No. Sidros means "iron" in Greek (and the name of an island), sideris means "star" in Latin. They are independently derived from Proto Indoeuropean (PIE) *sweid which means "to shine". Shiny metal, shiny star. That is the relationship.
The big problem is the mass. Such a mission requires a lot more mass than we can cost-effectively launch right now.
As your comment indicates in passing the real big problem is money. A mission to Mars will cost a lot of money to develop and dispatch. No one if offering up the necessary money at present.
Launch costs are a modest part of the problem. Even if we could put stuff in space for free the mission would be very expensive simply due to the cost of spaceflight qualified hardware, and getting back off of Mars would not be free. (I assume we are not sending people to Mars simply to look at it from orbit.)
If they knew it fell from space, then it would literally be other worldly to them.
They wouldn't. You find meteorites on the ground long after they fall. Observed falls with recovery are extremely rare, even on a much more densely inhabited Earth, and of metallic meteors (which are only about 0.1% of all falls) almost unknown.
No one on Earth knew of the extra-terrestrial origin of meteors until the Eighteenth Century.
Not exactly. If you smelt iron from ore or from iron-rich soil, the iron is what is left behind in the oven. In other words: you melt the ore from the iron. The iron you have left in the oven is very porous and brittle, and contains a huge amount of carbon (making it extra brittle). It therefore takes quite some work to convert this iron into any workable steel or iron.
Not exactly. The iron never melted in an Iron Age smelter. It forms a loose porous mass of reduced metal saturated with slag called a "bloom". This is taken out and hammered to from "wrought iron", which can then be shaped and perhaps carbonized in the a forge to make a harder surface.
Techniques to use melted iron - either directly as cast iron, or else by reducing it to eliminate the excess carbon - were developed much later. But it was easier to make smelters not quite hot enough to melt the iron anyway.
People discovered how to work metal by finding "native" forms. Hunks of pure or nearly pure copper, silver and gold. Iron doesn't form these...
Or rather, it is quite rare that it does. This is called telluric iron. The only major deposit of this is in Greenland (and was used by the Inuit) but small deposits might exist elsewhere. Examining the artifacts would be needed to confirm that this was not from some unknown telluric iron source.
This is a more informative answer, thanks. So is it that Earth's iron has been exposed to too much oxygen over the billions of years and oxidized, but meteoric iron has not? I'm just trying to understand the why...
Yes. Meteoric iron rusts away just like regular iron and turns to a lump of reddish iron oxide. Lots of historic meteor fall sites are full of red lumps of oxidized meteors. To make a useful tool you must recover a meteorite before this happens. A large chunk of meteor metal though could take a long time to completely oxidize, and if recovered from the desert (this is the Middle East) it could survive without rusting completely for thousands of years.
In the Bronze Age - the period before we had discovered how to smelt iron...
The Bronze Age is the period where nearly all metal tools were made of bronze -- which is the primary observable fact.
Claiming that this was entirely a "period before we had discovered how to smelt iron" is a conclusion that must be derived from actual data, not simply asserted.
There were iron artifacts being made during the Bronze Age. It could have been the case that iron smelting existed and was conducted on a small scale, but simply had not supplanted bronze. Without examining the actual evidence we would not know which is the case.
"Gyroscopes" aren't "rigid in space". Perfect gyroscopes are, but not ordinary real gyroscopes. Friction makes the kinds of demo gyros you using as "proof" insensitive to gradual changes in orientation. You can put a gyroscope on lazy susan, and when the lazy susan is turned sufficiently slowly (but much faster than the rotation of the Earth) the gyroscope will turn also, showing that it is not really "rigid in space". This is why gyroscopes used in actual navigation or physics experiments - if they are spinning rotors - are magnetically levitated in vacuums, or else use more exotic technologies (laser gyros, or oscillating mass MEMs gyros). Commercial inertial navigation systems easily detect the rotation of the Earth, and their algorithms must model it exactly.
