"They are the second most encephalized beings on the planet," says Marino.
But it's not just size that matters. Dolphins also have a very complex neocortex, the part of the brain responsible for problem-solving, self-awareness, and variety of other traits we associate with human intelligence.
I think you mean sulphur hexafluoride. Sulphur tetrafluoride releases HF on contact with water, which is not recommended. Uranium hexafluoride is pretty unhealthy too.
See my back of the thumbnail calculation - adding a thousand tonnes of volatiles to the atmosphere (by impact) every hour would give Mars around an Earth's atmosphere (to an order of magnitude) in a mere 110 million years. It's fiction.
if you could have your 100 impactors of [Chixulub] size delivered in a short period of time, what effect would that much energy have on the core of the planet (minimal I suppose)
I agree the effects would be minimal. To a first approximation, a crater is around 1/10th it's diameter in depth. So for Chixulub, the initial crater would have been some 18km deep. which would get you to the lower crust. IF you could stack all 100 together, you'd have a crater 1800km deep, which is about 2/3 of the way to the outer core. Of course, such a deep crater is unfeasible- the sides would be collapsing in as the initial crater is formed. (Incidentally, after the first couple of impactors, there wouldn't be much in the way of atmosphere on the site to worry about. Landing in vacuum.)
and how long would it take for the atmosphere to settle dwon afterwards. Of course the Martian conservation movement would be up in arms.
Since a large part of the kinetic energy of the impactor comes back to the atmosphere (as either direct heat from the hot crater heating the atmosphere as it rolls back, or as frictional heating from the impact of secondary projectiles), so many major impactors in a short period would be very destructive. If you stacked them in one location, the secondary impactors would still probably strip most of the atmosphere.
So you're actually looking for the time for a new atmosphere to form by outgassing. That may simply not happen, if there aren't enough volatiles left in the mantle (or it's not mobile enough to degas effectively).
If you were going to try to bump up an atmosphere by several hundred-fold (as needed to make Mars vaguely liveable), you're going to need to add (thinks... Earth's atmosphere is 5.1480Ã--10^18 kg (Wikipedia) ; Mars' 2.5 x 10^16... but Mars is a smaller radius planet ; let's say 10^18kg of volatiles ; as long as there's nitrogen for bulk, we can dump CO2 into the ground as carbon and sort out the chemistry later) a thousand tonne (10^6 kg) dirty snowball every day for 10^12 days... OK, one every hour for ~4*10^10 days. 110 million years. And you'd need a managed landing zone- say a few hundred km wide around the equator of the planet.
Terraforming Mars is wonderful science fiction. But nonetheless, it's science FICTION.
... for HUMan INTelligence - the act of collecting information about your opponents, their staff, supporters and minions, that could possibly be of future use to suborn, undermine, influence, control or discourage those people.
Nothing new here - not even storing such information on a database. The Roman Emperors did the same without calling it a database, just calling it "politics".
Did anyone really consider this a barrier to changing their phone OS?
The Marketing Department of Apple ^H^H^H^H^H^H the Sirius Cybernetics Corporation (a " bunch of mindless jerks who'll be the first against the wall when the revolution comes.")
Actually, since DNA was well known as an Apple Fan-boy (and wasn't afraid to parody himself over it), it's moderately amusing to watch Apple's slavish following of the Sirius Cybernetics model from the outside.
At most 99.8% of other people out there. I've never taken a video on my phone either. Why the fuck would I?
I suspect that low-end usage of mobiles is a lot more common than you think. My dad never uses anything other than voice and SMS (and precious little of the latter) ; Mum doesn't even use the land line, let alone a mobile.
Like FDR responding to the German declaration of war, after the Japanese attack.
Using this argument - and it's not without merit - Roosevelt could perfectly well have fought the Japanese first, being the "clear and present danger". During that time, Hitler could have consolidated in Europe, possibly succeeded in invading and conquering Britain. And then, in about 1945, proposed to America a joint offensive against Russia with the Americans coming overland from their takeover of China (after destroying Japan), and Operation Barbarossa being properly supplied and organised.
