Posts by Frumious Bandersnatch

Would putting all the climate scientists in a room solve global warming...

two questions on abbreviations

#1 Which "Met" are you talking about as having attended? I know that in the UK, the Met is usually the Metropolitan Police, but here in Ireland, the Met is the Meteorological Office. I would have assumed you meant the latter except for the comment wondering why they attended.

#2 CBR on page 3... is this supposed to be Cosmic Background Radiation? If so, I think this is the wrong phrase since CBR refers to the ambient radiation left over from the Big Bang. Isn't it?

Overall, nice article. Not nearly (as pointed out) as editorialising as your other articles. Which is nice because we get a chance to comment. That seems to have been a good call as (so far) the comments haven't descended into religious flaming. Thumbs up.

MIRACULOUS new AIRSHIP set to fly by 2013

only four solutions that I can think of

#1 Invest heavily in portable fusion generators. These will be able to provide lift, obviously, but it will give us a closed cycle where we can transmute between water, hydrogen and helium to tweak the overall craft density without unsafe build-up of hydrogen gas.

#2 Go to Jupiter and find some of the giant jellyfish that float in the atmosphere there. Through years of selective breeding we can get them to tolerate the lower pressures and rarefied atmospheric conditions here on Earth, until we have a new viable beast of burden.

#3 Lock Steven Hawking and Umberto Eco in a room until they work out the mechanics of creating a wormhole into a parallel dimension and building a probe capable of returning a sample of ice-9 from one of the Vonnegutian realms. Then get the Darpa boffins to work out a safe fuel cycle along the lines of that in point #1 using this new material. Cross our fingers that the blimp doesn't crash land over any ocean, lake, reservoir, waterway or ground water. If we can't get into the Vonnegutian realm immediately we may have to employ an I Ching expert to help navigate through a Dickian space or Gernsbach continuum first. This might be risky, though, as we might end up finding that we've already solved the problem of Zeppelin explosions before the Hindenburg disaster precipitating a full tilt into one of those Teutonicly dominated timelines.

#4 Forget about it and make do with getting around in our flying cars.

Elite coder readies £15 programming gadget for schools

Forth

Not such a bad little language, IMO. If you really wanted some twisted teens, you'd teach them brainfuck or INTERCAL. Befunge would be a slightly more practical language.

Actually, scratch that entirely. If you want to destroy them completely, go ahead and put BASIC on it.

Apple reportedly plans ARM shift for laptops

third option

http://en.wikipedia.org/wiki/Fat_binary

Of course, this doesn't help with existing apps (do I have to put a TM after this since it's an Apple (TM) article?) which would need to be recompiled and someone ultimately has to pay for the recompilation. But at least in principle it doesn't strike me as being too difficult a transition for people to make. The wiki page has more useful observations which would seem to be quite relevant to this article.

Fukushima's toxic legacy: Ignorance and fear

@Andrewdaws

Hi again, Andrew. Thanks for elucidating more of the picture for us. I must admit that I did overlook the fact that a fission event will often create one (or more?) radioactive isotope(s) which will in turn decay, causing more energy output. I think lurking in the background of my mind at the time was the notion that a lot of the daughter atoms are considered waste products in the general sense and reduce the reactor's efficiency. I remember reading that in an explanation of the thorium fuel cycle at energyfromthorium.com, but I guess it applies to any nuclear fuel cycle. I can't remember the exact mechanism for these causing reduced reactor efficiency, but I think I had mentally filed it away as meaning that the daughter atoms were less effective in producing heat, which is the whole point of the reactor in the first place, so I naturally discounted them as the major heat producer in the reactor. Thinking about it now, perhaps efficiency in this case isn't only referring to the ability to convert fuel to heat, but includes an element of how effectively a chain reaction can be sustained or how much total energy can be extracted from a given amount of fuel before the waste products must be separated?

