cabinpark

It doesn't surprise me in the least. Germany is a country of insane regulations and rules. They absolutely love paperwork - all the Germans apologized to me when I first moved here and set everything up - and have a very strict way of operating. The American way of doing things, as the article briefly mentions, is very different. I'm not saying it is better or worse, just different. This is a cultural thing that doesn't magically change overnight. I know I still get annoyed at how different things are sometimes compared with back in North America, but that is the way things operate here and you have to learn to play the game otherwise you will lose.

The credit card thing is also true too. Cash is king here and I routinely see people with hundreds of Euros of cash like it is nothing. I always see people paying for groceries with 100 Euro notes. Furthermore, I know Germans are much more concerned with personal security and privacy that there is also going to be a push back about having to share personal information with an American company.

Also I live in Frankfurt, and, to be honest, I have no idea why people even use taxis. To get from the Hauptbahnhof to practically anywhere in the city is only a < 20 minute U-Bahn ride. Also, the public transportation in Europe tends to be insanely good and efficient so a ride-sharing app will also have to compete with this as well.

I cannot emphasize this point enough. If you are new to the gym, please get a personal trainer (or someone who knows wtf they are doing) for a session or two to show you the correct form. It's more important that you are doing the exercise correctly with no weight than incorrectly with a lot.

If you've never been to a gym before or done weights, please, please, please get a personal trainer for a session or two to show your the correct form. I see way too many people at the gym who have shit form but "lift" a lot of weight and it is ineffective and can be dangerous. Form is way more important than weight. Remember, many exercises are designed with a specific muscle to target and if you don't do it properly, you won't get any of the benefits.

I was very lucky, growing up, to be the son of a sports medicine doctor because, from birth, healthy eating and exercise and their benefits were grilled into my brain.

Unfortunately I see too many people in my job (academia) who don't exercise despite the huge potential benefits to their productivity and life. So this makes me wonder: what is it about exercise that turns people off? Is it a communication issue? Is it the lack of confidence? Lack of knowledge? It seems that there are constant pushes in the media to be more healthy and exercise but it never seems to stick.

The end state is fairly obvious - every light, every doorknob will be connected to the internet.

Why does my doorknob need to be connected to the internet? Does my fork need to be connected to the internet as well? How about my shelf? Or my towel?

And if they are connected to the internet, who is collecting that data? Is it secure? What will it be used for?

I have no qualms with mathematical physics at all. I love mathematical physics to the extent my undergraduate degree is in mathematical physics. But the problem is that they are calling it reality. To my mind, string theory is nothing but a mathematical exercise that likely has nothing to do with reality.

I hate when theorists take some abstract crazy idea and then say the universe has 10 or 11 dimensions when they have no basis for saying that.

Sorry it was late but I know what you mean. I meant "theoreticians" in the sense that the article is talking about, i.e. those who work on string theory or loop quantum gravity. Many of my colleagues are nuclear physicists who work exclusively in theory.

I think high level theory is wandering aimlessly through a field blindfolded with little guidance or where to look. This is because our current theories are so good, we have no idea where to look. So it begins conjecturing and conjecturing. What it ends up with is nonsensical garbage that does little to advance physics.

But yet, there isn't a crisis in physics at all since these theorists are so far removed from reality, I don't really care what they think. They don't really tell use anything useful or interesting so I tend to ignore them. Instead, I focus on things we do know exist but cannot explain, say astrophysical jets, pulsars, or supernovas. We know they exist and we can see them, yet we understand them very little. We have models that are getting better and better over time, but they all exist within the current understanding of physics. This is where physics really is. Whatever garbage the theorists put up on the arxiv can be ignored with little loss.

Instead, those of us "in the trenches" can continue our work trying to explain observed phenomena with our current theories. There is no need to add in extra dimensions or cohomology. Maybe, when we've done really understanding our current theories can we talk to those theorists again.

Incidentally, since I started my PhD in physics doing numerical relativity, my views on science have changed completely. I used to be interested in stuff like string theory, but actually sitting down and trying to do it left me feeling empty inside. Now that I work in an area that is very closely related to observations, I feel like I am actually learning something about the universe. It's hard to explain philosophically, but I really believe in experiments as the guiding principle of science. In my case, we see pulsars (2500+ of them) and we have yet to provide a full explanation of their nature. To me there is something more real and scientific about this then trying to explain multiverse theory but I don't know the words to describe it.

What's a thing explainer? But unfortunately since quantum computing is still really only an academic pursuit, you're only going to find technical literature or dumbed down to the point of not being worth it.

Saying that, there is one book I like called Quantum Processes Systems, and Information by Schumacher (who coined the term qubit) and Westmoreland since it is an introductory text and has a good discussion of the basics of quantum computing. It does, however, assume you are a physics student with a good understanding of linear algebra.

