At least if you're living in the US. Move to a country that has some sanity in their healthcare system, even if you're not into the whole public option thing. Germany, for example. You can private health insurance if you're self-employed there.
If you save diligently, it doesn't take much time to accumulate a tidy sum.
Pray that cancer or any of the other nasty, life-changing disease don't get you first then.
There are insurance options available that are designed to cover catastrophic health care needs. They tend to be priced quite reasonably for the young.
You conveniently forgot "for the young and healthy". By pure coincidence, health insurance is usually quite affordable if you're young and healthy, not just catastrophic coverage.
There are other insurance options that replace your income (or a portion of it) if you're unable to work.
Oh, I see. I'm sure you mean those options that you only get if you're young and healthy, right? Those don't work for me. Or at least the ones that don't require the reason for me losing my income being either death or an accident.
My wife recently had some fairly extensive dental work done. [...] There are ways to get what you need without worrying about losing your house.
Dental work!? Don't make me laugh. Dental work is dirt-cheap compared to, say, cancer treatment. And dental work doesn't keep you from earning money for a few months or years, and postponing dental work for a few days or weeks might be unpleasant, but usually not fatal.
Do you have a reference for this? Because if the rich (or rather, the upper middle class I would assume) has infinitely better health care than the rest of the world, it seems surprising that the _overall_ healthcare is amongst the worst in the world.
Strawman argument. OP did not say that overall healthcare is amongst the worst in the world. Cuba and Costa Rica are still lightyears ahead in health care compared to, say, half of Africa or places like Afghanistan.
But for a trip that involves actually stopping at AC, that won't work; you have to turn over and slow down and that needs as much engine as speeding up.
Not if you dump half of your spacecraft halfway down the road and have used up more than half of your fuel already.
Also, I imagine that the reactor doesn't last forever and would need servicing and replacement parts after a couple of years, which is difficult and/or dangerous to do in space.
2) that the ETs are interested in exploring space. Maybe they live on a lush jungle world and live in harmony with their environment, and are perfectly happy to stay there.
Or maybe space travel isn't such a big deal for the ETs anymore, so they can cherry-pick the worlds they colonize. If they're looking for a nice, rocky planet with 1.3g (+/- 0.1g), then our solar system is utterly unappealing to them.
could simple add another term to the Drake Equation for the proportion of civilizations that become "enlightened"
Maybe the "enlightenment" consist in figuring out when and how the universe becomes uninhabitable, and concluding that there's basically no point in colonizing like crazy since it'll all be wiped out eventually and inevitably.
The other way to think of this is that getting up to a speed k*c requires you to completely convert a fraction of your mass equal to "1/sqrt(1-k^2) - 1" to energy.
That's a interesting point. I haven't thought about this aspect yet.
Uranium fission converts about 0.1% of the mass each fissioned nucleus into energy, so you can't get to 0.1c using fission if you're carrying along all the fuel.
That's something spacecraft usually don't do, even today. The shuttles weight at takeoff is about 2000 tons, 1700 of which being fuel. What actually ends up in orbit is the 100-ton shuttle.
This probably brings us back to the old argument why chemical rockets can't go into space - "you'd need to add more fuel, which requires a bigger rocket, which requires even more fuel, so the thing will always be too heavy or have too little thrust to get into orbit". Turns out that this was mostly an engineering problem (building a rocket motor that provides enough thrust, using a multistage design, etc) and didn't have anything to do with an actual barrier imposed by physics. Who knows, maybe the first spacecraft that goes to AC will be a multistage design, too. At least this saves you from having to do major maintenance to the nuclear reactors - just jettison the thing once it's burnt out and fire the next stage.
Which means your top speed needs to be pretty close to c.
The formula for the Lorentz factor is 1 / sqrt(1 - v^2/c^2). And there's a huge difference between being close to c (0.9c) and being close to c (0.999c): The Lorentz factor for the former case is a measly 2.3, while it's 22.4 for the latter case even though the object in question is only moving about 10% faster.
And then there's the problem of 9 TeV hydrogen atoms hitting your windshield if you go fast enough. Not something you really want to deal with if you can avoid the problem altogether by making the trip take 10% longer.
If you're going to have a realistic acceleration (or even an unrealistic one like 4 or 5 g, as specified) and you want to go 4+ light years in less than a decade you're going to have to go pretty close to the speed of light.