But the many hundreds of Foucault pendulums everywhere precess in the swing at exactly the rate determined by latitude (sin(lat)*360/1440 for degrees per minute). You can look up the closest Foucault pendulum to you in the list, and go there, and time it yourself to confirm this.
In fact Foucault pendulums are gyros, and sensitive ones at that. They are of the oscillating mass type, but using gravity rather than elasticity to provide the oscillating force.
Please list the "many subtle effects" that you fantasize affect the operation of pendulums. There are really just two - gravity (which is essential) and motion through the air. This last causes gradual damping of the swing (and thus perpetual pendulums have an electromagnet to provide a kick at each swing), and requires protection from gross air currents, but you can just start a heavy pendulum (everyone used heavy pendulums) and it will reveal the rotation of the Earth quite nicely before damping becomes serious. Try it. Use the burning thread release technique.
The fact that you are unaware that spinning gyros are far more prone to disturbing effects (the aforementioned friction, and air currents, imperfections in balance, etc.) confirms you know nothing about what you speak.
But it is a waste of time to argue with a cowardly guy hiding behind anonymity. I post this really for the benefit of other readers here, and will ignore your further fantasies and display of profound ignorance.
I know, I know, all of the 324 Foucault pendulums listed and are displayed in public for all to observe are part of the world-wide Foucault Conspiracy which you alone have penetrated and revealed! Such brilliance! And you keep your identity a secret! Don't you realized that fame and fortune are yours for the taking if you but drop your cloak of anonymity?
Quite a number of them are in high schools where students can observe the rotation of the Earth for themselves, exactly as you recommend.
This territory, stoutly defending a ridiculous position with misrepresented "evidence" is old news. I liked reading the Braheian Debater while in college which asserted a similarly silly idea - that of the Geocentric Universe. It was an amusing intellectual game.
Instead of picking out and misrepresenting miscellaneous "cherries" you would be much more interesting if you went back to the history of science where the sphericity of the Earth was proved (Eratosthenes) and likewise the Heliocentric solar system, and disprove the pieces of evidence used to demonstrate them conclusively. But that would be hard, probably impossible to do so convincingly, since after all you are attempting to demonstrate something that isn't true.
Omuamua has such an unusual shape (approximately 10x as long as it is wide), that many astronomers have joked that it could be a rocket.
It is the only "asteroid" ever discovered which is so much longer than wide.
It would be extremely interesting to send a probe to take a closer look at Omuamua, just in case...
Extremely difficult though. Impossible when you consider what be needed to do it.
It is already receding from us, and has a solar velocity excess greater than any human-made object. We would have to boost a probe to 2.6 times more kinetic energy per kg than any payload ever launched on rockets just to match its speed, much less catch up to it. The fastest probe ever launched was New Horizons which required a three stage launch system. An exotic electromagnetic propulsion system would be required to get the velocity and it would need to be ready to go now.
Even an extraordinary crash program would probably never be able to reach it since we would likely never be able to find it again once we caught up to it many years from now.
OTOH, he could offer a free lift to scientists who will contribute a payload. I know one who studies the distribution of dust in the solar system, but so far has to do it all from Earth's orbit. He cannot afford his own mission farther out in the solar system, and no other mission has let him piggy back a payload yet (usually they have their own over-subscribed payloads that get cut).
Sure he might lose the instrument package, but he builds many and sends them up on one-shot ballistic trajectories anyway. There are probably many scientists who would take the chance if offered.
Allowing people to do actual science on a mission to Mars orbit would be useful. The Roadster, not so much.
The Prius is a hybrid, and the article's graph says yes, they are more expensive, but it also shows electric is cheaper right off the bat.
Which may be true in some areas, but not where I live. I have priced the fuel cost per mile of an EV, vs my Prius, and with the marginal price for my electricity the EV costs more to fuel.
