How do you go about tracking the spread of a non-toxic, colourless, odourless gas through an environment made up of a mixture of colourless odourless gases?

I'm not a chemist/physicist/meteorologist so the only way I can think of is to use a radioactive gas like radon. Technically, does this mean the government are simulating a dirty bomb by using an actual dirty bomb?

Of course, the "7/7" bombings happened the same day as a near-identical training exercise.

but it's our dirty bomb.

So long as it's not commonly found on the streets.

e.g. some halocarbon like CFCs, but which hasn't been in industrial production and isn't a product of a natural process.

Then get your favourite spectrometer out and watch for the peaks.

Some odourless, invisible gases are fairly rare in the wild, but are harmless. If the concentration of one of those gases was artificially raised, it should be measurable against the background levels.

My bet is on Argon. With a molecular weight of 18 compared to 14 for N2 and 16 for O2, it should hang around at ground level for long enough to be tracked.

It's given on the website linked in the article.. perfluorocarbons

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

"I'm not a chemist/physicist/meteorologist so the only way I can think of is ..."

... a worthless guess based on nothing more than hysterical paranoia and your amazing powers of ignorance.

Why do people even bother posting comments that begin with "I have no idea what I'm talking about"? Do you really think that was a worthwhile contribution to anything at all?

"Sadly the DAPPLE website doesn't give an example of genuine DAPPLE identity documents, which could leave an opening for dastardly gas-attack terrorists packing fake IDs to masquerade as righteous government dirty-bomb boffins, allowing them to carry out their fiendish plans unmolested. But no doubt the Home Office has factored this into its calculations."

Do you actually think they are smart enough to have thought of that and then created a counter measure? These are the same people who cannot hold on to personal information, or secure a peice of hardware.

You have a lot more faith in them than I do.

I think that was sarcasm....

I used atomic number instead of weight.

Should have said "...molecular weight of 40 compared to 28 for N2 and 32 for O2..."

duh. I hate getting old!

In my defence, it is 40 years since I did 'O' level chemistry.

"Of course, the "7/7" bombings happened the same day as a near-identical training exercise."

Didn't 9/11also have a near-identical training exercise?, maybe the terrorist are working as anti-terrorist groups - well that would make as much sense as half the stuff the media is peddling these days (see killer terrorist robots and exploding liquids). And most people still seem uninterested, its interesting to watch what they will come up with next to try and get us all scared, maybe the next big threat is kamikaze Cream Eggs.... oh wait a second!

I look forward to the simulated rocket bombs from Eurasia. Sorry, Eastasia.

So, there's no bomb involved, but some gas canisters.

And they aren't spreading radioactive debris and detritus, but a gas...

I can see how this might relate to measuring the likely effects of a nerve gas attack, but in no way is it a simulation of a dirty bomb.

""I'm not a chemist/physicist/meteorologist so the only way I can think of is ..."

... a worthless guess based on nothing more than hysterical paranoia and your amazing powers of ignorance."

Well, I am a physicist and he made a reasonable hypothesis for a self declared layman. The gas cannot be tracked by sight or smell so he came up with the idea of a radioactive marker. That is not hysterical paranoia, it's a perfectly intelligent suggestion for someone who doesn't know how portable a spectrometer can be nowadays.

He certainly made a more worthwhile contribution than your self-righteous bile.

At least UK gov are not using live biological agents such as E.Coli this time like they have done in the past over large areas of the UK: http://www.guardian.co.uk/politics/2002/apr/21/uk.medicalscience

At least as far as we know anyway, guess we'll find out in 50 years time.

The 'air' in London is rarely non-toxic, colourless nor odorless so it should be quite easy to track such an alien gas!... HELP, HELP THEY'RE ATTACKING US WITH CLEAN!!!!

Does anyone think terrorist will ever be arsed with dirty bombs when it seems pretty clear that a good old fashioned car bomb will be just as if not more effective than some half arsed attempt at spreading radioactivity through the streets??

If you look at the check list for a dirty bomb, and compare it to a normal one, you'll see the main stumbling block is the radioactive materials - not easy to come by/handle/etc.

The fact that to my knowledge there has never been a dirty bomb attack, yet over the years there has been countless normal bomb attacks would hint at how useful terrorists see them as being...

when a dirty bomb goes up its going to scatter tiny little bits of radioactive shtuff in the wind,

you measure how the air flows round the streets and you know the path the radioactive material is going to take,

so they will know after a dirty bomb goes off that ground zero is a bad place to be as are streets X,Y and Z however the amount of crap down streets A,B and C is lower so rescue services /hadmat people can get in there with lower risk

They should put up thousands of sensors, track in real time, and put up a video of the sensors sensing the spread.

