I know this runs against everything/. but I have seen it work a couple of times.
Why do you think that an unconfirmed anecdote being presented fallaciously as an argument is against everything/.?
It would actually be astonishing if no one had "seen it work a couple of times", for several reasons. One, if there were a 100% failure rate dousing would have been abandoned years ago. Even pre-scientific peoples mostly abandoned things that were never, ever correlated with their nominal goals.
Second, given humans are known to be prone to confirmation bias, we can predict that almost everyone who has ever seen a dowser identify one of the many, many places where water can be found will come away believing "dowsing works".
So a large number of scientifically illiterate people saying, "Hey I saw it work a few times that proves it's true so I believe it!" is exactly what science would predict if dowsing doesn't work.
If dowsing did work science would predict a bunch of peer-reviewed studies systematically detailing how accurate it is and investigating the factors that influence it's accuracy.
We see the former, not the latter.
Posts like yours actually constitute evidence that dowsing does not work.
One of the most interesting episodes I saw was when they were testing something Jamie said in an earlier episode: That if two trucks collide at 55 MPH, it's like one truck hitting a brick wall at 110 MPH. At first I thought "duh, everyone knows that's true" and I continued to think that as they set up experiments, right until they were about to let two clay blocks swing into each other at which point a light bulb lit up above my head, and so I quickly hit the pause button and thought about what was going to happen, and realized that since each block of clay was simply going to stop the movement of the other, each was going to end up in the same condition it would have been in had it simply slammed into the "immovable object" instead, and thus two vehicles each going 55 MPH in a head-on collision is exactly like just one vehicle hitting a brick wall in a 55 MPH collision....and I suppose it's solvable with math too, given e = m * v, and so if two objects slowing down one unit of speed yields two units of energy, or one unit per object, then one object slowing down two units of speed yields four units of energy, which is four times as much, even though the difference in speeds is identical in each case....but I was certainly misinformed about how it worked, and I don't think I was the only one, so it was totally worth doing an episode on, indeed it was one of my favorites since I actually learned something.
First, E = 1/2 m*v^2, not m*v, although your later statement seems to acknowledge that.
Second: you are correct that the two situations are not the same, because the energy in the center-of-motion (zero momentum) frame of the two vehicles is what matters (you can think about this as the kinetic energy that is available to deform the vehicles in the crash, leaving them with a lot of bent metal and no momentum after the crash.)
With two trucks moving toward each other at equal and opposite velocities, the zero momentum frame is the just the ground, where the total energy is m*v^2 (twice the energy of each individual vehicle).
In the case of hitting a wall, the wall has effectively infinite mass, so the zero momentum frame is moving with an infinitesimal velocity toward the truck, and the total energy is 2*m*v^2 (where "v" is still 55 MPH and the multiplier come from squaring the factor of two in front of it to get the full 110 MPH of the single truck).
So in the case of hitting a brick wall, there is twice the energy available. This is quite different, conceptually, from the explanation you've given, which is wrong. In the case of a vehicle hitting a brick wall at v = 55 MPH the energy is just 1/2 m*v^2, not m*v^2 as in the case of two colliding vehicles, or 2*m*v^2 as in the case of a vehicle at 2v hitting the wall.
The history of science teaches us that what is intuitive to any particular person is unrelated to the best way of understanding the world, and your reasoning is a nice example of this: it got you part way toward a correct conclusion, but fell short of the full understanding that the general principles of Newtonian physics give us.
Or both. Any new understanding of the world will be used in as many ways as people can think of using it. I wrote a novel that speculates on precisely the topic of what might happen with exactly this kind of technology, and part of the fun was thinking about how different groups might use it for good or ill: http://www.amazon.com/Darwins-...
Oh gosh, look the screenshots of her evidence tweets came twelve seconds after the tweets themselves, from someone who was not logged in and hadn't done a search.
Almost as if...
...she got a notification of the tweets aimed at her, viewed them without logging in and screen-capped it.
The level of paranoid thinking required to believe that it is more likely that a public figure like Sarkeesian would violate the law by faking threats of this nature than that an obviously hate-filled, fragile and easily offended group of nutjobs has a few members who are so over-the-top that they would actually threaten her speaks to a deeply deranged sense of the world.
Look at the discussion here on/. There are people who are absolutely incensed at her relatively mild and well-documented criticisms of some common features of video games. I personally find her theoretical approach a tad doctrinaire, but for depth and quality it easily exceeds the bar required to get a PhD from a decent school (I have a PhD--in physics--from a decent school, and have friends in a number of fields, so I've seen the standards of humanities departments up-close-and-personal.)
So what is more likely: that a large, irate, irrational, angry mob contains a few nutjobs who would go so far as uttering actual death threats, or that a well-known, widely respected, widely reviled public figure would go to such lengths to fake threats, putting her in a position of risk of discovery and criminal charges when it is inevitably found out?
Anyone who picks the second option as more likely is living in a paranoid fantasy of the kind that might lead them to, well, make death threats against a public figure they disagree with.
What I am saying is that the world is controlled right now by politically correct, professionally offended people. Everything everywhere is a stereotype.
You do realize that "politically correct, professionally offended people" is a stereotype, right?
I don't agree with all of Sarkeesian's criticisms, and find much of her analysis doctrinaire and tendentious, but for all of that her work or something like it is clearly needed, as evidenced by the backlash against it.
She isn't being "professionally offended": she's engaging in legitimate, deep analysis of an important artistic medium. Even granted that I disagree with some of her theoretical positions, he work has tremendous value even at the level of raw empiricism. Her episode on "the damsel in distress" trope is a compelling argument that sexism makes for very bad art, and that the way women are used in a large number of video games is lazy and stupid.
