Mars has a thick crust. It has no plate tectonics. It has the large Tharsis bulge (many hundreds of millions of years old at a minimum), which is a huge load, much bigger than the polar caps, but which is supported by that thick crust. All of this has been known since Viking, if not Mariner 9 (i.e., for 30+ years).
Oh, and thick and cold means that the temperatures are well below the melting point of rock, not water. Doesn't mean that there is subsurface liquid water, but does mean that there isn't, either.
I was also involved in Viking. At that time, we did not know about the long term (30Kyr and longer) cycles in the Martian obliquity and solar insolation. During the cycle the polar regions lose and gain material - the layering at the poles is clear evidence of that.
Mars, as you point out, is at present very close to the triple point of water, but it is below it (so no liquid water). However, at other times in its dynamical cycle, surface conditions are almost certainly above the triple point, as water and CO2 are lost by the poles and put into the atmosphere. So, it seems pretty clear that Mars goes through wet and dry cycles, although the further implications of that are very much a matter of debate.
According to this BBBC Article, when they brought the "Baby" back up, they ran its first program on it again. I am not sure if that was Turing's program; if not, it's a little older.
My guess is that the oldest code is in some embedded processor somewhere, as those tend to last forever and not be changed, such as the computers controlling elevators and microwaves and the like.
I would also guess that this was not what the author had in mind.
I was being sloppy. An acceleration of 2 g's for 10 minutes or so would suffice. It's just, once you get going, the engine turns off.
In orbital dynamics, it's often called an impulse, as you are not powered most of the time, compared to powered flight, which requires constant thrust.
One thing that might be a problem is that you probably wouldn't be able to leave your seat the whole time. Maybe they would put depends in with the barf bags.
It was a bright cold day in April, and the clocks were striking thirteen.
Yes, it was set in London. And you can still see the building that suggested the Ministry of Truth to Orwell, just off Tottenham Court Road at UCL (University College London). During World War II it was the Ministry of Propaganda, and Orwell worked there.
There was an old series of drawings of "the airplane as seen by [various engineers]." The aircraft as seen by the propulsion engineers was of course entirely one big engine.
I remember when the SR-71 set the transcontinental speed record in the late 1970's. (They have since improved on it a little.) The boom was quite loud and clearly double, and I was impressed at how much energy was wasted by it, given that I was 30-40 km away, and that it made the same boom across the entire country. That flight was a little under a km / sec average velocity.
That's why, unless there is some real drag breakthrough, I think that rocket planes are the way to truly fast passenger travel. One ballistic impulse of 7 km / sec or so to get up above the atmosphere and on your way is 50 times the energy requirement of the SR-71 to get to maximum speed, but that would get you across the Pacific in 30 - 40 minutes and use less energy than a Mach-3 aircraft, which would take 2 or 3 hours for the same trip. Plus, except at re-entry, a rocket plane has no sonic booms.
My first programming was on punched paper tape, which I can still read. I am not saying I have a machine that could read it, but at least I can look at the punches and figure out what the characters were.
When I was in grad school, there was some data stored on punched paper tape, stored fan-folded. The tape had dried out and cracked where the folds were. (The cracks would be in the middle of a byte, especially a high one, as they would have more holes punched in them.) They wanted to save the data, so they hired a under-grad to spend all summer sending the tape through a reader, one 4 foot section at a time, figure out what the byte was where the crack was, type that in, and then proceed to the next 4 foot section. I still think that that must have been the worst IT job ever.
Just wait for weekend Gigabytes, and TV commercials explaining Gigabyte friend circles and how you can carry your Gigabytes over from one month to the next !
The thing that should worry anyone is that cell phone companies make much of their money from overage fees.
I predict that if this goes into place, rather than improving the service, their effort will go into ever more complicated and confusing fee schedules.
The 200-300 msec round trip latency between the US and India or China is thought to be fatal to such long distance surgery (no pun intended). However, the US DOD is, I think, interested in short distance telesurgery, say Kuwait to Iraq, which should be technically possible.
These are not robots. These are medical telepresence devices. They have no artificial intelligence or autonomy at all; they are intended to provide the surgeon with tiny hands and eyes in places they could not otherwise reach.
