-structures can in some cases be necessary in order to achieve a goal (e.g. performance). However in most cases it's actually used to lock-in the user (prevent user from directly accessing data, prevent third-party tools from working). E.g. the way that iPods appear to store the music files and metadata is extremely complex, at least last time I checked (all files are renamed, so you can't simply copy files to-and-from the device). The correct solution is to use open formats. In cases where you absolutely can't use an established standard, the right thing to do is to release all your internal docs so that others can easily build upon it or extend it.
To summarize: yes, there are cases where making a product more 'open' will decrease its quality in other ways. But, actually, there are many examples where you can leave the option for openness/interoperability without affecting the as-sold quality of the product. (Worries about 'users breaking their devices and thus harming our image' do not persuade; the user owns the device and ultimately we're talking about experience users and third-party developers.) So, we should at least demand that companies make their products open in all those 'low-hanging-fruit' cases. We can then argue in more detail about fringe cases where there is really a openness/quality tradeoff.
I'm somewhat more hopeful than you, based on advances in x-ray optics.
For typical x-ray photons (e.g. 10 keV), the refractive index is 0.99999 (delta = 1E-5). Even though this is very close to 1, we've figured out how to make practical lenses. For instance Compound Refractive Lenses use a sequence of refracting interfaces to accumulate the small refractive effect. Capillary optics can be used to confine x-ray beams. A Fresnel lens design can be used to decrease the thickness of the lens, giving you more refractive power per unit length of the total optic. In fact, you can use a Fresnel zone plate design, which focuses the beam due to diffraction (another variant is a Laue lens which focuses due to Bragg diffraction, e.g. multilayer Laue lenses are now being used for ultrahigh focusing of x-rays). Clever people have even designed lenses that simultaneously exploit refractive and diffractive focusing (kinoform lenses).
All this to say that with some ingenuity, the rather small refractive index differences available for x-rays have been turned into decent amounts of focusing in x-ray optics. We have x-rays optics now with focal lengths on the order of meters. It's not trivial to do, but it can be done. It sounds like this present work is suggesting that for gamma-rays the refractive index differences will be on the order of 1E-7, which is only two orders-of-magnitude worse than for x-rays. So, with some additional effort and ingenuity, I could see the development of workable gamma-ray optics. I'm not saying it will be easy (we're still talking about tens or hundreds of meters for the overall camera)... but for certain demanding applications it might be worth doing.
We have combined ultrasensitive magnetic resonance force microscopy (MRFM) with 3D image reconstruction to achieve magnetic resonance imaging (MRI) with resolution <10 nm. The image reconstruction converts measured magnetic force data into a 3D map of nuclear spin density, taking advantage of the unique characteristics of the 'resonant slice' that is projected outward from a nanoscale magnetic tip. The basic principles are demonstrated by imaging the 1H spin density within individual tobacco mosaic virus particles sitting on a nanometer-thick layer of adsorbed hydrocarbons. This result, which represents a 100 million-fold improvement in volume resolution over conventional MRI, demonstrates the potential of MRFM as a tool for 3D, elementally selective imaging on the nanometer scale.
I think it's important to emphasize that this is a nanoscale magnetic imaging technique. The summary implies that they created a conventional MRI that has nanoscale resolution, as if they can now image a person's brain and pick out individual cells and molecules. That is not the case! And that is likely to never be possible (given the frequencies of radiation that MRI uses and the diffraction limit that applies to far-field imaging.
That having been said, this is still a very cool and noteworthy piece of science. Scientists use a variety of nanoscale imaging tools (atomic force microscopes, electron microscopes, etc.), but having the ability to do nanoscale magnetic imaging is amazing. In the article they do a 3D reconstruction of a tobacco mosaic virus. One of the great things about MRI is that is has some amount of chemical selectivity: there are different magnetic imaging modes that can differentiate based on makeup. This nanoscale analog can use similar tricks: instead of just getting images of surface topography or electron density, it could actually determine the chemical makeup within nanostructures. I expect this will become a very powerful technique for nano-imaging over the next decade.
The image analysis question is interesting. You are trying to read dial positions, so conventional OCR is probably useless (unless there is a package to do exactly that?).
What you can do is use image processing commands (in your favorite programming language; a shell script, Python, etc.) to crop the image to generate a small image for each dial. Then convert to grayscale (and maybe increase the contrast to highlight the dial). To then calculate the preferred orientation in the image, you calculate gradients along different directions. There will be a much higher value for the gradient along directions perpendicular to the preferred axis. This procedure is described very briefly in this paper:
Harrison, C.; Cheng, Z.; Sethuraman, S.; Huse, D. A.; Chaikin, P. M.; Vega, D. A.; Sebastian, J. M.; Register, R. A.; Adamson, D. H. "Dynamics of pattern coarsening in a two-dimensional smectic system" Physical Review E 2002, 66, (1), 011706. DOI: 10.1103/PhysRevE.66.011706
This is easiest to do if you use a graphics package that has directional gradients built-in (but coding it yourself probably wouldn't be too hard). Basically you create copies of the image and on one you do a differentiation in the x-direction, and for the other one a differentiation in the y-direction. Let's call these images DIFX and DIFY. Then you compose two new images:
NUMERATOR = 2*DIFX*DIFY
DENOMINATOR = DIFX^2-DIFY^2
Then you calculate a final image:
ANGLES = atan2( NUMERATOR, DENOMINATOR )
(All the above calculations are done in a pixel-by-pixel mode.) The final image will have an angle map (with values between -pi to pi) for the image. It should be easy to then use the avg or max over that image to pull out the preferred direction. You may also improve results by tweaking the initial thresholding, or by adding an initial "Sharpen Edges" step, or by blurring the NUMERATOR and DENOMINATOR images slightly before doing the next step.
In any case, the above procedure has worked for me when coding image analysis for orientation throughout an image (coding was done in Igor Pro in my case). So maybe it is useful for you.
As a chemist and practicing scientist, I can attest to the phenomenal costs of doing modern science (much of which comes from safety regulations, and associated "certified" equipment). So I do agree that it is very difficult in the modern age for a hobbyist in their garage to make a groundbreaking discovery... That having been said, i think there are many reasons why hobbyist chemistry (and hobbyist science in general) is a good thing:
1. The combinatorial space in science (and in the production of chemicals especially) is absolutely massive. There is no practical way for chemists to explore it all, so of course they make educated guesses about what is both (a) reasonably easy to make; and (b) of some practical value. However because the combinatorial space is large, there is still plenty of uncharted territory for others to explore. Random fortuitous discoveries are certainly a part of science.
2. Hobbyists can afford to do research that is risky and has no obvious application (I mean "risky" in the sense of "it might not work or lead anywhere" and not in the sense of "it might be dangerous"). They don't have to satisfy funding agencies or pragmatic concerns. They can just explore. Thus they can sometimes pursue crazy lines of inquiry that established scientists wouldn't touch.
3. There is such a thing as having your creativity inhibited by institutionalized concepts. A hobbyist isn't as restricted by the "well-established-rules" of the field, and thus may make creative discoveries others would have missed. (This is rare, by the way: the vast majority of science comes from pushing along using well-established procedures and concepts... but rare "out of the box" discoveries are also important in science.)
4. Doing chemistry (or science in general) on a budget, using only commonly-available equipment, can actually force specific kinds of discoveries. Specifically, it helps to discover things that are cheap (which industry loves!) since it can be done with commodity chemicals and tools. (Who knows, there may be a cheap way to make a better antifreeze using only what is in your house and back-yard.) So hobbyists actually have a chance to discover things that will actually make an impact on industry (whereas the chance that they discover something fundamentally new, without modern diagnostic tools, is slimmer).