In a well-ordered world she would be getting a PhD for work of this depth and quality. And again, in case you missed it: I don't particularly agree with a goodly chunk of her theoretical frame, and she often says things that I think are simply wrong. I would love to see a cogent, relevant critique of her positions, but people who are driven by simplistic stereotypes of "professionally offended people" are making that impossible. There is so much noise that any rational discussion is simply impossible to maintain.
Science is the discipline of publicly testing ideas by systematic observation, controlled experiment and Bayesian inference. As such, proof is simply not relevant to what it does, which is produce knowledge. Knowledge--unlike faith--is inherently uncertain.
It'll take a few hundred years for the popular science press to catch up to this. What is being presented here is evidence that the idea p-p fusion powers the sun is correct, so the posterior pluasibility of that idea goes up, although not to 1 (which would be a certainty, and therefore an error: an idea that was immune to additional evidence.)
If neutrinos had not been detected, the plausibility would have gone down, although not to 0 because that would be the same error. Science never disproves anything any more than it proves anything. Proof and certainty are like the philosopher's stone sought by alchemists: a fundamentally mistaken goal.
Philosophers are the alchemists of epistemology, discovering all kinds of cool things while on a hiding to no-where.
I think you'll find that the utility of falsification is established philosophically, not by observational fiat.
But falsification is at best marginally relevant to science, which is the discipline (not method) of publicly testing ideas by systematic observation, controlled experiment and Bayesian inference.
Falsification simply never comes into it, outside of outlandishly models of science promoted by ignorant philosophers. Promoters of "scientific method" and falsification are almost never scientists, and most scientists will quietly ridicule the ideas if you give them a couple of beer.
Bayesian logic is established by mathematical deduction using an argument from invariance of a kind that originated within mathematical physics (Einstein's arguments for relatively are the most famous of the kind).
Philosophers don't even have the right goal--they are always running after "certainty", which we now know to be a epistemic error. Knowledge is not certain and cannot be certain, because only Bayesian reasoning can produce knowledge, and Bayesian reasoning is not capable of producing a posterior plausibility of 1 or 0 (ie certainty).
If your view that "everyone is complete shit at statistics", that should include statisticians.
This has been my experience as well. I would go so far as to say that statisticians understand probability less well than most working experimental scientists. They are overly-enamoured of abstract models and rarely dig down to the raw probability distributions underneath, which is what working scientists actually care about.
The hubris of thinking "it's OK, I'm a trained professional, nothing bad can happen" is mind boggling.
What is mind-boggling is that anyone takes a virulently anti-science organization like the dishonestly-named "Bulletin of the Atomic Scientists" seriously as a source of news about anything.
All you have to do is look at the source, and dismiss the claims as hysteria and lies.
This is not to say there might not be a story here, or something worth discussing, but until it is sourced from something other than an outlet for anti-science, anti-technology political shills it is all noise and no signal.
The article doesn't explain why the idea of this particular body being one mass instead of a rubble pile has been dismissed. Is there a good one?
Asteroids are believed to be aggregations of relatively loosely bound matter. They have likely experienced some local melting due to collisions, but it is very unlikely that they ever were entirely melted into a single mass. As such, they are quite peculiar bodies, much less akin to a mountain than a pile of rubble, and they likely aren't even all that close to a pile of rubble because the individual components they are made from were never part of a larger, more coherent body.
If you think about asteroid formation, you have to start with dust that accretes into small pellets, which then collide to form semi-melted rock-like-things, which then clump into asteroids (all the while suffering more collisions which produce local melting but not whole-body melting of the kind planets experienced.) This is all a consequence of the collisional statistics and dynamics in the early solar system.
So the proposition "Asteroids are loosely bound" is pretty plausible, and ones with high spin are therefore interesting because require us to revisit that plausibility, and who wouldn't want to do that?
Every time I hear someone explain lift with "air on the top of the wing has to move faster, so... lift!" I want to...
There's nothing at all wrong with that explanation. It is neither better nor worse than any other explanation that is less than a full solution to the Navier-Stokes equation, and it provides a naive and surprisingly practical guide to interacting with airfoils, which the vorticity explanation, for example, does not.
Except none of your points applies to climate change.
The effect is robust: there was a whole independent project to determine if the thermodynamically meaningless "global average temperature" is increasing. It is: http://www.bbc.com/news/scienc...
The threshold of measurement is around 0.5 C for a single station, and we have an effect that is about 1 C over the past 100 years. Not as big a margin as one would like, but difficult to ignore. And growing.
No one has produced any results that show the instrumental temperature record in the past century is not real. There are debates about causes, but the reality of the phenomenon is not in doubt.
Everyone who has looked at the question agrees that there is about a 1.6 W/m**2 addition to the Earth's heat budget from anthropogenic CO2, so clearly when taking the "positive cases" there is still good agreement.
There are large and legitimate areas of disagreement with regard to climate change (far more than the moron, anti-science, "the science is settled crowd" would have you believe) but the basic phenomenon, unlike the EMDrive, is not just consistent with but actually required by the laws of physics.
Finally: the summary is terrible, even by/. standards. The article does not point out any errors in the experiments. Rather it points out that reporters have been lying about the experiments, pure and simple. That is not the fault of the scientists, who honestly reported their null results.
but since when has any self-respecting scientist been led away from a beautiful hypothesis by pragmatism? Much less a physicist?
More frequently than you might think.
I highly recommend Lisa Randall's "Warped Passages" as a fairly recent meditation from a working physicist on the strengths and weaknesses of multi-dimensional theories, as well as some of the background on what motivates them.
The short story is that higher dimensions make it easier to generate universes like ours, which are almost flat gravitationally and have this ridiculous difference in scale between gravity and everything else. Regular 3+1 dimension Standard Model physics requires a ridiculous level of fine-tuning for this to happen, so it is interesting to look for deeper theories where these features arise naturally.
The problem with String Theories in particular--and as other posters have pointed out it really is a family of theories--is that they are almost useless for "model building", which is the activity of generating simplifications we can actually calculate with to describe the world as it is today vs the world as it was a few Planck times after the Big Bang.
