## Archive for the 'Physics' Category

### This Just In: Cold Fusion Still Not Working!

Starts With a Bang: The E-Cat is back, and people are still falling for it!

Ethan critiques a “cold fusion” effort. I have a few comments.

Look, let’s get a few things out into the open first. If there is a cold fusion device that actually works, that can harness the power of nuclear fusion to create energy, it would change the world.

I think this is too strong a statement. The requirement for cold fusion to change the world is more than it simply existing. If the device produces energy but we can’t harness it, it’s not particularly useful — if it can’t boil water to make steam and drive a turbine, thus producing electricity (or the equivalent via some other means), all we’ve made is a nifty hand-warmer. Thus, the bar for cold fusion is a little higher than simply seeing it occur. What we really want is warm fusion, at the very least.

However, this particular claim is about a device that gets hot enough to do so. But Ethan is correct in terms of the tests one needs to run in order to confirm this as legitimate.

[T]hey’re again claiming that this is nickel + hydrogen fusion, which should result in copper. Now, it’s important to know, the last time this was claimed, the nickel that was analyzed was found to contain the isotopic ratios of normal nickel mined on Earth, while the copper (10% of the product) was found to contain the isotopic ratios of copper found naturally on Earth, not the ratio you’d expect to find copper in if nuclear fusion had occurred! (Since only Nickel-62 and Nickel-64 can fuse with hydrogen into copper, it’d be impossible to get a 10% copper product in any case!)

This, to me, is a dealbreaker, though it took me a few minutes to decrypt the statement*. Nickel has several stable isotopes, so at first glance one might think you could get many isotopes of copper. However, absorbing a proton to become Copper is only energetically favorable for two of them, Ni-62 and Ni-64, which would form Cu-63 and Cu-65, respectively (the two stable isotopes of Cu). All the other candidates that might become Cu undergo electron-capture to become Ni again, which means you have to add several MeV of energy to run the reverse reaction — and cold fusion only has a fraction of an eV of thermal energy. Even if by some miracle these reactions occurred, the decays are quick. By the time you assayed the sample, there would be essentially none of those isotopes left.

In a naturally occurring sample of Ni, only about 3.6% is Ni-62, and just under 1% is Ni-64, which why Ethan can correctly say that a sample of nickel could never become 10% copper — there isn’t enough raw material for that to take place! If fusion were actually happening, you would expect the sample to be depleted of only these two isotopes of Ni, and you would expect the Cu isotopes to be present in just short of a 4:1 ratio, rather than the ~7:3 split that we see in a naturally occurring sample.

Given the blatant impossibility of this result, I don’t really care if or how the energy readings were fudged, or if it was an error on their part. It doesn’t work as advertised.

*It turns out I could have gone to his previous post on the topic for the answer, but it was a nice exercise to figure it out. All the details are there. Same result.

### Coordinate Transformation, Fred Astaire Edition

Dancing on the Ceiling

The room in the video actually rotates as a unit, and all of the furniture is nailed to the walls and ceiling. Also, the camera remains attached to the rotating room, making it appear as though the dancers are defying gravity.

Famed Broadway dancer Fred Astaire popularized this method in a dancing routine from the 1951 movie “Royal Wedding.”

### Don’t Worship at the Altar, Because It Doesn’t Exist

Challenge, don’t worship, the chiefs and high priestesses of science

This is a piece from the Guardian published last week, and I was intrigued: I perk up a bit whenever I see a mention of high priests or priestesses, or any intimation of science as a religion. Such a straw man is often a beacon that crackpottery is nearby.

Science today, and the way we share it with the rest of the world, is based on layers upon layers of deference. We spend our lives crawling up to senior scientists, and those who pay them, sitting and waiting to be told what to think. We shouldn’t be so complacent.

I agree with the conclusion, though not for the same reason the author does. Yes, by all means do not be complacent when it comes to scientific result — go out and get some science education, if you don’t have it. Because that’s the only weapon you have against having to trust someone else to interpret some scientific finding. I would absolutely love it if people could think for themselves about this. The problem that we have today is that people don’t go down that path. They simply choose to trust someone else (often someone with a political agenda) to do the interpretation. Science is not challenged, and the problem of people not thinking for themselves hasn’t gone away.

The problem is that science literacy isn’t going to completely solve the issue. You aren’t going to become an expert on a subject. What literacy allows is a chance to filter the bogus claims and spot the con artists in the discussion. It will help you identify whom to trust.

