Slashdot Mirror

I'm pretty sure that the effort required to put the necessary calories into your body is a lot higher, and less environmentally friendly, than burning a few gallons of gasoline in a car engine.

Required reading: MPG of a Human

This comes to the conclusion that, taking food production into account, walking/biking use about 18-34 and 70-130 MPG respectively

Right now it doesn't matter if it were 1.5 light seconds away. We can't get there.

Ummm, the moon is 1.5 light seconds away, and Mars is 4 light minutes away. We can, and have, send stuff to both of those, so 1.5 light seconds isn't this intractable distance you think it is ... if you were walking it would essentially be infinitely far away. But with rockets from the 60's it was more like a few days.

I'm not suggesting we're going to reach these any time soon, but you have to remember that relative to the scales we're talking about, 22 light years in astronomical terms is a very close distance.

I haven't bought a ticket, but you need to re-think your concept of what is 'infinite' and what kind of distances are truly insurmountable.

> With near unlimited robot labor it is trivial to provide a substantial lifestyle to every human for free.

Even with 100% robot labor and 0% human employment, you still have the energy problem. There is more than enough energy coming in from the sun to support our standard of living for the current population of the world, but if growth continues on an exponential curve, we will outstrip it in a few generations.

Unfortunately, our technical prowess in computers, robotics, bioengineering and nanotech are reaching a peak just as the fossil fuel era is moving into decline. If we don't move into the "fusion era" soon, we don't have much hope of sustaining civilization. The robots that come after us may do better.

You should read up on Confirmation Bias. An excellent paper is Confirmation Bias: A Ubiquitous Phenomenon in Many Guises" (1998, Nickerson, RS)

http://physics.ucsd.edu/do-the-math/2011/07/galactic-scale-energy/

Pop over to the Do the Math blog. With current energy growth, somewhere between 400 and 500 years from now, the oceans start to boil. http://physics.ucsd.edu/do-the-math/2011/07/galactic-scale-energy/

First, you misstate Goedel's Incompleteness Theorem: it says either those trees don't cover the whole space or they overlap, not both (although both is certainly possible). That's important: we assume all logics we use are consistent and accept that they are incomplete.

More importantly, when talking about programs you actually get three choices, not two: "good", "bad", and "I don't know". Incompleteness means you cannot ever make an analysis that doesn't answer "I don't know" sometimes, but you can guarantee that your analysis is never wrong. If you are trying to verify something is safe, then you reject any programs that you get "I don't know" for along with any that can be verified as "bad", then you can be certain (modulo the correctness of your analysis which can be formally proven correct) that every program you say is "good" is actually good.

See Quark for a research prototype of a browser that is formally verified to have no security holes. There could still be a bug in the OS sandbox (uh, run it on seL4, I guess?) or, theoretically, in the theorem prover itself, but both are very unlikely. (The downsides of the current implementation are: (1) its security model is not precise enough to capture exactly how different domains are supposed to be allowed to interact and (2) is a slower than other browsers, although fast enough to run GMail and Facebook at acceptable speeds.)

>Well its all fricking moot anyway isn't it?

It feels like this is certain. Partly since the ideas you mentioned to circumvent the problem are not really all that workable. Imagine the >2000 nuclear power plants you need to substitute the energy stored in coal, oil, and gas. What will the rate of >=INES6 events be? Remember we still can't eat wild animals in some parts of Germany due to Chernobyl, so much for the backyard.

Then you shouldn't forget that all geological resources need more and more energy to get them out of the ground over time due to declining concentration, so at some point your netto energy always declines to where your society reverts to a simpler state if you can't find anything new and better.

Then you always have the waste problem that you hope the environment will swallow but doesn't - that also affects your netto energy.
The problem now with our favourite waste CO2 is that it will stay with us for a long time, look at the following for a good explanation ( http://www.youtube.com/watch?v=CsnaXlhctLY ).

Combine this with the fact that we haven't come up with any clean replacement technologies that are put into production in a credible way (renewables in my country support ~2% of electric energy consumption and we seem somewhat committed), it should become apparent that the catastrophic non-linear climate change will hit us right in time when we run out of energy to deal with it.

