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Comment: Simple Solution (Score 1) 353

by Roger W Moore (#46771383) Attached to: Kids Can Swipe a Screen But Can't Use LEGOs

I gave my daughter a earfull having my granddaughter use the ipad at 2 to keep her entertained. No you play with her using physical objects, and interaction.

There is a simple, less confrontational solution to this which solves both problems at once and provides an important, although expensive, lesson about not giving toddlers unsupervised access to delicate electronics. Introduce your granddaughter to the joys of a toy wooden hammer - the sort that comes with the hammer through peg sets. Then stand back and watch the fun although of course once the screen cracks you'll need to remove the iPad for safety. Even if the hammer is removed I was always amazed at how much our kids liked to hammer using any available implement once they got the hang of it.

Comment: Specialized Pieces (Score 3, Interesting) 353

by Roger W Moore (#46771223) Attached to: Kids Can Swipe a Screen But Can't Use LEGOs

Those same pieces can be used to build what ever you can imagine.

No so easily nowadays. Lego comes with huge numbers of very specialized pieces which are taylor made for that particular model. You can get the basic bricks but most Lego today is aimed at building one model and then playing with it rather than getting a pile of bricks and letting your imagination run wild.

There is one exception though: Mindstorms! This is simply brilliant and the new EV3 version even runs Linux! It's one of the few toys that are around today that I really wish I had been available when I was a kid.

Comment: Re:Survival of the Species (Score 1) 307

by Roger W Moore (#46764495) Attached to: Should NASA Send Astronauts On Voluntary One-Way Missions?

Unless there is continuous exchange of genes, i.e. people going back and forth, they quickly wouldn't be us anymore.

How much interbreeding was there between humans in Europe and the southern parts of Africa for the ~1000 years after the Roman empire? How much interbreeding was there with the North American tribes before 1492? Nobody regards first nations or africans as not being part of the human race.

If in a few centuries time space travel has not become as least as easy as the transatlantic voyages of the 16th century I'd be surprised and we did not see the North American colonies evolve differently despite the limited interchange.

Comment: Re:Only less than 1% (Score 1) 431

by Roger W Moore (#46761655) Attached to: UN: Renewables, Nuclear Must Triple To Save Climate
Well given that this is from statistics based on a gaussian distribution and Gauss was born 50 years after Newton died clearly the answer is no. Something for which Newton ought to be extremely thankful since I doubt he would have survived 1,000 apples falling on his head to get the necessary statistics! ;-)

However there is also a more serious reason for this: Newton's experiments were simple and easy to reproduce. Rather than rely on one or two experiments done be large collaborations with massive resources Newton's experiments could be performed by anyone with enough interest, moderate wealth and a few hours of time on their hands. Newton himself could repeat them multiple times to convince himself that they were right.

Unfortunately we cannot afford to build 30 LHCs with 60 experiments and measure the Higgs boson mass 60 different times and so we have to get very particular with statistics. In the same way we do not have 100 different, independent global temperature datasets for the past century or more nor 100 different international teams to analyze them. When you only have one or two experiments which cannot be easily repeated multiple times you HAVE to get very careful with statistics.

Comment: Becoming Canadian (Score 1) 416

We should probably raise capital gains tax on unbacked securities (i.e. the stock market). ... Investment in start-ups and other venture behavior is useful

Simplified tax code and reduced capital gains for investors in startups? I think you've been at the maple syrup again...

Comment: C64 on the BBC B Successor (Score 4, Funny) 165

by Roger W Moore (#46750063) Attached to: Reviving a Commodore 64 Computer Using a Raspberry Pi
Ah but there is something amusing about someone taking the successor of the BBC Model B and then using it to reproduce one of its main competitors from the period. However it's good to see that the 1980s 8-bit home computer religious wars finally ended in mutual cooperation! ;-)

Comment: Only less than 1% (Score 4, Insightful) 431

by Roger W Moore (#46744439) Attached to: UN: Renewables, Nuclear Must Triple To Save Climate
Actually, as a physicist, rather than trying to make simplistic arguments as to why experts in the field might be wrong you should just look at the statistics that the experts quote in the first line of the summary:

On the heels of a study that concluded there was less than a 1% chance that current global warming could be simple fluctuations...