Alternative history - but perfectly credible. Even if Roosevelt's personal inclinations would have favoured supporting Britain against Germany, there was enough sympathy for the isolationist position in America that they could have made it fly.
A good candidate for the filter is the ability to do math. Think about how few humans can even do calculus.
Doesn't really matter much. Look at the history of the event : in an Europe of a few 10s of millions of people, at least two (2) came up with pretty much the same idea independently and simultaneously (and several others were groping around the edges of the idea). That implies that the proportion of people capable of coming up with that idea is in the order of 1 in 10^7.
Once you've got a population in the tens of millions, someone is going to come up with the idea around once a generation. So within a handful of generations at worst (people as sociable as Newton slow population growth), you're going to have someone come up with the idea AND be willing / able to teach it to others.
The great thing about cultural evolution (as opposed to physical evolution, is that it is Lamarkian. Not only can parents directly pass on the products of their life experience to their offspring, but the offspring can pass it back to the previous generation too.
semi-intelligent species with number systems with only 3 numbers: one, two, and many.
What - like crows (who get to 3 or 4, possibly even 5 depending on whose reports you believe)? Or humans, who invented Hilbert's Hotel as a way of taming Cantor's infinity of infinities. There are human cultures whose culture only needs words for "one, two, many" but they're all part of a species that can populate Hilbert's Hotel. Crows, meanwhile, only seem to need to count to 4 or 5. Squirrels, on the other hand, can get up to around a hundred (counting nut caches). You evolve what is appropriate for your situation.
Abiogenesis is very difficult to study. It left no evidence,
That's probably not true. It hasn't left any clear and unambiguous evidence capable of convincing even the most die-hard of sceptics, which has been found and identified as such. That's true. There is quite a lot of evidence concerning abiogenesis, but it's all ambiguous, unclear and capable of multiple interpretations. (Or hasn't been found and convincingly interpreted yet.)
and all early forms of life have long since been consumed by their more-adapted descendants.
Again, we don't know that. But we do know that conditions on the surface of the planet are greatly different to the conditions under which the first lifeforms developed, because we have physical fossils (e.g. stromatolites) which pre-date the last occurrence of detrital iron pyrites and uraninite (both of which are highly sensitive to the presence of free di-oxygen in the air.
For rotorcraft on take-off or landing, being able to see another aircraft isn't necessarily a near miss, as long as one or both are near stationary and not one above another.
The rules haven't changed, and I still don't see a reason for them to change. Quite why drone fan-boys want to fly their toys in the couple of percent of the country within sight of an airfield is something awaiting explanation and justification.
Three weeks after moving into a new house and I still don't have a phone line (as in, physical line), or any internet connection other than intermittent connection on my mobile phone.
Almost any connection (e.g., 28k8) is better than no connection.
I suggest you have a look at the dictionary definition of ritual. It very much has a religious intent to it.
... however, when it is used by ARCHAEOLOGISTS in an ARCHAEOLOGICAL context, that is not what it means. (Incidentally, "context" is another term that has a noticeably different usage in archaeology to common English.).
Why not just use a term like "activity" instead of ritual which has a clear religious slant to it?
Great idea. Where do I come to get into the time machine and go back and change the terminology used a century and a bit ago?
Aligning the stones when the site was built over such a long period wouldn't even remotely need any kind of complex knowledge.
Your surveying protocol. Let's start with a field. You do not have a compass. You do have an abundance of string, and as many sticks as you want to drive into the ground. And as much astronomical ingenuity as you want. What is your first step?
Talk of need of an atomic clock is laughable - perhaps yes, if you've worked in academia all your life and have no real world pragmatic, practical competence whatsoever.
Look up "metaphor". It's a Greek word, so you may not have hear it before.
And yes, we do know they align astronomically
At this moment, they align with some astronomical phenomena, but not with others. (Incidentally, what is the fucking use of marking a solstice? What you really need is the approaching vernal equinox, to allow you to get the seed into the ground. By the time you get to the solstice, you've already either got a good harvest in the making, or killed your family in the coming winter. Marking the solstice has no detectable utility (unless you can come up with a reason, so it's "ritual" sensu archaeologicae.) But since they were build 4 to 6 thousand years ago, and the skies were different then, that doesn't tell us what they were used for when they were built.
simply realising that when the sun hits stone about 3/4 of the way down the left hand stone of arch A is probably sufficient for most communities in an "Oh well, we didn't get it quite right but that tells us what we need to know" kind of way.