If we discover evidence of prokaryotic life on Mars, that would not prove that abiogenesis occurred independently on the two planets. As you point out, some bacteria could have taken a ride on a rock from one planet to the other.
But what if we discover evidence of ancient Martian life on a scale and complexity comparable to a trilobite (but, obviously, not something specifically found in the Terran fossil record)? That's not something that could easily be explained away as a Terran life form that travelled to Mars on a meteorite. I would interpret such a discovery as strong evidence that the evolution from unicellular life to trilobite-complexity life occurred independently on the two planets. That is a good point. We should be able to tell, depending on what the "running code" looks like. If it has DNA and RNA and all of that, with the same handedness, I would lean towards a common origin. If there are major differences, not so much.
I have my suspicions about the archaebacteria (or archaea, if you prefer). They are everywhere, but different from us, and even from our bacteria. If they turned out to be related to stuff from elsewhere it would not surprise me.
Alas, none of this is likely for transfers between solar systems - the travel times are much longer, probably much too long for viability.
We have found meteorites from Mars that have not been severely shocked. (By shocked, I mean have been metamorphosed by high velocity shock waves passing through the material, which would kill any bacteria.) This was a surprise when found, but now numerical modeling shows that the shock waves from a very large meteor strike (the kind that makes 100 km sized craters) will reflect off the internal structure in the planet, lifting large amounts of material "gently" into space. Of that material, modeling of the celestial mechanics shows that some small fraction will rapidly pass from one planet to the other, not being in space long enough to kill bacteria from, e.g., solar radiation. Fragments of kilogram size or larger will generally go through the atmosphere of either the Earth or Mars and land on the surface without heating the interior enough to kill bacteria. We know that all of this has happened from Mars to Earth, and it should also happen from Earth to Mars. Whether such material could escape from the thick atmosphere of Venus is dubious. (This does not mean that any particular meteorite has bacteria, much less living bacteria, just that it is possible, and, if it is possible, it has happened frequently given the frequency of cratering event on both planets.)
So, I predict that we will eventually find life on Mars, and it will be related to terrestrial life, probably the Acidophilic extremophiles.
So if you simply planet hopped to all planets closet to your planet and then colonized and then repeated the process you could colonize the galaxy a lot faster than it took for evolution to go from single cell creatures to mammals... Heck... You could do it before amphibian and dinosaurs show up.
There is a third possible answer - that the ecological niches in the galaxy tend to be already filled with entities that are hostile to such exponential growth. (As, indeed, are the ecological niches on Earth.) That suggests that the Great Silence may be a defensive mechanism, which would have very worrying implications for us, as we sit here broadcasting away the fact of our existence.
Mars is too close to us to say much about exobiology IMHO. The Earth and Mars have been exchanging tons of biologically active material for their entire existence (large meteor strikes cause material to be ejected to escape velocity, and some small fraction of that will be treated gently enough not to kill any bacteria).
So, there is is likely to be life on Mars, and it is likely to be pretty similar to some life on Earth, proving nothing on the big question of where is everybody.
Uh, my EVD0 USB dongle from Sprint is about 2.5 inches long, and weighs 2.01 ounces. I carry my MacBook around all of the time with it attached and in use. I sure wouldn't give up WiFi and Bluetooth to put it inside.
I think that this is one of those things that will never really be sorted out until we finally make contact with Aliens (if we ever do). The real question in my opinion is : is there something about our brains that makes our mathematics come out the way that it does ? Or would any intelligent creature come to the same conclusion ? I don't see how you can answer that without seeing a few independent realizations.
I see lots of waivers coming out of this. Let me guess - no additional funding will be provided to the "Small agencies that won't qualify for their own connection". Let me also guess - certain well connected companies will be doing the 50 gateways !
When the DOD did this, no new money was provided for the switch, vendor "H" was the only source of outside assistance, at their usual outrageous prices, and everyone who could waivered out.