Your post also begs the question... with the errors and omissions in the way I described the meltdown process corrected, does this mean that my confidence in a meltdown being effectively contained without causing a further disaster is actually misplaced? I'm genuinely curious to know, even if it contradicts what I originally thought. Or do we end up with being able to say that even if the core melts down, so long as we can cool it down in time and continue to actively cool it, that we don't have much to worry about? And what of the initial topic of the China Syndrome? Is the residual heat production capability sufficient, in your view, to melt through the bottom of the containment vessel, or is a conflagration of the melted material a more practical concern? Should I upgrade my assessment from "not much to worry about" to "everybody panic again?"

wrong end of the stick?

Hi Andydaws. I had to read your post a couple of times before realising that you're effectively agreeing with what I said. I take it your main quibble is that criticality isn't necessary to cause a reactor meltdown. That's fair enough. I was aware that it's not just neutron recapture that causes the temperature of the core to increase. I did mention (or at least hint) that the decay puts out other decay particles, not just neutrons and as you mentioned, these are the main reason why the core heats up. But I also have to quibble with your explanation, as without fission events there would be no mass->energy conversion and hence no increase in core temperature. So yes, technically criticality isn't needed for the core to be hot or get hotter, the rate of neutron recapture is, I think, quite relevant in understanding thermal runaway since, if I understand it correctly, a linear increase in the rate of neutron recapture results in an exponential increase in heat output. So maybe criticality per se isn't the main issue, but the underlying idea of neutron recapture and the chain reaction definitely is.

> Pretty much by definition, within a bolus of melted fuel, it's hard to have moderation - especially in a water-cooled and moderated reactor!

Yes, we're in agreement here. I deliberately glossed over the issue of fast neutrons versus neutrons slowed down by a moderator. But since you mentioned it, I'd just like to point out to other readers, if it's not clear to them, that the right moderator and the right geometry actually serve to increase the rate of neutron recapture and hence push the reaction towards become self-sustaining, or at least generating usable amounts of heat energy. For what we're talking about, namely core meltdown and what happens after, moderation is actually a bad thing because it contributes to thermal runaway. My initial point was that if the fuel rods melt down and there is nothing more than a puddle of fuel with all the moderating material boiled off, then there is nothing to slow down neutrons enough to be recaptured, and the rate of fission greatly decreases. And as you said, the main problem at that stage is just dealing with residual heat. I simplified it by saying that the puddle of fuel simply didn't have the right geometry to sustain a chain reaction (though as you point out, my simplification of saying criticality here was technically wrong), but you can also explain it in terms of the lack of a moderating medium. On the whole, though, saying the geometry isn't right is probably more to the point, so that's why I tried to explain it in those terms.

containment vessels & co

I did a search this morning to see if I could find anything about some of the cores not having a protective containment vessel, but I couldn't find anything to back up that assertion. Maybe you were referring to the state of some of the reactors which were fully shut down and so only had residual heat to dissipate, and so had no risk of meltdown?

I didn't actually read Lewis's article that mentioned the China Syndrome initially, so my "nobody has mentioned" comment might have been off the mark. The best articles I've read on the events as they unfolded have been written by Dick Ahlstrom in the Irish Times, as he's done a really good job of explaining the actual problems and defusing the hysteria.

As to the risk of fire in the spent fuel ponds, that certainly is something to be concerned about, but it's an entirely different issue, and thankfully that also seems to be under control now.

Just one more comment about reports of the Japanese authorities being deceitful or reticent about reporting on the extent of the problem. This isn't something you raised, but has certainly been a line that has been trotted out by many media outlets recently. While there may be some element of this in general due to a general culture of not wanting to admit mistakes or collectively "lose face", I've actually got the opposite impression, and trust that the authorities are mostly open and honest about problems if they recognise that they are actually big problems. Two things make me think this way. Firstly, the last time there was a major nuclear incident in Japan was when workers mixed fuel by hand in buckets rather than using the equipment/tools they should have done, causing several deaths and damage to buildings, etc. I was actually living in Japan at the time, and was following events as they unfolded on TV. The initial reports might have been a bit vague, but within a day or two, there was no doubt about what had actually happened and we were getting updates about the state of the situation, readings on radiation levels, etc.