And if your neighbours, literally two hours walk away come up with a completely different answer to the same question, that raises one weird circumstance. Or if they were answering a completely different question, that's another different set of questions for interpreting the sites. (how far apart are parishes in your community? Here they're about miles in the country, and a few hundred metres in town. There are 4 parish churches between my house and the supermarket, of which three are abandoned and derelict, or deconsecrated and up for rent.)
Fuck's sake - what a pile of bullshit over a stupid choice of terminology a century ago. I remember a comment in AI to the effect of 'call your programme units "QDR45" instead of "ResolveParadox", to avoid giving yourself and anyone else false expectations of what the code actually does. I don't think "ritual" was a good term to choose - "frumpstiggle" would have been less confusing - but it was the term that was chosen and unless you want to pick a fight with the whole archaeological community (which will take the rest of your life, and probably fail) then you're not going to see it change. Or you could build that time machine.
It would be interesting to use this technique to gain more insight on the origins and migration patterns of early north and south american populations.
Just send the samples to Svante's Lab, and we'll get the results.
What? Finding appropriate samples in good enough conditions is the hard part? And that's what is holding thing up?
We have measured the current loss rate due to the solar wind interaction for different species: Q(O+) = 1.6 * 10^23 per second = 4 grams per second (g s^â'1), Q(O2+) = 1.5 * 10^23s^â'1 = 8 gs^â'1 , and Q(CO2+) = 8 * 10^22 s^â'1 = 6 gs^â'1 in the energy range of 30 to 30,000 electron volts per charge.
So, the Martian atmosphere is losing about 20g/s of material (well upwards of that, but they're the main species involved.
A year is 60 * 60 * 24 * 365.25 = 31557600 seconds, so you're talking about 631152 kg a year of material being lost (Earth year, not Martian year) : 630 tonnes a year need supplying to maintain the current atmosphere.
Mars needs, for a human - usable atmosphere, about 100 times as much of it. Modelling how much would be lost a year is going to be hard - there's a non-trivial screening of deeper atmosphere by higher atmosphere. So I think my back-of-a-thumbnail estimate of a thousand tonnes a year being needed isn't far wrong.
That's a thousand tonnes a year of H, O, N, and C. Otherwise known as comet material. You could ship in a kilotonne of ammonia/ CO2 ice and evaporate that on the ground if you liked, but you'd still need to bring in that material.
To increase the mass of the atmosphere by the 100-fold factor needed, you're going to need a lot more. As you suggest, it has taken around 3 billion years to reach the current state, so to reverse those billion years in a century, you'd need (today's kilotonne/year) * 3 billion / century, which is 30 million kilotonnes a year. For a century. I make that a 20 km diameter comet every year for a century.
Chixulub was that sort of size impactor. The (alleged) dinosaur killer impactor. Every year for a century. Now, I'm a geologist, and there are genuine questions about whether Chixulub was a dinosaur killer, or a very bad hair day for them. But to have one arriving every year for a century... the amount of energy you're delivering to the atmosphere isn't going to be good for anyone o nthe surface of the planet while "atmosphere delivery" is going on. It's not going to be good.
Terraforming Mars is good SF, but atrocious resource management and a bloody difficult way to not achieve your aims.
Car registration (license) plates are unique in the same sense then. My (legal) registration in the UK might match one form 70 years ago in Swaziland. But the system is designed to encourage uniqueness, even though it's not strictly necessary. (MACs only need to be unique on a particular segment.)
One of the first bits of network troubleshooting I had to do was debugging an address conflict on HP-9800 series machines, which had a dip-switch set equivalent to a MAC on (I've forgotten the name of their network ; used stacked Centronics-like connectors... HP-IB (Hewlett-Packard Interface Bus), now known as IEEE-488. 48 or 64 address bits sounds a bit better than 5 address bits.