5. Finally, even if the hobbyist doesn't actually discover anything new or interesting (which is, by far, the most likely outcome), it has a positive effect on the participants. The people doing it are doing so for fun (presumably), and that in itself is reason enough. Moreover it may be the catalyst for someone to go into science professionally. The ability to make kids enthusiastic about science should not be overlooked. Like most hobbies, hobby-science is more about the process than the end result.
As a chemist, I definitely like the idea of hobby chemists, and/or home laboratories. People should be free to do science at home if they are so inclined. But this is in some sense a bad example:
Charles Goodyear figured out how to vulcanize rubber with the same stove that his wife used to bake the family's bread.
You should never use the same equipment for your chemistry as for your other household things. If you're going to do chemistry at home, do it safely. This means having a separate (well-ventilated) room for your work, and using separate ovens, microwave, glassware, and other equipment for your work. Chemical contamination is a real threat. You may look at a chemical reaction and deem all the reactants and products to be safe... but if you make a mistake you may contaminate a room/oven/glassware with a more dangerous side-product. And you do not want to be then ingesting these contaminants (worse, you do not want to expose your family and friends).
So, like I said, be safe and use dedicated equipment for your experiments. (And don't brush your teeth with the toothbrush you use to clean your test tubes.)
The parts of TFA that talk about "self-assembly" are referring to the recent advances in using "block copolymers" to take a given lithographic pattern and "multiply" it into a high-density pattern.
For anyone with access, these two article's from today's issue of Science Magazine describe this research:
Ricardo Ruiz, Huiman Kang, François A. Detcheverry, Elizabeth Dobisz, Dan S. Kercher, Thomas R. Albrecht, Juan J. de Pablo, and Paul F. Nealey "Density Multiplication and Improved Lithography by Directed Block Copolymer Assembly", Science 15 August 2008: 936-939,
DOI: 10.1126/science.1157626
Ion Bita, Joel K. W. Yang, Yeon Sik Jung, Caroline A. Ross, Edwin L. Thomas, and Karl K. Berggren "Graphoepitaxy of Self-Assembled Block Copolymers on Two-Dimensional Periodic Patterned Templates" Science 15 August 2008: 939-943. DOI: 10.1126/science.1159352
Block copolymers are polymers (long-chain molecules that make up, for example, plastics) that are designed in such a way that they spontaneously form well-defined nano-patterns when allowed to equilibrate. So for instance a block-copolymer cast as a coating might spontaneously form nano-sized cylinders inside it (where the 'cylinder' and 'matrix' are formed of two different components... the two 'blocks'). Depending on what kind of copolymer you synthesize, you can form nano-cylinders, nano-sheets, nano-spheres, and other shapes (check out this, and this for some examples of the morphologies one can obtain).
One of the problems with block-copolymers, however, is that although they form very well-defined shapes (of exceedingly small and regular size), that's useless if you can't put those nano-objects where you need them. That's where this new work in "Templated Self-Assembly" comes into play. Basically you create a conventional, big pattern using the tried-and-tested techniques used to make microchips (optical lithography, e-beam lithography, etc.). Then you use that as a template for the block-copolymer. It fills in the gaps in the big pattern with its much smaller-scale nano-objects... which are now placed at well-defined positions because of the larger-scale template. So basically you get "density multiplication" of whatever pattern you're able to make.
So if you can use normal lithography to make a pattern of 100 nm, the block-copolymer can fill in the gaps and give you a pattern with sizes of 20 nm. Also, this "self-assembly" process has a way of "healing" over defects, basically giving you a very well-defined pattern even if your original template wasn't perfect.
The patterns in question can be "chemical templates" (basically stripes of different chemicals on a surface), or "topographical templates" (physical channels), which is what the two above-mentioned papers deal with, respectively. (Other kinds of directed-assembly, like surface treatments, electric fields, or thermal fields, are also possible.)
The research is coming along very nicely, and Hitachi seems pretty serious about it. There's no guarantee that this will end up in real technology someday, but I'd say this is looking more and more viable as the research pours in.
(Disclosure: My research covers similar topics, and I've worked with some of the above-mentioned people on occasion.)
I was actually at the Smithsonian Air and Space Museum a week ago. The museum overall is simply fantastic--a must see for any die-hard geek. Actually, the Air and Space is split into two parts: a museum in downtown DC that has some planes and the lunar re-entry vehicles; and a larger hangar near the airport (Dulles, in Virginia) that has larger planes and space vehicles (including the Space Shuttle Enterprise). Best of all, the Smithsonian Museums all have free admittance. (I probably sound like an ad for the Smithsonians--I just really enjoyed it!)
I saw the UAV exhibit, and it is indeed quite cool to see the sizes and designs of these vehicles. (FYI: the UAV exhibit is at the downtown DC museum.) On the one hand the UAVs are quite large, if you compare them to RC planes and helicopters. On the other hand, it's amazing how far the technology has come, that we can build a flight-capable system with high-quality (military-grade surveillance) optics in such a small package.
If the numbers in TFA are true (36 million students, growing to 52 million by the end of 2009), then this is absolutely huge in terms of Linux install base. In fact, I think this project would approximately double the install base.
I know that "counting" the number of Linux installs is essentially impossible, but here are some random numbers I've accumulated that point to the approximate size of the Linux user base:
1. The Linux Counter estimated 29 million installs in 2005. This estimate involved numerous assumptions, such as extrapolating from 8 million installs reported by Red Hat in 1998.
2. According to an IDC study, the Linux marketshare for PCs was ~3% in 2003.
3. There are about 1 billion Internet users. Browser logs indicate that Linux accounts for ~0.8% to ~3.9% of web traffic. This gives us an estimate of 8 million to 39 million Linux users. (The upper estimate is undoubtedly an over-estimate since the value comes from W3Schools, which probably has a greater fraction of 'technical' users.)
4. According to Canonical's server logs from OS updates, there are approximately 6 million active users of Ubuntu (see here and here). Assuming that Ubuntu represents 30% of Linux usage (based on this), you can come up with an estimate of 20 million Linux users.
5. According to Fedora's logs for OS updates, there are approximately 2.8 million installations of Fedora Core 6, and 1.6 million of Fedora 7. Assuming Fedora represents 9% of Linux installs (again, based on this), you can estimate 48 million Linux users.
Obviously all of these methods have their own problems. I'm not claiming that any of these estimates are robust. However they do at least suggest a range for the number of Linux users (~20 million) and the marketshare of Linux (~1% to 2%).
So, this single project, it would seem, is drastically increasing (doubling?) Linux usage. This is huge, in my opinion, because a generation of students who have learned Linux will be far more likely to use and improve upon FLOSS when they enter the job market.
I also wonder why closed source vendors don't open their code. They don't have to release it under the GPL, they can reatain all their copyrights, just publish the source. How could it hurt them? They retain copyrights and presumably patents so it's not like anyone could copy them. Only the companies know for sure why they keep it closed-source, but explanations that have been suggested at various times include:
1. The drivers contain code licensed from third-parties, such that opening the source would require extensive contracts, negotiations, and more licensing. Probably most of these third-party software vendors won't agree to have their code opened for the same reasons that all closed-source companies keep their source closed.
