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Two Exocomet Families Found Around Baby Star System

ganv Re:Wrong distance away (23 comments)

Maybe it matters even if we can't easily travel there. For example, how many super-nova candidates are within 1000 light years of home? Not all stuff is 'good stuff'. There are good reasons to be glad that we are in a pretty low density region of the galaxy.

yesterday
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Two Exocomet Families Found Around Baby Star System

ganv Re:Wrong distance away (23 comments)

That error jumped out to me also. Its like describing a city 93 miles away and instead saying it is 93 million miles away which instead of being 1.5 hour drive is all the way to the sun. It is really useful to get a cosmic distance scale in your head: billions of light years is the size of the visible universe, millions of light years are distances to nearby galaxies. 30,000 light years is the distance to the center of our galaxy. 4 light years is the distance to the nearest stars.

3 days ago
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The Physics of Why Cold Fusion Isn't Real

ganv Re:Amusing (349 comments)

We just discovered that we are made of atoms a little over one century ago, and our ignorance is vast. But we should also be careful not to err on the side of blindly assuming that anything is possible. It is essential to think clearly about what might and might not be possible based on what we know now in order to direct our investigations. Will we discover new laws of physics that are relevant to releasing energy from nuclear reactions? I suspect the answer to that is probably no, and the reason is the high precision we achieve from our current theories in describing the behavior of atoms and nuclei. Careful experiments of nuclear excitation energies, fusion cross sections, etc agree with theoretical calculations, often to many significant digits. There just isn't much place to hide new physics in this energy range. Of course new fundamental discoveries (dark matter, etc) are very likely. They just are unlikely to change our predictions for nuclear phenomena by a quantitatively significant amount. Would it be better to stay open minded because one can never be sure? (See http://www.preposterousunivers...) Or is it better to make audacious, falsifiable hypotheses, such as the hypothesis that we already know the laws underlying the physics of everyday life? (http://www.preposterousuniverse.com/blog/2010/09/23/the-laws-underlying-the-physics-of-everyday-life-are-completely-understood/)

That doesn't tell us much about how to engineer processes that obey the known laws of physics. Predicting what humans will be able to do is very very difficult...and people regularly get it badly wrong being both too optimistic and too pessimistic. In my mind, good hypotheses based on careful consideration of the best evidence are never premature. They just might be wrong.

about a week ago
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2014 Nobel Prize In Physics Awarded To the Inventors of the Blue LED

ganv Re:Useful but physics? (243 comments)

You imply that if string theory and fundamental particle physics must have practical relevance like the quantum theories of atomic and nuclear physics of 100 years ago. But they are dramatically different. At that point, they didn't understand what matter was made of. (And despite a few notorious quotes, the best scientists knew that they didn't know how to explain atoms and chemistry.) Now we can't find anything in our galaxy that deviates from our current theories. There just are not going to be any practical applications of the Higgs boson or dark energy (at least not for many thousands of years...). If you are among those who think that physics is discovering new fundamental laws and engineering is using those laws to understand and control phenomena that we care about, then your version of physics is ceasing to be relevant. Instead, physics is actually the attempt to explain and control the world we live in using our knowledge of the fundamental laws. That kind of physics is slowly taking over all of science and engineering.

about two weeks ago
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2014 Nobel Prize In Physics Awarded To the Inventors of the Blue LED

ganv Re:Useful but physics? (243 comments)

Maybe we can try to help those ignorant of applied physics, but you may be right that they are hard to help...