With this particular crisis, I'm no longer living in Japan, but we do have NHK broadcasts available to us on freeview satellite. Since the quake hit, the channel has been a pretty good source of information about what's currently happening, both regarding the situation with the power plant and the wider problems with dealing with the aftermath of the quake and tsunami. It mightn't have been the most technically detailed source, of course, but overall they've done a good job of explaining the situation to regular viewers who mightn't even know how a nuclear reactor works. Overall, I'd have to say that this reporting has been pretty good and impartial, which is actually more than I can say about some other major sources.

One last point about Japan's "dishonesty" in reporting is that actually they're obliged to report all kinds of accidents and events that can pose risk of radiation release or other incident to the IAEA, and nobody, I think, is suggesting that they've failed to report what they should. While the authorities there might be a bit slow in releasing information at first (due to the afforementioned cultural issues, but also not wishing to cause panic) I don't think that there's any doubt but that when they do admit to themselves that there's a real problem, there isn't any question of covering it up, and in general western reports to the contrary are as much, if not more, about sensational stories than they are about reporting the facts.

china syndrome

Actually, one thing that hasn't been mentioned in all of this is that even if there were a core meltdown did occur in Fukushima daiichi, the reactors were designed with this in mind. To wit: outside the reaction vessel, there is a containment vessel. Should a runaway reaction in the reaction vessel cause the fuel rods to melt, they will melt their way through the bottom of it and pool in the surrounding containment vessel.

The reason why the nuclear reaction in the reaction vessel was self-sustaining to begin with is mainly a matter of geometry. By having rods in such close proximity to each other, the rate of neutron capture increases to the point where a decaying Uranium atom's decay particles have an increasing chance of being absorbed by atoms in the surrounding rods, to the point where the cascade of absorption and decay events is sufficient to produce a self-sustaining nuclear reaction.

In (one of) the worst case scenario(s) the reaction not only achieves criticality (ie, probability of decay particles causing another decay = 1), but greatly exceeds it, then the core can melt down. But even if the core does melt down through the bottom of the reaction vessel, it will form a puddle at the bottom of the containment vessel. The shape/geometry of this mass of Uranium (+ reaction byproducts + other things that melted into the vessel) is such that now the probability that decay particles will spawn another decay event is much less than what's needed for the reaction to continue to be critical (ie, less than 1).

So this brings me to the reason why I responded specifically to your post... in this case, there is almost no chance that a full core meltdown would even escape the containment vessel or melt its way down "to the water table", let alone to the centre of the Earth. Because even reaching the water table would actually be very bad, obviously the people who design reactors (even 40 years ago) foresaw the risk and designed their reactors accordingly.

One last comment in general... thanks Lewis, it's nice to read your anti-hysterical articles. Ever since this crisis came to the fore, it's been writers like yourself (along with a moderate amount of background knowledge I had) that have helped me decide early on that there wasn't really anything to worry about with these particular reactors, despite all the media reports and grumblings to the contrary. Thanks as well for bringing our attention back to the much larger problems caused by the earthquake and tsunami. Thanks & well done.

"similarly named"

Dai-ichi means (more or less) "rank 1", while "dai-ni" means "rank 2". "Rank" is probably a bit over-formal a translation. "No. 1" and "No. 2" are perfectly acceptable translations.