2. Modern video cards (and other hardware too, probably) contain a surprising amount of their logic and "acceleration magic" in the driver. The card itself, though dedicated to a particular hardware task, is quite general and thus the code controlling the card contains many of the important 'tricks' to get good performance. (In fact I've been told that the difference between some cards and higher models is only in the driver.) In such cases, releasing the software code would be like releasing the hardware circuit diagram: it would reveal many of their trade secrets (some of which may be patent-protected, others not).
3. Even if it would be illegal, some people would modify and redistribute the code. Hobbyist hackers would alter the code and recompile. This might allow end-users to bypass restrictions on the card, enable other features (effectively upgrade the card by bypassing lockouts), and so on. This makes lock-in harder, and might reduce the frequency that people upgrade their hardware.
4. Their code, in all likelihood, violates a large number of competitor patents. As long as the violations are buried inside a binary, no one will notice. Opening the code would make it easy for a competitor to spot violations and sue. Probably all the companies violate each other's hardware and software patents, but they maintain an uneasy balance by all being secretive. If one company released too much information, the others would use it against them.
5. The company may worry about other liabilities that they become exposed to when users and competitors can peruse the codebase.
As I said, only the companies know for sure. But there are plenty of plausible reasons for why a hardware company wouldn't want to release driver source code. They are not great reasons (many of us would be more willing to buy the hardware if it had more documentation and/or open code), but they make business sense.
How could a tiny black hole engender a positive feedback loop? I'm not even speaking of Hawking's radiation here; but how would a few g big blackhole do anything? You're right that a micro black hole would have a very weak gravitational field (a nanogram black hole has the same gravitational attraction as a nanogram of ordinary matter). However if the black hole didn't evaporate, it would slowly accumulate mass just from random collisions with nearby atoms. An object that is a singularity (infinite density at core) will have an event horizon. Even though the gravitational field is not strong around a micro black hole, there is still a (very, very small) region where the field gradient is so large that nothing can escape.
For instance if a micro black hole was generated in the LHC but didn't evaporate, it would eventually drift into the sidewall of the collision chamber, and whatever matter it 'touched' (atoms pass beyond the event horizon) would not be able to escape and would add to the mass of the black hole. Slowly by slowly it would grow in size. Because matter is never lost out of the black hole, it would eventually accumulate a huge amount of matter. How exactly the scenario would play (in terms of rate of expansion, etc.) would be interesting to calculate (would it sink down into the earth? would it slowly consume the atmosphere?): but I think it would grow exponentially and ultimately consume the entire Earth.
That's assuming that such a small black hole is actually a stable singularity with an event horizon, and that it cannot evaporate or dissipate in any way. Our best understanding of black holes right now indicates that if they form at all in the LHC (which is itself a dubious notion), they will be so small that they will evaporate very quickly due to Hawking radiation.
The doomsayers worry that our theory of Hawking radiation is somehow wrong. But as others have pointed out, high-energy cosmic rays hit the earth all the time, and we haven't been converted into a black hole yet. So it's either very hard to form micro black holes, or they evaporate very quickly.
Re:In the future nobody touches anything
on
Meet the Laptop of 2015
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· Score: 4, Interesting
Agreed. Typing on rigid, flat surfaces is painful and inefficient.
Which is why a combination of the concepts presented in the article would be far more attractive than any of them separately (I'm surprised the author of the piece didn't pick up on this): One of the laptops is billed as being "for blind people" because the surface can deform to generate bumps that the blind can read. The rest of the laptops have flat touch-screens for keyboards. Which is great for dynamic layouts but sucks for typing.
But combining them would be amazing. Imagine a keyboard that can reconfigure not only what is displayed on each key (like the Optimus), but also the keys themselves. If this "surface deformation" technology was good enough (and could be integrated with flexible displays) then you could have a surface that acts as a flat screen some of the time (for reading e-books, as a drawing pad, etc.) but generates the tactile relief of keys when typing is required.
More generally, it could reconfigure to generate new keyboard layouts as required. This would also solve one of the criticisms with the iPhone and iPod touch: you can't operate them without looking directly at the keys. Imagine if in addition to visual changes on the screen, there were bumps and grooves that dynamically appeared so that by touch alone you could feel the current key layout.
This, to me, is the ultimate future for compact computing devices: we will have screens that can vary both display and topography. Of course the technology to do this will be difficult to "get right" (key topography is only half of typing: you need the keys to "spring" properly)... but there is nothing impossible in principle about having deformable surfaces with integrated flexible displays.
As the other poster mentioned, photons are affected by gravity in as much as they travel through a space-time that is curved by massive objects. So the path of a photon (e.g. light) can be deflected by a gravitational field.
To those who would then say "Aha! So clearly photons do interact with gravity!", it's important to note that photons may be affected by the curvature of spactime, but they don't have mass and thus don't interact gravitationally. For instance, photons cannot attract each other gravitationally (whereas matter does), and a photon won't attract matter gravitationally.
Most of the space occupied by the atom is exactly that, space, nothing more. The electron cloud is a fuzzy region of probability, not a solid thing. The "side" of an atom must be defined by a force, not a particle? You're right that an atom is mostly empty space, but that doesn't matter. An electron microscope works by shooting a beam of electrons at the sample, and measuring how many of those electrons are transmitted (this is called a TEM; an SEM works differently). The electrons that didn't go straight through the sample were scattered by the atoms of the material. Remember that electrons are charged: as the incident electrons travel through the atoms there will be very strong Coulomb forces. The incident electrons will be repelled by the electrons in the material. This interaction is 'long-range' by subatomic standards: even though the electrons themselves are vanishingly small, the Coulomb interaction distance is quite large.
To a first approximation, 'heavier' atoms (higher atomic number) will scatter electrons more strongly, since they have more electrons. On an electron micrograph, heavy atoms show up as dark (absorbed/scattered alot of electrons), whereas lighter atoms show up as being bright (most electrons were transmitted).
I'm glossing over many details, of course. The important thing to remember is that the incident charged electrons are interacting with the charged electron density surrounding the atoms in the material.
I'm not sure what the actual innovation is here. Using false-color in an image is certainly not the innovation. What is innovative is their use of corrective optics to achieve much higher signal (100-fold increase compared to conventional techniques), and the integration of energy-loss spectroscopy. This means that for each pixel in the image, they can determine what kind of atom is being measured. So they can generate false-color maps of atomic identity. Most electron microscopes simply measure electron density: you can guess which element is which based on density, but there can be ambiguities. Some microscopes include detectors for determining what elements are present, but not with high spatial resolution. This new refinement allows precise maps where individual atoms can be both localized, and elementally identified.
The image they show is impressive when you consider that each blob of color is actually an individual atom, and that they've identified exactly what kind of atom is at each position. In this case they were using it to analyze interdiffusion of atoms at an interface. As nanotechnology becomes more and more 'real' you can imagine how useful it will be to image nano-objects with atomic resolution and elemental discrimination.
I don't know about in England, but in the US that's considered a poor argument in favor of mob rule. You're right that just because "everyone is doing it" doesn't mean something should be legal. However it does mean we should take a moment to re-analyze why the law exists, and whether the law is achieving its aim.
For instance, driving speed limits are routinely broken, yet this doesn't mean we should abolish speed limits. The purpose they serve (increasing safety) may outweigh the consensus opinion. (Nevermind for a moment that a strong argument for raising speed limits could also be made.)
What's different about copyright, however, is that a large portion of the rhetoric for keeping the law revolves around "rights"--it is an implicitly moral argument. The fact that a large percentage of the population is ignoring the law suggests that (for better or worse), they do not feel the law has moral high-ground (as compared to theft for example; most people wouldn't steal a physical good even if they knew they wouldn't get caught, because they consider it immoral). In such cases it is worthwhile to reconsider the law: if the consensus is that this law isn't morally required, why do we have it?
