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Comment: Re: In Reverse (Score 1) 68

by RockDoctor (#48446269) Attached to: Extreme Shrimp May Hold Clues To Alien Life On Europa

If that really is how life got started then it's likely that primitive cells are still being spontaneously created near these vents today

Modern conditions are very considerably different to those in which life developed on earth.

For a start, there is oxygen. Now, it may be true that oxygen is essential for large organisms to develop (we only have a sample of one ecosystem, in which oxygen is almost ubiquitously associated with large organisms ; but that's an "almost ubiquitously", not an "always" ; the case may be suggestive, but it is certainly not proven.), but we're not talking about large organisms, we're talking about the formation of the first very small organisms. For certain, life evolved on Earth for a very long time before there was any significant amount of free oxygen in the ecosystem. Life and significant concentrations of oxygen have coexisted at best for a half of the duration of life on Earth.

For a second thing, the modern world is full of organisms that breakdown ad re-use organic molecules. While there is a lot of debate about what particular compounds were common in the pre-biotic/ peri-biogenetic environment, it is sure that the modern environment has been stripped of many of the more complex molecules. Some of that stripping is due to the molecules being broken up by reaction with oxygen (see above), but much of it is simply going to be eaten.

The likelihood of life spontaneously developing around modern deep-sea vents (or shallow-sea vents, for that matter) is considered pretty low, even though their ancient analogues are certainly sites of interest for biogenetic models.

Radical re-thinking about the possible environments for biogenesis happens almost every time there is a new student writing a paper on the subject. There is not a scientific consensus on the question (though there are certainly ideas that are more popular than others). If this clashes with what you've heard on Discovery Channel, then I'd advise you to swap their (pretty shoddy) "journalism" for actually reading the relevant science. Much of it is available open access.

Comment: Re:We've been doing it for a long time (Score 1) 326

You're making the common error of expecting that your opponents are stupid. That has killed a lot of people.

Your opponents may be wrong - or they may be right and you're wrong. They disagree with you, that is what "opponent" means. But it doesn't mean that they're stupid.

Comment: Re:We've been doing it for a long time (Score 1) 326

There are geoengineering schemes that you could build on a "fire and forget" basis. For example, you might place a fleet of solar sails near the Lagrange-1 point in the Earth-Sun-Solar system point, with electron/ magnetism thrusters for station keeping, and a telescopic monitoring system aimed at the Earth. Set the control logic up so that if the polar ice caps vary by more than 10% from present (pre-industrial norms), then the solar sail fleet re-configures to increase or decrease the insolation on the Earth by a couple of percent.

OK - it needs engineering on a multi-millennial reliability scale, and a control loop that thinks for a decade or so before taking any action, which are substantial pieces of engineering beyond present capabilities. But they don't violate the laws of physics.

Comment: Re:We've been doing it for a long time (Score 1) 326

With CO2 at over 400 ppm, even if everyone went zero-emissions tomorrow, the planet would still continue to warm up for at least a millennium, more likely five millennia.

FTFY

The experiment was done, on Earth, around 54 million years ago. It was called the Palaeocene-Eocene thermal maximum, and I've just finished drilling through the rocks laid down around that interval, with their associated fossil changes, changes in rock chemistry, etc. (Steering oil wells to land in particular horizons in this sequence is a bread-and-butter bit of industrial geology for me.) The temperature increases, as calibrated by Milankovitch 20kyr cycles in magnoetostratigraphic records) took about 5kyr, though our best estimates for the gas releases is more like 1kyr (runaway warming once the methane hydrates around the proto-Icelandic High started to rise above their stability limits).

Really, within the geological industry, the argument has been over for more than a decade. We know, with the confidence of seeing the results of the last experimental run, what is in the pipeline for us.

Comment: Re:We've been doing it for a long time (Score 1) 326

Venus is probably a better match for Earth's climate system than Mars is. There's a lot of water in the atmosphere of Venus.

So ... let's say we build a sunshade to start to lower the temperature of Venus' atmosphere at twice the rate we're raising the temperature on Earth. Let's say that we get it in place by 2050, to get our test running. That's about 4K/decade, and we've about 300K to decrease the surface temperature by.

So in about the year 2750 (if I've got my numbers right), our experiment will have reduced the temperature of Venus to the point that liquid water will start to condense to the surface. Then we'll get into a complex situation of convecting heat (as clouds of steam) from the surface rocks to the higher atmosphere, where the heat gets dumped to space. How long is that going to take? Tens of thousands of years, or hundreds of thousands of years? I wouldn't rule out millions of years - but I'm a geologist and I've got some sort of idea how long similar process took on the Hadean Earth.

Sorry, but wasn't the point to get some data relevant to the lives of your children/ grand children, or at least people who might know your name as an ancestor?

Comment: Re:We've been doing it for a long time (Score 1) 326

Bloody ACs, why don't they have the character to post under real accounts?

Let's say that we decide in 2020 that we have no option for survival beyond 2200 but to start a programme of geoengineering which will take 150 years to have sufficient effects. (That would be starting in 2050, and you can make a rough guess that we started having significant effects on the planets climate in around 1900. So I'm making a guess that it'll take as long to bring the problem under control as it took to cause the problem.)

So, how do you manage to test an areoengineering programme on Mars, in the 30 years leeway that you've got?

There's a more fundamental problem - Mars essentially lacks the large heat buffer that comprises our oceans. So the climate system of Mars is almost completely unlike that of Earth. The climate on Titan is probably a closer match in terms of processes.