Also notice that on the psychological level we won't be able to make the right decisions, first of all the effects of CO2 are delayed by around 40 years http://www.skepticalscience.com/Climate-Change-The-40-Year-Delay-Between-Cause-and-Effect.html this will take the otherwise sensible "show me" guys out of the pool of people you can get behind your "do something, anything" agenda. Then as things go down people will fall prey to hyperbolic discounting and say lets use those resources as the danger is far away.

They are under pressure from netto energy decline now and also decide against investing in new and uncertain technologies that will give them less netto energy anyway but could help with things in the future, (this has been called the energy trap http://physics.ucsd.edu/do-the-math/2011/10/the-energy-trap/, and is more generally mentioned by Denis Meadows while not involving energy), hyperbolic discounting at work again.

Notice that many people have researched the issues, politicians have attempted to deal with the issues in some halfhearted form and gotten nowhere. Also notice that people have no problem to go to war over resource issues and risk loss of live for more oil or gold (the latter being the worst reason). I'm pretty sure that they also have no problem accepting loss of live on a grand scale, but it does have to happen later and maybe stretched out over time and space so we don't notice that much.

Because of that, I'm 100% certain that no action will be taken regarding climate change that will amount to substantial preventative measures. Which is easy to say since way back in the 19th century was the time to plan ahead, and some good insights that could have led to action then, never had any impact.

Note that while the United Auto Worker's agreement with the UCSD system is easily found by following the given URL link, the Patent Agreement has no given URL link and can only be gotten from the various departments at UCSD. How fucked up is that? It's like they don't really want you to be able to review the patent agreement wording before you have to sign it!
.
And what's with the weird "State Oath of Allegiance" thing?? That's the first and only place I've ever heard about that!

What union represents computer programmers? There were some weird fights here in La Jolla as to which union (or even whether any union at all) ought to represent the graduate-student-teachers (also known as TAs = graduate teaching assistants). The final result is at the UCSD website and is that the graduate students are members of the United Auto Workers union: Graduate students appointed as teaching assistants, associates, readers or tutors (ASE'S) are represented by the Association of Student Employees/UAW under a collective bargaining agreement with the university. All salary payments under these titles are subject to a deduction of 1.15 percent for union membership dues or a 0.92 percent agency fee deduction for students who choose not to become members of the union. The university/UAW Agreement can be retrieved electronically at http://ogsr.ucsd.edu/ase.htm

What union represents computer programmers? There were some weird fights here in La Jolla as to which union (or even whether any union at all) ought to represent the graduate-student-teachers (also known as TAs = graduate teaching assistants). The final result is at the UCSD website and is that the graduate students are members of the United Auto Workers union: Graduate students appointed as teaching assistants, associates, readers or tutors (ASE'S) are represented by the Association of Student Employees/UAW under a collective bargaining agreement with the university. All salary payments under these titles are subject to a deduction of 1.15 percent for union membership dues or a 0.92 percent agency fee deduction for students who choose not to become members of the union. The university/UAW Agreement can be retrieved electronically at http://ogsr.ucsd.edu/ase.htm

Please read The Energy Trap. It addresses why developing and deploying renewable energy as soon as possible is important.

Who here thinks they would have made anything resembling a profit without the substantial help from government? First, they secured a $465 million loan from the Department of Energy. Second, they picked up $10 million from the California Energy Commission for machinery purchases. Finally, purchasers of the vehicle get $7,500 in tax credits from the Federal government.

Good thing the DoE made those loans. That was supposed to be an argument in favor of the loans to Tesla Motors, right?

Even thick cloud cover from a thunderstorm doesn't cut the power to unacceptable levels where I live.

Lucky you. Here in winter the power that comes from the dull gray sky is just about 200-300W, even though there is no snow here, at the latitude of 38 degrees North. There are locales in CA that are much worse.