Now "less that 1%" sounds low but is less than a 3-standard deviation (or 3 sigma) signal. In physics 3 sigma is generally the level at which you can claim "evidence for" a given effect and to prove it to others you need a 5-sigma signal which is less than a 1 in ~1.7 million chance.

The reason that we use these levels is because it is next to impossible to remove all human bias from an experiment. Hence you have to accept that there will always be some and it has been found from experience that these levels of proof tend to be ones which, once reached, are rarely found to be wrong. Although 3 sigma is just at the level where you can say "this is something likely to be true".

While I think it likely that humans have caused some degree of global warming it is a little worrying that the evidence for it is still so flimsy. If we then ask say whether more than 50% of global warming is due to humans I expect that the probability becomes even less certain. So to start motivating a major change in direction from fossil to nuclear (which has its own but different problems) we need a 3-sigma signal (less than 0.27%) that mankind is responsible for at least 50% of the current warming.

Comment: Re:Pseudo-science in the Survey! (Score 1) 470

by Roger W Moore (#46738265) Attached to: It's Time To Bring Pseudoscience Into the Science Classroom

The wavefunction doesn't represent the "size" of a particle in any meaningful way.

Yes it does. In fact it is the only meaningful way to define the size of the particle.

Analogously, if I describe your location as somewhere within the 1200 block of Broad St, it doesn't make sense to interpret that statement as saying you are actually the size of a city block.

No but I am not a quantum wave. If I were it would mean that the universe literally does not define my position better than a city block. It is like trying to say "at which point does a wave hit the beach": it is a meaningless question because the wave hits the beach over a range of points because the wave has a finite size.

Any actual interaction between particles requires decoherence and a collapse of the wavefunction to a more classical-like particle.

No it doesn't we do this all the time in particle physics with quantum field theory. You calculate and sum the amplitudes for different interactions to find total cross-sections which would not be possible if they have to be incoherent. An electron behaves like a particle when you are observing it on a scale much larger than its wavelength. This is how wave-particle duality works: pass an electron through an atomic grid and it diffracts, pass it through a 1 mm slit and it acts like a particle because the slit width is massive compared to the wavelength.

Comment: ...and without the oldest trades (Score 3, Interesting) 733

by Roger W Moore (#46737509) Attached to: Ask Slashdot: Are You Apocalypse-Useful?

The challenge is that scientists and engineers do not necessarily have the skills most critically required in the first decade or two of a new civilization

Not true. Many of the oldest trades no longer exist so you need someone to develop the techniques and skills again. As a physicist I've never made a steam engine or a large scale electrical generator but I know the basic principles behind them and given time could get one working or figure out how to repair one which breaks. Put that together with a chemist who can figure out how to extract copper and steel from ores and a biologist who can figure out the best crop rotations and dietary requirements and you have the skills needed to greatly increase your survival odds in the first few years.

The advantage of scientists and engineers is not that we are trained for some task but that we have the training to figure out how to do many, many different tasks. We routinely build and do things that nobody knows how to build or do because they have never been built or done before. In modern society it is more efficient to have individuals trained for each special task but without that scientists and engineers will be the ones who will need to reinvent everything which is missing and in the longer term teach the next generation.

Comment: Re:Pseudo-science in the Survey! (Score 1) 470

by Roger W Moore (#46680833) Attached to: It's Time To Bring Pseudoscience Into the Science Classroom
Nice try but actually the bound standing waves for hydrogen (~0.1nm) are quite a bit smaller than a free electron at room temperature (~7nm). A lead atom is only about twice the radius of hydrogen because although it has a lot more electrons it also has a far larger nuclear charge. So however you look at it, under the same conditions a free electron is always bigger than an atom.

Comment: Re:Pseudo-science in the Survey! (Score 1) 470

by Roger W Moore (#46680759) Attached to: It's Time To Bring Pseudoscience Into the Science Classroom

What you're describing here are pedantic objections, though, of which there will always be some to any question that isn't qualified to absurdity.

No, you just have to ask it in an appropriate way. There are professional survey writers who will take the questions you want to ask and then write them in a way that is very hard to misinterpret, not qualified to absurdity and not suggestive of an approved response.

For your example, the rest mass of an electron is smaller than the mass of any atom, so the wavefunction of any electron will be smaller than that of any atom at the same velocity (de Broglie wavelength) and in the same environment

Ok, lets try doing the calculation. The de Broglie wavelength is lambda=h/p where lambda is the wavelength and p is the momentum which is 'mv' for non-relativistc quantum. So for an atom with the same velocity as the electron the atom's momentum will be larger which means the wavelength of the atom will be SMALLER than the electron i.e. the free electron is bigger than the atom it would form.