Change the dimensions of legally manufactured bullets every few years. Do not repeat sizes. Do not mark any legally manufactured bullets with their size.
Illicit gun users (everyone outside the police firearms units and the military) will stop using their guns after losing one or both hands to misfires. Illicit ammunition manufacturers need hardware and consumables and space to work, which will greatly reduce the supply of ammunition.
A gun without ammunition is better known as a club - working range about 1.5m.
Could we not produce it faster than solar wind ripped it away?
That would mean delivering several thousands of tonnes of volatiles to the surface on a daily basis for the future. All of the future.
Or you could drop a megatonne comet fragment into the atmosphere about two Martian years in three.
That's certainly not impossible. BUT every delivery will be a significant hazard to the inhabitants of the planet. If you got a North Pole Ocean and dropped the gas supply there, one day you'll gete it wrong and make a big tsunami. If you tried dropping it into Hellas, then some day you'll git the side and cause earth(mars)quakes which will damage people elsewhere on the planet.
What if the research would require about 20% more energy than the LHC is capable of?
Technologies are under development (so years to decades away from an engineering proposal) that can exceed the LHC energies on a footprint comparable to the present-day SLAC site. Keeping the machine's dimensions down to the size of existing sites means that building the Next Big Thing remains credible, if expensive.
The annoying thing with a figure of eight (the standard climbing knot for attaching a rope to a harness) is that it can be quite hard to untie after falling on it.
Try going one turn beyond the figure-of-8 to the "figure-of-9" (there are other names). This has the strength of the fig-8, it's harder to jam after heavy loading, and it's pretty easy to tie safely (failure modes include the fig-10 and the fig-8, both perfectly fine knots.
Many cave rescue teams recommend the fig-9 for main belays, and particularly for Tyrolean traverse anchors, which get high tension. It's a useful knot to know.
The Alpine Butterfly has a good reputation too, particularly as it can be tied mid-rope, unlike a bowline. It does take learning though. But the person whose life depends on getting his knots right, and who doesn't learn how to tie the necessary knots properly, is a corpse waiting to stop moving.
You're not doing a course in programming... no, scratch that, my first computing course none of the students or teacher or school had a computer. There wasn't one in the town's Further Education College either. It was all done by mailing (snail, not e-mail) the coding forms to the computer centre and getting paper tape result back a week or two later.
So, what possible reason do you have for not accepting manuscript?
On the contrary, I'm arguing that this relatively modern belief that any less advanced society must be obsessed with rituals
"ritual" is a label for things which are organised, consistent and repeated, but whose purpose we don't understand. That is where it's meaning ends. Full stop, end of logical construct built on top of the label. Perhaps it would be better if archaeologists were to use the label "frumpstiggle", or "qwertgfdsa", but the usage developed some time ago, and terminology is one of the less flexible things in life.
What TV "archaeologists" mean by "ritual" may be another matter. The ones I pay attention to are always careful to make the point that "ritual" only means something we don't understand. But I do ignore or just not watch a lot of the crap that is on TV. It's possible that the careful choice of words of the interviewed archaeologists gets thrown on the cutting room floor to make space for adverts, but that is TV. Certainly there are a lot of archaeologists who refuse to participate in TV programmes because of the distortions put on their words to make exciting TV.
"Ritual" is probably the description that we'd apply to a football game which we knew of only through it's archaeological record : ritual sites (level fields with structures at each end and large amounts of surrounding seating) ; occasional carved depictions suggesting several dozen participants in the ritual, and the puzzlement that sometimes the ritual object is spherical, sometimes prolate, and sometimes oblate. Finding a discus on a site would complicate interpretation (maybe different rituals at different times of the year? Is there a calenderic purpose?) and digging up Jimmy Hoffa's body would be strong evidence that human sacrifice was at least sometimes part of the ritual.
If that sounds facetious, it is, slightly. But compare the game of football above (which even I know only involves a spherical ball in months with an "r" in them) with what we know of the Central American "ball game" and you may see the range of things that could get lumped under "ritual".
