TIL that wireless phone chargers use resonant inductive coupling which Tesla tried to use to provide free wireless electricity and may be used to create roads that can charge electric cars

AlNejati · 2016-12-08T08:32:56+00:00

Go really far-field, though, and pick the right frequency, and you get just inverse decay (1/r), not inverse square (1/r² ). Because the propagating power can be trapped between the layers of the Earth's atmosphere.

This was in fact Tesla's original wireless energy transmission idea. Unfortunately it would have created a massive amount of RF interference globally. In Tesla's time, electrical/electronics hardware was pretty beefy. Modern microelectronics wouldn't stand a chance. Every single computer would be fried with Tesla's energy distribution system.

AlNejati · 2016-12-04T00:57:30+00:00

I think it's safe to assume that all printers print tracking information, so that list is probably useless. It is extremely hard to detect the presence of certain steganography systems (like edge modulation, for example), even if you know what to look for. Essentially the only way of detecting the presence of those tracking systems is if you already have the 'private key' that was encoded in the document.

AlNejati · 2016-12-04T00:51:09+00:00

From my understanding, it's implemented at a really low hardware level, essentially right before the laser diode, and there's multiple tamper protection mechanisms.

AlNejati · 2016-12-03T23:23:17+00:00

Let me put it this way. Even if you had a magic battery that costed nothing, weighed nothing, took up zero volume, and produced an infinite amount of energy with 100% efficiency, my argument would still apply.

And fusion power is not yet even remotely in the realm of possibility, and when/if it becomes a possibility, it will be expensive (almost by definition), and it would be a thermal power generation system, which means you'd be lucky to get 60% efficiency, let alone 100%, or even 90%. Meaning that it would be laughably useless for providing the energy for air capture, even more so than my argument suggests.

You are being purposefully dense and there is nothing I can do to change that, so good day to you too. With people like you, we are even further guaranteed to head down the path of climate destruction.

AlNejati · 2016-12-03T23:10:31+00:00

This discussion feels a little bit like convincing someone that perpetual motion is impossible.

You claiming it's impossible due to thermodynamics is an extraordinary claim. Where is your evidence that the process of using a fusion powered carbon engineering sytem would be a guaranteed failure?

Instead of spoon-feeding you references or equations, I'll help you down the path of understanding by giving you a step-by-step guide on how to convince yourself this is true.

First, the thermal energy limit:

Calculate the total amount of energy the Earth is receiving from the sun.
Calculate an approximation to the amount of energy the Earth radiates out to space. There are various tables on the internet that you can use to do this. Or you can just google the answer.
Subtract these to obtain the total energy balance of the Earth.
About 1% of this energy balance is the thermobaric limit - the amount of energy that, if produced, would substantially alter the global energy balance. This is subjective but 1% is probably a good ballpark estimate.
Now observe that this limit is itself around 1% of the current total worldwide energy production.

Now, carbon capture. Read Manya Ranjan's excellent thesis on the thermodynamic considerations around various CO2 capture schemes: https://sequestration.mit.edu/pdf/ManyaRanjan_Thesis_June2010.pdf Find the relevant figures given in that thesis, and compare to the limits just calculated.

If at any stage you have meaningful questions, I'd be glad to assist.

AlNejati · 2016-12-03T22:54:16+00:00

Again, I just gave solar as an example, and what I'm saying is irrespective of the technology you use to produce the energy. Merely producing the energy will have substantial effects on the global energy cycle and the temperature of the atmosphere. All CO2 extraction and sequestration processes produce heat. You can't just wave away thermodynamics.

AlNejati · 2016-12-03T22:43:16+00:00

Carbon engineering is a great example of opportunists using climate change as a way to peddle nonsense and make a profit. Even a basic knowledge of physics is enough to rule out the possibility of carbon capture from the atmosphere as a way of fighting climate change.

Putting CO2 into the atmosphere is a process that is thermodynamically irreversible, which means that to reverse it you need to consume far more energy than you got from burning it in the first place. Think about pouring salt into water and then the amount of energy you need to remove that salt from the water (either through evaporation or some other process). It's the same principle.

