Which branch to specialize in given limited energy supplies in future?

[vrkosk]

In my lifetime, there will be at least two major challenges to human society: climate change (of which you have hopefully heard) and peak oil (of which not enough people are talking). The first necessitates decreasing emissions, going green, reducing consumption, likely a reorganizing of human society. The second necessitates reworking the entire food chain (agriculture, processing, transportation), manufacturing of most goods, energy production, and again likely a reorganizing of human society.

Let us be slightly optimistic. Let us assume the species will not destroy itself and that there will continue to be a high technology society. Let us also assume that due to the severe environmental constraints (stated above), energy supplies will be very restricted. There will be lots of competition for resources such as water and arable land, and also for green energy sources (hydropower, solar, wind, the usual suspects). There will be no oil or coal power plants that would provide nearly unlimited amounts of energy at very little cost. Nuclear fusion is still unusable, and will remain to be so (in large scale) for a couple of decades at least. (Nuclear fission will not remain a valid option once the world runs out of oil, as all mining vehicles run on diesel or gasoline -- and if you can't mine uranium, you can't run a fission reaction.)

If you start doing a PhD in physics right now, which branch does it make most sense to specialize in? By that I mean which branch will still have jobs when there is no more cheap energy.

As an example, the LHC can consume 180 MW at peak power (http://lhc-machine-outreach.web.cern.ch/lhc-machine-outreach/faq/lhc-energy-consumption.htm). You would need about 150-200 wind turbines in a good location or a large enough hydroelectric plant nearby to power just the LHC. In a resource and energy restricted world, this is not a sensible allocation of energy use.

Another example is astrophysics. I could not find any figures off Google what the typical power consumption of an array of telescopes is (I would be interested if you have any!), but I would guesstimate it to be larger than a couple dozen contemporary households. In addition to that, computing, say, the collision of two large galaxies on a supercomputer may not be possible at all; IBM Blue Gene/Q, for instance, draws about 6 MW at peak operation. (http://www.hpcwire.com/features/Lawrence-Livermore-Prepares-for-20-Petaflop-Blue-GeneQ-38948594.html ) And that is considered a very energy efficient supercomputer by the way.

I suppose my question can be rephrased: which branch of physics can do away with experiments with least energy use? HEP is out (in the form of mega experiments such as LHC, and that's where the remaining gaps in our knowledge are); most computational stuff is out; large telescopes may be out. What is left? Condensed matter? Plasma physics? Photonics? Binoculars?

Doing pure theory is of course an option, as you can do it with pen and paper, but I rather like actual experiments.

 

[Sankaku]

While the LHC's power requirements will probably never go down, I can imagine that a big telescope could make large power efficiency gains if need be. After investing huge dollars into building them, I doubt we will stop using the telescopes we have, even if energy becomes expensive. Whether we will be building more mega-scopes remains to be seen.

As far as research goes, there will be a lot more money thrown at fusion in the coming decades, regardless of current results. Of course, doing research in anything to do with renewable energy is also increasingly popular and lucrative.

Are you trying to choose a specialization now (starting PhD) or is this just general speculation?

 

[twofish-quant]

If you start doing a PhD in physics right now, which branch does it make most sense to specialize in? By that I mean which branch will still have jobs when there is no more cheap energy.

First of all, there are very few permanent jobs in physics anyhow. Second, I think you should thinking about what areas of physics would useful in *fixing* world resource demand problems. Shoot up a few solar power satellites and mine the asteroid belt and all of the resource problems disappear.

I suppose my question can be rephrased: which branch of physics can do away with experiments with least energy use? HEP is out (in the form of mega experiments such as LHC, and that's where the remaining gaps in our knowledge are); most computational stuff is out; large telescopes may be out. What is left? Condensed matter? Plasma physics? Photonics? Binoculars?

The amount of energy use in physics is pretty trivial compared to everything else, and I think people will put up with it, since doing more with less is going to involve a lot of physics research.

Look, we have about 1 billion Chinese and 1 billion Indians that are going to demand their right to live at US/Western European standards of living and right behind them are another 1 billion Africans. If we can't figure out a way of getting things so that Chinese, Indians, Africans, and people in what is now the third world have standards of living comparable to US/Western Europe, then we will have World War III. Chinese and Indians are pretty content right now, because they think that they *will* be able to live like Americans, and if that turns out not to be the case, the planet is going to get very nasty.

If we want to avoid WWIII, then we've just got to figure out a way to have high standards of living with less energy and resource use, and that seems to me to involve more physics.

Doing pure theory is of course an option, as you can do it with pen and paper, but I rather like actual experiments.

Theory is done with large scale computers.

 

[fasterthanjoao]

I'll contibute to this thread by chiming in with an agreement to what twofish says.

I would say your post is a misunderstanding of sorts: whilst it's obviously prudent to improve the efficiency of the way we (the world collective) work, suggesting that research for one will just stop happening because energy demands might reach a critical point in the future isn't the right thought.

For example, barring an apocalypse of sorts, there will never be a point in the future where we, as a society, will stop using computers. We won't stop working: this applies to both physicists and everyone else. Thus, the problem isn't only that we're using too much energy - it's also that we don't have enough.

If you're concerned about energy demands in the future, trying to imagine an area of research (much less physics) where you'll get by using no energy is just silly - you should consider joining the armada of researchers trying to solve the problem through novel ways of producing more.

 

[twofish-quant]

For example, barring an apocalypse of sorts, there will never be a point in the future where we, as a society, will stop using computers. We won't stop working: this applies to both physicists and everyone else. Thus, the problem isn't only that we're using too much energy - it's also that we don't have enough.

Also the problem isn't the quantity of energy. We have more than enough coal to last 1000 years, which is enough time to get the solar satellites and fusion reactors working. The problem is that if we burn all of it, it will wreck the planet.

One big use of computers is greenhouse gas modeling. At this point, there is no real disagreement that CO2 is changing the climate and in any realistic scenario, the planet is going to get a lot warmer. The big question that people are worried about is how much CO2 can we pump into the atmosphere before something really, really bad happens (think Venus). Also, people want to know what happens if we pump X and Y amounts of CO2 into the atmosphere that way we can make political and economic decisions about what to do.

If you're concerned about energy demands in the future, trying to imagine an area of research (much less physics) where you'll get by using no energy is just silly - you should consider joining the armada of researchers trying to solve the problem through novel ways of producing more.

Also, you might help by just doing something that has nothing obvious to do with energy production. The nice thing about physics is how something in one area gets used in another. The whole idea of greenhouse warming came from studying Venus.