There is a fantasy that lives on and on that physics is only the search for the fundamental rules of how the universe works. Physics does include the search for the most fundamental theory...things like trying to detect the higgs boson or understand dark energy. But those two pretty nicely define 'irrelevance' to the everyday lives of humans. If physics is only about the search for fundamental rules, then physics is essentially over as an enterprise with practical relevance. (See http://www.preposterousunivers...) But the overwhelming majority of physicists have long been working on applications of known fundamental physics to discover new emergent laws and new technological applications. Semiconductor and device physics is one of the great successes of 20th century physics and this achievement of fabricating gallium nitride with its large bandgap was a major advance, both in the fundamental science of crystal growth and in high frequency electronics as well as the production of blue light. This is exactly the kind of prize that should be given because we need the next generation of physicists to be finding fundamental problems that have practical relevance rather than using their talents on interesting but economically useless tasks like string theory. I predict that in the rest of the 21st cenury, there will be more Nobel prizes in physics given for biological, environmental, and neuroscience applications of physics than there will be for fundamental particle physics. If not, then the Nobel prize will be overshadowed by the Kavli prize or some other prize that recognizes accomplishments that have consequences for humans.

about three weeks ago
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When Scientists Give Up

ganv Propose the risky ideas after you demonstrate them (348 comments)

"The reviewers who decide which projects receive funding are risk-averse."

This hasn't been my experience. Reviewers and grant officers want to fund high risk/high reward science. But you are competing with others who have already tried a bunch of risky ideas and are only proposing the ones that happened to work. You basically have to make a significant discovery before you can be funded and then you can get funding to bring that idea to full bloom and hopefully fund a few risky projects on the side that will serve as the basis of the next grant proposal.

Most new ideas are bad ideas, so funding agencies have to have a pretty rigorous filter to sort out the promising ones. As a result, it will always be very hard to get funding to explore an idea before there is evidence that it is on the right track.

about a month and a half ago
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People Who Claim To Worry About Climate Change Don't Cut Energy Use

ganv Re:Why did they have to study this? (710 comments)

Individual choices to conserve resources are well known to be ineffective. Improvements in energy efficiency are also ineffective. Look up Jevon's paradox. Individual conservation mostly decreases the price of fuels which encourages others to use more. The main rational reason for an individual to decrease their energy usage is build the knowledge base and cultural values of conservation that can serve as a foundation for eventual society wide action. I know the libertarians are unable to think clearly about this subject, but there is simply no way to manage common resources like the atmosphere, rivers, and oceans without holding all polluters accountable for the pollution they emit.

about 3 months ago
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Half of Germany's Power Supplied By Solar, Briefly

ganv Re:Gigawatts per hour (461 comments)

Good to see I wasn't the only one who noticed the bad units. :) For those who missed it: Power is measured in Watts, which is energy per unit time (J/s). If you have 22 GW/hr, that is a rate of increase of power provided, so AvitarX calculated that after only 24 hours they would have 22*24=528 GW of solar power being produced, which is ridiculous, but that is what the post indicates.

about 4 months ago
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High Frequency Trading and Finance's Race To Irrelevance

ganv Re:A cautionary tale (382 comments)

I loved the Goat Bubble story. Thanks for linking to it.

about 5 months ago
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High Frequency Trading and Finance's Race To Irrelevance

ganv sounds like Wall street business as usual (382 comments)

We have been for a long time in the situation where the financial institutions are primarily extracting rents from producers rather that contributing to economic productivity. High frequency trading is simply a particularly obvious example of this. The situation is not particularly new. Those with wealth and power have always influenced the rules to their own benefit. The question is whether there are any counter-measures that effectively push people to contribute value rather than skim off value created by others.

about 5 months ago
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The Flaw Lurking In Every Deep Neural Net

ganv Re:The brain has multiple neural nets (230 comments)

Your model of the brain as multiple neural nets and a voter is a good and useful simplification. I think we still know relatively little about how accurate it is. You would expect evolution to have optimized the brain to avoid blind spots that threatened survival, and redundancy makes sense as a way to do this.