Additionally it depends on the marginal cost of your electricity. I live in an area where, due to a utility board that is captured by the power industry, and high air conditioning costs due an extremely hot climate, I pay about 30 cents per kilowatt-hour for every additional kilowatt-hour I use. This makes the fuel for an electric car more expensive that what I pay for gas for my Prius. So a more expensive car, more expensive fuel, means an electric car is absolutely not cheaper than my Prius.
What's harsh about space other than it being relatively cold?
What comes to mind:
A temperature of minus 455 degrees Fahrenheit (only about 5 degrees above absolute zero). Many materials and electrical components do not behave or age the same when subjected to decades of extreme temperatures and it wouldn't be a surprise at all to find some materials slowly getting brittle or changing shape or thermal or electrical conduction.
...
Heat dissipation. No atmosphere means there is no convection so all heat must be dissipated via radiation emissions, which can be very slow. This means if you have hot spots in your electronics or the RTG power system without proper heat sinks, it can build up to a thermal failure.
And in space, no one can hear you scream.
It is pretty cold out there. The mean temperature for matter in interstellar space is 3.2 K, which is the Cosmic Microwave Background of 2.7 K plus 0.5 K because of integrated starlight. But by far the major amount of heating Voyager gets its from its 3 RTGs mounted on a short boom that together still put out 4.5 kw of heat. Currently 249 watts of electrical power are available to run Voyager, a lot of that is used for electrical heaters (the transmitter is just 22.4 watts). I did a bit of Googling trying to find what the temperatures on Voyager itself likely are, but did not find much. I did find that in 2012 the electrical heater on the UV and IR spectrometers was cut-off and the temperature dropped to -79 C.
But all of the thermal effects were modeled and analyzed with care when the craft was designed so hot spots should not be a problem anywhere.
Radiation. A complete lack of protection from a planet's magnetic field or atmosphere means every single gamma ray heading the right direction hits it, hence the shielding and hardened components used to build the satellites. Maybe this drops off as it moves away from the sun, but we really don't know what the nature of space beyond the sun's immediate influence looks like.
We have a pretty good idea what the nature of space beyond the sun's immediate influence looks like. But collecting actual data on it is another thing than simply having a "pretty good idea".
The major radiation problem Voyager faced was not too long after launch when it went through Jupiter's radiation belts and encountered many times the radiation that would have been lethal to humans (hundreds of Sv). The radiation from galactic cosmic rays (not gamma rays) is about 340 uSv per day, or about 5 Sv over the last 40 years. So the significant radiation hazards would have been encountered for a few hours, 38 years ago.
South Australia (and Australia generally) is a special case for renewable energy since it is a small continent, and sparsely inhabited.
This is a fix for a remote corner in Australia, the edge of the 5th largest population center (Adelaide*) separated from it by 100 miles and isolated by hundreds of miles of emptiness from anywhere else. There is little redundant/backup infrastructure, or all that many people.
More generally battery facilities shouldn't be needed in larger, more populous continents (North America, Eurasia).
The solution to issues of variable power production is to connect the entire continent together with high voltage DC power lines (a nearly century old technology) which can ship power from one coast of North America to the other with losses of under 5%. You build enough excess solar and wind capacity that even under the worst conditions you still have enough for the entire continent (Canada and Mexico should be part of this grid also).
This also allows using the sun out west to power the evening peak back east, and so forth, leveling out production/consumption mismatches.
Pumped storage can service the entire grid since power can be transported long distances. The U.S. currently has enough pumped storage on-line to provide 2.2% of US grid capacity (and about twice this much more has been licensed), so it can be sited where ever geography makes it most convenient.
We need some national-level vision to help bring this about (good luck with that at present), but mostly this can be done by private investment.
*The greater metropolitan area of Adelaide has a population of 1,317,000 which is 77% of the entire population of South Australia (which is 50% larger than Texas). Things get really sparse really fast out past Adelaide's metro area.
> He will want to get to Mars without the elevated cancer risk
Not so much need for fancy shielding for one man, just fly solo in the middle of a densely packed cargo ship, you only need the equivalent of a few meters of rock to get the approximate shielding benefit of Earth's atmosphere, and I think it's only like a meter or so necessary to absorb most of the cosmic ray particle cascade.