So while string theory is neither "untestable in principle" nor "designed to resist testing" it is "naturally test-resistant." Some simpler variants--including a rather elegant heuristic model that Randall herself co-created--have been killed off by the LHC, but the diversity of possible low-energy models enabled by String Theory is so large and heterogeneous that in practical terms they cannot all be falsified.
In the meantime, String Theories continue to take up an inordinate amount of theoretical physicist's time and effort, and there have been fairly senior voices raised in concern about this, particularly because it has been going on for so long that we may end up with a generation of theorists who have never done anything but string theory and have come to the conclusion that it won't work.
Rather than waiting for this Big Reset, it would be nice if we started spending more time looking at non-stringy alternatives.
Then he came to the USA, and played the same con on Congress to fund his continued work here.
So in your view von Braun was an amoral, self-agrandizing liar who was willing to actively engage in the selection of slave labour working in death camps to build rockets that killed thousands of strangers just so he could play with cool toys? Because that's what you're describing.
I say "self-agrandizing" because everything that von Braun wanted to do would have been done without him, without the 12000 dead slave labourers, without the 9000 dead British civilians.
I've had some pretty extreme scientific and technical ambitions in my time, but have somehow been able to realize many of them without killing people, and have given up the rest because: killing people. So I'm willing to pass judgment on von Braun in this respect: if he faced a choice between following his dreams and not killing people I'd have to say the latter is the far better choice.
One of the key problems I've run into, not only in regards to ERP, but in general, is that when you outsource all of your development your future is in the hands of someone who doesn't have your companies best interests as their primary concern.
Even in those cases where you get a good service provider (which will depend on the specific people you've got working on your project much more than the company they work for, so anyone who says "Oracle = good" is missing the point) you still run into one of the most fundamental human problems: we suck at communication.
When you outsource something the degree of clear, concise, validated communication required is many times what is required for in-house development (where communication can still be a major problem). Capturing user needs and implementing them in a useful and user-efficient manner is hard enough with a high-bandwidth internal-communications channel. With outsourcing it is almost impossible for the people designing and building the system to get the information they need from the end-users.
So one question I would ask the OP is: how often do your provider's developers talk to your end users? (not your end user's managers, who don't have a clue what the system requirements actually are). If the answer is "never or hardly ever" then in-house is definitely the way to go, because your in-house team will have at least some chance of building a system that will serve end-user needs.
For me, the resistance comes when I look at the large reptiles of today which are descended from dinosaurs.They don't have feathers.
Which large reptiles are those? And which dinosaurs are they descended from? And how did dinosaurs, which were all killed at the KT boundary, manage to have descendents?
Dinosaurs are reptiles with their legs under their bodies. This makes them distinct from other reptiles (the kinds we have today, which are not descended from dinosaurs) which have their legs off to the side.
Mammals also managed the legs-under-the-body trick, and birds (which are descended from dinosaurs, unlike all modern reptiles, none of which are descended from dinosaurs, what with dinosaurs all being extinct without issue at the KT boundary.)
Of course brain surgeons don't "just do" brain surgery.... in any surgery, there's a ton of pre-operative work, investigation, preparation, paperwork, practice, etc
Most of which is not done by the surgeon. I've worked a lot with surgeons, and can assure you they are used to having other people do almost everything but surgery for them.
Surgeons are the equivalent of the "master programmer" team, which is a now mostly-obsolete team structure where there is one (or a very small number) of expert coders surrounded by a larger group of admin/build/whatever types who make sure the master programmer has nothing to do but code. It works on certain problems, but unlike surgery, the scope of what we expect software developers to do has grown far beyond what one person can handle in almost all interesting cases (I say this as a team of one who does everything from firmware to UI, but it is on a very narrowly defined embedded application that I've worked extremely hard to keep more-or-less within scope for a single very senior person.)
Try to imagine an alternate history where we emerged from the industrial revolution with effective, sustainable fusion and solar power without ever polluting the planet.
First off, what we can or cannot imagine has absolutely nothing to do with what is or is not real, so it isn't clear why you're bringing this up. Three hundred years of knowing what is real through publicly testing ideas by systematic observation, controlled experiment and Bayesian inference had demonstrated that the pre-scientific "method" of "imagining what might be the case and then reasoning from it" is a hiding to nowhere, knowledge-wise.
That said, as it happens I can imagine such an alternative history. One simple way of doing it is to have an intelligent species that evolved somewhat more quickly than we did on a planet formed in very short order after the supernova that birthed it exploded. Such a planet would have a good deal more 235U in the mix, making light-water moderated natural uranium nuclear reactors possible (of the kind that existed on Earth in at least one location 2 billion years ago).
An intelligent species on such a planet would likely never go down the hydro-carbon-fuels path, but would be all-nuclear, all-the-time from a very early stage of technological development (one presumes that in such an environment they would be evolved for somewhat higher radiation-tolerance than most terrestrial species.) As such, no hydrocarbon pollution would be evident.
Now, to be clear, I am not saying any of this is true. Merely that I can imagine it. There are quite possibly any number of subtle issues that make such a scenario impossible, and the failure of philosophy (knowing by imaging) tells us that we will be very hard-pressed to find them. But you asked for an imagining, and there one is.
Then, in that case, what separates pithovius from the prokaryotes?
Structure, from the sound of it, although mostly this is people committing various fallacies of reification and making false claims of "natural kinds".
Everything is a continuum. Humans divide the continuum up using acts of selective attention. The only infinitely sharp edge is the edge of our attention (because we scale the edge to match the scale we are attending to, so whatever scale we are attending to seems to have a sharp division between the things we are selecting out.)
"Species" do not have particularly crisp boundaries in the general case: they fade into each other, and we draw edges around them in more-or-less arbitrary ways. When we find new varieties we can either create new categories (by drawing new edges) or lump them into old categories (by moving old edges). Which move is to be preferred depends on the purposes of the knowing subject.
