Why all the failures to natural disasters?

Eblc/LNT-1995.PDFfor a rather carefully

It's a rather carefully considered study of why the linear no- threshold model may well be inadequate. This doesn't invalidate the no- threshold concept. From a biological point of view, any break in the DNA that has to be repaired is an opportunity for it to be repaired wrong, and a pontential contributor to the four or five mutations that seem to be required to turn a cell cancerous.

As a study, it make it blindly clear the epidemological data is subject to a large number of confounds, and using it to try and validate any model more complex than the linear no-threshold model isa waste of time.

-- Bill Sloman, Nijmegen

From a space platform.

Why didn't you suggest a cannon in space?

Though it would move a bit more (the cannon), the shot would fire just fine.

In the summer of 1957, a team working in the Nevada desert drilled a hole about 160 meters deep. It was sealed with a manhole cover weighing a few hundred kilograms. High-speed cameras were positioned to record the blast and the [nuclear] weapon was detonated. Later analysis showed that the cover had moved at a speed about six times faster than escape velocity. It was fast enough to escape, not just the Earth's gravitational field, but the Sun's as well.

IIRC the guy actually involved was careful to point out that the manhole cover would certainly have vapourized before actually leaving the atmosphere.

Cheers

Phil Hobbs

Minor correction: it could theoretically make sense, but it practically doesn't. Not by orders of magnitude. Even if all the engineering problems were solved overnight, the infrastructure costs to support it would be enormous and the payloads would have to be ridiculously robust. The latter would rule out almost all practical applications even if such a thing were buildable.

Currently, yes. It might not always be so, but even then it won't be launch from railguns that takes over.

I agree. You'd need an evacuated tunnel up to very high altitudes (>100 km) before even considering direct launch to orbit without rockets. That would be just one of a great many insane costs.

Yes, I'm not claiming that it actually supports beneficial effects of low-level radiation. The results suggests it, but correlation is not causation and a nonlinear (but still monotonically increasing) no-threshold model in conjunction with confounding factors could explain the results equally well.

Yes, or a contributor to killing a cell that already has some of those mutations. Biological systems are complex, and there are a great many interactions into which we have very little insight. There are plenty of cases where something is biologically useful in small amounts but deadly in much greater quantities. Ionising radiation may be one of those, or it may not.

Quite true.

It's a rather carefully considered study of why the linear no- threshold model may well be inadequate. This doesn't invalidate the no- threshold concept. From a biological point of view, any break in the DNA that has to be repaired is an opportunity for it to be repaired wrong, and a pontential contributor to the four or five mutations that seem to be required to turn a cell cancerous.

______________________________________ Very naive.

The no-threshold limit for damage is unsupported by evidence. There are hosts and hosts of chemicals, diseases, environments etc which clearly do not have linear effects and problems with small doses, and as far as I know none which have ever been demonstrated which do.

Obviously these things aren't linear. If 1 gram of some poison will kill you, eating a milligram of it every day for 3 years won't.

Catching mild diseases actually improves your health, as it improves immune system response. Much of the growth of auto-immune diseases (particularly asthma) is blamed on environments which are too clean.

This linear model is obviously bullshit. I am unaware of any poison, disease or environmental health hazard which has *ever* been demonstrated as having a linear effect. Overwhelmingly, these effects are such that halving the exposure reduces the problem by more than half. Take 20 sleeping tablets and you will wake up the next morning feeling fine. Take 40 and you won't wake up. Is this linear?

...

The evidence does tend to be ambiguous.

If there is a measurable non-linear effect, are low levels of radiation "beneficial" or simply "not as effective".

It's sometimes noted that larger doses of radiation at some sites (e.g. thyroid) tend to kill cells rather than allow them to develop into a cancer.

The theory that ionising radiation might be helpful in small quantities, by upping the level of DNA repair enzymes, strikes me as thoroughly implausible. There are plenty of other processes active in a cell that can lead to DNA damage, and the damage caused by small quantities of ionising radiation would be lost in the noise.

-- Bill Sloman, Nijmegen

Which is to say, uninformative.

"Not as effective" seems to be a lot more likely.

er.

Unfortunately, it isn't the cells that get killed that go on to give you cancer. Cancer depends on the accumulation of about four or five specific mutations(the statistics of the increase in cancer incidence with age make this fairly clear)in the cell that goes on to develop into a cancer. This coincidence is pretty improbable, but you've got a lot of cells.

-- Bill Sloman, Nijmegen

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This neglects what we know about the way radiation damage works.

The fact that there are a large number of chemical and environmental factors that are tolerated in small doses and damaging about some arbitrary threshold doesn't prevent the linear no-threshold model from being the default model.

makes the point that for infectious diseases it is pretty much impossible to get experimental data that can establish the existence of a real threshold.

That depends on the poison, and the mechanism of elimination. Long term exposure to low levels of mercury can cause a damaging accumulation in the body, as Alfred Stock illustrated

I first read that as a graduate student in chemistry, when I first started working with a mercury-vapour diffusion-pump based vacuum line.

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Which has nothing to do with radiation damage - the immune system isn't involved (except that enough radiation will wreck it, along with a lot of other functions).

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No. Death is a non-linear process. Don't confuse the action of the drug (and remember we aren't talking about a drug) with down-stream consequences of the action.

The virtue of the linear model is that it simplifies the analysis, and you've rarely got enough data to pin down the extra parameters needed to define a - by definition - more complex non-linear model.

This doesn't make the linear model bull-shit, merely a model that should not be extrapolated out of the region where it was - more or less - validated.

Most non-linear models can be adequately approximated by linear models over a sufficiently limited range - which can imply a positive or negative threshold, if you try to extrapolate back to a zero dose.

-- Bill Sloman, Nijmegen

Why do you pay so much attention to freshly laid turds?

Silly. How would you store all the energy? It's fabulously expensive to put mass into orbit, and capacitors store an insanely small amount of energy per kilogram compared to chemical fuel. Do the math.

And a rail gun kicks back all the projectile's momentum back into the launcher. A rocket doesn't. So if, for example, the ISS used a rail gun to fire a projectile further out into space, ISS would lose orbital velocity from the kick. So it would have to be boosted back into its proper orbit. And how would that be done? With rockets!

John

It's there in Japan. You can go pick up some cheap land, as long as you ship in water, food and everything else as well.

Selfishness. Gain on people's suffering.

Yes to people without compassion.

Yes. I am within 30 miles of San Onofre. I am not moving. I am moving the nuclear waste only. I DO NOT want to shutdown the reactors. I am using the electricity from San Onofre right now.

Ok, you are prejudiced against the military, and have no real idea what their capabilities are. Opinion acknowledged...

Charlie

You're assuming it would be shot out the leading edge of the ISS. It would be on the trailing edge, to get a free boost in altitude if they had any brains about orbital mechanics. Think about it.

Yawn. The US military has a long history with Nuclear power plants. They even had one in operation in the Washington DC area. read this:

Not only did the US Army build & use reactors, the plant at Fort Belvoir, VA was the first nuclar plant connected to a power grid. The SM-1A reactor was across the street from my barracks at Ft. Greely.

Another yawn. When TMI happened, a retired US Navy engineer from the USS Nautilus was called in to help.

The USS Nautilus was the nuclear submarine that cruised under the north pole.

Do you care to make any other stupid comments about the US military and nuclear power?

So, the US Marine construction engineers are all liars? They never built any buildings? What a freaking maroon!

nly

Nobody is asking them to repair reactors. We are asking them to assist in damage control and security.

You live in a very small world, but we don't.

So, they don't fight in Embassies? They have to withdraw because the buildings are damaged?

Not "primary", but essential.