Geoengineering is something that we're unlikely to have an opportunity to experiment with before having to implement it. Which means we'll have to be in a pretty desperate situation before trying it. So, maybe, just maybe, bringing our dangerous ecological destruction habits under control might just possibly be better. But since that is going to impact the ability of a small proportion of people to make money, that is a forbidden concept.

Comment: Re: I'm quite surprised it wasn't (Score 1) 493

by RockDoctor (#48442403) Attached to: What Would Have Happened If Philae Were Nuclear Powered?

a billions dollars on simple solar panels.

I think it was entirely appropriate to work out how much power they needed, then provide a power supply capable of achieving that, using materials that were acceptable to the people paying the bills (NB : not America, in the largest part). And they did it using some of the most sophisticated solar panels to go into space.

If they had used a Pu-238 RTG (which for political reasons may have been sourced from our neighbours - the Russians), and some 60-90kilos of instrument weight had been rejected from the orbiter to allow for the increased mass of the lander+RTG, and the lander had then landed, bounced, landed upside down, and achieved only 10% of the science package, would you have like to defend the RTG decision to the court of public opinion?

Ah, hindsight - the only 100% perfect telescope!

Comment: Re:I'm quite surprised it wasn't (Score 1) 493

by RockDoctor (#48442383) Attached to: What Would Have Happened If Philae Were Nuclear Powered?
I hardly consider myself to have more than the normal -for a nerd- interest in space science, astronomy and technology, but I'm astonished how you could have actually acquired or held that immensely mistaken a belief. Did you pay no attention at all to space technology since the month (or so) when we both signed up for Slashdot? Did you not notice the months of struggles to bring SOHO back from it's unplanned orientation excursion? Did you miss the years of worries over the build up of dust on the Mars rovers. Did the agonies of trying to manoeuvre the cripples Spirit rover to get the extra couple of degrees of tilt to try to survive it's final winter pass you by?

How can a Slashdot reader not be paying a modicum of attention to space science? After all, to the best of the evidence we have, that entire universe is ours, and we nerds are likely to be the first people to get out there and own it. (Or our logical descendents.)

Comment: Re:Toronto Municipal Gov't divided (Score 1) 168

by RockDoctor (#48442233) Attached to: City of Toronto Files Court Injunction Against Uber

They do not receive special safety inspections above and beyond the normal, the drivers do not receive special scrutiny above and beyond a normal driver, the only issue is insurance which the ride services already require be handled, or handle themselves.

Speak for your own country. Here, for certain taxi cabs and mini cabs receive special safety inspections. The normal regime of inspection is nothing for 3 years, then a mandatory annual inspection ; for taxis, it's a 6-monthly inspection from registration.

Taxi drivers who are to handle vulnerable people (unaccompanied minors, unaccompanied sub-normal adults) require a full criminal records check - as does anyone who works with vulnerable people.

All taxi drivers must display their photographic and hologrammed (i.e., fakable, but not trivially fakable) where the passenger can inspect it ; no ifs, no buts, no maybes - "must". All taxis must display their additional registration plate where it can be read, and that plate contains the registration plate of the vehicle.

Your country may have fucked up regulations which are not enforced, but that doesn't mean that the rest of the world is as badly fucked up.

I take it that you're not going to support the spread of Uber etc to countries with proper taxi regulation.

Comment: Re: "after four nearly sleepless days and nights" (Score 1) 88

by RockDoctor (#48414277) Attached to: After Four Days, Philae Team Gets to Rest
That's the job. Many of my trine es go on to supervise or plan such jobs. They leave me with no doubt of the drain they put on people. And, in my experience they remember, and fight a corner for 24x7 experienced cover. But if the people aren't there to hire, and the bed space isn't available ... then at least they understand the problems of the (person)in the field better. It's not perfect, but it's better than nothing.

Comment: Re: "after four nearly sleepless days and nights" (Score 1) 88

by RockDoctor (#48412821) Attached to: After Four Days, Philae Team Gets to Rest
I've been doing this since 1987, to varying degrees. Some years I've been down to about 1500 hours work (though we bill by the day, or part of, door to door), some years pushing 3000 hours, and utterly exhausted. The intensity increases with time, because you get sent to jobs with absolute greenhorn (instead of being the greenhorn yourself). And sometimes you do have to just dump raw data upstream for assessment there, but even then you need to verify that the collection parameters were recorded appropriately.

(An 8h x 5d x 48w year is 1920 hours. On the other hand, when I'm not at work, I can go for a week hill walking if I want, and there's nothing the Boss can say - it's my compensatory time for sleeping at the work site and being on 24x7 call.

Comment: Re: "after four nearly sleepless days and nights" (Score 1) 88

by RockDoctor (#48410609) Attached to: After Four Days, Philae Team Gets to Rest
When I'm at work, and we go from routine operations (where I have a lot to do) to evaluation operations (where I have a lot to do and can't delegate chunks of it to my night-shift/trainee, because they're a trainee) then yes, I have to do this regularly. Bouts of 4-5 days are normal; up to 8 days not uncommon, but deeply draining. Then there will unavoidably be 1-2 days of engineering/ maintenance work, and then the cycle repeats. Bouts like this happen a couple of times a month, then I'm rotated back to shore or my home country to recover.

Don't get me wrong- this is draining. But it's not impossible.

OTOH, there is a good reason that 90% of trainees move on to office work instead of staying in field work : a lot of them can't handle the fieldwork.

Your own mileage may vary.

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