However, I wouldn't classify blind spots as 'no problem whatsoever'. If the simple model of multiple neural nets and a voter is a good one, then there will be cases where several nets give errors and the conclusion is wrong. Knowing what kinds of errors are produced after what kind of training is critical to understanding when a redundant system will fail. In the end though, I suspect that the brain is quite a bit more complicated that a collection of the neural nets like those this research is working with.

about 5 months ago
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The Limits of Big Data For Social Engineering

ganv Re:Dream on (95 comments)

What does it take to specify the state of a car? Many would claim that the dimensions of all parts and the material properties of the alloys and composites is a pretty complete description. You don't need all the modern physics. You just need a model that is quantitatively adequate for the level of accuracy desired. Simulating the classical/solid mechanics of a full auto crash is still a bit beyond us, but we can simulate many parts of the process. Even before simulation, we developed an understanding that allowed major improvements in auto safety that was partly rooted in approximate theories and partly in phenomenology. That distinction between an approximate theory (classical mechanics plus solid mechanics) and a phenomenology (observing auto crashes and drawing conclusions about what the important processes must be) is very important. With human interactions, we have many pieces of phenomenology (some pretty complicated parts of this are taught as 'social skills' in pre-school). But we have nothing in the way of a theory whose approximations are understood and whose predictive power goes beyond the situations from which the phenomenology was derived. I would argue that predictions in social engineering are essentially extrapolations of phenomenology that might work and might not...you simply don't know until you do the experiment. Whereas in classical mechanics, you know much more about what is going to happen including the Lyapunov exponents for chaotic systems that tell you when your predictions will no longer be accurate.

Your last comment is about political control. You seem to mean that our phenomenology will improve as big data mines human behavior and we learn to use that data and those ideas to control others. We do need to be careful who controls that. Although I suspect that the degree of control achievable by such means is easy to overestimate.

about 6 months ago
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The Limits of Big Data For Social Engineering

ganv Re:Dream on (95 comments)

This hope for an effective theory of human behavior is a reasonable hope. There might be a simple effective model that could describe human behavior without accounting for all of the parameters needed to fully specify the problem. It happens in many fields. We can very accurately predict fluid flows without worrying about the parameters of all the molecules. But for humans, it really is hard to imaging how it might work out. Consider the fact that once some humans have a theory of how humans behave, someone will start using it to gain a competitive advantage and then other people will start changing their behavior in response to knowledge that the theory is being used. It is a fascinating way to be unknowable...to be guaranteed to change as soon as anyone figures it out.

about 6 months ago
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The Limits of Big Data For Social Engineering

ganv Dream on (95 comments)

"Social scientists will be able to understand and predict the interactions of people the way physicists understand and predict the interactions of objects."

Many of us technical types would love for this line of inquiry to be fruitful. But to have a 'physics of people' you have to know the values of all the parameters needed to specify the current state of a person and you need to know all interactions of that person with the rest of the universe. Phrased like that you can see how ludicrous it is to dream of using the methods of physics for social science. Physics works because the fundamental constituents of the universe happen to be only a small number of particles whose interactions are amazingly simple. For example all electrons are exactly identical and interact via only 3 forces (with some uncertainties about effects on scales larger than galaxies and energies higher than trillions of electron volts). The hope for a theory of sociology is a false hope. The hope for a useful phenomenology might be more reasonable and big data can help.

about 6 months ago
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Survey: 56 Percent of US Developers Expect To Become Millionaires

ganv retiring will require being a millionaire (467 comments)

With inflation and continued erosion of social security and other retirement income sources other than assets, my calculations say that I simply can't retire with a middle class income if I don't have quite a bit more than $1 million in 2040 when I retire. Real returns are below 5% these days, and $1million kicks off less than $50,000 per year which will likely be well below median in 2040. As others have noted, it is not all that hard to reach $1 million with regular investing and modest real returns (and assuming we don't have a market collapse which is not an entirely justified assumption). But it is a system that a large number of numerically handicapped Americans seem not to be able to plan for or cope with. I would translate the headline: "44% of US developers don't think they are going to be able to retire (or simply have never done the math)".

about 6 months ago
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Nat Geo Writer: Science Is Running Out of "Great" Things To Discover

ganv Re:Practical breakthroughs in fundamental physics? (292 comments)