The main reason for having copyright is, ostensibly, to promote the creation and dissemination of intellectual works. Thus the law is meant to increase the amount and value of intellectual works. However it is again clear from the behavior of individuals that they are extracting more value from the works by freely sharing them than by adhering to the restrictions of copyright law. So we must again ask if this consensus behavior is in fact telling us that copyright law, in its current form, is not properly maximizing the value, to society, of intellectual works.
My point here is only that the "mob rule" logic is germane to the copyright debate because copyright law is supposedly meant to increase value for this very mob. The opinions of common people on this topic are therefore relevant to the debate (whereas some laws should probably be insulated from the whims of the populace). Again, I agree that there are cases where the mob opinion would ultimately be detrimental to society (people can act selfishly to their ultimate detriment)--but it's by no means clear that this is true in the case of copyright law.
What about those journals (Nature and Science, maybe?) that do not allow this. Well Nature Magazine actually does allow you to publish even if you've put the article on a pre-print server (see this blog post that explains their editorial policy). In fact, Nature runs their own pre-print server called Nature Precedings, so they are obviously preprint-friendly. In fact, a large number of journals are preprint-friendly (about 2/3 of all journals, according to TFA). Although many journals are not yet supportive for open access (I can't find a preprint policy for Science Magazine), the trend is clearly towards allowing preprint archiving.
Does this mean that Harvard will break copyright agreements? According to TFA:
The new policy will allow faculty members to request a waiver, but otherwise they must provide an electronic form of each article to the provost's office
So evidently they will make it possible for authors to publish in more restrictive journals if necessary. But the overall push towards open access is clear.
My guess is that within a few more years, all the journals will be preprint-friendly. After all, the journals need the authors more than the authors need them. Any journal that refuses to allow these kinds of policies will find it difficult to attract high-profile publications in coming years.
You are clearly asked if this is okay when you install the application, so facebook is not doing anything unethical. It's all above the board... It's mostly above board. The part that isn't is that even if you don't install any Facebook applications, if one of your friends (who can see your private profile) decides to install an application, that app now has access to your profile. As TFA explains:
Many Facebook users set their profiles to private, which stops anyone but their friends from seeing their profile details. This is a great privacy feature that can protect users from cyberstalkers and is completely gutted by the application system. To restate things--if you set your profile to private, and one of your friends adds an application, most of your profile information that is visible to your friend is also available to the application developer--even if you yourself have not installed the application.
(Emphasis in original.)
You can disable this loophole in Facebook's settings (go to Privacy > Applications > Other Applications and set it to "do not share"), but it isn't made very clear that by default your private details are nevertheless accessible to third-party apps through your friends list. Facebook should make this much more explicit (or perhaps have this setting default to "do not share" for anyone who sets their main profile to private?).
You're right, of course. The fact is that Facebook provides a uniform, generic API. It's up to application developers which bits of information are relevant to their application.
But that's not to say this is the only way to do it. It would be possible, for instance, to have the API set such that the application initially makes a request for which database fields it will need to use. Then the application is only allowed to use those fields; all others are invisible. When a user installs an app, it clearly shows which fields the app will be using. This would allow users to make informed choices about which apps to install. If "SuperPoke" says it will access your friends list, that's fine. If it says it will access your address and phone number, that's suspicious.
My point is that Facebook decided to implement a binary security model: either you don't install the app, or you give it access to everything. This doesn't seem like the best model. As a general security rule, an application should be given access to the absolute minimum breadth of resources/data needed to do its job properly.
This is why I don't install Facebook apps: there is no mechanism for controlling the security or even establishing a chain of trust for the application developer.
IF MS were to change the way pages rendered with existing doctypes, millions of pages could/would render differently requiring businesses and individuals across the world to either re-vamp their websites or at least change the existing doctype to a new name that referred to the old rendering style. I don't buy it (or maybe I just don't get it--if so, please explain).
IE (just like Firefox, etc.) has a "quirks" mode which renders things in a non-standards compliant way, but is designed to "more or less work" with all the pages out there that are not strictly coded. This new tag is supposed to apply to web-pages where the web author has already explicitly said he wants strict rendering, because he said so in the DOCTYPE. But instead of just fixing IE so that it renders that standards-compliant code better and better, they propose to freeze that rendering sub-engine, and force web-developers to add a new tag that basically says "yes I really meant I wanted you to render strictly!"
It seems to me that the majority of pages that rely on rendering quirks will be okay, since they will be rendered in quirks mode. But pages that were intended to be standards-compliant should be treated as such.
Microsoft's plan isn't sustainable or elegant: they basically want the entire web-community to add another tag each time MS releases a new version of IE. (If they want a custom tag for the IE7->IE8 transition, they probably will want a new one for the next transition...) The entire point of these standards was to get away from browser-specific tags and hacks. A web developer shouldn't have to think about what browsers are on the market today (or 3 years from now): he should just code to the standard.
Put otherwise: Instead of asking everyone who has written a standards-compliant page to add-in a non-standard tag to make it work in IE... wouldn't it be easier to tell everyone "hey, if you've coded a page that is ~almost~ standards-compliant, but relies in some way on IE7-specific behavior, then add in this <NotQuiteStandard> tag, and IE8 will render it like IE7."
MS can go ahead and fund Windows training... but they should call it 'funding Windows training' or 'advertising' or 'market capture' (depending how honest they want to be). Calling it 'foreign aid' is a stretch, and part of the problem.
There is also the fact that MS is, apparently, only offering free training to schools that agree to be purely Windows institutions. If a Linux outfit offered free support, but only on condition of NOT using any non-Linux software, you can be sure that the community would cry foul. Providing Windows-only support is fine. Providing support only to purely Windows institutes? Nasty.
Lastly, there is the usual monopoly issue. Things that might be fair game for most companies can quickly become unfair (even illegal) for monopolies. This appears to be another case of MS leveraging their existing dominance (and corresponding cash) to create a monopoly in a new market. Generally, allowing a monopoly to extend itself like this, at the expense of competitors, is a bad thing.
Slashdot Mirror
The base-pair sequence of DNA determines its biological function. As you say, this sequence determines what kinds of proteins get made, including their exact shape (and more broadly how they behave).
But TFA is talking about the conformation (shape) of the DNA strand itself, not the protein structures that the DNA strand is used to make.
In living organisms, the long DNA molecule always forms a double-helix, irrespective of the base-pair sequence within the DNA. DNA double helices do actually twist and wrap into larger-scale structures: specifically by wrapping around histones, and then twisting into larger helices that eventually form chromosomes. There are hints that the DNA sequence itself is actually important in controlling how this twisting/packing happens (with ongoing research about how (innapropriately-named) "junk DNA" plays a crucial role). However, despite this influence between sequence and super-structure, DNA strands essentially are just forming double-helices at the lowest level: i.e. two complementary DNA strands are pairing up to make a really-long double-helix.
What TFA is talking about is a field called "DNA nanotechnology", where researchers synthesize non-natural DNA sequences. If cleverly designed, these sequences will, when they do their usual base-pairing, form a structure more complex than the traditional "really-long double-helix". The structures that are designed do not occur naturally. People have created some really complex structures, made entirely using DNA. Again, these are structures made out of DNA (not structures that DNA generates). You can see some examples by searching for "DNA origami". E.g. one of the famous structures was to create a nano-sized smiley face; others have 3D geometric shapes, nano-boxes and bottles, gear-like constructs, and all kinds of other things.