Since the Lorentz factor is 1 / sqrt(1 - v^2/c^2), there's a huge difference between going, say, 0.8c and 0.999c in terms of relativistic effects, even though the object in question is barely moving 25% faster from a stationary viewpoint.
A top speed of 0.8c would be pretty impressive and allow to make the trip in less than a decade given sufficient acceleration, without the need to deal with overly pesky relativistic effects (Lorentz factor of 1.667 compared to 22.4 for 0.999c).
Never underestimate the energy of macroscopic objects traveling at near-lightspeed.
You don't need to go anywhere near lightspeed (and we have another article here describing some of the problems you might face if you try, like 7 TeV hydrogen atoms). 0.1c would be pretty good for starters. It might take a few decades, but hey, you're going to another star system. That alone should be worth the wait. For an unmanned probe, even slower speeds would be ok. We're already waiting years for a probe to reach, say, Pluto. If we could send a probe to AC in 80 years or so, that'd be worth it.
Sending a Shuttle-sized craft to Alpha Centauri in a matter of years would require roughly the current total energy consumption of humanity.
Err... I don't think that accelerating a shuttle-sized craft at 4 or 5g requires the current total energy consumption of humanity. Probably only a tiny, tiny fraction of it. The only problem is coming up with a propulsion method that can provide such acceleration for long periods of time, and a nuclear reactor (fission/fusion/antimatter) small enough to fit on the craft.
Only when our civilization advances to the point that we harness a significant portion of the Sun's total energy output
Screw the sun. Way too bulky and pretty much useless once you get past Neptune or so. It's a bit like flight - you want the concept (aerodynamic lift/nuclear fusion), but not the actual implementation (flapping wings/gravitational confinement), but something that you can actually build.
One can suggest "sleeper ships", but building mechanical devices that will survive thousands of years is as hard a problem as throwing them across light years of distance.
Thousands of years? Are you proposing that someone rows that thing to Alpha Centauri? Unless we can go at least 0.01c, we shouldn't be thinking about leaving our solar system just yet, and at 0.01c the trip is going to be much shorter than thousands of years. At 0.1c it should be around a hundred years.
The next thought is to provide power to the ship during the long journey,
Big honkin' reactor. You might even be able to pull it off with a fission reactor, but I'd wait until we have either figured out fusion or come to the conclusion that artificial fusion reactors aren't feasible (let's hope not).
and, if you can comfortably survive for millennia in interstellar space, why even bother with stars in the first place?
Well, a sleeper ship isn't exactly "surviving". That'd be like saying "ok, if you have an aircraft, why bother with the ground".
Oh -- and the Fermi Paradox applies especially well. Assume that it takes even ten thousand years to colonize a remote solar system, and the entire galaxy would have been overrun by now if a colonizing civilization had started in the terrestrial Jurassic period.
Well, if you change the variables a little, it could take longer. Maybe it's not possible to colonize the galaxy in the way suggested by that approximation, since the stars aren't distributed evenly?
From a German perspective it sounds a bit weird, I mean, can there be any good argument against greater energy efficiency?
Yes: It requires significant up-front investment.
Even if there was no climate change, why waste energy?
Because wasting energy now is cheaper (in the short run) than investing big bucks in more efficiency. Also, not wasting energy might result in loss of convenience.
Most of the greenhouse gasses are water vapour, and you know, those giant oceans, and cloud systems. If there was some way that water vapour was actually a self-regulating mechanism for the planet, and some real true to life in the field scientists do wonder about this, then rising CO2 would not be a problem.
Err... you know which variable has the biggest influence on the amount of water vapor in the atmosphere?
Global average temperature.
This means that any increase in average global temperature purely from CO2 will result in an even larger temperature increase due to more water vapor in the atmosphere.
And CO2 causes more problems than just increased greenhouse effect. Ocean acidification, anyone?
Now explain the record-breaking colder temps being experienced across the country.
Global warming just refers to the average temperature. It says absofrickenlutely nothing about the variance. If the variance also rises (some hypotheses predict that), you'll see record low temperatures despite an increased average temperature.
But most people don't get statistics, anyway. Welcome to the club.
Explosives Disposal 101: Always assume an explosive device is functional, armed, and active.
With unexploded ordinance from god-knows-when it's even worse, since it will be deteriorated and possibly even more dangerous than a functional, armed and active explosive device fresh from the factory.
... how does this thing interact (communicate/measure/control) with the outside world, and what are the power demands of that?
