Wednesday, May 14, 2008

The Choreographers of Nature: Michio Kaku on Nuclear Energy


Michio Kaku, co-founder of string field theory and professor of theoretical physics at City University in New York City, makes some interesting points in a short interview with The India Times' Narayani Ganesh:

We're moving from being passive observers of nature to its active choreographers. This historic transition in science is enabled by discoveries in three fundamental areas: The DNA theory of life, the atomic theory of matter and computer technology that demonstrates that the workings of the mind are based on logic and electrical circuits.

I actually don't think computer technology demonstrates anything of the sort - it took aliens from Jupiter, after all, to cause the HAL 9000 to jump from human simulacra to human - but Kaku can likely run rings around my paltry doubts.

He's not too fond of nuclear energy:

Going for nuclear energy is like jumping from the frying pan into the fire. Fusion (based on hydrogen) is clean. But fission (based on uranium) generates tremendous waste. Nature uses fusion; for example, allowing the stars to recycle themselves cleanly. But nature does not use uranium, which is filthy. Nature only uses fusion, the power of the stars.

There appears to be some Gaia thinking in his formulation, but it's worth noting that nature doesn't actually "use" any energy source to generate electricity that man has harnessed for his own use, certainly not wind, solar, gas, coal, hydro or the rest. Using an energy source to generate heat has been understood as man's domain since Prometheus stole fire from the gods and man really did become the choreographer of nature. (Well, if he can do Gaia...)

Instead, he suggests:

Beyond 30 years, the goal of the ITER project in France is to find a way to control fusion. Within 40 years, commercial fusion power, which uses ordinary sea water as fuel, may become a reality.

He allows for this much wishful thinking because, he says, the polar ice sheets will have melted away by 2050 anyway. Kaku is a fascinating man and his current book Physics of the Impossible is well worth reading. His tendency is to think big - really big - and in the very long term. But practically, he reveals some of the pitfalls of an ivory tower genius brought low by the necessities of keeping society puttering along - at least until fusion gets itself together - maybe - someday.

9 comments:

Anonymous said...

Thinking in the very long term is nice, very nice.

But as John Maynard Keynes once said to his fellow economists, many afflicted with the same kind of ambitions as Kaku about the long term:

The long run is a misleading guide to current affairs. In the long run, we are all dead.

Joffan said...

Kaku says:
"Nature uses fusion; for example, allowing the stars to recycle themselves cleanly. But nature does not use uranium, which is filthy."

By a small stretch, we could describe the fusion in stars as including "recycling", when some of the heavier stars push past hydrogen fusion to helium and heavier element fusion. By the same token we could describe fission as another step of recycling the same process, since the Earth's uranium was created as an endproduct of stellar development (in a supernova).

However Kaku really should get up to date on the natural uranium reactors that ran for hundereds of thousands of years at Oklo. They've been known about for many decades now, so there's really no excuse. Nature has indeed used uranium in much the same way as we do - far closer, indeed, than the process in stars is to our current fusion research lines.

Flagg707 said...

...But nature does not use uranium, which is filthy. Nature only uses fusion, the power of the stars...

The good doctor apparently does not know his science as well as he would have us believe.

Nature, in fact, does use fission. The Oklo "reactor" is a screaming example of this.

As for fission and fission products themselves, this "filth" includes Mo-99, the parent of Tc-99m - the single most widelyl used imaging isotope in the world as well as a variety of other isotopes useful for therapy and diagnosis.

The good doctor also seems to forget that many types of fusion generate neutrons during the reaction, which can activate the reactor materials and create a radiation hazard.

Perhaps he could have phrased it that nuclear fission creates discrete waste products that are tiny in relation to the electricity generated and that any rational energy policy should include aspects of storage, reprocessing and transmutation.

Kirk Sorensen said...

Kaku, like many other scientists who get on TV too much, is waxing religious about how "clean" fusion is.

It ain't so clean--it's a good thing there's a lot of non-fusioning Sun between us and the fusion core of the Sun otherwise we'd get cooked by gamma rays from "clean" fusion pretty fast.

On another note, we live on a nuclear-powered planet, and I'm not just talking about solar nuclear fusion energy. Without the decay heating of uranium and thorium, plate tectonics would have stopped billions of years ago, and life would have consumed all the carbon dioxide out of the atmosphere and lost it all in the oceans in the form of calcium carbonate.

Life would have literally eaten itself to death. Fortunately, due to the heating effects of uranium and thorium decay driving plate tectonics, oceanic crust is subducted under continental crust and carbonates are recycled to the atmosphere by volcanic eruption.

Pretty nice, that uranium and thorium, here on our nuclear-powered world.

Rod Adams said...

There are even some pretty good pieces of evidence that point to the possibility that the Earth, itself is still using fission.

One of the guests that I interviewed for The Atomic Show, Dr. Marvin Herndon, has a very interesting theory called the georeactor.

I am not a geologist or even a scientist of any discipline, but the justifications for his theory seem pretty reasonable to me.

My friend NNadir has also convinced me that just about every fission product has value; and some of them are extremely valuable.

No - fission waste is only "dirty" if you decide not to use it. The same can be said about almost all byproducts of all natural processes including eating.

Stephen said...

Fusion is always going to be difficult and if we are going to just go with scaling up the Tokomak until it eventually gets past break-even than that's never going to be a viable power source for wide deployment because the design is inherently too complex, energy intensive and expensive.

With fusion you are faced with the challenge of making charged particles slam into each other so hard they'll fuse. They're all repelling each other to begin with so it's not like you can do it with something simple like a neutron that will work at a low energy.

No, you must create a superheated plasma and get it really stoked up by firing ions at it from accelerators or by hitting it with lots of microwaves or inducing a current in it. You need to maintain, control and contain this superheated plasma where your fusion occurs, keeping it hot and compressed, feeding it new fuel and removing the byproducts it generates.

Oh, and you have to do this all without touching it, by somehow balancing it within a magnetic or electrical field. If you touch it you destroy the material it touches and you stop the reaction by drawing away way too much heat.

That can never be simple or easy, at least unless there is some breakthrough new design.

The fusion reactor at MIT cost a huge amount to keep running just from cooling. The magnetic fields need to be enormous and this necessitates superconductors. A superconductor needs to be kept cold, but they're being hit with so much radiation that you need to keep pouring more and more liquid helium on them to compensate for the heat from the irradiation.

On the other hand, the first fission reactors were piles of graphite and uranium.

A fission reactor doesn't involve any pressures or temperatures that we can't handle with conventional materials. It's not using plasma or some other exotic technology. It just sits there, sustaining itself in equilibrium and happily fissioning and making energy.

Thus far, we have only built one kind of fusion reactor that is simple, effecient and makes more energy than it consumes. Unfortunately it also has the problem of burning all its fuel in a period of a few microseconds. But it works great as an island remover.

M. Simon said...

The tokamak is a dead end.

This looks like a better bet:

Easy Low Cost No Radiation Fusion

Ashutosh said...

While the dichotomy that Kaku makes between fusion and fission is strictly true, his statement seems to imply that what nature does not use is necessarily bad.

rsm said...

I remember Dr. Kaku's antinuclear work back in the 1970's. He even supported replacing nuclear with coal as he claimed coal was safer.

Now I feel REALLY old. ;-)