Slashdot Mirror
Mars has a thick crust. It has no plate tectonics. It has the large Tharsis bulge (many hundreds of millions of years old at a minimum), which is a huge load, much bigger than the polar caps, but which is supported by that thick crust. All of this has been known since Viking, if not Mariner 9 (i.e., for 30+ years).
Oh, and thick and cold means that the temperatures are well below the melting point of rock, not water. Doesn't mean that there is subsurface liquid water, but does mean that there isn't, either.
I was also involved in Viking. At that time, we did not know about the long term (30Kyr and longer) cycles in the Martian obliquity and solar insolation. During the cycle the polar regions lose and gain material - the layering at the poles is clear evidence of that.
Mars, as you point out, is at present very close to the triple point of water, but it is below it (so no liquid water). However, at other times in its dynamical cycle, surface conditions are almost certainly above the triple point, as water and CO2 are lost by the poles and put into the atmosphere. So, it seems pretty clear that Mars goes through wet and dry cycles, although the further implications of that are very much a matter of debate.
According to this BBBC Article, when they brought the "Baby" back up, they ran its first program on it again. I am not sure if that was Turing's program; if not, it's a little older.
My guess is that the oldest code is in some embedded processor somewhere, as those tend to last forever and not be changed, such as the computers controlling elevators and microwaves and the like.
I would also guess that this was not what the author had in mind.
The code in the Voyager spacecraft, at least, was extensively updated after launch and throughout the mission.
Yes, if it is supersonic.
I was being sloppy. An acceleration of 2 g's for 10 minutes or so would suffice. It's just, once you get going, the engine turns off.
In orbital dynamics, it's often called an impulse, as you are not powered most of the time, compared to powered flight, which requires constant thrust.
One thing that might be a problem is that you probably wouldn't be able to leave your seat the whole time. Maybe they would put depends in with the barf bags.
It was a bright cold day in April, and the clocks were striking thirteen.
Yes, it was set in London. And you can still see the building that suggested the Ministry of Truth to Orwell, just off Tottenham Court Road at UCL (University College London). During World War II it was the Ministry of Propaganda, and Orwell worked there.
Anyone who is surprised by this doesn't understand either the police, or politics.
There was an old series of drawings of "the airplane as seen by [various engineers]." The aircraft as seen by the propulsion engineers was of course entirely one big engine.
I remember when the SR-71 set the transcontinental speed record in the late 1970's. (They have since improved on it a little.) The boom was quite loud and clearly double, and I was impressed at how much energy was wasted by it, given that I was 30-40 km away, and that it made the same boom across the entire country. That flight was a little under a km / sec average velocity.
That's why, unless there is some real drag breakthrough, I think that rocket planes are the way to truly fast passenger travel. One ballistic impulse of 7 km / sec or so to get up above the atmosphere and on your way is 50 times the energy requirement of the SR-71 to get to maximum speed, but that would get you across the Pacific in 30 - 40 minutes and use less energy than a Mach-3 aircraft, which would take 2 or 3 hours for the same trip. Plus, except at re-entry, a rocket plane has no sonic booms.
My first programming was on punched paper tape, which I can still read. I am not saying I have a machine that could read it, but at least I can look at the punches and figure out what the characters were.
When I was in grad school, there was some data stored on punched paper tape, stored fan-folded. The tape had dried out and cracked where the folds were. (The cracks would be in the middle of a byte, especially a high one, as they would have more holes punched in them.) They wanted to save the data, so they hired a under-grad to spend all summer sending the tape through a reader, one 4 foot section at a time, figure out what the byte was where the crack was, type that in, and then proceed to the next 4 foot section. I still think that that must have been the worst IT job ever.
Just wait for weekend Gigabytes, and TV commercials explaining Gigabyte friend circles and how you can carry your Gigabytes over from one month to the next !
The thing that should worry anyone is that cell phone companies make much of their money from overage fees.
I predict that if this goes into place, rather than improving the service, their effort will go into ever more complicated and confusing fee schedules.
The 200-300 msec round trip latency between the US and India or China is thought to be fatal to such long distance surgery (no pun intended). However, the US DOD is, I think, interested in short distance telesurgery, say Kuwait to Iraq, which should be technically possible.