Sadly, there are lots of reasons why renewable sources won't solve our energy needs. Tom Murphy, a physics prof at UCSD, has a great blog http://physics.ucsd.edu/do-the-math/2012/02/the-alternative-energy-matrix/ where he works out the details. This was covered a while ago here: http://hardware.slashdot.org/story/11/08/02/2315207/limits-on-growth-of-energy-use-and-economies

Math is why the presidents limo isn't run by solar power. The idea that you power something like that by solar is absurd. Solar power cars tend to way as little as possible. While I don't specifics any more than any other lay person the presidents limo is built on a heavy duty truck chassis, is armored and it weighs quite a bit. These are mutually exclusive things that probably won't be resolvable for a few centuries at best.

http://physics.ucsd.edu/do-the-math/2011/11/mpg-of-a-human/

It's almost like you read the article. Unlike the headline and summary suggest,the article's thesis is actually that conservation is far more important than how we generate energy. And it actually does link to Do the Math which is a pro-conservation blog written by a physicist which has actual well-reasoned discussions of energy policy.

A more accurate synopsis of her argument is this:

"Since population growth and per capita economic growth are dependent on ever-increasing energy consumption, it is physically impossible for renewable energy to provide an indefenite supply of unlimited energy. Therefore, demand reduction is the only really-long-term answer."

While I actually agree with this position, it's freaking worthless. First off, the author's argument and the WWF paper are speaking to entirely different time scales. It's functionally equivalent to saying we shouldn't waste time advocating the use of seat belts because they don't protect pedestrians. Scope matters!

The second and larger issue here is that her counter-argument is just as reality-deprived as she claims the WWF paper to be. In her conlcusion, she states simply, "To which I say: Why don't we just not do it?" i.e. why don't we exert self-control as a species and stop growing. Stop adding to total population. Stop increasing per capita consumption. It simply doesn't matter how true that is on paper. I find it amusing that she name checks the Do the Math blog which has been linked on Slashdot previously. The blog is compelling and well-written. It also avoids the flippant suggestion that converting to a zero-energy-growth global society will somehow be as obvious as a Nike commercial. The "reality check" is that the reckoning over energy consumption will be painful. Death and violence are in the cards long before equilibrium is reached. Human beings have the capacity to plan for the future and execute on those plans, but the number of years forward we are motivated to act upon have finite congnitive limits. The climate change issue is a recent-but-not-exclusive example of these limitations at work.

There is of course an amusing logical fallacy in her argument as a whole. If we are to ever reach the equilibrium she seeks, whether that is by design or through painful reaction, that equilibrium would have to be completely fueled by renewable resources, since we must eventually run out of the non-renewable ones. Doh!

Still, I'm glad this got posted to Slashdot. Undeneath her specific arguments there is a clear undercurrent. "Physicists are smarter than all the rest of you because we deal with real stuff so all of you can suck it." That kind of attitude definitely belongs here.

Tom Murphy from the superb blog Do The Math does indeed go through all of the problems with that statement and many others, carefully analyzing about all energy sources and energy storage scheme that comes to mind. A very recommended read.

The excellent "Do The Math" blog estimates that we have 400 years until we're consuming as much energy as the planet is receiving from the sun. That's a good rule of thumb I think. Anything beyond that and by definition we can't have our current combination of albedo and surface temperature.

Interestingly that estimate also states we have about 1500 years until we're using as much power as the sun produces in total, and we'll need to use the entire galaxy's power output in about 2500 years.

The xkcd you are looking for is number 605.

The excellent "Do The Math" blog estimates that we have 400 years until we're consuming as much energy as the planet is receiving from the sun. That's a good rule of thumb I think. Anything beyond that and by definition we can't have our current combination of albedo and surface temperature.

Interestingly that estimate also states we have about 1500 years until we're using as much power as the sun produces in total, and we'll need to use the entire galaxy's power output in about 2500 years.

Even if there are good replacements for oil as an energy source, not investing in them soon enough before peak oil will likely cause serious problems for energy prices (and thereby the rest of the economy because everything requires energy). See "The Energy Trap" for an explanation of why the existence of alternatives isn't enough to protect us from the impact of running out of fossil fuels.

I thought of that too. Does anyone have any numbers on how many million years we can suck heat out of the ground before it becomes a problem?

