Bubbly billygoat-bursting boffinry brouhaha at MoD

As for just where the safety line is to be found in various kinds of pressure-change situation, the answer is that nobody really knows. Different organisations use different rules even for fairly cut-and-dried up-and-down dive profiles. Once you get into whipping someone up fast out of the deep sea and then quickly pressing him again in a chamber before he fizzes to death, well, that's relatively unknown territory.

But you'd like to know all about it, because one day you might have fifty or a hundred submariners exiting a doomed sub at depth and zooming up to the surface in their escape rigs. If you're on the rescue ship at the surface, compression chamber at the ready, you need to know what pressure to put them to, what gas mix to give them - what treatment will save the highest percentage. This isn't the kind of thing you want to be finding out on the job.

Goats, apparently, are relatively close to human physiology in this area. As the Herald notes, the unlucky caprines have been experimented on under pressure since 1905.

"Critics say that the data collected from thousands of experiments over more than a century should be more than sufficient to justify ending live testing and provide a base for computer simulations," adds the paper.

"The French navy has already abandoned its own live-test programme in favour of more humane methods."

On the other hand, helium certainly hasn't been in use for a century. Neon and hydrogen mixes are more recent still. Trimixes, with more than one inert component, are also quite new-fangled. Compression-chamber therapeutics is a field you would reasonably describe as being in its infancy - it wasn't that long ago that the Royal Navy could normally offer nothing more than pure oxygen or air in most of its operational chambers.

There's plenty of useful stuff still to learn - knowledge to be gained which could save human lives. How many lives, though? And how many goats would have to die or suffer to save those future divers, submariners etc.? How many goats would you torture to save one human? Does it matter if they get made into a tasty stew afterwards?

It doesn't stop there. Will there really be any divers and submariners in future? Won't it all be robots?

Maybe not, as a lot of key robotics tech - high bandwidth two-way wireless comms and satnav, for instance - doesn't work underwater.

The MoD told the Herald that its top people "are investigating a range of options for submarine escape and rescue, and life support, including and excluding animal experimentation. Any plans for further experiments using goats are subject to the findings of this review."

The Animal Liberation Front (sample quote: "the Boston Tea Party raiders did not consider themselves terrorists") said: "We call on QinetiQ to halt these experiments and hand all surviving animals over to suitable animal protection groups."

Deep waters, these. (Ah, thank you; it looks cold outside. My taxi? Ready for a fast getaway, you say?) ®