The radiation exposure for 6 months in interplanetary space is about 60 cSv (60 rems). This is 12 years of the maximum allowable dose for a radiation worker. NASA currently allows a 55 year old astronaut to accumulate 400 cSV (Musk is 46, and won't be going for many, many years). So the radiation exposure is within currently accepted occupational limits. So this is not really a problem.
As for closed loop environmental systems - there's already been tons of research done on the subject, and even the very first large scale attempt, Biosphere 2, was impressively successful. Besides, one of the things that makes Mars so much more appealing than the Moon is that you don't *need* to be closed system - you've got nigh-unlimited supplies of water and CO2 available on-site to work with, the bulk components of life. And you'd better believe finding easily harvestable sources of nitrogen and important trace elements is going to be a priority.
Getting nitrogen is easy. Just compress and liquefy the Martian air. At lower Martian elevations the pressure is about the same as an altitude of 30 km on Earth, where high altitude aircraft have flown. 1.9% of the atmosphere is nitrogen so in the process of collecting CO2 from the air, you can get whatever nitrogen you need.
But the problem is not really that it has to be "closed loop" (although it does, even on Mars). It is that the atmosphere has to be entirely manufactured and maintained at normal Earth conditions by mechanical systems, which if they fail kills everyone. To maintain a breathable atmosphere you must continuously remove CO2, and exhaled moisture, and any gases released by systems on board. Being on Mars "fixes" none of that. All of the oxygen is being manufactured somehow. Water recycling will be mandatory as there are not large accessible supplies of water that we know of.
The workload on the ISS simply to maintain the environmental systems is a full-time job for two people.
What you are saying is that since some people somewhere called each one Musk's ventures "nuttery" (although actually nothing you list is really implausible - only founding a new car company was a stretch), then no one anywhere can point to any of his claims as being factually suspect.
Not quite the "they laughed at Galileo" fallacy, but close.
Brings out the Tesla because he wants to cut pollution and save the planet, sets up space company which has a rocket that'll burn a million pounds of fuel in a matter of seconds just to send stuff to a space station that just sits there spinning round the globe.
Rated "Troll" I see, which is appropriate, but let me show just how stupid this post really is.
Last year the U.S. conducted a total of 22 space launches. The current Falcon 9's full up launch weight is 549 tonnes. If we assume that that weight is all fuel (it is mostly) then a Falcon 9 launch burns 549/3.56 = 154 tonnes of RP-1 kerosene (since the LOX to RP-1 mass ratio is 2.56/1), so this is an upper bound on the fuel used.
A fuel fuel load of a 747-400 is 165 tonnes, more than the Falcon 9. If every one of those 22 launches had been a Falcon 9 (7 of them were in fact) then the entire U.S. space launch program would have used as much fuel as just 22 regularly scheduled long distant wide body commercial flights.
This is 0.0065% of the 54 million tonnes of aviation fuel used by the U.S. airline industry in 2016.
How about providing extra power for climbing, allowing a smaller engine just for cruising? Should get better fuel efficiency that way. Also electric motors would be great to reduce noise on take-off and landing at urban airports.
At some point national governments will start issuing their own currency in blockchain form. They will define the parameters, and will do the mining, and issue the BitDollars (or whatever) and the value at issuance will accrue to the Treasury as seigniorage. New issues will be made as needed to maintain a stable currency. This is the real future of cryptocurrency as actual currency, and not a finite pool of speculative assets.
Slashdot Mirror
No. Sidros means "iron" in Greek (and the name of an island), sideris means "star" in Latin. They are independently derived from Proto Indoeuropean (PIE) *sweid which means "to shine". Shiny metal, shiny star. That is the relationship.
The big problem is the mass. Such a mission requires a lot more mass than we can cost-effectively launch right now.
As your comment indicates in passing the real big problem is money. A mission to Mars will cost a lot of money to develop and dispatch. No one if offering up the necessary money at present.
