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Comment Re:What's wrong with titanium dioxide? (Score 2) 114

Nothing, if you don't mind covering yourself in thick white paint. In nano-particle form it is less unsightly, but there are concerns about the health effects of nano-particles. Their small size gives them a high proportion of broken or strained chemical bonds, which can work as a chemical catalyst. There is concern that nano-sized particles could enter cells, and their reactivity could lead to DNA damage. Given the cumulative nature of such damage, and the long time scale for the effects to become apparent, it will be some time before the safety of nano-particles is properly established.

Comment Arduino should have done this (Score 1) 97

I don't think this will compete so much with the RaspberryPi, but it's clearly muscling in on Arduino territory. What a pity Arduino has stood still for so long. I know they've had some internal problems, but well before then the Arduino Uno was looking over-priced and long in the tooth. There are more powerful Arduinos but they are even more expensive, and lacking the focus which made the Uno such a success.

Compact, low-cost, low-power, modern processor, and built-in sensors and LEDs - the Micro Bit appears to have everything going for it as a successor to the ATmega328 based Arduinos. If the software support is as good as they promise, this will be a big hit.

Comment Observe, predict, test (Score 2) 364

Observe, predict, test.

Nobody says *how* you should go about doing the "predict" part, so long as you test carefully afterwards. It happens that in certain fields of science, especially fundamental physics, prediction has become very difficult. And that's why we need a bunch of theoreticians developing wild new theories which we, the experimentalists, will then test. But as I said, this process isn't easy and takes some time. It takes time to develop the theory far enough to make concrete, testable predictions, and it takes time to develop the technology to carry out those tests.

Take string theory. Nobody in particle physics is under any illusion that this has been through the complete scientific process. String theory is not a scientific result, it is merely an intermediary phase in the discovery of something more complete than the existing Standard Model.

Comment Parallax and perspective (Score 2) 191

I was going to ask how they deal with parallax and perspective: the need to account for the position of the driver's head so the the projected image properly lines up with the scene beyond. But the images in TFA make it clear: they haven't. This is a mock up. Nothing has been created, and Jaguar - Land Rover hasn't the faintest idea how to make it work for real.

Comment Re:Ok let me get this straight (Score 2) 103

Or it might be time to start looking at other things entirely. Especially seeing as there has already been a considerable amount of work on finding 5th forces both attractive and repulsive When new theories start contradicting experimental data or start making statements that are untestable, at some point you have to drop back and say you have been barking up the wrong tree.

I'm not sure what you're getting at. Science follows a simple recipe: observe, predict, test. We observe that galaxies rotate in a manner that cannot be accounted for by our existing understanding of gravity and matter. A whole bunch of predictions have been made according to different ideas about how to account for galactic dynamics, from gas clouds to black holes to brown dwarfs to modified gravity to exotic particles. From time to time somebody comes up with a new idea to add to the list. Those predictions are being tested and eliminated, and so far the one that's holding up best involves exotic particles. You can be sure the more prosaic possibilities were studied first, but it turns out they have not done a good job in matching observations. But it will take time any many experiments to uncover the truth. Meanwhile we will continue to bark up all the trees that are still standing, and search for new ones to climb.

Comment Re:Ok let me get this straight (Score 2) 103

Not only are they inventing a new particle, but a new force as well ? Which is needed to explain how the new particles behave ?

If dark matter particles interacted with any of the known forces (apart from gravity), they'd interact with ordinary matter and we'd be able to see them -- in other words, they wouldn't be dark. Whatever dark mater is made of, it almost certainly involves a new and undiscovered class of particles. Most likely particles in that new class will couple to each other in new ways -- which is another way of saying they experience new forces.

Really this seems to be nothing more than an attempt to create an explanation that doesn't make predictions and is as removed from testability as possible.

Many of the less exotic ideas have been eliminated by experiment. Negative results don't make good headlines, but much progress has been made on the search for dark matter and the number of possible theories has been greatly reduced. There is a real need for new ideas of this type.