We know that Stonehenge aligns well with determining time and importantly time of year,
Do we know that? It is a much-repeated idea on TV, but not given much detailed credence within the profession. I was talking with Clive Ruggles (Professor of Archaeoastronomy at University of Leicester) a couple of years ago when I bumped into him with my father (they've known each other for several decades) on the subject and he's considerably more dubious of the astronomical utility of such constructions. The processes necessary to work out where to put the stones would have required exactly as much astronomy and time-keeping, but these constructions are archaeologically invisible, and by implication were far smaller in scale and cheaper (by whatever metrics you apply to a non-monetary society). The actual keeping of time was done by the Neolithic equivalent of a caesium atomic clock in a basement somewhere, while Stonehenge served the "ritual" purposes associated with the equivalent of the Edinburgh Hogmanay street party.
Another datum which I brought to the conversation (and Clive was well aware of) was the 90-odd "recumbent stone circles" in NE Scotland, which repeatedly have an astronomical/ calender utility ascribed to them. The assertion so often made (I see it has crept back onto the wikipedia page. Again.) is that the orientation of the recumbent stone of the circle reflects some orientation of the moon in it's Saros cycle. Which is great - it gives a calendar marker every 18 and a bit years - just over one calendar mark per generation. And adjacent (a few miles apart - comparable with parish churches) stone circles can be up to 50 degrees separated in the orienta
Slashdot Mirror
You need to re-evaluate your collection of facts.
(from http://news.sciencemag.org/brain-behavior/2010/02/dolphin-person
See my back of the thumbnail calculation - adding a thousand tonnes of volatiles to the atmosphere (by impact) every hour would give Mars around an Earth's atmosphere (to an order of magnitude) in a mere 110 million years. It's fiction.
I agree the effects would be minimal. To a first approximation, a crater is around 1/10th it's diameter in depth. So for Chixulub, the initial crater would have been some 18km deep. which would get you to the lower crust. IF you could stack all 100 together, you'd have a crater 1800km deep, which is about 2/3 of the way to the outer core. Of course, such a deep crater is unfeasible- the sides would be collapsing in as the initial crater is formed. (Incidentally, after the first couple of impactors, there wouldn't be much in the way of atmosphere on the site to worry about. Landing in vacuum.)
Since a large part of the kinetic energy of the impactor comes back to the atmosphere (as either direct heat from the hot crater heating the atmosphere as it rolls back, or as frictional heating from the impact of secondary projectiles), so many major impactors in a short period would be very destructive. If you stacked them in one location, the secondary impactors would still probably strip most of the atmosphere.
So you're actually looking for the time for a new atmosphere to form by outgassing. That may simply not happen, if there aren't enough volatiles left in the mantle (or it's not mobile enough to degas effectively).
If you were going to try to bump up an atmosphere by several hundred-fold (as needed to make Mars vaguely liveable), you're going to need to add (thinks ... Earth's atmosphere is 5.1480Ã--10^18 kg (Wikipedia) ; Mars' 2.5 x 10^16 ... but Mars is a smaller radius planet ; let's say 10^18kg of volatiles ; as long as there's nitrogen for bulk, we can dump CO2 into the ground as carbon and sort out the chemistry later) a thousand tonne (10^6 kg) dirty snowball every day for 10^12 days ... OK, one every hour for ~4*10^10 days. 110 million years. And you'd need a managed landing zone- say a few hundred km wide around the equator of the planet.
Terraforming Mars is wonderful science fiction. But nonetheless, it's science FICTION.
Nothing new here - not even storing such information on a database. The Roman Emperors did the same without calling it a database, just calling it "politics".
The Marketing Department of Apple ^H^H^H^H^H^H the Sirius Cybernetics Corporation (a " bunch of mindless jerks who'll be the first against the wall when the revolution comes.")
Actually, since DNA was well known as an Apple Fan-boy (and wasn't afraid to parody himself over it), it's moderately amusing to watch Apple's slavish following of the Sirius Cybernetics model from the outside.
I suspect that low-end usage of mobiles is a lot more common than you think. My dad never uses anything other than voice and SMS (and precious little of the latter) ; Mum doesn't even use the land line, let alone a mobile.