Launch costs are a modest part of the problem. Even if we could put stuff in space for free the mission would be very expensive simply due to the cost of spaceflight qualified hardware, and getting back off of Mars would not be free. (I assume we are not sending people to Mars simply to look at it from orbit.)
If they knew it fell from space, then it would literally be other worldly to them.
They wouldn't. You find meteorites on the ground long after they fall. Observed falls with recovery are extremely rare, even on a much more densely inhabited Earth, and of metallic meteors (which are only about 0.1% of all falls) almost unknown.
No one on Earth knew of the extra-terrestrial origin of meteors until the Eighteenth Century.
Not exactly. If you smelt iron from ore or from iron-rich soil, the iron is what is left behind in the oven. In other words: you melt the ore from the iron. The iron you have left in the oven is very porous and brittle, and contains a huge amount of carbon (making it extra brittle). It therefore takes quite some work to convert this iron into any workable steel or iron.
Not exactly. The iron never melted in an Iron Age smelter. It forms a loose porous mass of reduced metal saturated with slag called a "bloom". This is taken out and hammered to from "wrought iron", which can then be shaped and perhaps carbonized in the a forge to make a harder surface.
Techniques to use melted iron - either directly as cast iron, or else by reducing it to eliminate the excess carbon - were developed much later. But it was easier to make smelters not quite hot enough to melt the iron anyway.
People discovered how to work metal by finding "native" forms. Hunks of pure or nearly pure copper, silver and gold. Iron doesn't form these...
Or rather, it is quite rare that it does. This is called telluric iron. The only major deposit of this is in Greenland (and was used by the Inuit) but small deposits might exist elsewhere. Examining the artifacts would be needed to confirm that this was not from some unknown telluric iron source.
This is a more informative answer, thanks. So is it that Earth's iron has been exposed to too much oxygen over the billions of years and oxidized, but meteoric iron has not? I'm just trying to understand the why...
Yes. Meteoric iron rusts away just like regular iron and turns to a lump of reddish iron oxide. Lots of historic meteor fall sites are full of red lumps of oxidized meteors. To make a useful tool you must recover a meteorite before this happens. A large chunk of meteor metal though could take a long time to completely oxidize, and if recovered from the desert (this is the Middle East) it could survive without rusting completely for thousands of years.
In the Bronze Age - the period before we had discovered how to smelt iron...
The Bronze Age is the period where nearly all metal tools were made of bronze -- which is the primary observable fact.
Claiming that this was entirely a "period before we had discovered how to smelt iron" is a conclusion that must be derived from actual data, not simply asserted.
There were iron artifacts being made during the Bronze Age. It could have been the case that iron smelting existed and was conducted on a small scale, but simply had not supplanted bronze. Without examining the actual evidence we would not know which is the case.
The ignorance you display is truly staggering.
"Gyroscopes" aren't "rigid in space". Perfect gyroscopes are, but not ordinary real gyroscopes. Friction makes the kinds of demo gyros you using as "proof" insensitive to gradual changes in orientation. You can put a gyroscope on lazy susan, and when the lazy susan is turned sufficiently slowly (but much faster than the rotation of the Earth) the gyroscope will turn also, showing that it is not really "rigid in space". This is why gyroscopes used in actual navigation or physics experiments - if they are spinning rotors - are magnetically levitated in vacuums, or else use more exotic technologies (laser gyros, or oscillating mass MEMs gyros). Commercial inertial navigation systems easily detect the rotation of the Earth, and their algorithms must model it exactly.
But the many hundreds of Foucault pendulums everywhere precess in the swing at exactly the rate determined by latitude (sin(lat)*360/1440 for degrees per minute). You can look up the closest Foucault pendulum to you in the list, and go there, and time it yourself to confirm this.
In fact Foucault pendulums are gyros, and sensitive ones at that. They are of the oscillating mass type, but using gravity rather than elasticity to provide the oscillating force.