Not sure what you mean there. Quantum mechanics is hugely important for everyday life--all the biochemistry of life is quantum mechanics. So the ability to build a quantum computer would be expected to open up vast new possibilities. But that will function on the basis of known physics. My comments about the limited engineering uses of quantum mechanics so far was meant to point out how it is easy to overestimate the practical use of fundamental theories even when the theories describe all the matter around us. The question at hand is whether unknown physics (dark matter, undiscovered particles, etc) affects everyday life or will have a practical impact on technology. If it does, it will probably be in applications that involve precision measurement where you need 15 digits of accuracy so that Feynman diagrams including particles beyond the standard model become important.

about 6 months ago
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Nat Geo Writer: Science Is Running Out of "Great" Things To Discover

ganv Re:Practical breakthroughs in fundamental physics? (292 comments)

It might have been better if I had phrased (2) a little more strongly like Carroll did: something like 'the physics of everyday life is completely understood' or 'there will be no practical applications of physics beyond our current theories (the standard model and general relativity)'.

Yes they might be compatible. But if (2) is true, then the discoveries of (1) quickly become irrelevant. This is what Horgan is getting at. If new theoretical ideas don't have any practical implications for our corner of the milky way galaxy, it is going to become very very hard to keep up a never ending sequence of experimentally confirmed discoveries.

Note that Carroll was not claiming that Newtonian mechanics explained all of everyday life. He was claiming that the standard model plus general relativity contained all of everyday life. The analogy to Newtonian mechanics is to help people see how little impact on everyday engineering practice even the discovery of quantum mechanics had (and QM is a hugely practical theory that explains materials, semi-conductors, etc as you note). My guess is that the quantitative discrepancies between current predictions and measurements leave little hope that discoveries beyond the standard model and GR are going to have any practical applications except maybe in the distant future if we need 15 digits in the magnetic dipole moment of the muon or are trying to travel outside our galaxy or are considering the heat death of the universe. Like Horgan, I would love to be wrong. But I just haven't heard any good empirical arguments to support claim (1) that are deeper than 'past performance predicts future results' mixed up with wishful thinking.

The mercury/Vulcan reference is an interesting one. Note that the precession of Mercury is a pretty small effect and the GR effects that produce it have only recently begun to have practical applications in the global positioning system clocks. Do you have modern candidates to propose where unobserved entities are hypothesized to patch up measurements with the standard model or GR? Dark matter and Dark energy are the obvious candidates. The Higgs particle also could have been such a thing. If it had not been observed we might have needed a paradigm shift, but even that probably would not have made much practical difference. You don't need to be able to predict the masses of the particles in the standard model for practical purposes. It works quite well to measure their properties and use that to predict how they behave.

A 19th century analogy is to chemistry. Chemists in the late 19th century were able to put in place much of modern chemistry without having correct ideas about how a chemical bond actually worked. Quantum physics did not replace chemistry. It mostly explained things that were already known. But it did something else...it suggested where to look for new discoveries: the addition of Hafnium to the periodic table for example. It also opened up precision calculations of bond energies, bond lengths, etc which have been quite useful. That is what happened when we finally figured out how ordinary matter works...the stuff we are made of. (1) is a guess that figuring out what dark matter is or the properties of possible non standard model particles formed at energies above 100GeV will guide us to new areas of inquiry that lead to breakthroughs and practical applications. But it seems an unsupported guess. We already have discoveries like the top quarks and tau neutrino that didn't lead to any significant breakthroughs or new technology. Does anyone have any dark matter hypotheses for which they have a potential application? It is just very hard to imagine what one could do with a source of gravitational force that interacts so weakly with ordinary matter than it is currently only detectable on length scales of an entire galaxy. And dark energy is much much farther from engineering use.

So let's keep trying to find new breakthroughs. But it is also good to be honest with ourselves about what we have reasons to expect and what is wishful thinking.

about 6 months ago
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Nat Geo Writer: Science Is Running Out of "Great" Things To Discover

ganv Practical breakthroughs in fundamental physics? (292 comments)

The subject of the likelihood of future breakthroughs in basic science is very important. But Horgan is not very good at articulating the main issues. Much better is Sean Carroll's blog: http://www.preposterousunivers...