There needs to be more people chasing their dreams rather then being cranked through the academia process.

I am reminded of the following story I experienced in my first year chemistry class. The class was being taught by the head of undergraduate studies for science and he asked us (a room of 500 students) how many people wanted to become chemists and maybe 20 or so people put up their hand. How many people want to become physicists? Maybe 30 or so put up their hand. How many people want to become doctors? A good 400 people put up their hand. He then said "only 20 of you will make it to med school, I hope you have a back-up plan."

The problem is that we only hear about the success stories not the vast amount of people who fail. That isn't to say don't follow your dreams, but be realistic about them and have other options available when things don't go your way.

Despite me not liking what he has done, I can't really find any faults with what he has done. If he purchased the drug legally then why can't he charge as much as he want? Can anyone point me to the law that says he can't do that? I'd be curious to know if he has done anything illegal.

Additionally, I wonder if he is doing this on person to make a point about drug pricing in the USA.

What I love about bouldering is it is very easy to mark progress. You can get higher on the wall or do a move. Very motivating. You can see it. I find that in the gym, progress is measured by moving the rod one weight down or adding another plate on the bar. Not a very visual thing.

When I was at Waterloo almost everyone I knew at the climbing gym was some combination of engineering, physics, mathematics, and computer science.

This doesn't surprise me since bouldering problems, as discussed here, are puzzles, akin to programming puzzles, where the solution is often some clever trick that, once known, makes a problem easy.

When you use this method you are implicitly making the function periodic. I can give you any function on some interval (sufficiently well behaved) and you can compute the Fourier series of it. Even though it's only defined on the interval, if you plotted the Fourier series you would still find it to be periodic. The same idea carries over to the spectral derivative. Even if the function isn't periodic, the method still works, it's just that the numerics near the discontinuity are going to be crap and can affect things further away. But if you are sufficiently far away, things are kosher. Note there are ways of dealing with this using Chebyshev interpolation (see http://math.mit.edu/~stevenj/fft-deriv.pdf section 6) which Trefethen's book also discusses.

And no FFTs are the only transformations I am aware of. I've never heard of anyone using other transformations in a general numerical context, outside of specialized problems.

This is called a spectral method and is widely used in numerical codes.

I highly recommend Spectral Methods in MATLAB by Trefethen (who someone mentions above) for a very good tutorial. You can freely ignore the MATLAB part and use whatever programming language you want, as long as you have an FFT routine.

I work in numerical relativity and our group produces many, many gravitational waveforms. I even visited LIGO this past summer. If Lawrence Krauss isn't bullshitting (and I have no reason to doubt he would be) then this is absolutely huge news. Nobel Prize worthy discovery no question.

Yeah I know. It's hard to squeeze information out of them. I actively tell them to please, please come to me if they don't understand something and I have office hours for a reason. Yet no one takes advantage. At a certain point, you can only do so much since I'm a grad student and not a lecturer and my time is finite.

The problem I've found with assignments though is that people copy and cheat. Many times someone will do very well on assignments and then do absolutely terrible on midterms and finals. It's very frustrating. I remember one course where everyone did nearly perfect on the assignments and yet the final and midterm followed the standard bell curve.

Interesting. Eigenvalues and eigenvectors are one of the most fundamental applications of linear algebra. In physics, quantum mechanics is a giant eigenvalue-eigenvector problem.

One application I really like is in machine learning: the eigenface algorithm.

Interesting. I used linear algebra with quantum mechanics where eigenvectors represent quantum state of the Hamiltonian which is how I initially understood them.

And as for TAing, have you ever TA'd? You definitely get a feeling but I can count numerous times when I've stood in front of the tutorial class and asked if there are any questions only to get no response back. I think it's a symptom of first years. I've TA'd calculus as well and I get similar responses. It's very frustrating sometimes.

I always see linear algebra on HN and many people comment on how they never understood the subject. This makes me ask: what exactly is it that people don't get about linear algebra? What makes it appear to be a difficult subject?

As someone who has used linear algebra almost every day in some form over the last decade, it's hard to get a perspective of what aspects are challenging to the beginner. And since I TA courses that involve linear algebra, it is good to know where the problems are.

I'd love to see new physics! Every physicist I know loves new physics.

But if you claim to violate the conversation of momentum, everyone is going to be skeptical and not believe it. We have hundreds of years of experiments and observations that support the law and have looked in many places from small to large and not seen violations. This is what makes people not believe it and thus physicists are going to assume you are wrong and not physics. It's not so much a negative concern, but more of a practical one. But should it be tested in a rigorous manner and reproduced, then physicists will believe it. It's just it hasn't and thus we are going to stick with the established very well understood and tested theory. Like are you sure you have properly counted all the initial momentum? Are you 100% you are not introducing energy to the system? The possible explanations is long and a good experiment will eliminate as many of these as possible.