However your argument is actually flawed because in the same environment thermodynamics requires the free electron to have the same kinetic energy as the atom. If you are capable of doing the calculation you'll find this means that the wavelength goes as 1/sqrt(mass) so even then the electron wavelength is larger than that of the atom.

So the correct, scientific conclusion is that a free electron is bigger than an atom if both are in thermodynamic equilibrium. Thinking of the electron as smaller than an atom means that you do not understand the implications of quantum mechanics or are letting your gut instincts override your rational reasoning. Quantum mechanics is often counter-intuitive and your instincts will often be wrong.

Or simply, since an electron is a component of an atom, any constituent electron will be smaller than the atom it inhabits.

You are thinking of Newtonian physics. What you say is just not true for quantum mechanics. The electrostatic potential well of the nucleus traps the electron wave and effectively compresses it over what a free electron would have in the same environment. To be more technical the addition of a potential term in the Schrodinger equation means that you end up with 3D spherical harmonic standing waves (at least for hydrogen) which have a shorter wavelength in the ground state than the free electron wave under the same thermal conditions. Still not convinced? The go read "Introduction to Quantum Mechanics" by David Griffiths which will go through the details provided you have enough maths to be able to cope with simple partial differential equations (since you have to solve the Schrodinger equation in spherical polar coordinates).

Comment: Pseudo-science in the Survey! (Score 3, Informative) 470

by Roger W Moore (#46669031) Attached to: It's Time To Bring Pseudoscience Into the Science Classroom
It also only works if there isn't pseudo-science in the survey. One of the questions was "Is an electron smaller than an atom" to which it appears they assumed the answer was yes. This is fine if you thin of the atom as a mini-solar system (the Bohr model) but this is wrong. The size of the atom is determined by the size of the electrons' 3D standing waves that are bound to the nucleus. So actually the size of an atom is literally the size of the electrons in it.

The problem is that the "size" of an electron depends on its state as anyone with an understanding of undergrad quantum mechanics should know. So did students answering 'no' to this question do so because they had no clue about atoms and electrons or because they actually understood the quantum wave description of the atom?

Apart from that the survey is very poorly worded for example the statement: "There are phenomena that physical science and the laws of nature cannot explain.". I could easily say "strongly agree" to that and think "dark matter" which is something that physical science cannot explain at the moment but which I'd hope we will eventually explain. So does the statement mean "cannot ever explain" or "cannot at the moment explain"?

So perhaps the survey authors ought to worry a bit more about pseudo-scientific surveys and a little less about pseudo-scientific beliefs among undergrads.

Comment: There is a line (Score 1) 328

by Roger W Moore (#46667715) Attached to: Federal Bill Would Criminalize Revenge Porn Websites

Isn't there a line that protects both free speech and human dignity?

There is. If the pictures were taken without the consent of the person in the picture when they had a reasonable expectation of privacy or are released without the consent of the person who took them e.g. they were stolen by hacking a computer, website, phone etc. then their release should be illegal. However I would be surprised if that is not already the case in which case the person releasing them should be held accountable not the website.

However if the pictures were taken openly and with the consent of the person in them the photographer owns the copyright and can release them as they see fit. If you want to preserve your dignity don't agree to pose for such a photograph. Of course it would also help a lot if the response of society to having a lapse of judgment taken cruel advantage of by an ex was one of compassion and understanding and not firing the victim from their job. Perhaps if we had a society like that people would be less inclined to run to pass new laws every time some idiot comes up with a new way to be antisocial.

Comment: Survival of the Species (Score 4, Insightful) 307

by Roger W Moore (#46654265) Attached to: Should NASA Send Astronauts On Voluntary One-Way Missions?

OK, aside from science fiction, find me the worthwhile reason to go.

Survival of the species. It is an established scientific fact that there have been mass extinctions on earth associated with massive volcanic eruptions and meteorite impacts and it is only a matter of time before there is another (although hopefully a long time!). Having a self sufficient human colony on a different planet is the best way there is to ensure that we survive as a species plus whatever species we take with us would survive as well.

I'm a Lisp variable -- bind me!