Insofar as that statement isn't gibberish (that is: not very far) it's anti-science.
Here's a question for you: is it a "scientific fact" that the impact of an extraterrestrial body occurred at the KT boundary and cause the mass extinction associated with that world-wide discontinuity in the geological record?
A fair majority of scientists concerned with the question certainly think so. But there are some notable hold-outs: http://en.wikipedia.org/wiki/C...
People whose area of expertise is directly relevant to the question at hand, who bring up cogent if not compelling counter-arguments, alternative interpretations of the evidence, facts that appear to be in contradiction to the impact theory, and so on.
Yet they don't have a crowd of anti-scientific loud-mouths calling them "Denialists" or accusing them of being shills for "Big Paleontology."
They sometimes get into heated discussions at scientific meetings, but that's the way science works: there is no limit on the questions we can ask and if we have evidence and Bayesian argument we get a seat at the table, no matter how wigged out the ideas might seem ab initio.
Only in the area of AGW has the arena become a completely political one, where anti-scientific loudmouths compete with shills for Big Hydrocarbon, and everyone ignores the serious question, which is: given its almost certain human activity is adding about 0.25% to the Earth's energy budget (1.6 W/m**2) and we have almost no idea how the climate will respond to that (despite what climatologists sometimes claim about their unphysical models) how do we best respond?
There is a loud and well-funded contingent who believe in "abstinence only" solutions, despite those having failed in every other case they have been applied to (drugs, alcohol, contraception...)
There are green-energy people promoting solar, wind, algal biodeisel, biomass, and other carbon-neutral forms of energy generation and storage.
There are people working on better battery tech (Heinlein's "shipstones").
There are people saying we should seriously consider nuclear power as the only currently known working alternative to base-load coal.
There are people saying we should investigate geo-engineering to stablize CO2 levels.
And there are people saying that since we don't know what is going to happen we should do nothing (see: Shills for Big Hydrocarbon, above)
All of that important stuff in the middle gets drowned out by the anti-scientific loud-mouths and bullies allied with the first and last of those groups, who do nothing but spew gibberish like "climate change is a scientific fact" as if that added something to the debate rather than helped to quell the debate we should be having.
"Scientific literacy" is not or should not be knowledge of discoveries, but a willingness to practice the discipline (not method) that is science: the discipline of testing ideas by systematic observation, controlled experiment and Bayesian inference. If you aren't practicing that discipline, you are almost certainly an enemy of science, because that is the natural state of the human mind.
Fragmentation and stagnation, despite some assurances to the contrary
I use Python both professionally and for fun (and C and C++ professionally) and don't get this impression at all. Major upgrades to shipped languages take time. The willingness to impose one-time incompatible changes for the sake of long-term improvements takes guts, and can certainly go wrong, but can very well be worth it.
As someone who worked in C and C++ pre-standardization, I recall (perhaps erroneously) that the new standards broke a fair bit of existing code, albeit in minor ways. And of course Microsoft's broken C++ compiler in Visual Studio 6 resulted in a vast amount of borken code when they finally caught up to the rest of the world.
That said, I haven't moved to Python 3 yet, although I believe all the libraries I really care about have now migrated. I tend toward late-adoption, though, and my sense of the Python community is that everyone accepts we are eventually going to move to 3. Big changes take years, so it's no surprise that lots of developers are still on 2.x. The real watershed will be when a few major libs (wxPython, say) drops 2.x support.
In contrast, my impression of Perl 6 is that it's the language of the future, and always will be. It appears so different from Perl 5 that it's a little weird the same name is being used, and it has mostly resulted in sucking the oxygen out of Perl 5 development.
Reading between the lines, it looks like it is a thin layer of mixed carbon and hydrogen with a structure that they have not yet properly characterized but which they have shown has the properties required for transparent electrodes in solar cells.
Specifically, they say the properties of the layer can be controlled by the properties of the polymer they start with, which suggests that it partakes in the polymer's nature, which would mean it is more than just a single layer of carbon atoms.
They may be being cautious and simply saying it is "graphene-like-enough" for this application, but having not fully characterized it may not want to claim it is "truly" graphene, which is a fairly vague term for a variety of single-sheet carbon materials that may have a variety of defects, in just the same was as "paper" is also fairly vague (from tissue to construction.)
I've used R, and it really has a lot of strong points, but I prefer to access it these days via Rpy, which gives me all the power of R along with everything else I get from Python (other libraries, better application development frameworks, etc.)
Both R and Python are real programming languages that are going to be completely useless to non-programmers, so neither of them is a SAS replacement, but of the two, I'd choose Python+Rpy over R for flexibility, power and ease of use (the latter is of course a strongly personal preference... if you really think like a traditional stats geek R will likely seem nicer, as it is clearly created for and by such people.)
Why are Denisovans considered different species, rather than simply a different race (or breed?) of the same Homo Sapiens?
"Variety" is probably a better word than "race" or "species". The "biological species concept" is extremely poorly defined, which is a bit of an embarrassment for a field largely based on a book called "The Origin of Species".
Like all concepts, the boundaries of a "species" are fuzzy, and the only really precise dividing line is the attention of the knowing subject. In many cases this is unprobelmatic: almost any knowing subject looking at the same population would draw the edges between species in the same way. There are, however, many cases where different people will draw different edges for different purposes.
Again: this is no different from any other concept, although people who don't get out much will often insist that the edges they choose to draw by an act of selective attention are "real" and everyone else's are "wrong".
In the extreme case, in the plant world, ubiquitous hybridization results in populations that are practically all genetically unique individuals, and the species concept breaks down entirely.
Slashdot Mirror
I know this runs against everything /. but I have seen it work a couple of times.
Why do you think that an unconfirmed anecdote being presented fallaciously as an argument is against everything /.?