Please list the "many subtle effects" that you fantasize affect the operation of pendulums. There are really just two - gravity (which is essential) and motion through the air. This last causes gradual damping of the swing (and thus perpetual pendulums have an electromagnet to provide a kick at each swing), and requires protection from gross air currents, but you can just start a heavy pendulum (everyone used heavy pendulums) and it will reveal the rotation of the Earth quite nicely before damping becomes serious. Try it. Use the burning thread release technique.
The fact that you are unaware that spinning gyros are far more prone to disturbing effects (the aforementioned friction, and air currents, imperfections in balance, etc.) confirms you know nothing about what you speak.
But it is a waste of time to argue with a cowardly guy hiding behind anonymity. I post this really for the benefit of other readers here, and will ignore your further fantasies and display of profound ignorance.
Foucault was a fraud, and his experiment has not been repeated.
Yeah about that.
I know, I know, all of the 324 Foucault pendulums listed and are displayed in public for all to observe are part of the world-wide Foucault Conspiracy which you alone have penetrated and revealed! Such brilliance! And you keep your identity a secret! Don't you realized that fame and fortune are yours for the taking if you but drop your cloak of anonymity?
Quite a number of them are in high schools where students can observe the rotation of the Earth for themselves, exactly as you recommend.
Oh, and why the hiding behind the AC label given all the effort you putting into this?
Create an identity so that we can track your posts of wisdom!
Mighty fine trolling there Oh AC!
This territory, stoutly defending a ridiculous position with misrepresented "evidence" is old news. I liked reading the Braheian Debater while in college which asserted a similarly silly idea - that of the Geocentric Universe. It was an amusing intellectual game.
Instead of picking out and misrepresenting miscellaneous "cherries" you would be much more interesting if you went back to the history of science where the sphericity of the Earth was proved (Eratosthenes) and likewise the Heliocentric solar system, and disprove the pieces of evidence used to demonstrate them conclusively. But that would be hard, probably impossible to do so convincingly, since after all you are attempting to demonstrate something that isn't true.
My mind filled in the blanks and made me read the authors name as David E Coli
You are not the only one!
That's Serattia marcencens, probably not worth much
Don't know about that! You could have the Eucharistic Miracle on the bottom of your shower. Take that Jesus-In-A-Tortilla!
http://www.planetary.org/multimedia/space-images/small-bodies/the-path-of-omuamua.html
Omuamua has such an unusual shape (approximately 10x as long as it is wide), that many astronomers have joked that it could be a rocket. It is the only "asteroid" ever discovered which is so much longer than wide.
It would be extremely interesting to send a probe to take a closer look at Omuamua, just in case...
Extremely difficult though. Impossible when you consider what be needed to do it.
It is already receding from us, and has a solar velocity excess greater than any human-made object. We would have to boost a probe to 2.6 times more kinetic energy per kg than any payload ever launched on rockets just to match its speed, much less catch up to it. The fastest probe ever launched was New Horizons which required a three stage launch system. An exotic electromagnetic propulsion system would be required to get the velocity and it would need to be ready to go now.
Even an extraordinary crash program would probably never be able to reach it since we would likely never be able to find it again once we caught up to it many years from now.
Elon Musk told us he was sending a car to space, then said he totally made it up
OTOH, he could offer a free lift to scientists who will contribute a payload. I know one who studies the distribution of dust in the solar system, but so far has to do it all from Earth's orbit. He cannot afford his own mission farther out in the solar system, and no other mission has let him piggy back a payload yet (usually they have their own over-subscribed payloads that get cut).
Sure he might lose the instrument package, but he builds many and sends them up on one-shot ballistic trajectories anyway. There are probably many scientists who would take the chance if offered.
Allowing people to do actual science on a mission to Mars orbit would be useful. The Roadster, not so much.
The Prius is a hybrid, and the article's graph says yes, they are more expensive, but it also shows electric is cheaper right off the bat.
