The rocket equation is an uncompromising bitch. Until we come up with a reactionless "woo woo" drive. Its all about efficiently expelling mass at high speed out of the back of your spacecraft (thrust and specific impulse). The only way to get high thrust, high impulse is with nuclear or antimatter (chemical and solar don't have the energy density)
Discovery from 2001 was a Nuclear Thermal propelled spacecraft (Hydrogen fuel heated by a nuclear reactor ala NERVA), although they never make clear if it was a solid core, or gaseous core reactor. It was not a nuclear bomb propelled craft (ala Orion)
No. There are no cities, structures and forests to burn (or oxygen to support fires) on Mars to produce all of the soot needed to cause a nuclear winter
Perhaps I was being slightly facetious, and I agree that the Convervatives have shifted more authoritarian in the past few years (which is why they have lost my support). While I'd agree that they are fiscally more right than the democrats, as hard to believe as it is, the Conservatives (when compared to the US) are left. Abortion, same sex marriage, healthcare, campaign finance reform, prostitution, while perhaps not vocally supportive of these, the Conservatives have remained largely hands off (when they could have easily passed laws on any of these). Our controversies de jour are Senate expense scandals, the long form census, and long gun registry. The biggest issue we face is bill C-51 (which even the Liberals supported), and the increasing beating the drum of "terrorism" when I'm still more likely to be killed by a moose.
Actually there were three if you count the release of heavy water and tritium they experienced in the past decade . Sorry must have missed that due to all the cancer I've developed from spending 12 years living downstream from Chalk River.
I guess the US Energy Research and Development Administration is blowing stuff out of their ass. (https://commons.wikimedia.org/wiki/File:U.S._historical_fusion_budget_vs._1976_ERDA_plan.png). This type of forecast isn't unusual either. ITER published a roadmap to DEMO and commercial fusion a few years back as well. The reality is that scientists and engineers have repeatedly laid out exactly what needs to be done and the likely costs associated with it (as they did with the Space Station, Space Shuttle and Commercial Crew), the problem is governments look at the numbers and decide they won't "play well with their constituents". As a result they underfund the programs and then complain that nothing gets done, things fail to live up to expectations, or projects get delayed (and end up costing more). The Shuttle was a fantastic example of this, as a highly reusable space truck (flying weekly) it was originally forecast to cost $10B to develop, Congress said, "sounds good, here's $5B, oh and it needs to carry twice the payload to handle a very unique DoD mission profile". Then people wonder why the Shuttle turned into an expensive hanger queen
About $30 billion away. When the predictions of fusion being 20 years away were made, they were based on there being an adiquately funded research program. Since then we've spent less than what was projected as the "fusion never" scenario, which lo and behold is what we've got. Even ITER took 20 years just to figure out who was going to pay for it (first proposed in 1985)
The data dump apparently contained ~5 million accounts marked as "female" with IP and email addresses. Strange that they would include that information, but scrub the fields indicating when said user had last checked their inbox
With the exception of some elements that were purchased from Russia (Zarya for example) and Soyuz flights, the rest of ISS is operated through barter agreements (e.g. in exchange for the Canada Arm2, Canada gets a certain number of flights to the station)
The problem is like the Shuttle, ISS was pennywise and pound foolish. Congress wasted much of a decade sending NASA back to the drawing board again and again to reduce the cost of Space Station Freedom, ultimately spending more in these redesign efforts than was saved by down scoping the station, and resulting in a station hampered in its ability to do research. Cancelling the Hab module for example means several racks on Destiny are used to provide ISS life support rather than R&D. The Centrifuge module was cancelled, along with the R&D opportunities it could have provided. Most importantly much of the funding originally planned to create an organization to facilitate research on the station and establish network of universities with supporting grants was cut. The original plan was to have something similar to the Space Telescope Science Institute (created for Hubble), in place for ISS operation. Rather we have CASIS which was only founded in 2011, and has been a complete and total disaster.
There is also speculation that the Moon is important in maintaining the dynamo in the Earths core that generates our magnetic field and plate tectonics that help manage the amount of water and carbon in our biosphere. That said, these are arguments that support the argument that complex multicellular life requires unique conditions, but many of these aren't required for life in general. That said, even if these conditions are horrendously unique, estimates on the number of planets out there are "astronomical". There may be upwards of 100 billion habitable planets in the Milky Way alone.
So you've just created your own definition, one that is'nt in consensus with the astronomical community. Since definitions are not scientific "truths" they require consensus, as fields of study require common terminology in order to effectively communicate. In this case, the consensus is that planets need to clear their orbit, which means Pluto doesn't qualify
I simply refuse to stop calling Broccoli a type of rock, why do a bunch of biologists get to decide to call it a vegetable. Definitions mean things, and generally the professionals who work with these terms on a daily basis are best positioned to create these definitions.