Patent row gets Playstation 3s banned from Europe

*I* have personally written code for CBE

Here's some code which, while not actually assembly, shows that you have to use assembly-like macros to get good use of the hardware (apologies for the length; I took as small a section as I could):

/* non-aligned read initialisation */

void

spu_narinit(char **mem, /* start location */

vec_uchar16 *selq, /* mask for selecting qw */

vec_uchar16 *selr, /* mask for selecting remainder */

int rem, /* "remaining" bytes */

vec_uchar16 *buf

)

{

unsigned int mask;

vec_uchar16 vmask;

/* check that mem pointer is aligned to 16 byte address */

if (((unsigned int)(*mem)) & 15) {

printf("Input memory address not aligned to 16 bytes\n");

exit (1);

}

/* load a full vector from memory */

*buf=*((vec_uchar16 *) (*mem));

(*mem)+=16;

/* since all bytes are aligned to begin with, the mask for selb

simply selects all bytes from the buffer */

*selq = (vec_uchar16) { 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 };

/* calculate the equivalent shuffle index register for reading only

rem bytes */

*selr=*selq; /* same order as selq */

/* selr needs to be masked so that the first rem bytes have a high

bit of zero, and all other high bits of 1 */

mask=(1 << (15 - rem)) -1; /* eg, 3 -> 0001111111111111 */

vmask=spu_maskb(mask); /* fsmb: bits of mask -> bytes */

vmask=spu_and(vmask, 128); /* only interested in high bit */

*selr=spu_or(*selr,vmask); /* mask shuffle index register */

}

So, for all you people who shout that all the people who complain about Sony removing the OtherOS function don't even use the thing or should just get a PC and shut up about it: some of us /have/ learned to code on the thing and /have/ written non-trivial applications using it. And we are very legitimately pissed off that the amount of time and effort spent on both of those things has been wasted by Sony's handling of the whole OtherOS fiasco.

The Big Yin put it best above. We bought a machine that was supposed to do A, B, C and D and then they say that we can no longer do both C and D and we must choose one or the other. I actually bought two machines, one for family gaming and the other for my programming use. I have no choice but to keep linux on both of them and not upgrade to restore PSN functionality because if one of the machines fail I will no longer have the programming platform which I originally bought the machines for. The knock-on effect is that some games won't work to their full effect due to needing a PSN logon, and I also miss out on some updates that would fix graphical/sound/other bugs in the game system.

So you can basically fuck right off with your sycophantic Sony fanboi line. I *do* use the CBE, the applications I write are *not* portable to other systems, and I *do* feel betrayed and shafted by Sony for fucking up the system for me both as a programming platform and a gaming system.

Oracle: 'Eight Android files are decompiled Oracle code'

looking at the code ...

It's hard to see how the function (or do the call them methods in Java?) could really have been implemented any differently. All the interface definition lines have to be the same anyway in order to ensure compatibility, and the semantics of the function (what it's supposed to do) will also dictate in general terms exactly what the general flow of the code should be. Add to that the fact that the code is only four "if" or "if/else" statements plus a short number of assignments, and I can't see any wiggle room for doing things any differently. In fact, the function looks for all the world like it's nothing more than a constructor/initialiser for some sort of object. Just how many ways are there to write such things anyway? My guess: just the one.

World shrugs as IPv4 addresses finally exhausted

apocalypse?

Surely that should be iPocalypse ...

Beeb say sorry for Stephen Fry A-bomb quip

japanese still don't apologise [citation needed]

http://en.wikipedia.org/wiki/List_of_war_apology_statements_issued_by_Japan

I take it that you're from the USA from the way you end one of your sentences. Period. I guess that the bias of your post is because of this. But your statement that the Japanese haven't apologised just doesn't wash, as a very quick web search confirms. I did a parallel search on US apologies for bombing Nagasaki and Hiroshima, but it turned up nothing except people (up to US presidents) basically saying "why? we have nothing to apologise for".

As someone who has spent some time living in Japan, I have, as you might expect, some sympathy for the plight of the Japanese in being the only country in the world to have had nuclear weapons used on them. You might think that the US has nothing to apologise for, but there is a fairly clear sentiment, particularly among older Japanese, that dropping the second bomb on Nagasaki was totally disproportionate and unnecessary. This is to say nothing of the horror of the use of nuclear weapons in the first place (to say nothing of the US firebombing campaign, but that's another issue). Perhaps you think that both bombings were necessary, and maybe even just, but I'm afraid that I, like many, just don't see such moral clarity in those actions.

