Here's an interesting companion to the worries of back-contamination with MSR: The worries that a particle physics experiment will destroy the Earth:

http://cosmiclog.msnbc.msn.com/archive/200...20/1043826.aspx

While the particulars are very different, the legal/PR issues are likely to be similar, since the opponents are equally unable to craft a real estimate of any of this. It's more of a Reverse Pascal's Wager argument, in that the potential negative outcome is Negative Infinity (all life on Earth destroyed), so however tiny the risk, the argument goes, the expected outcome is negative.

This may also be compared to the anti-plutonium picketing we saw with Cassini, although to the rational mind the cases are extraordinarily different. No one ever expected Cassini to have the potential to eradicate ALL life (or even 0.1% of it), though the worrisome prospect had SOME non-almost-zero probability of occurring. (Launch failure, nonzero radiation leak.)

Another similarity between the hadron case and that of MSR is that the best counter-argument is that if it were apt to happen, it already would have, thanks to nature.

The arguements are a little bit different.

Any weird and funky energy effects could have been created somewhere in the Universe (and still might be out there), just not "right here in our backyard". The risk is doing something that might potentially mess us up. So any funkiness might've happened "out there" (waaay beyond), but probably didn't happen "right here" (Earth).

Contamination of Earth from Mars is something that could have happened over and over after major impact events. For all we know, we are martian contamination. So any funkiness probably happened "right here" (Earth) already. Just to be a polite neighbor (and good scientists), it would be nice to do our best to avoid deliberate and accidental cross-contamination. (I"The Andromeda Strain" was my first scary sci-movie experience.)


The other main difference is that there are lawyers on Earth, but not on Mars.

Lawyer jokes aside, low forms of life can't sue.

-Mike

In re the Hadron Collider:

If you look at the Universe from a quantum point of view, anything is possible at any time... and most things are so improbable that they will not actually occur within the lifetime of the Universe.

That said, yes, it's possible that extremely energetic collisions, if they occur in just the right way, could generate nano-singularities. But we have absolutely no clue as to how such things might behave when operating in a quantum realm, at a scale where gravity is weaker than the strong atomic force. I've read several theories that such nano-singularities would dissipate almost immediately, their gravity overwhelmed by atomic forces and quantum effects. But it's all theoretical.

I think the odds of creating a doomsday singularity are so excessively remote, considering the very short time high energies will exist in these experiments, that I too will sleep quite well while this machine is operating. After all, there was better theoretical support (at the time) for the concept that a fission explosion would start a chain reaction firestorm that would burn off Earth's atmopshere than there is for the doomsday singularity scenario. At some point, you have to declare that the benefit to be gained (great) outweighs the risk (extremely extremely tiny).

In re Martian backcontamination:

When we brought samples back from the Moon, we quarantined them (and the people who collected them) because the risk of backcontamination (very very small) multiplied by the consequences if a pathogen were present in the samples (very very large) yielded, in Mike Collins' words, "a finite number" representing a threat level that you could take precautions against.

Now, we will have much better information, by the time of MSR, about organic materials in Martian soils and rocks than we had prior to Apollo about such things in Moon soils and rocks. We will have done an amazing amount of in situ analysis of a variety of Martian rocks and soils by the time MSR flies, and may have a very good idea of whether or not the samples coming back to us might contain organic materials.

If we even suspect there are organic materials in Martian samples, then the risk potential rises, and Mike Collins' equation states you have to give the issue more of your attention. But if you're more than reasonably certain that your samples have no extant organic materials, that risk potential goes down and the amount of time and money the issue deserves automatically decreases.

Myself, I think you can make a good argument for super-clean handling of returned Martian samples, on the dual arguments of eliminating backcontamination of Earth and also terrestrial contamination of the samples. If life of any kind is found in any Mars sample, we have to be as certain as possible that it didn't get there from handling contamination. I don't think it's necessary to sequester the samples in LEO or anything that extreme (or expensive), but I'd establish some pretty tough handling standards.

-the other Doug

Good analysis, Doug!

One other pragmatic factor re Mars samples: The very last thing anyone wants to do is to expose them to the terrestrial environment because organic contamination of them would happen in mere seconds, thus quite possibly wasting the entire effort to retrieve them. Systemically, this requirement serves the interests of all concerned parties rather neatly...

We do know that cosmic rays frequently produce more energetic collisions than the LHC will, in some cases by many orders of magnitude. Despite 4+ billion years of this bombardment, nothing we see in the solar system appears to have been gobbled up by micro black holes or strangelets. Nor do we see obvious signs of these things wreaking havoc in the universe at large.

I know you aren't arguing against the LHC, but it's worth pointing out that the energies involved aren't something unique in the modern universe. There are far bigger particle accelerators, they just aren't as conveniently located.

I find it ironic to think that even if we do accidently destroy the Earth and all living beings, that somehow, somewhere, there will be a lawyer ready to file a lawsuit.

You just can't win.

Yes, they're bigger, but do the pack a greater bang-per-particle?

Active galaxies are AFAIK the best guess for the source of ultra high energy cosmic rays, so yes, by many orders of magnitude.

On the other hand, suppose there's a Doomsday Particle with a half-life so short that it never makes it from any cosmic source to the Earth, but one in a lab will do us in.

I think we may have just solved the Fermi Paradox. Will the last one down the wormhole please turn out the lights.