Just having a plain uC alone doesn't do much. You'll also want some external circuitry to acutally make measurements (even if it's just some filter for a built-in ADC), communicate with the outside world (hm, could this thing use something similar to RFID when communicating?) and/or change things about the outside world (with a DAC or some output pins).
Slashdot Mirror
What downside?
At least if you're living in the US. Move to a country that has some sanity in their healthcare system, even if you're not into the whole public option thing. Germany, for example. You can private health insurance if you're self-employed there.
Don't ask GP a question that you don't want to see the answer to. ;)
If you save diligently, it doesn't take much time to accumulate a tidy sum.
Pray that cancer or any of the other nasty, life-changing disease don't get you first then.
There are insurance options available that are designed to cover catastrophic health care needs. They tend to be priced quite reasonably for the young.
You conveniently forgot "for the young and healthy". By pure coincidence, health insurance is usually quite affordable if you're young and healthy, not just catastrophic coverage.
There are other insurance options that replace your income (or a portion of it) if you're unable to work.
Oh, I see. I'm sure you mean those options that you only get if you're young and healthy, right? Those don't work for me. Or at least the ones that don't require the reason for me losing my income being either death or an accident.
My wife recently had some fairly extensive dental work done. [...] There are ways to get what you need without worrying about losing your house.
Dental work!? Don't make me laugh. Dental work is dirt-cheap compared to, say, cancer treatment. And dental work doesn't keep you from earning money for a few months or years, and postponing dental work for a few days or weeks might be unpleasant, but usually not fatal.
Got any better examples?
Strawman argument. OP did not say that overall healthcare is amongst the worst in the world. Cuba and Costa Rica are still lightyears ahead in health care compared to, say, half of Africa or places like Afghanistan.
Next?
Why can't you vote?
Maybe GP can't vote for reasons of age or lack of US citizenship.
I can't think of another situation where I can wholeheartedly sympathize though.
How about "not having the correct citizenship" (yet)?
Do we have any evidence that they were actually trying to created "child porn"?
What does "intentionally planting a camera and a microphone in a childs bedroom" look like to you?
Not if you dump half of your spacecraft halfway down the road and have used up more than half of your fuel already.
Also, I imagine that the reactor doesn't last forever and would need servicing and replacement parts after a couple of years, which is difficult and/or dangerous to do in space.
Or maybe space travel isn't such a big deal for the ETs anymore, so they can cherry-pick the worlds they colonize. If they're looking for a nice, rocky planet with 1.3g (+/- 0.1g), then our solar system is utterly unappealing to them.
Maybe the "enlightenment" consist in figuring out when and how the universe becomes uninhabitable, and concluding that there's basically no point in colonizing like crazy since it'll all be wiped out eventually and inevitably.
That's a interesting point. I haven't thought about this aspect yet.
Uranium fission converts about 0.1% of the mass each fissioned nucleus into energy, so you can't get to 0.1c using fission if you're carrying along all the fuel.
That's something spacecraft usually don't do, even today. The shuttles weight at takeoff is about 2000 tons, 1700 of which being fuel. What actually ends up in orbit is the 100-ton shuttle.
This probably brings us back to the old argument why chemical rockets can't go into space - "you'd need to add more fuel, which requires a bigger rocket, which requires even more fuel, so the thing will always be too heavy or have too little thrust to get into orbit". Turns out that this was mostly an engineering problem (building a rocket motor that provides enough thrust, using a multistage design, etc) and didn't have anything to do with an actual barrier imposed by physics. Who knows, maybe the first spacecraft that goes to AC will be a multistage design, too. At least this saves you from having to do major maintenance to the nuclear reactors - just jettison the thing once it's burnt out and fire the next stage.
The formula for the Lorentz factor is 1 / sqrt(1 - v^2/c^2). And there's a huge difference between being close to c (0.9c) and being close to c (0.999c): The Lorentz factor for the former case is a measly 2.3, while it's 22.4 for the latter case even though the object in question is only moving about 10% faster.
And then there's the problem of 9 TeV hydrogen atoms hitting your windshield if you go fast enough. Not something you really want to deal with if you can avoid the problem altogether by making the trip take 10% longer.
Since the Lorentz factor is 1 / sqrt(1 - v^2/c^2), there's a huge difference between going, say, 0.8c and 0.999c in terms of relativistic effects, even though the object in question is barely moving 25% faster from a stationary viewpoint.