You have to have courses in the field to even apply to write the PMP exam, and if you don't have a degree, the hours of experience required goes up substantially
What "issue with radiation"? We knew about radiation in the 1960's. This was for use on the moon, which has worse radiation exposure than Mars (the moon is closer to the sun and lacks an atmosphere)
For 12 years I lived about 4 blocks away from a decommissioned research reactor, and downwind and downstream of a major reactor complex. Never caused me concern because I've actually looked into the statistics and understand a concept called comparative risk. People rant and rave about "nuclear" just how bad and dangerous something becomes, simply by attaching an adjective to it. My mother is still alive thanks to nuclear technology. In her case the nuclear medicine used to treat her cancer 30 years ago.
Can you show your math? I just did the same with a 1km impactor blown into 2million chunks (one thousandth the mass chixulub), resulting in enough energy to light the continental US on fire.
Chuxulb weighing in at 1E15 kg (low estimate), smashed into 20m pieces (the same as Chelyabinsk) would result in 1E8 pieces (Chelyabinsk weighing in at 10000 tonnes) , each dumping 500kt of energy into the atmosphere, or 2.09E23J. That's enough to raise the temperature of the ENTIRE atmosphere of the planet by 40 degrees (2.09E23J / 1005 specific heat of air / 5E18kg mass of atmosphere)
It's not just the energy of things landing on your head. All that energy still goes somewhere, it doesn't just magically dissipate just because you've blown it into little pieces. Sure you don't get one big crater that puts enough dust into the atmosphere to cause global winter. You lite the hemisphere on fire which generates enough soot to cause a global winter.
Note the fireball for Chixulub was in the hundreds of kms in diameter
Lets take a 1km object, assuming a standard density carbon chondrite meteorite, it weighs in at 1.6E13 kg. Assuming we manage to blow it up into 20m chunks (about the same as the Chelyabinsk meteor). That's just shy of 2 million separate pieces, each dumping about 500kt of energy into the atmosphere or or about 3.5E15J of energy. This is enough to raise 5 billion cubic meters of air by a 1000C, or enough to lite the continental US on fire. This is just based on the pure conversion of energy released into heating of air. No radiative thermal effects have been taken into account.
Note this for a smaller object. Chixulub was 10 times bigger
Just how big of a nuke do you think we have? A 1km stony asteroid has a gravitational binding energy equivalent of a 500 megaton bomb (i.e. you would need a bomb 10 times bigger than the largest ever built to blow up a 1km asteroid, assuming 100% of the energy was absorbed into the structure of the asteroid)
A question, would you prefer getting hit in the arm with a 30mm round (losing your arm) or several dozen 9mm rounds,
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The rocket equation is an uncompromising bitch. Until we come up with a reactionless "woo woo" drive. Its all about efficiently expelling mass at high speed out of the back of your spacecraft (thrust and specific impulse). The only way to get high thrust, high impulse is with nuclear or antimatter (chemical and solar don't have the energy density)
Discovery from 2001 was a Nuclear Thermal propelled spacecraft (Hydrogen fuel heated by a nuclear reactor ala NERVA), although they never make clear if it was a solid core, or gaseous core reactor. It was not a nuclear bomb propelled craft (ala Orion)
No. There are no cities, structures and forests to burn (or oxygen to support fires) on Mars to produce all of the soot needed to cause a nuclear winter
Perhaps I was being slightly facetious, and I agree that the Convervatives have shifted more authoritarian in the past few years (which is why they have lost my support). While I'd agree that they are fiscally more right than the democrats, as hard to believe as it is, the Conservatives (when compared to the US) are left. Abortion, same sex marriage, healthcare, campaign finance reform, prostitution, while perhaps not vocally supportive of these, the Conservatives have remained largely hands off (when they could have easily passed laws on any of these). Our controversies de jour are Senate expense scandals, the long form census, and long gun registry. The biggest issue we face is bill C-51 (which even the Liberals supported), and the increasing beating the drum of "terrorism" when I'm still more likely to be killed by a moose.
As much as I dislike the Harper Government, in Canada, what we call "Authoritarian right-wing" is the equivalent of "left of the Democrats" in the US.
Actually there were three if you count the release of heavy water and tritium they experienced in the past decade . Sorry must have missed that due to all the cancer I've developed from spending 12 years living downstream from Chalk River.