Actually, a physics prof at UCSD did a pretty thorough analysis of geothermal energy. The verdict: there are places in the country where it's great, but in the majority of the USA, it just isn't a particularly dense resource, so the energy return on investment (you need to dig a whole lot of really deep holes and stick a whole lot of pipe in the ground) is pretty meh.

It probably will (and should) be developed more, but will remain a niche source of energy county and world-wide.

One of the interesting parts of this mission is MoonKAM, which let grade school and middle school kids select targets on the lunar surface for the orbiters' cameras to inspect. It returned some pretty interesting (if low-res) images until a solar flare recently took the imaging system down. If you're interested, there's some more info about GRAIL: today's announcement from NASA, and a public lecture tomorrow with a live feed.

there's simply no possible plausible scenario that is going to turn *millimeters* of change into *meters* of change in 20 years, or even 100 for that matter.

Correct; don't expect meters of sea-level rise in twenty years. Sea levels are rising, but not by half a meter per decade!

A meter in 100 years is within the band of uncertainty, but not necessarily something to bet on-- a hundred-year prediction depends too much on your expectation of the rate of emissions in the future. This paper http://ssi.ucsd.edu/scc/images/Schaeffer%20SLR%20at%20+1.5%20+2%20NatCC%2012.pdf suggests a mean of about 2 feet in a century, but I think their emissions scenario may be conservative.

Crowdfunding replaces a bank loan. It is interest-free lending for the Internet era. It is not investment. It has nothing to do with government or IPOs.

The problem with interest is that it is unsustainable.

Technology isn't going to break thermodynamics. Malthus was right. You on the other hand are kind of an idiot.

That's awesome - I never heard of it before. I might try to start using the phrase :)

For a bigger dose of Mr. Geisel's non-children's-book work, see The Advertising Work of Dr. Seuss and Dr. Seuss Went to War: A Catalog of Political Cartoons.

That's awesome - I never heard of it before. I might try to start using the phrase :)

For a bigger dose of Mr. Geisel's non-children's-book work, see The Advertising Work of Dr. Seuss and Dr. Seuss Went to War: A Catalog of Political Cartoons.

I don't think cars are going to get there. Not cars like we know them. A car is, from the point of view of efficiency, a lot of dead weight. The thing weights about a ton and a half when it could easily weight just about 1/3 of that. I think electric motorcycles, which are much more efficient as personal transportation, have a higher chance of becoming viable.

Here's an in-depth analysis of why electric cars won't happen anytime soon (I think he sets the bar for single-change mileage way too high, but nevertheless it's a good read): http://physics.ucsd.edu/do-the-math/2012/08/battery-performance-deficit-disorder/

Electric motorcycles and scooters are already viable. I can't set a foot outdoors without being almost run over by somebody thundering down the pedestrian path on an electric scooter. You can't hear those f*****s coming until they are practically about to run you over.

I don't think cars are going to get there. Not cars like we know them. A car is, from the point of view of efficiency, a lot of dead weight. The thing weights about a ton and a half when it could easily weight just about 1/3 of that. I think electric motorcycles, which are much more efficient as personal transportation, have a higher chance of becoming viable.

Here's an in-depth analysis of why electric cars won't happen anytime soon (I think he sets the bar for single-change mileage way too high, but nevertheless it's a good read): http://physics.ucsd.edu/do-the-math/2012/08/battery-performance-deficit-disorder/

You may want to read this before you start talking about how much energy we can use.

We can't just produce an infinite amount of energy here on Earth; all that energy ends up as waste heat. A back-of-the-envelope calculation is hard, but say we actually used all the sunlight we receive. An ideal earth-sized blackbody would be 5.3 degrees C. A body that reflects 30% more light than that (as the Earth does) should theoretically be about -18 degrees. The average surface temperature on Earth is about 14 degrees, so we can chalk up about 33 degrees to the normal atmospheric greenhouse effect. Absorbing all energy from the sun would get rid of that 30% thing and (assuming linear effects) raise the average surface temperature to ~37 degrees.

In the not-so-distant future we're going to have real problems with energy use, purely based on the waste heat. How much we can use of the sun's energy--or any other source--has nothing to do with dollars.