I for one welcome our invisible, odorless overlords. I will start bowing in all directions at random times. Laugh if you like but you'll all be sorry when I'm senior management (VP Visible Sector).

Who said it was going to be colourless? I read "the tracer gases are non-toxic and odourless,", nothing there about colourless, so perhaps they may just do the easiest thing and look?

of course they'll use a dirty bomb, i've seen it on 24 - it's what all the terrorists want to use

Surely for any such test to be accurate the simulations would have to be done with gaseous compounds of similar molecular size, weight, specific gravity, density and thermal characteristics to the materials they suspect will be released. Is this test going to be repeated in different atmospheric/weather conditions so each possible scenario can be appraised. Elsewise this is just an exercise in scaremongering and a waste of money. More propaganda to frighten the sheep. I guess it's all about appearances, the government appear to be doing something to fight a potential terrorist threat. Is the data going to be publicly available or just lost in the post for the consumption of any budding terrorist?

"The release was undertaken at 5:00pm on 15th May 2003 from a vehicle parked in York Street using two tracers: SF6 and the perfluorocarbon PMCH. Both were released for 15 minutes each, offset by 1.5 minutes. At the sampling stations, 10 consecutive 3 minute air bag samples were collected. All but one of the sampling stations were at ground level, the other being on the roof of WCC."

see http://www.dapple.org.uk/tracer%2003.html

Note they've been doing this since 2003. See, they've got nothing to hide :-)

How do you accurately model the distribution of heavy but finely-distributed particular solid material (radioactive dust basically) by releasing an organic gas?

It might model the release of, say, a nerve agent gas (assuming the two have very similar densities), but doesn't help a whole heap with planning for the distribution of something very different that you'd get in a dirty bomb.

Even then, our good friend Chaos theory tells us that what they are trying to model is essentially unpredicatble anyway. Maybe if they carry out their test a hundred times on different days with different wind conditions they might get SOME clue as to what can happen.

In the never ending catch-up that is all the govt seems capable of, has anyone though that maybe (just maybe) the baddies might do something novel?

If they *did* have the toxic material for a dirty bomb, and they wanted to distribute it, surely there are simpler and more fear (or should that be "awe") inducing ways that a boring old bomb?

This sounds a lot more like security theatre than a practical proposition. What happens if the baddies don't release their agents in the same street that the govt. run their test in? What happens if the wind is blowing in a different direction? What happens if it is/is-not raining?

There are far too many variables to make this test useful in any form other than a publicity ("there's nothing to fear") setting.

Dirty bomb? Check - Event reponse plan 34.r7

Nerve gas? Check - Event reponse plan 21.a1

Governement boffins? They're going to release governement boffins in a built up area? The bastards! What if they start breeding in the sewers?

Load of propagandist rubbish. Fluid and air flow simulation shouldn't require doing live tests with coloured gas especially in highly populated areas. This could be modelled quite accurately with computer based simulations. Just a bunch of Home Office jerks in their quest for extending power via efforts to create a percieved need for more funding.

WATCH OUT TERRORISTS, THINK OF THE CHILDREN, etc. . .

IF YOU HAVE NOTHING TO FEAR THEN WE'LL DO SOMETHING WRONG TO YOU, more like.

So that when the real terrorists do it we will think it's government scientists and not try do report it.

This would make sense if they have several computer models of the area, so that they can compare what really happens with what the computer models tell them. Then they can decide which model gives the best predictions, quickly enough to be useful.

As for the risk of the boffins being attacked as suspected terrorists, surely they should be escorted by uniformed police officers.

we'll be millionaires! Time to sell your WW1&2 surplus gas masks.

(Marketing courtesy of the Home Office, consumer rights protected only while wearing the mask. no refunds if mask has been worn. Thank you for being done by us.)

"Quick Ahmed, the infidels have just announced they are releasing harmless gas into the streets of London. Where did we put that sarin canister?

I think he has let slip the real agenda here - emergency planning is exactly what it says on the tin.

You really think that these 'emergencies' are just accidents? Of course not - they are carefully planned by Whitehall and the Illuminatti to keep the plebs trembling in their place.

PS - WHERE ARE THE WINGS!!!!!!!!!!!!!