The author then goes on to tie this in with the deficit model, and I think that’s a reach. The deficit model isn’t correct. It’s been found that in issues like climate change and evolution, the problem in convincing more people is not that the proper information isn’t being conveyed. But that’s only part of the audience — the ones who have already substituted some ideology that drives their acceptance of facts. The deficit model isn’t completely wrong, because if it was, nobody would ever learn anything. Schools would be useless, and we know they are not. People do learn science in schools. It’s just not in play once people have some kind of emotional attachment to an answer.

But deference is certainly not the issue for peopler who are claiming that global warming is a hoax or that evolution is obviously wrong. Some of the arguments put forth to buttress those claims boil down to a premise that scientists are idiots, which is pretty far from being deferential.

I also worry that the author is selling us short on having people “challenge” rather than “unquestionably listen”. I don’t think anyone is proposing the latter or denying the former. However, a challenge has to have some validity to it. It can’t simply be a roadblock from a crowd who, despite not knowing much about the science, somehow know that it’s wrong.

Then we get to this:

When I was looking into the Big Bang Fair last term, I learned that volunteers were briefed not to get pulled into debating “politics” of arms dealing or the fossil fuel industry, lest it distracted from the science. I’ve since heard similar briefings have been issued for science events running over the summer. It’s also a line I heard all too often when I worked at Imperial College.

It’s bullshit. Simple bullshit. Politics doesn’t distract from the science. An over-emphasis on decontextualised science is used to distract from the politics.

There’s some bullshit there, that’s for sure. Science has an impact on politics, to be sure, and science will always involve people, which has ramifications, but the way nature behaves — which is what science investigates — is not political. If it’s true, it’s going to be true whether you are a conservative or a liberal. There is no Republican version of the laws of thermodynamics*, or a variant of relativity that only works for Democrats.

One might question the naiveté of a statement such as that, when we’ve just heard from politicians in both the US and Canadian governments about how they want to interject themselves further into the process. That, on top of the usual background noise of politicians grousing about teaching evolution, or that global warming is a hoax, and threats and attacks on scientists doing that kind of research. Politics doesn’t distract from the science? Really?

* No legitimate version. I’m aware of Conservapedia.

### Not Coming to a Reality TV Show Near You

Who’s the greatest American physicist in history?

[T]he sparse list of great homegrown American physicists makes two things clear. Firstly, that America is truly a land of immigrants; it’s only by including foreign-born physicists like Fermi, Bethe, Einstein, Chandrasekhar, Wigner, Yang and Ulam can the list of American physicists even start to compete with the European list. Secondly and even more importantly, the selection demonstrates that even in 2013, physics in America is a very young science compared to European physics.

### It’s All Because of the Wave

WHEN THE UNCERTAINTY PRINCIPLE GOES UP TO 11…

Unfortunately, the uncertainty principle continues to be explained — at least in many pop sci accounts […] — in terms of the disturbance that a measurement causes to a quantum system. This rather frustratingly fails to put across the fundamental essence of the uncertainty principle and can be somewhat misleading for students.

The uncertainty principle is simply an unavoidable and natural consequence of imbuing matter with wavelike characteristics.

“Somewhat misleading” is a tad tame, here. It’s wrong. Even though it’s how he originally framed it, the Heisenberg Uncertainty Principle is not the measurement problem.

### The Dream is in a Pipe

A House Powered by Exercise Will Keep You in Shape While You Keep the Lights On

According to the artist’s statement, “the house offers an ironical model of citizenship for future sustainable societies: the ‘Jane Fonda model of citizenship’” (the fitness celebrity whose initials the home bears) “which defines the ideal citizen as an individual who can satisfy all her domestic energy needs through her own bodily exercise.”

Not a chance in hell, unless we’re talking about a massively scaled-down lifestyle.

Other articles on the topic discuss this as supplying part of one’s energy needs through exercise, and that’s true, but as I’ve explained several times before in this space, it’s silly. Unless you’re going to do the exercise anyway and want to minimize wasting the output.

Trying to do all of the energy is a pipe dream. This is an art project, so it’s pretty clear that little consideration was given to the physics and biology of the matter, but it’s pretty simple: the maximum sustained power output of top athletes is around 500 Watts — that’s what Floyd Landis was able to do for ~4 hours for part of the Tour de France (and, remember, he was doping!) But the average customer in the US uses energy at a rate of around 1.3 kiloWatts, on average, over the course of the day.