Developments like this are awesome, because they open up the possibility of doing exactly what the summary describes -- using solar power to recharge things where size / weight / surface area is at a premium.

But those sorts of scenarios are few and far between. Most of the time, cost is the limiting factor, and these high-efficiency designs are always costly.

That's okay, though: PV panels are already plenty efficient for their desired function in most cases.

A typical location within the U.S. gets an annual average of 5 full-sun-equivalent hours per day. This means that the 1000 W/m solar flux reaching the ground when the sun is straight overhead is effectively available for 5 hours each day. Each square meter of panel is therefore exposed to 5 kWh of solar energy per day. At 15% efficiency, our square meter captures and delivers 0.75 kWh of energy to the house. A typical American home uses 30 kWh of electricity per day, so we’d need 40 square meters of panels. This works out to 430 square feet, or about one sixth the typical American house’s roof (the roof area of a two-car garage). What’s the problem?

Cheers,

b&

Tom Murphy, a physics professor at UC San Diego has a great blog called Do the Math that covers this specific topic (viability of wind power on a massive scale along with other sustainable energy sources) using reasonable estimates on each resource potential.

tl;dr;

While wind is a significant resource, it's not useful everywhere - solar energy has a lot more potential to be used everywhere. Which makes sense since in the end - wind power is derived from solar power. But wind has other advantages (primarily cost right now) which means that we should deploy it wherever it makes sense.

Tom Murphy, a physics professor at UC San Diego has a great blog called Do the Math that covers this specific topic (viability of wind power on a massive scale along with other sustainable energy sources) using reasonable estimates on each resource potential.

tl;dr;

While wind is a significant resource, it's not useful everywhere - solar energy has a lot more potential to be used everywhere. Which makes sense since in the end - wind power is derived from solar power. But wind has other advantages (primarily cost right now) which means that we should deploy it wherever it makes sense.

Interesting. This also ties in nicely to the problem of waste heat from human technology being a bounding limit --- see ``Exponential Economist Meets Finite Physicist'':

http://physics.ucsd.edu/do-the-math/2012/04/economist-meets-physicist/

I have moved from being a climate change and peak oil activist to the doomer camp

I suppose I'm somewhere in-between.

If you're really interested in knowing how much it's gonna save, take a look at :
http://physics.ucsd.edu/do-the-math/2012/05/my-neighbors-use-too-much-energy/

As for abandoning hope, I especially like this quote from the aforementionned article :

In the end, it’s more important for me to know that we can trim energy use by a large factor while still engaging in important pursuits than it is that we all do reduce our energy right now. Of course, immediate widespread reduction would be my preference, being the most conservative approach to the possible energy precipice ahead. We could let off the gas and take stock of our future rather than barrel ahead under the assumption that our energy resources are guaranteed. Being wrong on the cornucopian gamble could be far more ruinous than easing off ahead of time.

The University of California-San Diego is the home of the Center for Medicinal Cannabis Research, funded directly by the Californian state government. Guess who most medical marijuana researchers get their cannabis from: the National Institute on Drug Abuse, part of the National Institutes of Health, itself part of the United States Department of Health and Human Services, ie the Federal Government.

A photo is sufficient, and it doesn't have to be a great photo either. http://vision.ucsd.edu/~blaxton/sneakey.html Additionally and anecdotally, many locksmiths can read the bitting of a key by sight.

I saw a counter-argument there that this was an issue / bounding limit for human growth / use of energy:

``Exponential Economist Meets Finite Physicist''

http://physics.ucsd.edu/do-the-math/2012/04/economist-meets-physicist/

``Alright, the Earth has only one mechanism for releasing heat to space, and that’s via (infrared) radiation. We understand the phenomenon perfectly well, and can predict the surface temperature of the planet as a function of how much energy the human race produces. The upshot is that at a 2.3% growth rate (conveniently chosen to represent a 10× increase every century), we would reach boiling temperature in about 400 years.''

William

However, this is not necessarily something we can rely on in the future. If you project our long-sustained energy growth into the future, in 450 years, the surface temperature of Earth will be the boiling point of water. This is ignoring greenhouse gases, global warming, etc. — it's purely based upon simple thermodynamics.