A top speed of 0.8c would be pretty impressive and allow to make the trip in less than a decade given sufficient acceleration, without the need to deal with overly pesky relativistic effects (Lorentz factor of 1.667 compared to 22.4 for 0.999c).
Still, no need to go anywhere near 0.99c even if the trip is supposed to take less than a decade.
You don't need to go anywhere near lightspeed (and we have another article here describing some of the problems you might face if you try, like 7 TeV hydrogen atoms). 0.1c would be pretty good for starters. It might take a few decades, but hey, you're going to another star system. That alone should be worth the wait. For an unmanned probe, even slower speeds would be ok. We're already waiting years for a probe to reach, say, Pluto. If we could send a probe to AC in 80 years or so, that'd be worth it.
Err ... I don't think that accelerating a shuttle-sized craft at 4 or 5g requires the current total energy consumption of humanity. Probably only a tiny, tiny fraction of it. The only problem is coming up with a propulsion method that can provide such acceleration for long periods of time, and a nuclear reactor (fission/fusion/antimatter) small enough to fit on the craft.
Only when our civilization advances to the point that we harness a significant portion of the Sun's total energy output
Screw the sun. Way too bulky and pretty much useless once you get past Neptune or so. It's a bit like flight - you want the concept (aerodynamic lift/nuclear fusion), but not the actual implementation (flapping wings/gravitational confinement), but something that you can actually build.
One can suggest "sleeper ships", but building mechanical devices that will survive thousands of years is as hard a problem as throwing them across light years of distance.
Thousands of years? Are you proposing that someone rows that thing to Alpha Centauri? Unless we can go at least 0.01c, we shouldn't be thinking about leaving our solar system just yet, and at 0.01c the trip is going to be much shorter than thousands of years. At 0.1c it should be around a hundred years.
The next thought is to provide power to the ship during the long journey,
Big honkin' reactor. You might even be able to pull it off with a fission reactor, but I'd wait until we have either figured out fusion or come to the conclusion that artificial fusion reactors aren't feasible (let's hope not).
and, if you can comfortably survive for millennia in interstellar space, why even bother with stars in the first place?
Well, a sleeper ship isn't exactly "surviving". That'd be like saying "ok, if you have an aircraft, why bother with the ground".
Oh -- and the Fermi Paradox applies especially well. Assume that it takes even ten thousand years to colonize a remote solar system, and the entire galaxy would have been overrun by now if a colonizing civilization had started in the terrestrial Jurassic period.
Well, if you change the variables a little, it could take longer. Maybe it's not possible to colonize the galaxy in the way suggested by that approximation, since the stars aren't distributed evenly?
Yes: It requires significant up-front investment.
Even if there was no climate change, why waste energy?
Because wasting energy now is cheaper (in the short run) than investing big bucks in more efficiency. Also, not wasting energy might result in loss of convenience.
Yes, it's really that sad and simple.
Convenience. And a wasteful, supposedly god-given and -mandated lifestyle.
Err ... you know which variable has the biggest influence on the amount of water vapor in the atmosphere?
Global average temperature.
This means that any increase in average global temperature purely from CO2 will result in an even larger temperature increase due to more water vapor in the atmosphere.
And CO2 causes more problems than just increased greenhouse effect. Ocean acidification, anyone?
Now explain the record-breaking colder temps being experienced across the country.
Global warming just refers to the average temperature. It says absofrickenlutely nothing about the variance. If the variance also rises (some hypotheses predict that), you'll see record low temperatures despite an increased average temperature.
But most people don't get statistics, anyway. Welcome to the club.
Remind me again why temperatures are lower on Mercury than on Venus, despite Mercury receiving about four times the solar irradiance of Venus?
Explosives Disposal 101: Always assume an explosive device is functional, armed, and active.
With unexploded ordinance from god-knows-when it's even worse, since it will be deteriorated and possibly even more dangerous than a functional, armed and active explosive device fresh from the factory.
Has political correctness come so far that you can't even call someone a fatass any more?
If you're a professional bodybuilder, you might be a customer of size, but not a fatass.
Just having a plain uC alone doesn't do much. You'll also want some external circuitry to acutally make measurements (even if it's just some filter for a built-in ADC), communicate with the outside world (hm, could this thing use something similar to RFID when communicating?) and/or change things about the outside world (with a DAC or some output pins).