It would actually be astonishing if no one had "seen it work a couple of times", for several reasons. One, if there were a 100% failure rate dousing would have been abandoned years ago. Even pre-scientific peoples mostly abandoned things that were never, ever correlated with their nominal goals.
Second, given humans are known to be prone to confirmation bias, we can predict that almost everyone who has ever seen a dowser identify one of the many, many places where water can be found will come away believing "dowsing works".
So a large number of scientifically illiterate people saying, "Hey I saw it work a few times that proves it's true so I believe it!" is exactly what science would predict if dowsing doesn't work.
If dowsing did work science would predict a bunch of peer-reviewed studies systematically detailing how accurate it is and investigating the factors that influence it's accuracy.
We see the former, not the latter.
Posts like yours actually constitute evidence that dowsing does not work.
One of the most interesting episodes I saw was when they were testing something Jamie said in an earlier episode: That if two trucks collide at 55 MPH, it's like one truck hitting a brick wall at 110 MPH. At first I thought "duh, everyone knows that's true" and I continued to think that as they set up experiments, right until they were about to let two clay blocks swing into each other at which point a light bulb lit up above my head, and so I quickly hit the pause button and thought about what was going to happen, and realized that since each block of clay was simply going to stop the movement of the other, each was going to end up in the same condition it would have been in had it simply slammed into the "immovable object" instead, and thus two vehicles each going 55 MPH in a head-on collision is exactly like just one vehicle hitting a brick wall in a 55 MPH collision. ...and I suppose it's solvable with math too, given e = m * v, and so if two objects slowing down one unit of speed yields two units of energy, or one unit per object, then one object slowing down two units of speed yields four units of energy, which is four times as much, even though the difference in speeds is identical in each case. ...but I was certainly misinformed about how it worked, and I don't think I was the only one, so it was totally worth doing an episode on, indeed it was one of my favorites since I actually learned something.
First, E = 1/2 m*v^2, not m*v, although your later statement seems to acknowledge that.
Second: you are correct that the two situations are not the same, because the energy in the center-of-motion (zero momentum) frame of the two vehicles is what matters (you can think about this as the kinetic energy that is available to deform the vehicles in the crash, leaving them with a lot of bent metal and no momentum after the crash.)
With two trucks moving toward each other at equal and opposite velocities, the zero momentum frame is the just the ground, where the total energy is m*v^2 (twice the energy of each individual vehicle).
In the case of hitting a wall, the wall has effectively infinite mass, so the zero momentum frame is moving with an infinitesimal velocity toward the truck, and the total energy is 2*m*v^2 (where "v" is still 55 MPH and the multiplier come from squaring the factor of two in front of it to get the full 110 MPH of the single truck).
So in the case of hitting a brick wall, there is twice the energy available. This is quite different, conceptually, from the explanation you've given, which is wrong. In the case of a vehicle hitting a brick wall at v = 55 MPH the energy is just 1/2 m*v^2, not m*v^2 as in the case of two colliding vehicles, or 2*m*v^2 as in the case of a vehicle at 2v hitting the wall.
The history of science teaches us that what is intuitive to any particular person is unrelated to the best way of understanding the world, and your reasoning is a nice example of this: it got you part way toward a correct conclusion, but fell short of the full understanding that the general principles of Newtonian physics give us.
Or both. Any new understanding of the world will be used in as many ways as people can think of using it. I wrote a novel that speculates on precisely the topic of what might happen with exactly this kind of technology, and part of the fun was thinking about how different groups might use it for good or ill: http://www.amazon.com/Darwins-...
Oh gosh, look the screenshots of her evidence tweets came twelve seconds after the tweets themselves, from someone who was not logged in and hadn't done a search.
Almost as if...
...she got a notification of the tweets aimed at her, viewed them without logging in and screen-capped it.
The level of paranoid thinking required to believe that it is more likely that a public figure like Sarkeesian would violate the law by faking threats of this nature than that an obviously hate-filled, fragile and easily offended group of nutjobs has a few members who are so over-the-top that they would actually threaten her speaks to a deeply deranged sense of the world.
Look at the discussion here on /. There are people who are absolutely incensed at her relatively mild and well-documented criticisms of some common features of video games. I personally find her theoretical approach a tad doctrinaire, but for depth and quality it easily exceeds the bar required to get a PhD from a decent school (I have a PhD--in physics--from a decent school, and have friends in a number of fields, so I've seen the standards of humanities departments up-close-and-personal.)
So what is more likely: that a large, irate, irrational, angry mob contains a few nutjobs who would go so far as uttering actual death threats, or that a well-known, widely respected, widely reviled public figure would go to such lengths to fake threats, putting her in a position of risk of discovery and criminal charges when it is inevitably found out?
Anyone who picks the second option as more likely is living in a paranoid fantasy of the kind that might lead them to, well, make death threats against a public figure they disagree with.
What I am saying is that the world is controlled right now by politically correct, professionally offended people. Everything everywhere is a stereotype.
You do realize that "politically correct, professionally offended people" is a stereotype, right?
I don't agree with all of Sarkeesian's criticisms, and find much of her analysis doctrinaire and tendentious, but for all of that her work or something like it is clearly needed, as evidenced by the backlash against it.
She isn't being "professionally offended": she's engaging in legitimate, deep analysis of an important artistic medium. Even granted that I disagree with some of her theoretical positions, he work has tremendous value even at the level of raw empiricism. Her episode on "the damsel in distress" trope is a compelling argument that sexism makes for very bad art, and that the way women are used in a large number of video games is lazy and stupid.
In a well-ordered world she would be getting a PhD for work of this depth and quality. And again, in case you missed it: I don't particularly agree with a goodly chunk of her theoretical frame, and she often says things that I think are simply wrong. I would love to see a cogent, relevant critique of her positions, but people who are driven by simplistic stereotypes of "professionally offended people" are making that impossible. There is so much noise that any rational discussion is simply impossible to maintain.