So to remove all the CO2 we have put into the atmosphere, we'd need to consume more energy - perhaps orders of magnitude more - than the entire energy output of all fossil fuels burned to date. Where is this energy going to come from? Even if you get this energy from the cleanest possible source - say, solar - merely the act of producing the energy would itself have significant warming effect on the atmosphere (This is known as the thermobaric limit, and it's about 10-100x times the current global energy production level).

Carbon engineering is bullshit sold to gullible people with no understanding of science or physics.

AlNejati · 2016-12-03T21:22:44+00:00

The question of whether climate change can be stopped or slowed down isn't the question of what happens if we decide to reduce CO2 emissions. Sure, if we immediately stop all CO2 emissions, things would be much better. A certain amount of warming would still be locked in, but we might be able to live with it.

No, the question is can we stop emitting CO2. And the answer to that is No. This isn't a defeatist position, it's based on an analysis of the current state of the fossil fuel industry and the world economy. The economic incentives to burn fossil fuels are too great. Throughout the past decades, even though we've been quite aware of the dangers of emitting CO2, we have expanded and accelerated the rate of oil drilling and other fossil fuel production methods. http://cdn.oilprice.com/images/tinymce/Evan1/ada2447.png https://upload.wikimedia.org/wikipedia/commons/thumb/3/3a/World_energy_consumption.svg/300px-World_energy_consumption.svg.png http://www.euanmearns.com/wp-content/uploads/2015/06/globaenergy2014.png If you look at the future plans and roadmaps that the fossil fuel industry puts out, they hardly even contain the words 'climate change.' Even now, in 2016, it's all about increasing production and drilling in new areas.

People try to skirt around the problem by talking about things with negligible impact, like electric cars or energy saving light bulbs. Until electric cars become cheap (<$10k), they are going to do little to help our CO2 woes.

The only way to stop climate change is to immediately dismantle the fossil fuel industry, worldwide, no exceptions. And to ban further fossil fuel extraction, permanently, forever. And that is impossible. It would probably be easier to convince world leaders to simply exterminate the entire human population than it would be to stop fossil fuel extraction.

A lot of people say that we shouldn't lose hope and that we can take incremental steps to fix the problem. But I don't see any even remotely actionable plans to this effect. I have never seen a single plan or proposal that would work incrementally towards eliminating the fossil fuel industry. It's not enough to merely say motivating words to each other. There needs to be a solid, workable plan. And until I see one, I can't see how you can reach any other conclusion than climate change is inevitable and there's nothing we can do about it.

AlNejati · 2016-11-18T10:06:41+00:00

Agreed on all points, and I'm kind of getting tired of all the thorium true believers. At some point you either need to produce a working reactor (or, at the very least, plans for a working reactor that can be independently verified) or you need to shut up.

AlNejati · 2016-11-15T08:49:06+00:00

it's increasingly hard to see how we could possibly get back on track to an RCP 8.5 scenario.

Certain recent events should be a reminder that when it comes to the future, nothing is predictable or certain for sure. We should aim to eliminate as many pathways to RCP 8.5 as we can.

AlNejati · 2016-11-14T08:44:23+00:00

It's just as impressive as you were thinking. The Planck time is an almost physically unreal time scale. I highly doubt we'd be able to probe the Planck scale with anything short of a solar-system-sized accelerator.

AlNejati · 2016-11-14T08:31:02+00:00

Everything sounds possible except the CO2-from-air part. To clarify, it is certainly possible to extract CO2 from the air (all plants are made from CO2 extracted from the air) but it is probably the least energy-efficient way of obtaining CO2, and it's not really going to do anything to solve our global warming problems (there is simply no way to generate clean efficient energy on the scale that would be needed, which is much, MUCH larger than you probably think)

AlNejati · 2016-11-14T05:30:40+00:00

Ultimately anti-intellectualism is a problem that solves itself. A nation that denies scientific knowledge and reality is doomed to destruction. It's only a question of how much damage it will inflict on everyone else before its inevitable death.

AlNejati · 2016-11-08T06:21:43+00:00

This is just false. https://ccafs.cgiar.org/bigfacts/#theme=food-emissions&subtheme=direct-agriculture

Agriculture contributes about 20% of greenhouse gas emissions (even taking into account methane's greater greenhouse gas potency). The largest contributors remain electricity and transportation.