Maybe, as the blog’s title says, you could keep the lights on. Especially with CFL or LED technology replacing incandescent lights, and you don’t need it especially bright, and you have the ability to cycle hard for an hour every day, perhaps you could store up the energy to run some lights. If you’re going at a 250 W rate, that’s enough to run a pair of 60W equivalent CFL bulbs for the evening (~5 hours’ worth). 250W of electricity production is around a kW of effort, because of the efficiency of our bodies, so you also gain in your heating bill…if it’s cold outside. If it’s warm, this is extra energy the air conditioner has to remove.

But doing this as a reason unto itself, look at the cost. That kw-hr of energy you burned up is 860 Calories of food, which is the intake of a decent-sized meal (or ~one bite shy of a quarter pounder® w/cheese and medium fries, if fast food makes for an easier conversion). Several dollars’ worth of eating for a dime’s worth of electricity. Just for the lights. There is neither an economic nor a sustainability justification for this.

There’s a reason humans went away from individual labor and used other animals and machinery driven by the sun, wind or stored sun (i.e. fossil fuels) as we grew our civilizations. Offering human power as a substitute is incredibly naive. Or, viewed another way, there’s a reason the world’s population was limited before we made these adoptions. What we do in modern society is energy intensive. Without machinery running on the sources of energy we’ve tapped into, we couldn’t come close to our current lifestyle.

### Top 10 Commander Chris Hadfield Videos from the ISS

Top 10 Commander Chris Hadfield Videos from the ISS!

It goes to 11, since there’s a bonus video.

### The Power of Thermodynamics

Short, but dramatic.

It gets hot, the rails want to expand but since the rails are clamped down to the ties, nothing can happen…until the ties start sliding. The rails are apparently welded together, and there must be a good reason for doing this and not leaving an expansion gap every so often — rails weren’t always welded. It may be that a gap causes problems for higher speeds. Or maybe it’s as simple as shorter lengths of rail being too easy to steal, and the disaster that ensues when a train encounters a missing rail.

OK, wikipedia tells me maintenance is cheaper and it allows for higher speeds and a smoother ride. Plus they mention flash butt welding. Tee hee.

### Pay Lots of Attention to the Scientists Behind the Curtain

One of the things I think about from time to time is the uneven representation of scientists, and physicists in particular — how often a biology/life sciences person is portrayed as representing a generic scientist, and within physics, how often particle physics is offered up as being representative of all physics. I think part of that can be gleaned from following the money. (In the US, federal funding (pdf alert, table 2) for life sciences is about half of all research spending at more than $30 billion. Physical sciences clocks in at under$6 billion) The other part comes from the sexiness of the work. Particle physics is big bucks and large collaborations, and is played up when the media latches onto “god particle” phrasing, or someone screws up a timing calibration and the shimmering spectre of superluminal neutrinos appears. Stories that can be written and appeal to people without too much of the gory detail of the actual physics appearing.

I am not alone in this thinking. Backreaction: What do “most physicists” work on?

The field I work in myself, quantum gravity, is among the over-represented fields. If you believe what you read, the quest for quantum gravity has become the “holy grail” of theoretical physicists all over the planet, and we’re all working on it because the end of science is near and there’s nothing else left to do.

Bee breaks down the numbers and finds

[This] tells you that “most physicists” don’t even do high energy physics, certainly not quantum gravity, and have no business with multiverses, firewalls, or “micro-landscapes of black holes”.

### The Chladni Plate? Mmmm, That Sounds Good.

A metal plate, supported by a post in its center, is vibrated at a single frequency by use of a mechanical driver. For most frequencies, nothing at all happens; when certain special frequencies are hit, however, standing waves appear on the plate, driving the sand away from the points of large vibration to the points of no vibration. By varying the frequency of oscillation, we can find a large number of the so-called resonance frequencies and their accompanying patterns, which become increasingly complex and beautiful as we up the rate of oscillation.

### I Wonder if They Called “Bank Shot”

Scientists Bounce Laser Beams Off Old Soviet Moon Rover

Neat.

One thing that I don’t quite get is this:

a laser beam naturally loses its intensity with distance

If they mean that it spreads out, then it depends on where the beam is focused. Using a beam focused on the moon, (or at twice that distance so the return beam was still converging) would probably be hard, and definitely be an incredibly silly way to do the experiment, since a small beam means you’d have to know precisely where the target was. Using a beam that was expanding (unless you have a laser that has a kilometer-scale beam output) is the right way to do it, so you’re forced by expediency into using an expanding beam with it’s decreasing intensity, but that’s not the same as saying it’s inherent to the laser.

If the claim is something else, then I don’t get it at all.

### Tiger, Tiger, Sparking Bright

Nice little demo that shows that a flame is (or contains) a plasma

(h/t to imatfaal)