Nothing has been proven.
Correct.
Science is the discipline of publicly testing ideas by systematic observation, controlled experiment and Bayesian inference. As such, proof is simply not relevant to what it does, which is produce knowledge. Knowledge--unlike faith--is inherently uncertain.
It'll take a few hundred years for the popular science press to catch up to this. What is being presented here is evidence that the idea p-p fusion powers the sun is correct, so the posterior pluasibility of that idea goes up, although not to 1 (which would be a certainty, and therefore an error: an idea that was immune to additional evidence.)
If neutrinos had not been detected, the plausibility would have gone down, although not to 0 because that would be the same error. Science never disproves anything any more than it proves anything. Proof and certainty are like the philosopher's stone sought by alchemists: a fundamentally mistaken goal.
Philosophers are the alchemists of epistemology, discovering all kinds of cool things while on a hiding to no-where.
I think you'll find that the utility of falsification is established philosophically, not by observational fiat.
But falsification is at best marginally relevant to science, which is the discipline (not method) of publicly testing ideas by systematic observation, controlled experiment and Bayesian inference.
Falsification simply never comes into it, outside of outlandishly models of science promoted by ignorant philosophers. Promoters of "scientific method" and falsification are almost never scientists, and most scientists will quietly ridicule the ideas if you give them a couple of beer.
Bayesian logic is established by mathematical deduction using an argument from invariance of a kind that originated within mathematical physics (Einstein's arguments for relatively are the most famous of the kind).
Philosophers don't even have the right goal--they are always running after "certainty", which we now know to be a epistemic error. Knowledge is not certain and cannot be certain, because only Bayesian reasoning can produce knowledge, and Bayesian reasoning is not capable of producing a posterior plausibility of 1 or 0 (ie certainty).
If your view that "everyone is complete shit at statistics", that should include statisticians.
This has been my experience as well. I would go so far as to say that statisticians understand probability less well than most working experimental scientists. They are overly-enamoured of abstract models and rarely dig down to the raw probability distributions underneath, which is what working scientists actually care about.
The hubris of thinking "it's OK, I'm a trained professional, nothing bad can happen" is mind boggling.
What is mind-boggling is that anyone takes a virulently anti-science organization like the dishonestly-named "Bulletin of the Atomic Scientists" seriously as a source of news about anything.
All you have to do is look at the source, and dismiss the claims as hysteria and lies.
This is not to say there might not be a story here, or something worth discussing, but until it is sourced from something other than an outlet for anti-science, anti-technology political shills it is all noise and no signal.
Most of the time it just boils down to a nifty story devoid of any evidence.
Yup, and such things belong in novels, not scientific papers: http://www.amazon.com/Darwins-...
The article doesn't explain why the idea of this particular body being one mass instead of a rubble pile has been dismissed. Is there a good one?
Asteroids are believed to be aggregations of relatively loosely bound matter. They have likely experienced some local melting due to collisions, but it is very unlikely that they ever were entirely melted into a single mass. As such, they are quite peculiar bodies, much less akin to a mountain than a pile of rubble, and they likely aren't even all that close to a pile of rubble because the individual components they are made from were never part of a larger, more coherent body.
If you think about asteroid formation, you have to start with dust that accretes into small pellets, which then collide to form semi-melted rock-like-things, which then clump into asteroids (all the while suffering more collisions which produce local melting but not whole-body melting of the kind planets experienced.) This is all a consequence of the collisional statistics and dynamics in the early solar system.
So the proposition "Asteroids are loosely bound" is pretty plausible, and ones with high spin are therefore interesting because require us to revisit that plausibility, and who wouldn't want to do that?
Every time I hear someone explain lift with "air on the top of the wing has to move faster, so... lift!" I want to...
There's nothing at all wrong with that explanation. It is neither better nor worse than any other explanation that is less than a full solution to the Navier-Stokes equation, and it provides a naive and surprisingly practical guide to interacting with airfoils, which the vorticity explanation, for example, does not.
Except none of your points applies to climate change.
The effect is robust: there was a whole independent project to determine if the thermodynamically meaningless "global average temperature" is increasing. It is: http://www.bbc.com/news/scienc...
The threshold of measurement is around 0.5 C for a single station, and we have an effect that is about 1 C over the past 100 years. Not as big a margin as one would like, but difficult to ignore. And growing.
No one has produced any results that show the instrumental temperature record in the past century is not real. There are debates about causes, but the reality of the phenomenon is not in doubt.
Everyone who has looked at the question agrees that there is about a 1.6 W/m**2 addition to the Earth's heat budget from anthropogenic CO2, so clearly when taking the "positive cases" there is still good agreement.
There are large and legitimate areas of disagreement with regard to climate change (far more than the moron, anti-science, "the science is settled crowd" would have you believe) but the basic phenomenon, unlike the EMDrive, is not just consistent with but actually required by the laws of physics.
Finally: the summary is terrible, even by /. standards. The article does not point out any errors in the experiments. Rather it points out that reporters have been lying about the experiments, pure and simple. That is not the fault of the scientists, who honestly reported their null results.
but since when has any self-respecting scientist been led away from a beautiful hypothesis by pragmatism? Much less a physicist?
More frequently than you might think.
I highly recommend Lisa Randall's "Warped Passages" as a fairly recent meditation from a working physicist on the strengths and weaknesses of multi-dimensional theories, as well as some of the background on what motivates them.
The short story is that higher dimensions make it easier to generate universes like ours, which are almost flat gravitationally and have this ridiculous difference in scale between gravity and everything else. Regular 3+1 dimension Standard Model physics requires a ridiculous level of fine-tuning for this to happen, so it is interesting to look for deeper theories where these features arise naturally.
The problem with String Theories in particular--and as other posters have pointed out it really is a family of theories--is that they are almost useless for "model building", which is the activity of generating simplifications we can actually calculate with to describe the world as it is today vs the world as it was a few Planck times after the Big Bang.