The 'trick' is to violate the assumptions of DNA base-pairing that occur in nature. In living cells, DNA sequences are created as two long complementary strands, which pair up with each other. The idea in DNA nanotechnology is to create an assortment of strands. None of the strands are perfectly complementary to each other, but 'sub-regions' of some strands are complementary to 'sub-regions' on other strands. As they start pairing-up with each other, this creates cross-connections between all the various strands. The end result (if your design is done correctly) is that the strands spontaneously form a ver well-defined 3D structure, with nanoscale precision. The advantage of this "self-assembly" is that you get billions of copies of the intended structure forming spontaneously and rapidly. Very cool stuff.
This kind of thing has been ongoing since 2006 at least. TFA erroneously implies that this most recent publication invented the field. Actually, this most recent publication is some nice work about how the design process can be made more robust (and software-automated). So, it's a fine paper, but certainly not the first demonstration of artificial 3D DNA nano-objects.
Human sorting tends to be rather ad-hoc, and this isn't necessarily a bad thing. Yes, if someone is sorting a large number of objects/papers according to a simple criterion, then they are likely to be implementing a version of some sort of formal searching algorithm... But one of the interesting things about a human sorting things is that they can, and do, leverage some of their intellect to improve the sorting. Examples: ...).
1. Change sorting algorithm partway through, or use different algorithms on different subsets of the task. E.g. if you are sorting documents in a random order and suddenly notice a run that are all roughly in order, you'll intuitively switch to a different algorithm for that bunch. In fact, humans very often sub-divide the problem at large into stacks, and sub-sort each stack using a different algorithm, before finally combining the result. This is also relevant since sometimes you actually need to change your sorting target halfway through a sort (when you discover a new category of document/item; or when you realize that a different sorting order will ultimately be more useful for the high-level purpose you're trying to achieve;
2. Pattern matching. Humans are good at discerning patterns. So we may notice that the documents are not really random, but have some inherent order (e.g. the stack is somewhat temporally ordered, but items for each given day are reversed or semi-random). We can exploit this to minimizing the sorting effort.
3. Memory. Even though humans can't juggle too many different items in their head at once, we're smart enough that we encounter an item, we can recall having seen similar items. Our visual memory also allows us to home-in on the right part of a semi-sorted stack in order to group like items.
The end result is a sort that is rather non-deterministic, but ultimately successful. It isn't necessarily optimal for the given problem space, but conversely their human intellect is allowing them to generate lots of shortcuts during the sorting problem. (By which I mean, a machine limited to paper-pushing at human speed, but implementing a single formal algorithm, would take longer to finish the sort... Of course in reality mechanized/computerized sorting is faster because each machine operation is faster than the human equivalent.)
(emphasis added) Your implication is that physicists have invented parallel universes, adding them to their theories. In actuality, parallel realities are predictions of certain modern theories. They are not axioms, they are results. Max Tegmark explains this nicely in a commentary (here or here). Briefly: if unitary quantum mechanics is right (and all available data suggests that it is), then this implies that the other branches of the wavefunction are just as real as the one we experience. Hence, quantum mechanics predicts that these other branches exist. Now, you can frame a philosophical question about whether entities in a theory 'exist' or whether they are just abstractions. But it's worth noting that there are plenty of theoretical entities that we now accept as being real (atoms, quarks, spacetime, etc.). Moreover, there are many times in physics where, once we accept a theory as being right, we accept its predictions about things we can't directly observe. Two examples would be: to the extent that we accept general relativity as correct, we make predictions about the insides of black holes, even though we can't ever observe those areas. To the extent that we accept astrophysics and big-bang models, we make predictions about parts of the universe we cannot ever observe (e.g. beyond the cosmic horizon).
Indeed. But while we can't directly observe other branches of the wavefunction, we can, through experiments, theory, and modeling, indirectly learn much about them. We can have a lively philosophical debate about to what extent we are justified in using predictions of theories to say indirect things are 'real' vs. 'abstract only'... but my point is that parallel realities are not alone here. Every measurement we make is an indirect inference based on limited data, extrapolated using a model we have some measure of confidence in.
Occam's Razor is frequently invoked but is not always as useful as people make it out to be. If you have a theory X and a theory X+Y that both describe the data equally well, then X is better via Occam's Razor. But if you're comparing theories X+Y and X+Z, it's not clear which is "simpler". You're begging the question if you say "Clearly X+Y is simpler than X+Z! Just look at how crazy Z is!" More specifically: unitary quantum mechanics is arguably simpler than quantum mechanics + collapse. The latter involves adding an ad-hoc, unmeasured, non-linear process that has never actually been observed. The former is simpler at least in description (it's just QM without the extra axiom), but as a consequence predicts many parallel branches (it's actually not an infinite number of branches: for a finite volume like our observable universe, the possible quantum states is large but finite). Whether an ad-hoc axiom or a parallal-branch-prediction is 'simpler' is debatable.
Again, the parallel branches are not a postulate, but a prediction. They are a prediction that bother many people. Yet attempts to find inconsistencies in unitary quantum mechanics so far have failed. Attempts to observe the wavefunction collapse process have also failed (there appears to be no
I disagree. Yes, there are tensions between openness/hackability/configurability/variability and stability/manageability/simplicity. However, the existence of certain tradeoffs doesn't mean that Apple couldn't make a more open product in some ways without hampering their much-vaunted quality.
One way to think about this question to analyze whether a given open/non-open decision is motivated by quality or by money. A great many of the design decisions that are being made are not in the pursuit of a perfect product, but are part of a business strategy (lock-in, planned obsolescence, upselling of other products, DRM, etc.). I'm not just talking about Apple, this is true very generally. Examples:
- Having a single set of hardware to support does indeed make software less bloated and more reliable. That's fair. Preventing users from installing new hardware (at their own risk) would not be fair.
- Similarly, having a restricted set of software that will be officially supported is fine. Preventing any 'unauthorized' software from running on a device a user has purchased is not okay. The solution is to simply provide a checkbox that says "Allow 3rd party sources (I understand this comes with risks)" which is what Android does but iOS does not.
- Removing seldom-used and complex configuration options from a product is a good way to make it simpler and more user-friendly. But you can easily promote openness without making the product worse by leaving configuration options available but less obvious (e.g. accessed via commandline flags or a text config file).
- Building a product in a non-user-servicable way (no screws, only adhesives, etc.) might be necessary if you're trying to make a product extremely thin and slick.
- Conversely, using non-standard screws, or using adhesives/etc. where screws would have been just as good, is merely a way to extract money from customers (forcing them to pay for servicing or buy new devices rather than fix old hardware).
- Using bizarre, non-standard, and obfuscated file formats or directory/data-structures can in some cases be necessary in order to achieve a goal (e.g. performance). However in most cases it's actually used to lock-in the user (prevent user from directly accessing data, prevent third-party tools from working). E.g. the way that iPods appear to store the music files and metadata is extremely complex, at least last time I checked (all files are renamed, so you can't simply copy files to-and-from the device). The correct solution is to use open formats. In cases where you absolutely can't use an established standard, the right thing to do is to release all your internal docs so that others can easily build upon it or extend it.
To summarize: yes, there are cases where making a product more 'open' will decrease its quality in other ways. But, actually, there are many examples where you can leave the option for openness/interoperability without affecting the as-sold quality of the product. (Worries about 'users breaking their devices and thus harming our image' do not persuade; the user owns the device and ultimately we're talking about experience users and third-party developers.) So, we should at least demand that companies make their products open in all those 'low-hanging-fruit' cases. We can then argue in more detail about fringe cases where there is really a openness/quality tradeoff.