He also used early (and not terrible efficient) germ warfare. They may not have known what they were doing, but they knew what their aim was.
Like FDR responding to the German declaration of war, after the Japanese attack.
Using this argument - and it's not without merit - Roosevelt could perfectly well have fought the Japanese first, being the "clear and present danger". During that time, Hitler could have consolidated in Europe, possibly succeeded in invading and conquering Britain. And then, in about 1945, proposed to America a joint offensive against Russia with the Americans coming overland from their takeover of China (after destroying Japan), and Operation Barbarossa being properly supplied and organised.
Alternative history - but perfectly credible. Even if Roosevelt's personal inclinations would have favoured supporting Britain against Germany, there was enough sympathy for the isolationist position in America that they could have made it fly.
His "specialist tools" are a manhole-lifting tool, and an Einstein-Rosenberg wormhole time machine.
Doesn't really matter much. Look at the history of the event : in an Europe of a few 10s of millions of people, at least two (2) came up with pretty much the same idea independently and simultaneously (and several others were groping around the edges of the idea). That implies that the proportion of people capable of coming up with that idea is in the order of 1 in 10^7.
Once you've got a population in the tens of millions, someone is going to come up with the idea around once a generation. So within a handful of generations at worst (people as sociable as Newton slow population growth), you're going to have someone come up with the idea AND be willing / able to teach it to others.
The great thing about cultural evolution (as opposed to physical evolution, is that it is Lamarkian. Not only can parents directly pass on the products of their life experience to their offspring, but the offspring can pass it back to the previous generation too.
What - like crows (who get to 3 or 4, possibly even 5 depending on whose reports you believe)? Or humans, who invented Hilbert's Hotel as a way of taming Cantor's infinity of infinities. There are human cultures whose culture only needs words for "one, two, many" but they're all part of a species that can populate Hilbert's Hotel. Crows, meanwhile, only seem to need to count to 4 or 5. Squirrels, on the other hand, can get up to around a hundred (counting nut caches). You evolve what is appropriate for your situation.
That would be the Chinese empire.
Might it not be quicker for them to develop a rocket to get the rest of Alabama out of the Earth's atmosphere while leaving MSFC undamaged?
Not thinking far enough out of the box?
That's probably not true. It hasn't left any clear and unambiguous evidence capable of convincing even the most die-hard of sceptics, which has been found and identified as such. That's true. There is quite a lot of evidence concerning abiogenesis, but it's all ambiguous, unclear and capable of multiple interpretations. (Or hasn't been found and convincingly interpreted yet.)
Again, we don't know that. But we do know that conditions on the surface of the planet are greatly different to the conditions under which the first lifeforms developed, because we have physical fossils (e.g. stromatolites) which pre-date the last occurrence of detrital iron pyrites and uraninite (both of which are highly sensitive to the presence of free di-oxygen in the air.
For rotorcraft on take-off or landing, being able to see another aircraft isn't necessarily a near miss, as long as one or both are near stationary and not one above another.
The rules haven't changed, and I still don't see a reason for them to change. Quite why drone fan-boys want to fly their toys in the couple of percent of the country within sight of an airfield is something awaiting explanation and justification.
Almost any connection (e.g., 28k8) is better than no connection.
Great idea. Where do I come to get into the time machine and go back and change the terminology used a century and a bit ago?
Your surveying protocol. Let's start with a field. You do not have a compass. You do have an abundance of string, and as many sticks as you want to drive into the ground. And as much astronomical ingenuity as you want. What is your first step?
Look up "metaphor". It's a Greek word, so you may not have hear it before.
At this moment, they align with some astronomical phenomena, but not with others. (Incidentally, what is the fucking use of marking a solstice? What you really need is the approaching vernal equinox, to allow you to get the seed into the ground. By the time you get to the solstice, you've already either got a good harvest in the making, or killed your family in the coming winter. Marking the solstice has no detectable utility (unless you can come up with a reason, so it's "ritual" sensu archaeologicae.) But since they were build 4 to 6 thousand years ago, and the skies were different then, that doesn't tell us what they were used for when they were built.