Plus it was so bad, he mentioned it twice. I remember the time I died of radiation sickness after visiting the barren wasteland that is Chalk River
I guess the US Energy Research and Development Administration is blowing stuff out of their ass. (https://commons.wikimedia.org/wiki/File:U.S._historical_fusion_budget_vs._1976_ERDA_plan.png). This type of forecast isn't unusual either. ITER published a roadmap to DEMO and commercial fusion a few years back as well. The reality is that scientists and engineers have repeatedly laid out exactly what needs to be done and the likely costs associated with it (as they did with the Space Station, Space Shuttle and Commercial Crew), the problem is governments look at the numbers and decide they won't "play well with their constituents". As a result they underfund the programs and then complain that nothing gets done, things fail to live up to expectations, or projects get delayed (and end up costing more). The Shuttle was a fantastic example of this, as a highly reusable space truck (flying weekly) it was originally forecast to cost $10B to develop, Congress said, "sounds good, here's $5B, oh and it needs to carry twice the payload to handle a very unique DoD mission profile". Then people wonder why the Shuttle turned into an expensive hanger queen
About $30 billion away. When the predictions of fusion being 20 years away were made, they were based on there being an adiquately funded research program. Since then we've spent less than what was projected as the "fusion never" scenario, which lo and behold is what we've got. Even ITER took 20 years just to figure out who was going to pay for it (first proposed in 1985)
This is the Pacific Northwest that is currently on fire (as in 500km away I can hardly see across the street due to the smoke from Washington State)
The data dump apparently contained ~5 million accounts marked as "female" with IP and email addresses. Strange that they would include that information, but scrub the fields indicating when said user had last checked their inbox
With the exception of some elements that were purchased from Russia (Zarya for example) and Soyuz flights, the rest of ISS is operated through barter agreements (e.g. in exchange for the Canada Arm2, Canada gets a certain number of flights to the station)
The problem is like the Shuttle, ISS was pennywise and pound foolish. Congress wasted much of a decade sending NASA back to the drawing board again and again to reduce the cost of Space Station Freedom, ultimately spending more in these redesign efforts than was saved by down scoping the station, and resulting in a station hampered in its ability to do research. Cancelling the Hab module for example means several racks on Destiny are used to provide ISS life support rather than R&D. The Centrifuge module was cancelled, along with the R&D opportunities it could have provided. Most importantly much of the funding originally planned to create an organization to facilitate research on the station and establish network of universities with supporting grants was cut. The original plan was to have something similar to the Space Telescope Science Institute (created for Hubble), in place for ISS operation. Rather we have CASIS which was only founded in 2011, and has been a complete and total disaster.
There is also speculation that the Moon is important in maintaining the dynamo in the Earths core that generates our magnetic field and plate tectonics that help manage the amount of water and carbon in our biosphere. That said, these are arguments that support the argument that complex multicellular life requires unique conditions, but many of these aren't required for life in general. That said, even if these conditions are horrendously unique, estimates on the number of planets out there are "astronomical". There may be upwards of 100 billion habitable planets in the Milky Way alone.
So you've just created your own definition, one that is'nt in consensus with the astronomical community. Since definitions are not scientific "truths" they require consensus, as fields of study require common terminology in order to effectively communicate. In this case, the consensus is that planets need to clear their orbit, which means Pluto doesn't qualify
I simply refuse to stop calling Broccoli a type of rock, why do a bunch of biologists get to decide to call it a vegetable. Definitions mean things, and generally the professionals who work with these terms on a daily basis are best positioned to create these definitions.
Venus and Mercury don't have moons, so are they not planets?
You have to have courses in the field to even apply to write the PMP exam, and if you don't have a degree, the hours of experience required goes up substantially
What "issue with radiation"? We knew about radiation in the 1960's. This was for use on the moon, which has worse radiation exposure than Mars (the moon is closer to the sun and lacks an atmosphere)
http://www.astronautix.com/cra...
For 12 years I lived about 4 blocks away from a decommissioned research reactor, and downwind and downstream of a major reactor complex. Never caused me concern because I've actually looked into the statistics and understand a concept called comparative risk. People rant and rave about "nuclear" just how bad and dangerous something becomes, simply by attaching an adjective to it. My mother is still alive thanks to nuclear technology. In her case the nuclear medicine used to treat her cancer 30 years ago.
Can you show your math? I just did the same with a 1km impactor blown into 2million chunks (one thousandth the mass chixulub), resulting in enough energy to light the continental US on fire. Chuxulb weighing in at 1E15 kg (low estimate), smashed into 20m pieces (the same as Chelyabinsk) would result in 1E8 pieces (Chelyabinsk weighing in at 10000 tonnes) , each dumping 500kt of energy into the atmosphere, or 2.09E23J. That's enough to raise the temperature of the ENTIRE atmosphere of the planet by 40 degrees (2.09E23J / 1005 specific heat of air / 5E18kg mass of atmosphere)
It's not just the energy of things landing on your head. All that energy still goes somewhere, it doesn't just magically dissipate just because you've blown it into little pieces. Sure you don't get one big crater that puts enough dust into the atmosphere to cause global winter. You lite the hemisphere on fire which generates enough soot to cause a global winter. Note the fireball for Chixulub was in the hundreds of kms in diameter
Lets take a 1km object, assuming a standard density carbon chondrite meteorite, it weighs in at 1.6E13 kg. Assuming we manage to blow it up into 20m chunks (about the same as the Chelyabinsk meteor). That's just shy of 2 million separate pieces, each dumping about 500kt of energy into the atmosphere or or about 3.5E15J of energy. This is enough to raise 5 billion cubic meters of air by a 1000C, or enough to lite the continental US on fire. This is just based on the pure conversion of energy released into heating of air. No radiative thermal effects have been taken into account. Note this for a smaller object. Chixulub was 10 times bigger
Just how big of a nuke do you think we have? A 1km stony asteroid has a gravitational binding energy equivalent of a 500 megaton bomb (i.e. you would need a bomb 10 times bigger than the largest ever built to blow up a 1km asteroid, assuming 100% of the energy was absorbed into the structure of the asteroid) A question, would you prefer getting hit in the arm with a 30mm round (losing your arm) or several dozen 9mm rounds,