To simplify the situation to make it comprehensible, consider two hypotheses about the future of science. (1) Science will have an eternal sequence of groundbreaking discoveries/paradigm shifts. (2) The highly successful models we currently use are so accurate that they will continue to be used forever.

The first hypothesis is beloved by scientists in search of funding and by sociologists of science who wish to treat science as merely a social construct. It really is a strange alliance, but a common cause can make strange bedfellows. The second hypothesis is much less widely defended. Partly because it is clearly false in a fundamental sense...we know that current models don't describe dark matter for example, and so they have to be wrong and are likely to be replaced. But the weight of the second hypothesis is on the 'accuracy' of our current models of fundamental physics. As Carroll clearly argues, there is nothing of practical importance in everyday life that we can show to be in violation of the current laws of physics. Of course there will be major breakthroughs in applied physics...major things like figuring out how atoms and cells form brains and intelligence or discovering how to compute solutions of quantum many body systems. But if we are forced to choose between the two hypotheses, I think the evidence leans toward Carroll's side: the fundamental physics of everyday phenomena does not deviate in any significant ways from known physics.

Many people can't seem to see the vast gulf that exists between the discoveries of Maxwell's equations or quantum mechanics (which are necessary to describe matter and light, fundamental aspects of our lives) and current work on dark matter and primordial gravitational waves (which require precision detectors observing things from outside our galaxy). Also, before you dismiss (2) with references to late 19th century quotes about the end of physics, take a few minutes and look at the history beyond the quotes. Those quotes were mined for science funding publicity. Many scientists in the late 19th century knew that they couldn't explain atomic spectra...Kelvin even worked on vortex models of atoms. And if you focus your attention on 'practical' physics, the claims that late 19th century physics was nearly complete turn out not to be too far off...engineers spend almost no time studying quantum mechanics or relativity. It might be 1 or 2 courses out of 20 that cover physics that was discovered since the end of the 19th century. In mechanical engineering there are typically zero courses on quantum mechanics or relativity.

about 6 months ago
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Scientists Publish Letter Saying, "We Need More Scientific Mavericks"

ganv Re:NOW they realize this (126 comments)

Yes, a more realistic vision of managing science would be an important improvement. Currently you make your way to a permanent position by producing a lot of results that impress established scientists, which in practice often means you extend and confirm their work. This expands the community in which the senior established scientists run the show. But they are expected to manage and do science. Many of them are not skilled in managing, and when they do manage well, they are no longer able to engage in the actual science in a very substantial way. But the managing and doing can't be fully separated. How are management decisions to be made without an awareness of the subtle questions about where barriers to progress will pop up?

If I had one simple way to improve the situation, it would not be to encourage more maverick science. (It is just too difficult to separate true genius mavericks who will make major contributions from the much larger number of delusional smart people who are dreaming up new ways of being totally useless. If there are breakthroughs to be made by genius mavericks, they probably are going to need to make them while serving as patent clerks in the time honored model of Einstein.) I would replace the system of giving credit for large number of papers cited many times. This system reinforces a kind of 'follow the crowd' style of science that creates huge numbers of papers, none of which are particularly clearly written or provides a major advance. More credit needs to be given to people who write fewer clearer papers which waste less of their colleagues valuable time trying to review and decipher. The emphasis should be on the number of significant new ideas contributed and not on the number of highly cited papers which is more a measure of scientific fads than of substance.

about 7 months ago
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Harvesting Power When Freshwater Meets Salty

ganv Re:Big problem here... (151 comments)

No, you already input energy to separate the water and the salt. Remixing them will release part of the energy which could be harnessed, but inevitable losses in conversion will make it better to just use your original energy if you didn't need the fresh water. One nice thing about this article is that they explicitly state the most important point...that it is impractical to use this method in the only context where it would have potential for significant impact which is in the mixing of fresh water rivers with ocean water.

about a year ago

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