Comment Re:Hardly Either Or (Score 2) 137

Frovingslosh is saying dark matter doesn't exist. He's wrong.

That's a very strong statement. I personally would say no more than "Something we don't fully understand is causing an effect".

Our statements are almost identical. The term "dark matter" is just shorthand for "something we don't understand, exerting a gravitational effect". There's also the possibility that there is no "something" and our understanding of gravity is wrong, but that has now been all but ruled out.

You spend 8 billion to get 100 million worth of R&D it's not a great use of funds.

This is a separate argument, but I'll answer it with two important points:

1. You can't put a value on fundamental research. The Higgs Boson in unlikely to have any direct application in the near future, but what about superconductors, or RF generators, or ion sources, or ultra-high vacuum techniques? All technologies which have been heavily developed for particle physics, and which have already found their way into industry. Even if you came up with a figure for the value of those technologies up to now, there's no way you can measure their future value. Yet future progress without them is unthinkable. All our technology is built on fundamental research, so if technology (and by extension, civilisation) is to advance so must fundamental research.

2. Could you develop the same technology more cheaply, without building huge science experiments? No. Of course not. Who would spend their whole career perfecting some obscure device if there wasn't a chance of participating in a great discovery? Industry just can't generate that kind of motivation.

Comment Re:Hardly Either Or (Score 2) 137

Frovingslosh is saying dark matter doesn't exist. He's wrong. He's saying the effort devoted to finding out what it is is fruitless. He's wrong on that too.

The question of priorities is much more complex, and everybody has their preferences. As it happens large accelerators are delivering more and more-useful spinoffs than ever before: the technologies developed to build the most recent generation of accelerators have direct applications in industry and medicine. Some people claim the same technology could be developed more cheaply without the involvement of particle physics research, but so far nobody has figured out a way to make that happen.

Comment Re:Aether (Score 5, Interesting) 137

Dark Matter is the Aether of the 21st century. Eventually we'll stop wasting money on finding it.

...and the enlightened explanation for galactic rotation curves will be, what?

There's strong evidence for the presence of unseen stuff in galaxies. It shows itself in its gravitational effects on the way stars orbit around galaxy centres. Either our understanding of gravity is wrong (an option on which money has also been "wasted"), or there is some invisible "dark" matter out there. Figuring out what that matter is will mark a huge advance in cosmology and likely determine the future direction of particle physics too.

If you feel that understanding our universe and our origins is wasted effort, then we will never see eye to eye.

Comment Why is this a bash bug? (Score 2) 329

Why does bash have to worry about security? It's just a shell, a thin interface supposed to execute whatever commands it receives. Surely the bug lies with Apache et al. for not properly censoring the data they receive from outside and send to bash for execution.

I understand that the exploit works by appending malicious commands after a function definition contained in an environment variable. The environment variables aren't meant to contain anything more than the function, so executing the extra code is a bug. In that sense the bug belongs to bash. But the shells were never designed to be secure against this kind of attack, and as we're now discovering there are all kinds of related vulnerabilities. Server software such as Apache is made to be secure: it has to worry about sending arbitrary commands to bash, so why not worry about setting arbitrary environment variables too?

Comment Re:Wrong interpretation of energy (Score 1) 135

When the article is talking about 1 MeV, it falsely interprets this as if the laser is emitting a single photon at 1 MeV. That is not what happen

He is indeed talking about 1 MeV per photon. He's discussing the theoretical limits of photon power density in a hypothetical gamma-ray laser with an adjustable wavelength. An ordinary laser pointer stores more than 1 MeV of energy in its lasing cavity, although a physicist would not typically use eV to describe the combined energy of a light beam.

Comment Re:If you want to hoard bits... (Score 1) 983

That's what I thought. I have a backup server in the basement, built out of two Raspberry Pis attached to four USB disk enclosures. Goodsync takes about 15 minutes to scan my 4TB of data, depending on how many new files there are. It would be faster over a wired network. Scaling that up to 20TB across five 4TB drives doesn't sound expensive or difficult.

Chemist who falls in acid will be tripping for weeks.