Which may be true in some areas, but not where I live. I have priced the fuel cost per mile of an EV, vs my Prius, and with the marginal price for my electricity the EV costs more to fuel.
Additionally it depends on the marginal cost of your electricity. I live in an area where, due to a utility board that is captured by the power industry, and high air conditioning costs due an extremely hot climate, I pay about 30 cents per kilowatt-hour for every additional kilowatt-hour I use. This makes the fuel for an electric car more expensive that what I pay for gas for my Prius. So a more expensive car, more expensive fuel, means an electric car is absolutely not cheaper than my Prius.
What's harsh about space other than it being relatively cold?
What comes to mind:
A temperature of minus 455 degrees Fahrenheit (only about 5 degrees above absolute zero). Many materials and electrical components do not behave or age the same when subjected to decades of extreme temperatures and it wouldn't be a surprise at all to find some materials slowly getting brittle or changing shape or thermal or electrical conduction.
Heat dissipation. No atmosphere means there is no convection so all heat must be dissipated via radiation emissions, which can be very slow. This means if you have hot spots in your electronics or the RTG power system without proper heat sinks, it can build up to a thermal failure.
And in space, no one can hear you scream.
It is pretty cold out there. The mean temperature for matter in interstellar space is 3.2 K, which is the Cosmic Microwave Background of 2.7 K plus 0.5 K because of integrated starlight. But by far the major amount of heating Voyager gets its from its 3 RTGs mounted on a short boom that together still put out 4.5 kw of heat. Currently 249 watts of electrical power are available to run Voyager, a lot of that is used for electrical heaters (the transmitter is just 22.4 watts). I did a bit of Googling trying to find what the temperatures on Voyager itself likely are, but did not find much. I did find that in 2012 the electrical heater on the UV and IR spectrometers was cut-off and the temperature dropped to -79 C.
But all of the thermal effects were modeled and analyzed with care when the craft was designed so hot spots should not be a problem anywhere.
Radiation. A complete lack of protection from a planet's magnetic field or atmosphere means every single gamma ray heading the right direction hits it, hence the shielding and hardened components used to build the satellites. Maybe this drops off as it moves away from the sun, but we really don't know what the nature of space beyond the sun's immediate influence looks like.
We have a pretty good idea what the nature of space beyond the sun's immediate influence looks like. But collecting actual data on it is another thing than simply having a "pretty good idea".
The major radiation problem Voyager faced was not too long after launch when it went through Jupiter's radiation belts and encountered many times the radiation that would have been lethal to humans (hundreds of Sv). The radiation from galactic cosmic rays (not gamma rays) is about 340 uSv per day, or about 5 Sv over the last 40 years. So the significant radiation hazards would have been encountered for a few hours, 38 years ago.
South Australia (and Australia generally) is a special case for renewable energy since it is a small continent, and sparsely inhabited.
This is a fix for a remote corner in Australia, the edge of the 5th largest population center (Adelaide*) separated from it by 100 miles and isolated by hundreds of miles of emptiness from anywhere else. There is little redundant/backup infrastructure, or all that many people.
More generally battery facilities shouldn't be needed in larger, more populous continents (North America, Eurasia).
The solution to issues of variable power production is to connect the entire continent together with high voltage DC power lines (a nearly century old technology) which can ship power from one coast of North America to the other with losses of under 5%. You build enough excess solar and wind capacity that even under the worst conditions you still have enough for the entire continent (Canada and Mexico should be part of this grid also).
This also allows using the sun out west to power the evening peak back east, and so forth, leveling out production/consumption mismatches.
Pumped storage can service the entire grid since power can be transported long distances. The U.S. currently has enough pumped storage on-line to provide 2.2% of US grid capacity (and about twice this much more has been licensed), so it can be sited where ever geography makes it most convenient.
We need some national-level vision to help bring this about (good luck with that at present), but mostly this can be done by private investment.
*The greater metropolitan area of Adelaide has a population of 1,317,000 which is 77% of the entire population of South Australia (which is 50% larger than Texas). Things get really sparse really fast out past Adelaide's metro area.