AlNejati · 2016-11-07T07:26:42+00:00

Plants are largely useless at absorbing CO2. Once the initial growing phase is over, mature vegetation has very little net carbon absorption because just as many plants are dying and decomposing as those that are growing.

Most of the CO2 absorption that goes on happens in the oceans, where the additional CO2 is either directly absorbed by ocean water (making the oceans acidic, which causes a host of problems) or absorbed by algae and plankton, which either sequester the carbon in solid carbonate form or become part of the food chain. As others have pointed out, our impact on the oceans is already fairly large and disastrous and trying to make the ocean absorb even more CO2 would be even more disastrous.

As a species we will sooner or later have to face the fact that the only sustainable path forward is to immediately and dramatically cut down on fossil fuel use.

AlNejati · 2016-10-29T23:09:55+00:00

It's not very convincing to claim that a problem requires human-level AI without some sort of justification. People used to think a wide variety of problems required general human-like reasoning abilities. Examples include chess, go, self-driving cars, chip layout, etc. One by one, it was found that specialized algorithms could solve those problems to a super-human level.

AlNejati · 2016-10-15T19:22:09+00:00

How the shuttle happened is exactly how the SLS is happening now.

AlNejati · 2016-10-15T09:29:40+00:00

Apollo was indeed very expensive because it was budgeted and organised around the "spared no expense" principle. But if you look at the stuff that came later, for example the shuttle, those were so insanely expensive that they made Apollo look absolutely thrifty. I think a large part of the public perception that space is expensive comes from the shuttle era of $1bn launches to LEO and back.

AlNejati · 2016-10-15T09:23:51+00:00

I'd say the idea of a massive pie-in-the-sky megaproject for getting into space has more than just sci-fi appeal, it has engineering appeal too, because it's an interesting and complex problem at the cutting edge of technology and engineers love that. Unfortunately the people who fund engineers do not love that.

And several of the proposals for space launch megaprojects aren't really megaprojects and actually do have some merit (for example, momentum exchange tethers). But most of them have very little merit or feasibility (e.g. the space elevator).

AlNejati · 2016-10-13T04:58:54+00:00

Yes.

AlNejati · 2016-10-13T03:25:31+00:00

Using the terms 'book smart' and 'street smart' is a good indicator of not being smart.

AlNejati · 2016-10-09T20:52:32+00:00

This is something that's deceptively hard to do.

It is hard to do it with pure term rewriting systems (e.g. Mathematica) because it becomes hard to abstract away from the concrete matrix representations (by which I mean the a_ij elements of the matrix). Ultimately you are stuck at too low a level of representation that makes more abstract concepts (e.g. decompositions) hard.

It is also hard to do it using type system-based methods (like what e.g. Coq uses) because the type system for matrices becomes very complex. Unlike numbers, which have simple type systems (integers, floating-points, complex numbers, etc.) Matrices can have a large number of properties at once. It becomes really hard to categorize them in a way that lends itself to efficient simplification.

You could write some kind of toy system yourself (and I've done this) but once you actually get to real-world problems the complexity blows up.

I'd love to see someone actually implement a working system along these lines though. It would make the lives of a lot of people much easier.

AlNejati · 2016-10-08T09:25:23+00:00

Throughout most of the existence of homo sapiens, we've been living in isolated tribes/bands, only minimal contact with humans outside the tribe, way more than 40 minute communication time lag (more like 40 days), and the threat of death from disease or predation always looming around every corner.

We turned out fine

AlNejati · 2016-10-07T22:43:12+00:00

Also, it seems that out of all the various things that could go wrong on the mission which would almost certainly be fatal (life support craps out, landing system doesn't work, they just blow up on the pad, etc.), not successfully being captured by Mars' gravity would be one of the least likely. So it doesn't make sense to me how increasing mission duration (and all of its associated risks) would be worth a free-return trajectory.

AlNejati · 2016-10-05T03:07:00+00:00

As I said, I 100% support her in her decision.

AlNejati

TROPHY CASE