I'm somewhat more hopeful than you, based on advances in x-ray optics.
For typical x-ray photons (e.g. 10 keV), the refractive index is 0.99999 (delta = 1E-5). Even though this is very close to 1, we've figured out how to make practical lenses. For instance Compound Refractive Lenses use a sequence of refracting interfaces to accumulate the small refractive effect. Capillary optics can be used to confine x-ray beams. A Fresnel lens design can be used to decrease the thickness of the lens, giving you more refractive power per unit length of the total optic. In fact, you can use a Fresnel zone plate design, which focuses the beam due to diffraction (another variant is a Laue lens which focuses due to Bragg diffraction, e.g. multilayer Laue lenses are now being used for ultrahigh focusing of x-rays). Clever people have even designed lenses that simultaneously exploit refractive and diffractive focusing (kinoform lenses).
All this to say that with some ingenuity, the rather small refractive index differences available for x-rays have been turned into decent amounts of focusing in x-ray optics. We have x-rays optics now with focal lengths on the order of meters. It's not trivial to do, but it can be done. It sounds like this present work is suggesting that for gamma-rays the refractive index differences will be on the order of 1E-7, which is only two orders-of-magnitude worse than for x-rays. So, with some additional effort and ingenuity, I could see the development of workable gamma-ray optics. I'm not saying it will be easy (we're still talking about tens or hundreds of meters for the overall camera)... but for certain demanding applications it might be worth doing.
C. L. Degen, M. Poggio, H. J. Mamin, C. T. Rettner, D. Rugar Nanoscale magnetic resonance imaging PNAS 2009, doi: 10.1073/pnas.0812068106.
The abstract:
I think it's important to emphasize that this is a nanoscale magnetic imaging technique. The summary implies that they created a conventional MRI that has nanoscale resolution, as if they can now image a person's brain and pick out individual cells and molecules. That is not the case! And that is likely to never be possible (given the frequencies of radiation that MRI uses and the diffraction limit that applies to far-field imaging.
That having been said, this is still a very cool and noteworthy piece of science. Scientists use a variety of nanoscale imaging tools (atomic force microscopes, electron microscopes, etc.), but having the ability to do nanoscale magnetic imaging is amazing. In the article they do a 3D reconstruction of a tobacco mosaic virus. One of the great things about MRI is that is has some amount of chemical selectivity: there are different magnetic imaging modes that can differentiate based on makeup. This nanoscale analog can use similar tricks: instead of just getting images of surface topography or electron density, it could actually determine the chemical makeup within nanostructures. I expect this will become a very powerful technique for nano-imaging over the next decade.
The image analysis question is interesting. You are trying to read dial positions, so conventional OCR is probably useless (unless there is a package to do exactly that?).
What you can do is use image processing commands (in your favorite programming language; a shell script, Python, etc.) to crop the image to generate a small image for each dial. Then convert to grayscale (and maybe increase the contrast to highlight the dial). To then calculate the preferred orientation in the image, you calculate gradients along different directions. There will be a much higher value for the gradient along directions perpendicular to the preferred axis. This procedure is described very briefly in this paper:
Harrison, C.; Cheng, Z.; Sethuraman, S.; Huse, D. A.; Chaikin, P. M.; Vega, D. A.; Sebastian, J. M.; Register, R. A.; Adamson, D. H. "Dynamics of pattern coarsening in a two-dimensional smectic system" Physical Review E 2002, 66, (1), 011706. DOI: 10.1103/PhysRevE.66.011706
This is easiest to do if you use a graphics package that has directional gradients built-in (but coding it yourself probably wouldn't be too hard). Basically you create copies of the image and on one you do a differentiation in the x-direction, and for the other one a differentiation in the y-direction. Let's call these images DIFX and DIFY. Then you compose two new images:
NUMERATOR = 2*DIFX*DIFY
DENOMINATOR = DIFX^2-DIFY^2
Then you calculate a final image:
ANGLES = atan2( NUMERATOR, DENOMINATOR )
(All the above calculations are done in a pixel-by-pixel mode.) The final image will have an angle map (with values between -pi to pi) for the image. It should be easy to then use the avg or max over that image to pull out the preferred direction. You may also improve results by tweaking the initial thresholding, or by adding an initial "Sharpen Edges" step, or by blurring the NUMERATOR and DENOMINATOR images slightly before doing the next step.
In any case, the above procedure has worked for me when coding image analysis for orientation throughout an image (coding was done in Igor Pro in my case). So maybe it is useful for you.
As a chemist and practicing scientist, I can attest to the phenomenal costs of doing modern science (much of which comes from safety regulations, and associated "certified" equipment). So I do agree that it is very difficult in the modern age for a hobbyist in their garage to make a groundbreaking discovery... That having been said, i think there are many reasons why hobbyist chemistry (and hobbyist science in general) is a good thing:
1. The combinatorial space in science (and in the production of chemicals especially) is absolutely massive. There is no practical way for chemists to explore it all, so of course they make educated guesses about what is both (a) reasonably easy to make; and (b) of some practical value. However because the combinatorial space is large, there is still plenty of uncharted territory for others to explore. Random fortuitous discoveries are certainly a part of science.
2. Hobbyists can afford to do research that is risky and has no obvious application (I mean "risky" in the sense of "it might not work or lead anywhere" and not in the sense of "it might be dangerous"). They don't have to satisfy funding agencies or pragmatic concerns. They can just explore. Thus they can sometimes pursue crazy lines of inquiry that established scientists wouldn't touch.
3. There is such a thing as having your creativity inhibited by institutionalized concepts. A hobbyist isn't as restricted by the "well-established-rules" of the field, and thus may make creative discoveries others would have missed. (This is rare, by the way: the vast majority of science comes from pushing along using well-established procedures and concepts... but rare "out of the box" discoveries are also important in science.)
4. Doing chemistry (or science in general) on a budget, using only commonly-available equipment, can actually force specific kinds of discoveries. Specifically, it helps to discover things that are cheap (which industry loves!) since it can be done with commodity chemicals and tools. (Who knows, there may be a cheap way to make a better antifreeze using only what is in your house and back-yard.) So hobbyists actually have a chance to discover things that will actually make an impact on industry (whereas the chance that they discover something fundamentally new, without modern diagnostic tools, is slimmer).
5. Finally, even if the hobbyist doesn't actually discover anything new or interesting (which is, by far, the most likely outcome), it has a positive effect on the participants. The people doing it are doing so for fun (presumably), and that in itself is reason enough. Moreover it may be the catalyst for someone to go into science professionally. The ability to make kids enthusiastic about science should not be overlooked. Like most hobbies, hobby-science is more about the process than the end result.
Charles Goodyear figured out how to vulcanize rubber with the same stove that his wife used to bake the family's bread.
You should never use the same equipment for your chemistry as for your other household things. If you're going to do chemistry at home, do it safely. This means having a separate (well-ventilated) room for your work, and using separate ovens, microwave, glassware, and other equipment for your work. Chemical contamination is a real threat. You may look at a chemical reaction and deem all the reactants and products to be safe... but if you make a mistake you may contaminate a room/oven/glassware with a more dangerous side-product. And you do not want to be then ingesting these contaminants (worse, you do not want to expose your family and friends).
So, like I said, be safe and use dedicated equipment for your experiments. (And don't brush your teeth with the toothbrush you use to clean your test tubes.)