> He will want to get to Mars without the elevated cancer risk
Not so much need for fancy shielding for one man, just fly solo in the middle of a densely packed cargo ship, you only need the equivalent of a few meters of rock to get the approximate shielding benefit of Earth's atmosphere, and I think it's only like a meter or so necessary to absorb most of the cosmic ray particle cascade.
The radiation exposure for 6 months in interplanetary space is about 60 cSv (60 rems). This is 12 years of the maximum allowable dose for a radiation worker. NASA currently allows a 55 year old astronaut to accumulate 400 cSV (Musk is 46, and won't be going for many, many years). So the radiation exposure is within currently accepted occupational limits. So this is not really a problem.
As for closed loop environmental systems - there's already been tons of research done on the subject, and even the very first large scale attempt, Biosphere 2, was impressively successful. Besides, one of the things that makes Mars so much more appealing than the Moon is that you don't *need* to be closed system - you've got nigh-unlimited supplies of water and CO2 available on-site to work with, the bulk components of life. And you'd better believe finding easily harvestable sources of nitrogen and important trace elements is going to be a priority.
Getting nitrogen is easy. Just compress and liquefy the Martian air. At lower Martian elevations the pressure is about the same as an altitude of 30 km on Earth, where high altitude aircraft have flown. 1.9% of the atmosphere is nitrogen so in the process of collecting CO2 from the air, you can get whatever nitrogen you need.
But the problem is not really that it has to be "closed loop" (although it does, even on Mars). It is that the atmosphere has to be entirely manufactured and maintained at normal Earth conditions by mechanical systems, which if they fail kills everyone. To maintain a breathable atmosphere you must continuously remove CO2, and exhaled moisture, and any gases released by systems on board. Being on Mars "fixes" none of that. All of the oxygen is being manufactured somehow. Water recycling will be mandatory as there are not large accessible supplies of water that we know of.
The workload on the ISS simply to maintain the environmental systems is a full-time job for two people.
This is silly fallacy.
What you are saying is that since some people somewhere called each one Musk's ventures "nuttery" (although actually nothing you list is really implausible - only founding a new car company was a stretch), then no one anywhere can point to any of his claims as being factually suspect.
Not quite the "they laughed at Galileo" fallacy, but close.
Brings out the Tesla because he wants to cut pollution and save the planet, sets up space company which has a rocket that'll burn a million pounds of fuel in a matter of seconds just to send stuff to a space station that just sits there spinning round the globe.
Rated "Troll" I see, which is appropriate, but let me show just how stupid this post really is.
Last year the U.S. conducted a total of 22 space launches. The current Falcon 9's full up launch weight is 549 tonnes. If we assume that that weight is all fuel (it is mostly) then a Falcon 9 launch burns 549/3.56 = 154 tonnes of RP-1 kerosene (since the LOX to RP-1 mass ratio is 2.56/1), so this is an upper bound on the fuel used.
A fuel fuel load of a 747-400 is 165 tonnes, more than the Falcon 9. If every one of those 22 launches had been a Falcon 9 (7 of them were in fact) then the entire U.S. space launch program would have used as much fuel as just 22 regularly scheduled long distant wide body commercial flights.
This is 0.0065% of the 54 million tonnes of aviation fuel used by the U.S. airline industry in 2016.
How about providing extra power for climbing, allowing a smaller engine just for cruising? Should get better fuel efficiency that way. Also electric motors would be great to reduce noise on take-off and landing at urban airports.
https://tech.slashdot.org/story/17/11/28/148213/firms-team-up-on-hybrid-electric-plane-technology#
At some point national governments will start issuing their own currency in blockchain form. They will define the parameters, and will do the mining, and issue the BitDollars (or whatever) and the value at issuance will accrue to the Treasury as seigniorage. New issues will be made as needed to maintain a stable currency. This is the real future of cryptocurrency as actual currency, and not a finite pool of speculative assets.