And if your neighbours, literally two hours walk away come up with a completely different answer to the same question, that raises one weird circumstance. Or if they were answering a completely different question, that's another different set of questions for interpreting the sites. (how far apart are parishes in your community? Here they're about miles in the country, and a few hundred metres in town. There are 4 parish churches between my house and the supermarket, of which three are abandoned and derelict, or deconsecrated and up for rent.)
Fuck's sake - what a pile of bullshit over a stupid choice of terminology a century ago. I remember a comment in AI to the effect of 'call your programme units "QDR45" instead of "ResolveParadox", to avoid giving yourself and anyone else false expectations of what the code actually does. I don't think "ritual" was a good term to choose - "frumpstiggle" would have been less confusing - but it was the term that was chosen and unless you want to pick a fight with the whole archaeological community (which will take the rest of your life, and probably fail) then you're not going to see it change. Or you could build that time machine.
Just send the samples to Svante's Lab, and we'll get the results.
What? Finding appropriate samples in good enough conditions is the hard part? And that's what is holding thing up?
Who'da thunk it?
It's been done, along with measurements.
From their abstract :
So, the Martian atmosphere is losing about 20g/s of material (well upwards of that, but they're the main species involved.
A year is 60 * 60 * 24 * 365.25 = 31557600 seconds, so you're talking about 631152 kg a year of material being lost (Earth year, not Martian year) : 630 tonnes a year need supplying to maintain the current atmosphere.
Mars needs, for a human - usable atmosphere, about 100 times as much of it. Modelling how much would be lost a year is going to be hard - there's a non-trivial screening of deeper atmosphere by higher atmosphere. So I think my back-of-a-thumbnail estimate of a thousand tonnes a year being needed isn't far wrong.
That's a thousand tonnes a year of H, O, N, and C. Otherwise known as comet material. You could ship in a kilotonne of ammonia/ CO2 ice and evaporate that on the ground if you liked, but you'd still need to bring in that material.
To increase the mass of the atmosphere by the 100-fold factor needed, you're going to need a lot more. As you suggest, it has taken around 3 billion years to reach the current state, so to reverse those billion years in a century, you'd need (today's kilotonne/year) * 3 billion / century, which is 30 million kilotonnes a year. For a century. I make that a 20 km diameter comet every year for a century.
Chixulub was that sort of size impactor. The (alleged) dinosaur killer impactor. Every year for a century. Now, I'm a geologist, and there are genuine questions about whether Chixulub was a dinosaur killer, or a very bad hair day for them. But to have one arriving every year for a century ... the amount of energy you're delivering to the atmosphere isn't going to be good for anyone o nthe surface of the planet while "atmosphere delivery" is going on. It's not going to be good.
Terraforming Mars is good SF, but atrocious resource management and a bloody difficult way to not achieve your aims.
One of the first bits of network troubleshooting I had to do was debugging an address conflict on HP-9800 series machines, which had a dip-switch set equivalent to a MAC on (I've forgotten the name of their network ; used stacked Centronics-like connectors ... HP-IB (Hewlett-Packard Interface Bus), now known as IEEE-488. 48 or 64 address bits sounds a bit better than 5 address bits.
Illicit gun users (everyone outside the police firearms units and the military) will stop using their guns after losing one or both hands to misfires. Illicit ammunition manufacturers need hardware and consumables and space to work, which will greatly reduce the supply of ammunition.
A gun without ammunition is better known as a club - working range about 1.5m.
That would mean delivering several thousands of tonnes of volatiles to the surface on a daily basis for the future. All of the future.
Or you could drop a megatonne comet fragment into the atmosphere about two Martian years in three.
That's certainly not impossible. BUT every delivery will be a significant hazard to the inhabitants of the planet. If you got a North Pole Ocean and dropped the gas supply there, one day you'll gete it wrong and make a big tsunami. If you tried dropping it into Hellas, then some day you'll git the side and cause earth(mars)quakes which will damage people elsewhere on the planet.
It's a major hazard.