For anyone with access, these two article's from today's issue of Science Magazine describe this research:
Block copolymers are polymers (long-chain molecules that make up, for example, plastics) that are designed in such a way that they spontaneously form well-defined nano-patterns when allowed to equilibrate. So for instance a block-copolymer cast as a coating might spontaneously form nano-sized cylinders inside it (where the 'cylinder' and 'matrix' are formed of two different components... the two 'blocks'). Depending on what kind of copolymer you synthesize, you can form nano-cylinders, nano-sheets, nano-spheres, and other shapes (check out this, and this for some examples of the morphologies one can obtain).
One of the problems with block-copolymers, however, is that although they form very well-defined shapes (of exceedingly small and regular size), that's useless if you can't put those nano-objects where you need them. That's where this new work in "Templated Self-Assembly" comes into play. Basically you create a conventional, big pattern using the tried-and-tested techniques used to make microchips (optical lithography, e-beam lithography, etc.). Then you use that as a template for the block-copolymer. It fills in the gaps in the big pattern with its much smaller-scale nano-objects... which are now placed at well-defined positions because of the larger-scale template. So basically you get "density multiplication" of whatever pattern you're able to make.
So if you can use normal lithography to make a pattern of 100 nm, the block-copolymer can fill in the gaps and give you a pattern with sizes of 20 nm. Also, this "self-assembly" process has a way of "healing" over defects, basically giving you a very well-defined pattern even if your original template wasn't perfect.
The patterns in question can be "chemical templates" (basically stripes of different chemicals on a surface), or "topographical templates" (physical channels), which is what the two above-mentioned papers deal with, respectively. (Other kinds of directed-assembly, like surface treatments, electric fields, or thermal fields, are also possible.)
The research is coming along very nicely, and Hitachi seems pretty serious about it. There's no guarantee that this will end up in real technology someday, but I'd say this is looking more and more viable as the research pours in.
(Disclosure: My research covers similar topics, and I've worked with some of the above-mentioned people on occasion.)
I was actually at the Smithsonian Air and Space Museum a week ago. The museum overall is simply fantastic--a must see for any die-hard geek. Actually, the Air and Space is split into two parts: a museum in downtown DC that has some planes and the lunar re-entry vehicles; and a larger hangar near the airport (Dulles, in Virginia) that has larger planes and space vehicles (including the Space Shuttle Enterprise). Best of all, the Smithsonian Museums all have free admittance. (I probably sound like an ad for the Smithsonians--I just really enjoyed it!)
I saw the UAV exhibit, and it is indeed quite cool to see the sizes and designs of these vehicles. (FYI: the UAV exhibit is at the downtown DC museum.) On the one hand the UAVs are quite large, if you compare them to RC planes and helicopters. On the other hand, it's amazing how far the technology has come, that we can build a flight-capable system with high-quality (military-grade surveillance) optics in such a small package.
If the numbers in TFA are true (36 million students, growing to 52 million by the end of 2009), then this is absolutely huge in terms of Linux install base. In fact, I think this project would approximately double the install base.
I know that "counting" the number of Linux installs is essentially impossible, but here are some random numbers I've accumulated that point to the approximate size of the Linux user base:
1. The Linux Counter estimated 29 million installs in 2005. This estimate involved numerous assumptions, such as extrapolating from 8 million installs reported by Red Hat in 1998.
2. According to an IDC study, the Linux marketshare for PCs was ~3% in 2003.
3. There are about 1 billion Internet users. Browser logs indicate that Linux accounts for ~0.8% to ~3.9% of web traffic. This gives us an estimate of 8 million to 39 million Linux users. (The upper estimate is undoubtedly an over-estimate since the value comes from W3Schools, which probably has a greater fraction of 'technical' users.)
4. According to Canonical's server logs from OS updates, there are approximately 6 million active users of Ubuntu (see here and here). Assuming that Ubuntu represents 30% of Linux usage (based on this), you can come up with an estimate of 20 million Linux users.
5. According to Fedora's logs for OS updates, there are approximately 2.8 million installations of Fedora Core 6, and 1.6 million of Fedora 7. Assuming Fedora represents 9% of Linux installs (again, based on this), you can estimate 48 million Linux users.
Obviously all of these methods have their own problems. I'm not claiming that any of these estimates are robust. However they do at least suggest a range for the number of Linux users (~20 million) and the marketshare of Linux (~1% to 2%).
So, this single project, it would seem, is drastically increasing (doubling?) Linux usage. This is huge, in my opinion, because a generation of students who have learned Linux will be far more likely to use and improve upon FLOSS when they enter the job market.
1. The drivers contain code licensed from third-parties, such that opening the source would require extensive contracts, negotiations, and more licensing. Probably most of these third-party software vendors won't agree to have their code opened for the same reasons that all closed-source companies keep their source closed.
2. Modern video cards (and other hardware too, probably) contain a surprising amount of their logic and "acceleration magic" in the driver. The card itself, though dedicated to a particular hardware task, is quite general and thus the code controlling the card contains many of the important 'tricks' to get good performance. (In fact I've been told that the difference between some cards and higher models is only in the driver.) In such cases, releasing the software code would be like releasing the hardware circuit diagram: it would reveal many of their trade secrets (some of which may be patent-protected, others not).
3. Even if it would be illegal, some people would modify and redistribute the code. Hobbyist hackers would alter the code and recompile. This might allow end-users to bypass restrictions on the card, enable other features (effectively upgrade the card by bypassing lockouts), and so on. This makes lock-in harder, and might reduce the frequency that people upgrade their hardware.
4. Their code, in all likelihood, violates a large number of competitor patents. As long as the violations are buried inside a binary, no one will notice. Opening the code would make it easy for a competitor to spot violations and sue. Probably all the companies violate each other's hardware and software patents, but they maintain an uneasy balance by all being secretive. If one company released too much information, the others would use it against them.
5. The company may worry about other liabilities that they become exposed to when users and competitors can peruse the codebase.
As I said, only the companies know for sure. But there are plenty of plausible reasons for why a hardware company wouldn't want to release driver source code. They are not great reasons (many of us would be more willing to buy the hardware if it had more documentation and/or open code), but they make business sense.
For instance if a micro black hole was generated in the LHC but didn't evaporate, it would eventually drift into the sidewall of the collision chamber, and whatever matter it 'touched' (atoms pass beyond the event horizon) would not be able to escape and would add to the mass of the black hole. Slowly by slowly it would grow in size. Because matter is never lost out of the black hole, it would eventually accumulate a huge amount of matter. How exactly the scenario would play (in terms of rate of expansion, etc.) would be interesting to calculate (would it sink down into the earth? would it slowly consume the atmosphere?): but I think it would grow exponentially and ultimately consume the entire Earth.
That's assuming that such a small black hole is actually a stable singularity with an event horizon, and that it cannot evaporate or dissipate in any way. Our best understanding of black holes right now indicates that if they form at all in the LHC (which is itself a dubious notion), they will be so small that they will evaporate very quickly due to Hawking radiation.
The doomsayers worry that our theory of Hawking radiation is somehow wrong. But as others have pointed out, high-energy cosmic rays hit the earth all the time, and we haven't been converted into a black hole yet. So it's either very hard to form micro black holes, or they evaporate very quickly.
Agreed. Typing on rigid, flat surfaces is painful and inefficient.