So while string theory is neither "untestable in principle" nor "designed to resist testing" it is "naturally test-resistant." Some simpler variants--including a rather elegant heuristic model that Randall herself co-created--have been killed off by the LHC, but the diversity of possible low-energy models enabled by String Theory is so large and heterogeneous that in practical terms they cannot all be falsified.
In the meantime, String Theories continue to take up an inordinate amount of theoretical physicist's time and effort, and there have been fairly senior voices raised in concern about this, particularly because it has been going on for so long that we may end up with a generation of theorists who have never done anything but string theory and have come to the conclusion that it won't work.
Rather than waiting for this Big Reset, it would be nice if we started spending more time looking at non-stringy alternatives.
Then he came to the USA, and played the same con on Congress to fund his continued work here.
So in your view von Braun was an amoral, self-agrandizing liar who was willing to actively engage in the selection of slave labour working in death camps to build rockets that killed thousands of strangers just so he could play with cool toys? Because that's what you're describing.
I say "self-agrandizing" because everything that von Braun wanted to do would have been done without him, without the 12000 dead slave labourers, without the 9000 dead British civilians.
I've had some pretty extreme scientific and technical ambitions in my time, but have somehow been able to realize many of them without killing people, and have given up the rest because: killing people. So I'm willing to pass judgment on von Braun in this respect: if he faced a choice between following his dreams and not killing people I'd have to say the latter is the far better choice.
One of the key problems I've run into, not only in regards to ERP, but in general, is that when you outsource all of your development your future is in the hands of someone who doesn't have your companies best interests as their primary concern.
Even in those cases where you get a good service provider (which will depend on the specific people you've got working on your project much more than the company they work for, so anyone who says "Oracle = good" is missing the point) you still run into one of the most fundamental human problems: we suck at communication.
When you outsource something the degree of clear, concise, validated communication required is many times what is required for in-house development (where communication can still be a major problem). Capturing user needs and implementing them in a useful and user-efficient manner is hard enough with a high-bandwidth internal-communications channel. With outsourcing it is almost impossible for the people designing and building the system to get the information they need from the end-users.
So one question I would ask the OP is: how often do your provider's developers talk to your end users? (not your end user's managers, who don't have a clue what the system requirements actually are). If the answer is "never or hardly ever" then in-house is definitely the way to go, because your in-house team will have at least some chance of building a system that will serve end-user needs.
For me, the resistance comes when I look at the large reptiles of today which are descended from dinosaurs.They don't have feathers.
Which large reptiles are those? And which dinosaurs are they descended from? And how did dinosaurs, which were all killed at the KT boundary, manage to have descendents?
Dinosaurs are reptiles with their legs under their bodies. This makes them distinct from other reptiles (the kinds we have today, which are not descended from dinosaurs) which have their legs off to the side.
Mammals also managed the legs-under-the-body trick, and birds (which are descended from dinosaurs, unlike all modern reptiles, none of which are descended from dinosaurs, what with dinosaurs all being extinct without issue at the KT boundary.)
Of course brain surgeons don't "just do" brain surgery .... in any surgery, there's a ton of pre-operative work, investigation, preparation, paperwork, practice, etc
Most of which is not done by the surgeon. I've worked a lot with surgeons, and can assure you they are used to having other people do almost everything but surgery for them.
Surgeons are the equivalent of the "master programmer" team, which is a now mostly-obsolete team structure where there is one (or a very small number) of expert coders surrounded by a larger group of admin/build/whatever types who make sure the master programmer has nothing to do but code. It works on certain problems, but unlike surgery, the scope of what we expect software developers to do has grown far beyond what one person can handle in almost all interesting cases (I say this as a team of one who does everything from firmware to UI, but it is on a very narrowly defined embedded application that I've worked extremely hard to keep more-or-less within scope for a single very senior person.)
Try to imagine an alternate history where we emerged from the industrial revolution with effective, sustainable fusion and solar power without ever polluting the planet.
First off, what we can or cannot imagine has absolutely nothing to do with what is or is not real, so it isn't clear why you're bringing this up. Three hundred years of knowing what is real through publicly testing ideas by systematic observation, controlled experiment and Bayesian inference had demonstrated that the pre-scientific "method" of "imagining what might be the case and then reasoning from it" is a hiding to nowhere, knowledge-wise.
That said, as it happens I can imagine such an alternative history. One simple way of doing it is to have an intelligent species that evolved somewhat more quickly than we did on a planet formed in very short order after the supernova that birthed it exploded. Such a planet would have a good deal more 235U in the mix, making light-water moderated natural uranium nuclear reactors possible (of the kind that existed on Earth in at least one location 2 billion years ago).
An intelligent species on such a planet would likely never go down the hydro-carbon-fuels path, but would be all-nuclear, all-the-time from a very early stage of technological development (one presumes that in such an environment they would be evolved for somewhat higher radiation-tolerance than most terrestrial species.) As such, no hydrocarbon pollution would be evident.
Now, to be clear, I am not saying any of this is true. Merely that I can imagine it. There are quite possibly any number of subtle issues that make such a scenario impossible, and the failure of philosophy (knowing by imaging) tells us that we will be very hard-pressed to find them. But you asked for an imagining, and there one is.
Then, in that case, what separates pithovius from the prokaryotes?
Structure, from the sound of it, although mostly this is people committing various fallacies of reification and making false claims of "natural kinds".
Everything is a continuum. Humans divide the continuum up using acts of selective attention. The only infinitely sharp edge is the edge of our attention (because we scale the edge to match the scale we are attending to, so whatever scale we are attending to seems to have a sharp division between the things we are selecting out.)
"Species" do not have particularly crisp boundaries in the general case: they fade into each other, and we draw edges around them in more-or-less arbitrary ways. When we find new varieties we can either create new categories (by drawing new edges) or lump them into old categories (by moving old edges). Which move is to be preferred depends on the purposes of the knowing subject.