Mine's the strait jacket

<<Even then, our good friend Chaos theory tells us that what they are trying to model is essentially unpredicatble anyway. >>

No it doesn't. What it tells us that what YOU would be trying to model wouldn't work, but that's something unrelated.

If you release a gas at one point (a delta-peak distribution) you would want to know how fast it spreads (a gauss distribution with higher and higher variance), for example: no problem in modelling this moving front of the contamination, even if you know you cannot track individual molecules.

Since when is it a theory anyway? Oh right, since Jurassic park. Sorry.

Given what we know our states get up to, 'hysterical paranoia' towards them seems to be a reasonable attitude. Frank Olson released 'hot agents' over the US including in subways as part of his biological weapons work at Camp Detrick back in the 50's.

Project Artichoke - http://www.youtube.com/watch?v=8MlFajrqKDc

"Of course, the "7/7" bombings happened the same day as a near-identical training exercise."

Yes indeedy. As did the Madrid and 9/11 events.

I'm off ...

Maybe the government aren't really going to do the exercise after all and are just going to keep an eye out for any opportunistic wannabe terrorists trying to pass themselves off as government pseduo-terrorists, and then simply round them up?

Posted anonymously since if I'm right, they'll be out to get me for foiling their plan...

With several 000 tons of radioactive depleted Ur covering Iraq, it must be hoped none of that sand gets imported to grit roads. But according to a WHO commissioned report, prepared in the UK and subsequently buried by WHO, the "deposition" of that Ur and weather conditions prevalent at the time indicated the average Briton would have already inhaled 27 million of said carcinogen by the time Bush ludicrously proclaimed Game Over.

It nearly is Game Over. It's the Final Set. And still few see the Nu Insect Overlards.

"As for the risk of the boffins being attacked as suspected terrorists, surely they should be escorted by uniformed police officers."

But you know these nasty sneaky terrorists might be able to get hold of police uniforms, so that's no security, really. How about accompanied by well known politicians and TV stars. With sandwich boards saying "Government boffins in action, Not doing anything nasty, DO NOT BE AFRAID."

Then we'd all know there was nothing abnormal going on.

Because we can always trust what they say, can't we. Pardon? What's that?

See, there's nothing wrong with this beefburger. Eggs? Who mentioned

salmonella in eggs? See, see, he's got millions of WMDs up his left nostril,

just there.

Oh wait.. politicians and TV stars actually walking down the public street... that's not normal either is it.

We're doomed, doomed I say!

Sadly , the US government authorized many of it's mad insane scientists from the end of WW2 and through out the Cold War did the same thing in real time with real radio active substances using the unfortunate residents in Washington State and Nevada as living guinea pigs for their mostly crazy insane experiments . In Hanford some 80,000 pages of documents of these utterly insane pointless experiments were at one point declassified , the side effects were well known prior to live questionable public testing by the way.

The French did like wise in the sixties with all the residents and tourists visiting Tahiti when playing ersatz god in the sixties and seventies !

Am I the only person who read the headline as "Gay boffins to carry out simulated London dirty bombing"?

is that nickj and I seem to be the only people who visited the website to find information about the tracer. Had others visited the site they could have discovered it for themselves. Instead people waste "precious" (hahaha) thought on creating a controversy when there is no controversy.

Oddly enough, it sounds just like the experiment under discussion. A waste of resources to study and problem that doesn't exist and trouble people for no reason.

nickj also said "Note they've been doing this since 2003"...strange coincidence that the paranoia factor in the UK hit all time new levels beginning around '03? I think not!!! The government is gassing all of you to cause paranoia. Now they have succeeded with their gas and propaganda and the scientists will be beaten or stabbed by citizens scared of terrorists.

"Maybe the government aren't really going to do the exercise after all and are just going to keep an eye out for any opportunistic wannabe terrorists trying to pass themselves off as government pseduo-terrorists, and then simply round them up?" .... A honeypot, perhaps?

By Anonymous Coward Posted Wednesday 27th February 2008 19:47 GMT

And the sweetest of moneypots, AC, for any opportunistic psychopathic boffin wannabes with wannabe Beta pseudo-government Programs/Agendas/Projects.

A wannabe squared opportunistic psychopathic boffin with Beta pseudo-government Programs/Agendas/Projects.is not something anyone can simply round up, it is something you keep an eye out for and then exercise with a Paper Round ....... Discretionary/Distressed Off-Balance Funding.

And with so much Toxic Sub-Prime Liquidity clogging up the System, there is absolutely no excuse in not Resting such Funds in an Account for their Accruing of Engaging and Driving Interest.