These are not robots. These are medical telepresence devices. They have no artificial intelligence or autonomy at all; they are intended to provide the surgeon with tiny hands and eyes in places they could not otherwise reach.
They are cool machines, but they are not robots.
What I would like to know is how much of MADD's money comes from government agencies.
If we discover evidence of prokaryotic life on Mars, that would not prove that abiogenesis occurred independently on the two planets. As you point out, some bacteria could have taken a ride on a rock from one planet to the other.
But what if we discover evidence of ancient Martian life on a scale and complexity comparable to a trilobite (but, obviously, not something specifically found in the Terran fossil record)? That's not something that could easily be explained away as a Terran life form that travelled to Mars on a meteorite. I would interpret such a discovery as strong evidence that the evolution from unicellular life to trilobite-complexity life occurred independently on the two planets. That is a good point. We should be able to tell, depending on what the "running code" looks like. If it has DNA and RNA and all of that, with the same handedness, I would lean towards a common origin. If there are major differences, not so much.
I have my suspicions about the archaebacteria (or archaea, if you prefer). They are everywhere, but different from us, and even from our bacteria. If they turned out to be related to stuff from elsewhere it would not surprise me.
Alas, none of this is likely for transfers between solar systems - the travel times are much longer, probably much too long for viability.
No, not proven, but likely.
We have found meteorites from Mars that have not been severely shocked. (By shocked, I mean have been metamorphosed by high velocity shock waves passing through the material, which would kill any bacteria.) This was a surprise when found, but now numerical modeling shows that the shock waves from a very large meteor strike (the kind that makes 100 km sized craters) will reflect off the internal structure in the planet, lifting large amounts of material "gently" into space. Of that material, modeling of the celestial mechanics shows that some small fraction will rapidly pass from one planet to the other, not being in space long enough to kill bacteria from, e.g., solar radiation. Fragments of kilogram size or larger will generally go through the atmosphere of either the Earth or Mars and land on the surface without heating the interior enough to kill bacteria. We know that all of this has happened from Mars to Earth, and it should also happen from Earth to Mars. Whether such material could escape from the thick atmosphere of Venus is dubious. (This does not mean that any particular meteorite has bacteria, much less living bacteria, just that it is possible, and, if it is possible, it has happened frequently given the frequency of cratering event on both planets.)
So, I predict that we will eventually find life on Mars, and it will be related to terrestrial life, probably the Acidophilic extremophiles.
There is a third possible answer - that the ecological niches in the galaxy tend to be already filled with entities that are hostile to such exponential growth. (As, indeed, are the ecological niches on Earth.) That suggests that the Great Silence may be a defensive mechanism, which would have very worrying implications for us, as we sit here broadcasting away the fact of our existence.
Yes, I know, 15 billion light years is so limiting. I feel cramped just thinking about it.
Mars is too close to us to say much about exobiology IMHO. The Earth and Mars have been exchanging tons of biologically active material for their entire existence (large meteor strikes cause material to be ejected to escape velocity, and some small fraction of that will be treated gently enough not to kill any bacteria).
So, there is is likely to be life on Mars, and it is likely to be pretty similar to some life on Earth, proving nothing on the big question of where is everybody.
Uh, my EVD0 USB dongle from Sprint is about 2.5 inches long, and weighs 2.01 ounces. I carry my MacBook around all of the time with it attached and in use. I sure wouldn't give up WiFi and Bluetooth to put it inside.
I think that this is one of those things that will never really be sorted out until we finally make contact with Aliens (if we ever do). The real question in my opinion is : is there something about our brains that makes our mathematics come out the way that it does ? Or would any intelligent creature come to the same conclusion ? I don't see how you can answer that without seeing a few independent realizations.
I see lots of waivers coming out of this. Let me guess - no additional funding will be provided to the "Small agencies that won't qualify for their own connection". Let me also guess - certain well connected companies will be doing the 50 gateways !
When the DOD did this, no new money was provided for the switch, vendor "H" was the only source of outside assistance, at their usual outrageous prices, and everyone who could waivered out.
This is a story about the UK, "common carrier " is a US concept, and US ISP's are not covered by common carrier protections.