'Porn lock' heralds death of WikiLeaks, internet, democracy, universe

"This is a very serious matter," said the politician

"Something must be done."

"This is something, therefore we must do it..".

MEGA DINO-WHALE from 'Valley of the Whales' exhibited

they're still assembling partial skeleton for that one

In keeping with the one mentioned in the article it'll be called "sybilosaurus"

Car immobilisers easily circumvented by crafty carjackers

check your reading comprehension, Ru

> The solution, of course, is to take the people who undertake such studies to court for their criminal attempts [...]

If you'd read the article, you'd see that car thefts had already (predating this study) been on the rise. The guy(s) who put this study together is/are obviously in the full disclosure camp. By having one of these "white hats" release their results basically explains how the "black hats" have been savvy to this sort of attack for a while, and points the way towards better security all round.

That wasn't so hard to understand, I hope?

US rejected Brown's McKinnon case plea

your post ...

is probably the dumbest ever "he deserves to do time" [post].

Punctuation: see how it works?

Plasma space-drive aces efficiency numbers: Set for ISS in 2014

no need to reverse engines half-way

You can use the gravity well at the other end as a brake. In theory, it's easy to calculate by doing things in reverse. You pick a stable orbit around the mass, work out the escape velocity and then project that out to find a few points on the escape trajectory and the associated velocities at each of those points. Then, since you can reverse the time component of the equation, you know that if you approach the mass along the given trajectory with a given velocity, you will end up in a stable orbit, without necessarily needing to slow down.

In practice, things are going to be a lot more complex, though. The first issue, which isn't that difficult is that depending on the mass of the planet that you're trying to achieve orbit around, you'll find that there's a maximum velocity that you can be travelling at, above which you'll never be captured by its gravity well unless you hit it, which is probably not desired. Then there's the issue of navigation and having accurate sense of where the craft is at any given moment along with position and velocity relative to the target planet and any other major masses in the area. A lot of this can be pre-computed, but things might not go completely to plan (eg, differences between observed and theoretical velocities of other deep-space probes) so on the fly adjustments will need to be made, thus necessitating good telemetry data and the ability to recompute trajectories as needed.

The major problem, as I understand it (and this is only from pre-University level Applied Maths and some other reading I've done) is that while specific trajectory equations are reversible, the general equations aren't. That is to say we can easily come up with a trajectory which will escape or be trapped by the planet's gravitational field, there's no easy way to figure the best or most efficient approach. As I understand it (again) it's a problem of sensitive dependence on initial conditions (as per Lorentz or Mandelbrot). We might find lots of trajectories which will bring us into orbit, but it might take a long time for us to reach a stable orbit or, worse, our trajectory will cause us to collide with the planet or its atmosphere.

If the general set of equations aren't reversible (since, unlike a 3-D Lorentz attractor, we're dealing with a 4-D system and that isn't generally solvable, AFAIK) the only thing we can do is to run many simulations, trying out lots of different target orbits and "escape" velocities until we find one that's good enough. Only then can we plan the trajectory and hope to hit it without too much margin of error...

For extra shits and giggles, there's nothing to stop you from including acceleration/deceleration at various points along the flight path, too, of course. But to get back to my previous point, strictly speaking there may not be any need to decelerate at the half-way point or even any later point.

Like I said, this is just as I understand it. I wouldn't mind being corrected by someone more knowledgeable if I am, in fact, wrong on any of these points... cheers

won't work the way you think

Leaving aside your guesstimate of how long it'd take to reach c at a constant acceleration, which I'm pretty sure you didn't calculate, you're not going to get anywhere near c thanks to special relativity and Relativistic mass. The relativistic mass approaches infinity as speed approaches c, meaning that you approach infinite energy to apply any more acceleration on it at all.