Pay as you Boldly Go with Capital Investment Secured and Intact/Untouchably Banked with Driver Interest Creditted as Driver Interests Require.

Ps Not all psychopaths are mad, and it does them a disservice to think them so, most are probably actually In Sane. Certainly the SMARTer Ones most definitely are.

* Magical Mystery Turing Wizardry with Beta Skunk Workings/ CyberIntelAIgently Designed Protocols/Intellectual Property Portfolios.

For the umpteen+1th time:

U238 is barely radioactive. U235 is quite radioactive. Depleted uranium is 99.9% U238. And thus, depleted uranium is not dangerously radioactive. It's about as toxic as lead, so don't swallow the stuff, but you can put away the lead shield. And the paranoia.

And unless there have been some radical changes to the symbology since I last checked, the symbol is 'U' not 'Ur'.

(Currently about the third most odious NuLabour minister)

They may not kill you, but perfluorocarbons ARE potent greenhouse gases - has McNulty done an environmental assessment of releasing these chemicals? And how many hippies will we have to plant to offset this test?

And to go back in the thread, some basic chemistry.

Argon wouldn't be a very good gas to use as a tracer in the atmosphere, since there's already about 0.8% of the stuff floating around

And no, you shouldn't swallow U238, not only because its toxic, but because its an alpha emitter and could do various nasties to your GI tract as it worked its way through.

Of course, further to the above post mentioning Colossal TEMPEST Works, one could very reasonably ask why anyone would want to saddle themselves with interfering incompetent ne'erdowells rather than just ignoring them completely and boldly going the Private Route to Reward the True Entrepreneur with a Proven Track Record.

The Madness would be in not using that Root and therefore the Perfect Sense In Sanity would be to use it and IT, instead.

After All, if the/a Government and its Supposed Support Intelligence Services aren't ahead of the Game with all of the Public Purse [and the Bank of England] at its Beck and Call ..... ITs PlayDough .... then it is Incompetents stacked in the Cabinet, is it not?

J'accuse.

And of course, such Disaffection, if even Vaguely Valid [and that is always the Caveat which allows for Immediate Remedial Action to address the Perception] will always Permit Foreign Interests which may be more Public than Private to Enter the PlayZone and ITs PayZones. And who would fault them for their Bold Enterprise?

Although with such a Pink Society as regales the masses with dancing on ice and cooking with bored and boring celebs, we can hardly expect them to be led by Hardy Boys and Girls whether from the Y or not ........ and can you imagine this from the Land of Soap Artists trailering Trash/Sub Prime Programming ..... http://blog.wired.com/27bstroke6/2008/02/air-force-launc.html

This is designed to cheer up, youTubes ....... and it is Prescient too in ITs Own Inimitable Enigmatic Way :-) .... http://www.youtube.com/watch?v=OEoJlV003p4&feature=related.

If the Nation had a Monarchy which could Lead Right Royally, we wouldn't be having this Monologue. Wake Up, Charlie Boy, Wales XXXXpects and all that Jazz.

cc HMGCC

From the World Health Organisation ( www.who.int/mediacentre/factsheets/fs257/en/ ) :

"In case of uranium or DU intake, the radiation dose limits are applied to inhaled insoluble uranium-compounds only. For all other exposure pathways and the soluble uranium-compounds, chemical toxicity is the factor that limits exposure."

So it's the toxicity, not the radiation, that causes the overwhelming portion of the damage if ingested.

Of course, this debate is kinda pointless unless you're a health professional treating DU ingestion. For the rest of us, whether you die from the radiation or from the poisoning, you're still dead, so it doesn't matter.

I'm surprised that no-one has yet mentioned the test of an explosive device to spread anthrax spores in 1942. It was carried out on the island of Gruinard, just off the coast of Scotland. The detectors were live sheep in pens around ground zero, and registered their readings by dropping down dead, which they began to do three days after the explosion. The island was rendered inaccessible for 48 years. It was declared safe in 1990 after a massive decontamination exercise including the removal of most of the topsoil (to where, one wonders?).

The experiment was a "proof of concept" exercise to see if it was feasible for the Nazis to mount a biological attack against Allied cities. One school of thought was that any explosion powerful enough to disperse an infectious agent would also destroy the agent, so rendering the attack harmless. The Gruinard experiment proved this view wrong.

For details, see: http://news.bbc.co.uk/1/hi/scotland/1457035.stm

A search on "anthrax island" will throw up lots of sources, and references to similar experiments.