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Comment Re:100 million quest to waste 100 million (Score 1) 208 208

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.

Comment Re:we prefer Little Planet (Score 1) 321 321

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

Comment Re:WTF? (Score 1) 321 321

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.

Comment Re:Not fear but precaution (Score 1) 419 419

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.

Comment Re:Effect of nukes on NEOs (Score 1) 272 272

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)

Comment Re:Effect of nukes on NEOs (Score 1) 272 272

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

Comment Re:Effect of nukes on NEOs (Score 1) 272 272

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

Comment Re:Effect of nukes on NEOs (Score 1) 272 272

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,

Comment Re:Effect of nukes on NEOs (Score 1) 272 272

No, because those millions of small pieces release the same amount of energy into the Earth system, just now into the atmosphere now rather than the planet surface. Rather than ejecting material, earthquakes, tsunamis, you flash fry the hemisphere.

Comment Re:Effect of nukes on NEOs (Score 1) 272 272

Or to put it another way (to more accurately reflect the energies involved), would you rather be hit in the arm by a 30mm round (taking your arm off), or hit by several dozen 9mm rounds. The problem isn't the impact, its all the kinetic energy needs to go somewhere. Either into the Earth which vaporizes rock and spreads it around, or in the atmosphere that flash cooks the hemisphere

Comment Re:Not fear but precaution (Score 1) 419 419

It's all about statistics and comparative assessment of risk. It comes down to how likely is an individual person to be killed or injured in a motor vehicle accident vs. being killed or injured by "highly toxic radio nucleotides which last tens of thousands of years" released during a launch failure? The answer is, or course, that you are orders of magnitude more likely to be harmed in a car accident (or slipping in the shower) than you would by an RTG launch. Surrounding it with hyperbolic descriptors such as "toxic" or "highly harmful" doesn't make any difference to the statistics, nor the fact that each of us make the choice to participate in far more risky endeavors on a daily basis. Adding the word "nuclear" to something that has a 0.0000001% of killing you, means it still has a 0.0000001% of killing you. Besides Pu-238 (used in RTGs) has a half life of 87 years. So it most definitely wont be hanging around for "tens of thousands of years"

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