You may want to check a physicists's view on energy instead of looking for pink unicorns (as conservatives and libertarians are wont to).
http://physics.ucsd.edu/do-the-math/

Define practical; it doesn't get much simpler than a weight on a servo. In contrast, how much torque can you get from a small compact flywheel and how much is it going to cost? How quickly can you regeneratively brake it with decent energy recovery?

(You might be interested in this control-moment gyro controlled ballbot.)

Oh, were you serious? Tesla did a lot of great work, but his tower was not a power plant (it was intended to transmit power, not create it, and it didn't even do that especially well) and wave power is interesting, but not a slam-dunk solution by any stretch.

There are a lot of reasons to be physically present at a "brick and mortar" university with an instsructor in the room with you.

  To the extent that universities want to break from this model, it isn't about education at all. It isn't even about making an education cheaper; it's about extracting money from suckers.

  So, good for Khan Academy for doing what they're doing and giving it away for free. All the bottom feeders (including Bill Gates) who want to charge money for this stuff have nothing useful to offer and are just trying to game the system in one or another way for a buck.

Maybe this:
Link

http://ucsdnews.ucsd.edu/newsrel/science/09-15BiologicalClock.asp

ESI will collect your DNA sample, package it into a storage container mounted on the company's Lunar Descent Vehicle and fly it to the surface of the moon where it will be preserved for all time.

Inside a container subject to extreme temperatures hot and cold and with no meaningful protection against cosmic radiation?

Nothing is forever:

Forty years ago, Apollo astronauts placed the first of several retroreflector arrays on the lunar surface. Their continued usefulness for laser ranging might suggest that the lunar environment does not damage optical devices. However, new laser ranging data reveal that the efficiency of the three Apollo reflector arrays is now diminished by a factor of 10 at all lunar phases and by an additional factor of 10 when the lunar phase is near full Moon. These deficits did not exist in the earliest years of lunar ranging, indicating that the lunar environment damages optical equipment on the timescale of decades. Dust or abrasionon the front faces of the corner-cube prisms may be responsible.

Long-term degradation of optical devices on the Moon

I remember one sci-fi writer arguing that quantum effects would set a limit to any form of suspended animation. In time too much information would be erased to make revival possible.

We may not have a few centuries. If we continue our current 2.3% energy growth per year, then in a bit above 400 years the earth's surface temperature will reach the boiling point. Something has to give long before that, and that may put a wrench in our space dreams.

Yes, but the link makes a lot of assumptions I would question, first of which is dismissing space out of hand. The biggest energy consumers are not domestic but industrial. By moving industrial manufacturing into space, you short circuit his growth graph, and short circuit it even further by taking into account the marvellous efficiencies we can achieve using advancing technology.

Ebooks for example use almost no energy, and supplant almost all need for paper books, newspapers, that entire energy intensive industry. And thats a technology, just one, in its infancy. We should soon even be able to grow meat without the cattle, by all accounts. If agriculture and industry move to space, where then the extrapolation? It doesn't just cut down on the amount of energy needed on earth, it cuts down on the rate of growth in energy demand. It might even reverse it or stabilise it entirely.

Note that even having a StarTram on one side won't help for the return trip.

It doesn't need to, there are easily accessable asteroids creaking with all the volatiles we need hanging right up there. The hardest step by far is getting up there. After that everything is much more economical.

Such optimism!

Ultimately, perhaps even within the next few centuries,

We may not have a few centuries. If we continue our current 2.3% energy growth per year, then in a bit above 400 years the earth's surface temperature will reach the boiling point. Something has to give long before that, and that may put a wrench in our space dreams.

we're going to see a situation where the abundant resources in our solar system are harvested and processed by mostly automated engines,

It's far from clear that the EROEI (Energy Return On Energy Invested) of space resources is ever going to be greater than 1. Even for ores where the EROEI is less relevant, the energy cost still has to be compared to that of earth-based mining solutions and it's unlikely to be competitive. It looks like we will at most be able to capture a select few light asteroids (those coming close to the earth with just the right speed), but that won't provide abundant resources to everyone on earth. Note that even having a StarTram on one side won't help for the return trip.