Also, we already had Sputnik 2. It was the one with the first astro-dog, Laika.

Christians vs metalheads in FB flame war

aren't Satanists ...

just a sub-cult of the entire Judeo-Christian thingie? Or are they, like Satan himself, nothing more than a bogey-man invented to keep children scared and under control?

Flames, cos that's obviously where I'm headed

Shut up, Spock! How Battlestar Galactica beat Trek babble

not really

Soap operas don't have singing soap.

'Pervy' private chat case springs back into life

I put on my robe and wizard hat

Oh no you don't! You're nicked!

Gov may restrict unfair dismissal claim rights

correlation is not causation

first thought here too, though not in Latin

Fans roast Microsoft for Silverlight demotion

a chance for moonlight to catch up?

Ha! That makes me laugh. "Oh look, Silverlight is reaching the end of the cul-de-sac. If we speed up now we might catch it!"

Alien Earthlike worlds 'like grains of sand', say 'wobble' boffins

or even ...

ooo-la!

Over 100,000 stops-and-searches: zero terrorists

sadly ...

I think you're right on the money about a lot of politicians reading this as a resounding success.

If only I had the ears (not literally; don't arrest me) of said politicians. I'm sure I'd be able to sell them a large shipment of Tiger Attack Prevention Rocks ... see www.notigers.com (non-commercial).

One-third of iPad fanbois don't download apps

as an investor...

wouldn't you also be interested in getting dividends?

Phone 7: Another Vista or another XP?

three buttons mandated

I'm sure users are looking forward to many happy times pressing back-search-start on these machines.

Benoit Mandelbrot, father of fractals, dies at 85

Barnsley / fractal compression

Well it depends on what you mean "not working well"... the collage theorem was/is very successful in producing very high compression ratios. Of course the problem was finding the right set of iterated function systems that would be a good approximation of what you wanted to compress and do it in a reasonable amount of time (compared to other lossy compression schemes). As for getting money to do the research, I think it was probably worthwhile even if it didn't fulfill the initial promise.

I might be wrong on this point, but I seem to remember Barnsley eventually proving that there wasn't a tractable algorithmic way of searching for the minimal set of coding IFS's. It was always possible for humans to come up with tuned sets of IFSs that would have good compression properties, but without being able to codify that in an algorithm, it wasn't going to work, so the proof was a kind of variation on the Church-Turing thesis, iirc.On the other hand, the wikipedia page seems to contradict this, so I don't really know at this point...

interdimensional - lol

it's funny cos "inter" means between :-).

ACS:Law's mocking of 4chan could cost it £500k

Who the hell is James May?

Marble cake, also the game.

IBMer blames mistress for making him mis-talk

played like a fish?

Sorry, I just don't get that. The closest I can think of is a swordfish trombone. And that's not a real musical instrument, is it? Or is it ... ?

HP boffin claims million-dollar maths prize

Like trying to teach Zero to an ancient Roman

But why would you want to? Far better would be to keep him in the dark and contract yourself out to him for any multiplication or long division sums he needs to carry out in his work.

Turkish groom accidentally sprays wedding guests with bullets

rough calculation from terminal velocity

A bullet fired straight up won't come down at as fast as it left the gun barrel, due to air resistance. But it will generally reach terminal velocity, and that, multiplied by the mass of the bullet can easily be enough to break through someone's skull. If the gun is fired at a shallower angle, the speed of the projectile at impact is going to depend on a number of things including the angle it was fired at, the total distance and time traveled in horizontal and vertical planes (fairly complex integration, but easy enough to simplify to get a rough answer) and the drag coefficient of the bullet (which can be estimated). And not to forget that the final force is equal to speed times mass, so the mass of the bullet also has a big effect on the amount of damage on impact.