As an example, look at the OPERA experiment which found to have superluminal signals. New physics? Nope, just a faulty piece of equipment. BICEP showing gravitational waves? Nope, just poor data interpretation and neglecting interstellar dust. So if you want to claim new physics, be damned sure you have ironclad proof.

Now show me the e-mails from investors of the hundreds of start-ups that get rejected and fail.

This is actually my PhD research! Yes the current thought is that neutron star mergers are the source of heavy elements (iron and greater) over supernova. Looking at the elements produced by nucleosynthesis from the outflow yields very positive results when compared with abundance curves in our solar system.

Also because we know how much material is released in a mrger and how much material there is in our galaxy, we can work out how frequent neutron star mergers are and these results agree with other independent estimates of frequency of merger.

Bullshit. I live in Germany and am learning German but everyone here speaks English. If you even sound the slightest bit non-German they respond in English. It does vary from city to city but I have experienced this universally and have colleagues who have lived elsewhere in Germany that this is indeed the case.

Course-work based masters perhaps, but definitely not thesis-based.

My Master's degree was entirely paid for and I actually made money. I wrote a thesis that contained original research and published a paper with my supervisor on the research. This is awesome. It's a 'PhD-lite'. It showed me how to do research and whether or not I would want to continue on with a PhD.

Good stuff! I love Fibonacci algorithms and if you dig deeper, there are even faster algorithms that exploit even more identities like the fast doubling and look-up tables.

It's a fun recreational mathematics thing, but unfortunately I've never come across a problem where I need to solve Fibonacci insanely quickly. However I still keep my hopes up!

I am doing a PhD here in Germany and I absolutely love it. It's completely free (except for the 300 euro fee per semester, but that includes the UBahn ticket which is like 200 of the 300 fee and is worth it) and I actually get paid really, really well. Plus PhDs are only 3 years and I don't have to deal with TAing and can just research. And because I am a student, I don't have pay taxes because my salary is considered a "stipendium" or whatever. It's quite nice. And where I am living, Frankfurt, which is apparently very expensive, is still cheap to me.

But, as others have said in this thread, there are drawbacks, which have been addressed. But that's true of anything anywhere.

So overall I highly recommend Germany for studies. Plus German is just a cool language to know as well.

I pay 40 euro a month for my health insurance.

In all my time working in scientific computing and talking with others, I only know of one case.

The huge amount of libraries for Python, C, C++, and Fortran make them the obvious choice.

Plus functional programming paradigms aren't always the best to do scientific programming. It can be done, but it's really not the right tool for the job, in most cases.

I'm amazed that you say that calculus has had a much greater impact on society when virtually every database, graphics manipulation or economic analysis uses principles of linear algebra.

I'm not. Consider all of physics. Physics is written down in terms of differential equations. You need calculus to get these equations. In terms of graphics, for example, are you magically creating only static images that never change in time? How do you think people came up with the algorithms to do things like refraction or reflection? These all involve calculus. Calculus is the most important tool in applying mathematics to the real world. It is how we derive the models for pretty much everything I can think of. Any time you want to model something where anything changes, that is calculus. Any time you want to find an optimal solutions, that is calculus. I can't think of a single area of applied mathematics that doesn't use calculus in some form. Even mathematics in general, calculus is used in some form pretty much everywhere in some form, except maybe in the foundations of mathematics like set theory or logic.

Solving them, on the other hand, is a different problem. This is where linear algebra is important. When solving an ODE or PDE, when I discretise it, all I am doing is re-writing it as a giant linear algebra problem. Quantum mechanics, for example, is dedicated to finding the eigenvalues and eigenvectors of the Hamiltonian. Linear algebra provides the tools to solve the problems posed by calculus. But it isn't always required.

In fact, if you look at the history of linear algebra, it only really became wide-spread when quantum mechanics was developing since there is a deep connection between linear algebra and quantum mechanics. Heisenberg had never heard of a matrix before despite discovering Heisenberg matrix mechanics. He was told by Max Born that what he had been doing is actually this thing mathematicians called "matrices". Now linear algebra is a required course for physicists (incidentally, linear algebra was the first lecture I ever attended at university).

So I would argue that learning calculus is the most important thing someone should know mathematically, since it is the tool we use to build models. The second most is linear algebra since it provides us the tools to solve these problems. But in my mind, knowing how to derive these models is a lot more important than being able to solve them. That and linear algebra doesn't give you any insight into why we are solving the problem that way, it is just a tool to solve the problem.

Also in Calculus 1,2,3 and so on, you learn increasingly more complicated techniques of calculus to solve more problems. But when you start numerically solving them, linear algebra doesn't care. It doesn't care if your equation came from the Einstein field equations or Newton's second law. It's all the same to it. So in a sense, I can teach you everything you'll need to know about linear algebra in a single course but the same is not true of calculus, which requires multiple courses.