Yes, but climate change is scientific fact.
Insofar as that statement isn't gibberish (that is: not very far) it's anti-science.
Here's a question for you: is it a "scientific fact" that the impact of an extraterrestrial body occurred at the KT boundary and cause the mass extinction associated with that world-wide discontinuity in the geological record?
A fair majority of scientists concerned with the question certainly think so. But there are some notable hold-outs: http://en.wikipedia.org/wiki/C...
People whose area of expertise is directly relevant to the question at hand, who bring up cogent if not compelling counter-arguments, alternative interpretations of the evidence, facts that appear to be in contradiction to the impact theory, and so on.
Yet they don't have a crowd of anti-scientific loud-mouths calling them "Denialists" or accusing them of being shills for "Big Paleontology."
They sometimes get into heated discussions at scientific meetings, but that's the way science works: there is no limit on the questions we can ask and if we have evidence and Bayesian argument we get a seat at the table, no matter how wigged out the ideas might seem ab initio.
Only in the area of AGW has the arena become a completely political one, where anti-scientific loudmouths compete with shills for Big Hydrocarbon, and everyone ignores the serious question, which is: given its almost certain human activity is adding about 0.25% to the Earth's energy budget (1.6 W/m**2) and we have almost no idea how the climate will respond to that (despite what climatologists sometimes claim about their unphysical models) how do we best respond?
There is a loud and well-funded contingent who believe in "abstinence only" solutions, despite those having failed in every other case they have been applied to (drugs, alcohol, contraception...)
There are green-energy people promoting solar, wind, algal biodeisel, biomass, and other carbon-neutral forms of energy generation and storage.
There are people working on better battery tech (Heinlein's "shipstones").
There are people saying we should seriously consider nuclear power as the only currently known working alternative to base-load coal.
There are people saying we should investigate geo-engineering to stablize CO2 levels.
And there are people saying that since we don't know what is going to happen we should do nothing (see: Shills for Big Hydrocarbon, above)
All of that important stuff in the middle gets drowned out by the anti-scientific loud-mouths and bullies allied with the first and last of those groups, who do nothing but spew gibberish like "climate change is a scientific fact" as if that added something to the debate rather than helped to quell the debate we should be having.
"Scientific literacy" is not or should not be knowledge of discoveries, but a willingness to practice the discipline (not method) that is science: the discipline of testing ideas by systematic observation, controlled experiment and Bayesian inference. If you aren't practicing that discipline, you are almost certainly an enemy of science, because that is the natural state of the human mind.
Fragmentation and stagnation, despite some assurances to the contrary
I use Python both professionally and for fun (and C and C++ professionally) and don't get this impression at all. Major upgrades to shipped languages take time. The willingness to impose one-time incompatible changes for the sake of long-term improvements takes guts, and can certainly go wrong, but can very well be worth it.
As someone who worked in C and C++ pre-standardization, I recall (perhaps erroneously) that the new standards broke a fair bit of existing code, albeit in minor ways. And of course Microsoft's broken C++ compiler in Visual Studio 6 resulted in a vast amount of borken code when they finally caught up to the rest of the world.
That said, I haven't moved to Python 3 yet, although I believe all the libraries I really care about have now migrated. I tend toward late-adoption, though, and my sense of the Python community is that everyone accepts we are eventually going to move to 3. Big changes take years, so it's no surprise that lots of developers are still on 2.x. The real watershed will be when a few major libs (wxPython, say) drops 2.x support.
In contrast, my impression of Perl 6 is that it's the language of the future, and always will be. It appears so different from Perl 5 that it's a little weird the same name is being used, and it has mostly resulted in sucking the oxygen out of Perl 5 development.
What exactly is a "substitute carbon nanosheet"
Reading between the lines, it looks like it is a thin layer of mixed carbon and hydrogen with a structure that they have not yet properly characterized but which they have shown has the properties required for transparent electrodes in solar cells.
Specifically, they say the properties of the layer can be controlled by the properties of the polymer they start with, which suggests that it partakes in the polymer's nature, which would mean it is more than just a single layer of carbon atoms.
They may be being cautious and simply saying it is "graphene-like-enough" for this application, but having not fully characterized it may not want to claim it is "truly" graphene, which is a fairly vague term for a variety of single-sheet carbon materials that may have a variety of defects, in just the same was as "paper" is also fairly vague (from tissue to construction.)
So can Python do everything that R can?
No, but Rpy can.
I've used R, and it really has a lot of strong points, but I prefer to access it these days via Rpy, which gives me all the power of R along with everything else I get from Python (other libraries, better application development frameworks, etc.)
Both R and Python are real programming languages that are going to be completely useless to non-programmers, so neither of them is a SAS replacement, but of the two, I'd choose Python+Rpy over R for flexibility, power and ease of use (the latter is of course a strongly personal preference... if you really think like a traditional stats geek R will likely seem nicer, as it is clearly created for and by such people.)
Why are Denisovans considered different species, rather than simply a different race (or breed?) of the same Homo Sapiens?
"Variety" is probably a better word than "race" or "species". The "biological species concept" is extremely poorly defined, which is a bit of an embarrassment for a field largely based on a book called "The Origin of Species".
Like all concepts, the boundaries of a "species" are fuzzy, and the only really precise dividing line is the attention of the knowing subject. In many cases this is unprobelmatic: almost any knowing subject looking at the same population would draw the edges between species in the same way. There are, however, many cases where different people will draw different edges for different purposes.
Again: this is no different from any other concept, although people who don't get out much will often insist that the edges they choose to draw by an act of selective attention are "real" and everyone else's are "wrong".
In the extreme case, in the plant world, ubiquitous hybridization results in populations that are practically all genetically unique individuals, and the species concept breaks down entirely.