Which is why a combination of the concepts presented in the article would be far more attractive than any of them separately (I'm surprised the author of the piece didn't pick up on this): One of the laptops is billed as being "for blind people" because the surface can deform to generate bumps that the blind can read. The rest of the laptops have flat touch-screens for keyboards. Which is great for dynamic layouts but sucks for typing.
But combining them would be amazing. Imagine a keyboard that can reconfigure not only what is displayed on each key (like the Optimus), but also the keys themselves. If this "surface deformation" technology was good enough (and could be integrated with flexible displays) then you could have a surface that acts as a flat screen some of the time (for reading e-books, as a drawing pad, etc.) but generates the tactile relief of keys when typing is required.
More generally, it could reconfigure to generate new keyboard layouts as required. This would also solve one of the criticisms with the iPhone and iPod touch: you can't operate them without looking directly at the keys. Imagine if in addition to visual changes on the screen, there were bumps and grooves that dynamically appeared so that by touch alone you could feel the current key layout.
This, to me, is the ultimate future for compact computing devices: we will have screens that can vary both display and topography. Of course the technology to do this will be difficult to "get right" (key topography is only half of typing: you need the keys to "spring" properly)... but there is nothing impossible in principle about having deformable surfaces with integrated flexible displays.
Thank you (and the other posters) for the correction. I clearly didn't think about that one for long enough.
As the other poster mentioned, photons are affected by gravity in as much as they travel through a space-time that is curved by massive objects. So the path of a photon (e.g. light) can be deflected by a gravitational field.
To those who would then say "Aha! So clearly photons do interact with gravity!", it's important to note that photons may be affected by the curvature of spactime, but they don't have mass and thus don't interact gravitationally. For instance, photons cannot attract each other gravitationally (whereas matter does), and a photon won't attract matter gravitationally.
To a first approximation, 'heavier' atoms (higher atomic number) will scatter electrons more strongly, since they have more electrons. On an electron micrograph, heavy atoms show up as dark (absorbed/scattered alot of electrons), whereas lighter atoms show up as being bright (most electrons were transmitted).
I'm glossing over many details, of course. The important thing to remember is that the incident charged electrons are interacting with the charged electron density surrounding the atoms in the material.
The image they show is impressive when you consider that each blob of color is actually an individual atom, and that they've identified exactly what kind of atom is at each position. In this case they were using it to analyze interdiffusion of atoms at an interface. As nanotechnology becomes more and more 'real' you can imagine how useful it will be to image nano-objects with atomic resolution and elemental discrimination.
For instance, driving speed limits are routinely broken, yet this doesn't mean we should abolish speed limits. The purpose they serve (increasing safety) may outweigh the consensus opinion. (Nevermind for a moment that a strong argument for raising speed limits could also be made.)
What's different about copyright, however, is that a large portion of the rhetoric for keeping the law revolves around "rights"--it is an implicitly moral argument. The fact that a large percentage of the population is ignoring the law suggests that (for better or worse), they do not feel the law has moral high-ground (as compared to theft for example; most people wouldn't steal a physical good even if they knew they wouldn't get caught, because they consider it immoral). In such cases it is worthwhile to reconsider the law: if the consensus is that this law isn't morally required, why do we have it?
The main reason for having copyright is, ostensibly, to promote the creation and dissemination of intellectual works. Thus the law is meant to increase the amount and value of intellectual works. However it is again clear from the behavior of individuals that they are extracting more value from the works by freely sharing them than by adhering to the restrictions of copyright law. So we must again ask if this consensus behavior is in fact telling us that copyright law, in its current form, is not properly maximizing the value, to society, of intellectual works.
My point here is only that the "mob rule" logic is germane to the copyright debate because copyright law is supposedly meant to increase value for this very mob. The opinions of common people on this topic are therefore relevant to the debate (whereas some laws should probably be insulated from the whims of the populace). Again, I agree that there are cases where the mob opinion would ultimately be detrimental to society (people can act selfishly to their ultimate detriment)--but it's by no means clear that this is true in the case of copyright law.
Does this mean that Harvard will break copyright agreements? According to TFA: So evidently they will make it possible for authors to publish in more restrictive journals if necessary. But the overall push towards open access is clear.
My guess is that within a few more years, all the journals will be preprint-friendly. After all, the journals need the authors more than the authors need them. Any journal that refuses to allow these kinds of policies will find it difficult to attract high-profile publications in coming years.
You can disable this loophole in Facebook's settings (go to Privacy > Applications > Other Applications and set it to "do not share"), but it isn't made very clear that by default your private details are nevertheless accessible to third-party apps through your friends list. Facebook should make this much more explicit (or perhaps have this setting default to "do not share" for anyone who sets their main profile to private?).
You're right, of course. The fact is that Facebook provides a uniform, generic API. It's up to application developers which bits of information are relevant to their application.
But that's not to say this is the only way to do it. It would be possible, for instance, to have the API set such that the application initially makes a request for which database fields it will need to use. Then the application is only allowed to use those fields; all others are invisible. When a user installs an app, it clearly shows which fields the app will be using. This would allow users to make informed choices about which apps to install. If "SuperPoke" says it will access your friends list, that's fine. If it says it will access your address and phone number, that's suspicious.
My point is that Facebook decided to implement a binary security model: either you don't install the app, or you give it access to everything. This doesn't seem like the best model. As a general security rule, an application should be given access to the absolute minimum breadth of resources/data needed to do its job properly.
This is why I don't install Facebook apps: there is no mechanism for controlling the security or even establishing a chain of trust for the application developer.
IE (just like Firefox, etc.) has a "quirks" mode which renders things in a non-standards compliant way, but is designed to "more or less work" with all the pages out there that are not strictly coded. This new tag is supposed to apply to web-pages where the web author has already explicitly said he wants strict rendering, because he said so in the DOCTYPE. But instead of just fixing IE so that it renders that standards-compliant code better and better, they propose to freeze that rendering sub-engine, and force web-developers to add a new tag that basically says "yes I really meant I wanted you to render strictly!"
It seems to me that the majority of pages that rely on rendering quirks will be okay, since they will be rendered in quirks mode. But pages that were intended to be standards-compliant should be treated as such.
Microsoft's plan isn't sustainable or elegant: they basically want the entire web-community to add another tag each time MS releases a new version of IE. (If they want a custom tag for the IE7->IE8 transition, they probably will want a new one for the next transition...) The entire point of these standards was to get away from browser-specific tags and hacks. A web developer shouldn't have to think about what browsers are on the market today (or 3 years from now): he should just code to the standard.
Put otherwise: Instead of asking everyone who has written a standards-compliant page to add-in a non-standard tag to make it work in IE... wouldn't it be easier to tell everyone "hey, if you've coded a page that is ~almost~ standards-compliant, but relies in some way on IE7-specific behavior, then add in this <NotQuiteStandard> tag, and IE8 will render it like IE7."
MS can go ahead and fund Windows training... but they should call it 'funding Windows training' or 'advertising' or 'market capture' (depending how honest they want to be). Calling it 'foreign aid' is a stretch, and part of the problem.
There is also the fact that MS is, apparently, only offering free training to schools that agree to be purely Windows institutions. If a Linux outfit offered free support, but only on condition of NOT using any non-Linux software, you can be sure that the community would cry foul. Providing Windows-only support is fine. Providing support only to purely Windows institutes? Nasty.
Lastly, there is the usual monopoly issue. Things that might be fair game for most companies can quickly become unfair (even illegal) for monopolies. This appears to be another case of MS leveraging their existing dominance (and corresponding cash) to create a monopoly in a new market. Generally, allowing a monopoly to extend itself like this, at the expense of competitors, is a bad thing.