Technologies are under development (so years to decades away from an engineering proposal) that can exceed the LHC energies on a footprint comparable to the present-day SLAC site. Keeping the machine's dimensions down to the size of existing sites means that building the Next Big Thing remains credible, if expensive.
Try going one turn beyond the figure-of-8 to the "figure-of-9" (there are other names). This has the strength of the fig-8, it's harder to jam after heavy loading, and it's pretty easy to tie safely (failure modes include the fig-10 and the fig-8, both perfectly fine knots.
Many cave rescue teams recommend the fig-9 for main belays, and particularly for Tyrolean traverse anchors, which get high tension. It's a useful knot to know.
The Alpine Butterfly has a good reputation too, particularly as it can be tied mid-rope, unlike a bowline. It does take learning though. But the person whose life depends on getting his knots right, and who doesn't learn how to tie the necessary knots properly, is a corpse waiting to stop moving.
Justfy that.
You're not doing a course in programming ... no, scratch that, my first computing course none of the students or teacher or school had a computer. There wasn't one in the town's Further Education College either. It was all done by mailing (snail, not e-mail) the coding forms to the computer centre and getting paper tape result back a week or two later.
So, what possible reason do you have for not accepting manuscript?
Do you also refuse to accept Braille scripts?
"ritual" is a label for things which are organised, consistent and repeated, but whose purpose we don't understand. That is where it's meaning ends. Full stop, end of logical construct built on top of the label. Perhaps it would be better if archaeologists were to use the label "frumpstiggle", or "qwertgfdsa", but the usage developed some time ago, and terminology is one of the less flexible things in life.
What TV "archaeologists" mean by "ritual" may be another matter. The ones I pay attention to are always careful to make the point that "ritual" only means something we don't understand. But I do ignore or just not watch a lot of the crap that is on TV. It's possible that the careful choice of words of the interviewed archaeologists gets thrown on the cutting room floor to make space for adverts, but that is TV. Certainly there are a lot of archaeologists who refuse to participate in TV programmes because of the distortions put on their words to make exciting TV.
"Ritual" is probably the description that we'd apply to a football game which we knew of only through it's archaeological record : ritual sites (level fields with structures at each end and large amounts of surrounding seating) ; occasional carved depictions suggesting several dozen participants in the ritual, and the puzzlement that sometimes the ritual object is spherical, sometimes prolate, and sometimes oblate. Finding a discus on a site would complicate interpretation (maybe different rituals at different times of the year? Is there a calenderic purpose?) and digging up Jimmy Hoffa's body would be strong evidence that human sacrifice was at least sometimes part of the ritual.
If that sounds facetious, it is, slightly. But compare the game of football above (which even I know only involves a spherical ball in months with an "r" in them) with what we know of the Central American "ball game" and you may see the range of things that could get lumped under "ritual".
Do we know that? It is a much-repeated idea on TV, but not given much detailed credence within the profession. I was talking with Clive Ruggles (Professor of Archaeoastronomy at University of Leicester) a couple of years ago when I bumped into him with my father (they've known each other for several decades) on the subject and he's considerably more dubious of the astronomical utility of such constructions. The processes necessary to work out where to put the stones would have required exactly as much astronomy and time-keeping, but these constructions are archaeologically invisible, and by implication were far smaller in scale and cheaper (by whatever metrics you apply to a non-monetary society). The actual keeping of time was done by the Neolithic equivalent of a caesium atomic clock in a basement somewhere, while Stonehenge served the "ritual" purposes associated with the equivalent of the Edinburgh Hogmanay street party.
Another datum which I brought to the conversation (and Clive was well aware of) was the 90-odd "recumbent stone circles" in NE Scotland, which repeatedly have an astronomical/ calender utility ascribed to them. The assertion so often made (I see it has crept back onto the wikipedia page. Again.) is that the orientation of the recumbent stone of the circle reflects some orientation of the moon in it's Saros cycle. Which is great - it gives a calendar marker every 18 and a bit years - just over one calendar mark per generation. And adjacent (a few miles apart - comparable with parish churches) stone circles can be up to 50 degrees separated in the orienta