A quick web search should turn up plenty of good sites dealing with this particular "myth" (which it isn't) in general and the physics of it in particular (with terminal velocity in a viscous fluid being the most important).

Women, gorillas likelier to have sex with men wearing red

pretty women out walking with gorillas

Well that explains the first line of that Joe Jackson song. Doesn't quite explain why the gorillas are attracted to males as per headline.

<-- icon tailor made

Malaysia bans 'satanic' Man Utd kit

idiot

way to:

(a) make blanket generalisations about an entire country based on a few of its occupants and

(b) display your total lack of understanding of the connection between Red Cross and Red Crescent organisations

Oh, and:

(c) let everyone know what a dickhead you are

Academics challenge moral consensus on sex and the net

not so unexpected

Rule 34 and all that...

Finn finishes Finnish mini-digger odyssey

well done ...

birch twigs all around

Brazilian banker's crypto baffles FBI

starting a sentence with a digit?

Well you could always start and end a sentence with a single digit... the third one.

mural: yonder nor sorghum stenches

shut ewe ewes cymbal fray says four ink rip shuns.

Linux game-time refined with latest Wine

duke nukem forever

I'm afraid that the Linux version is a bit deprioritised at the moment. We're busy getting the GNU HURD version done first...

Google seeks interwebs speed boost with TCP tweak

I'm sure you mean ...

127.0.0.1 analytics.google.com

Oh, and reboot your computer? I lol'd ...

Russian video chat site mulls todger filter

on the plus side ...

this software would be great for those looking for images of todgers. If you're into that sort of thing, of course. Er, shuffling right along ... I wonder if it'll be GPL?

NASA: Civilization will end in 2013 (possibly)

list of fucked things

you forgot the bees. And a lot of the amphibians too, but we don't think they're as cute.

pedantry ^ 4

Photons can travel at speeds far less than c, depending on the medium they're traveling in. So it's completely possible for something to travel faster than light. Just not faster than c... but I agree with your original gripe... photons aren't "nothing" despite having no rest mass (we assume).

Top-killing, crisp spam and cooling the Tube

improved viscosity of wildlife

Life imitates art...

http://www.theonion.com/articles/massive-oil-spill-results-in-improved-wildlife-vis,895/

Thumbs up for the Warren Zevon reference ...

McKinnon family awaits final, final extradition decision

let's hope that justice prevails ...

and that Gary gets a fair trial, the presumption of innocence until proven guilty, freedom from cruel and unusual punishment, and all the other human rights and all that other malarkey that he (and everybody else) deserves.

nice hat, Ms Bee

would you like a stupid car analogy instead?

Oh, and what do they call that? A bonnet, you say? What a quaint country you English have!

Siphon Wars: Pressurist weighs into Gravitite boffin

**atmosfanbois

Maybe "atmosphreaks"?

I thought reg readers were smarter than this!

> gravity merely causes a vacuum to form at the top.

No. Gravity would cause a *partial* vacuum to form. Or, more concretely, it reduces the pressure at the top of the siphon. If the pressure is low enough, the liquid will evaporate--it'll be more *like* a vacuum, since water vapour is less dense than liquid water, but still not a vacuum. Nature abhors those, apparently, and the effect is that water is pulled up from both legs to prevent this. Of course, if the water at the top *does* evaporate, then a new equilibrium is reached. This time, the vapour can expand (either by losing pressure, which a gas can do more easily than a liquid, or by causing more liquid to evaporate) much more than the pull of gravity down the long leg of the siphon can compensate for, and so no more liquid can flow past the hump.

> If the pressure is completely removed, then there will be a total vacuum both inside and outside the siphon.

No. There's no total vacuum in the tube for a start (it's why we call it a "vapo(u)r lock". And you've failed to account for the weight of water above the tube in the higher container.

> I'm baffled as to why more people didn't learn this in high school physics

It's probably something to do with the "state of education" nowadays. As it always was, probably.