If you connect a 12-volt battery to a 4-ohm lamp, 3 amps of current will flow through the circuit by Ohm’s Law, V=IR. Power = VI = 36 watts will be dissipated by the lamp. If you add a 2-ohm resistor in series with the lamp, the resistances add to 6 ohms, the current is [...]
Archive for the 'Energy' Category
Two new items that are follow-ons to the Moore’s Law for Energy thread: A story at Technology Review about new electronics that improve the usable power from existing solar panels by 5-25%. The advance is new smarter electronics that allows for an inverter for each panel instead of one big one for the whole system. [...]
There was a gratifyingly large response to last Friday’s post Acolytes of neo-Malthusian Apocalypticism. Several of the commenters seemed to think I was trying to refute the LtG model, but that would require a whole book instead of one blog post. I consider LtG to have been demolished in detail by people with a lot [...]
When I was in college 35 years ago, there was a major fad of neo-Malthusian doom-mongering, led by the “Limits to Growth” book and movement. A retreat was organized from the college, and some concerned, environmentally conscious professors and students, myself included, went off for a concentrated seminar in which we educated each other about [...]
Another step along the Moore’s Law-like trend line for solar power: Ink-Jet Printing for Cheaper Solar Cells at Technology Review. (see also Nanoscale Inkjet Printing)
In this post I pointed out that in the foreseeable future, nanotech devices are likely to be energy-starved. Chris Peterson asks in a comment whether there would be a problem from the heat dissipation from this energy use. The analysis is worth a post of its own, so here goes: About 100 thousand terawatts of [...]
Earlier this week I was at the premiere of Transcendent Man, a biographical overview of Ray Kurzweil’s views on the coming Singularity. Kurzweil’s main argument is that the power of the exponential in technology is major, systemic, and underappreciated. The specific item of interest in this post is Kurzweil’s claim, repeated in the movie, that [...]
MIT scientists have demonstrated the usefulness of biological frameworks for combining distinct functional elements to make a device.
I recently heard a talk by Patri Friedman about seasteading. Seasteading means “homesteading the sea,” or at least building floating cities and establishing permanent residences there, and ultimately alternative polities in hopes of enabling beneficial economic competition in the field of governance. Before saying more, let me point out that I am generally in agreement [...]
The power density is large compared to that of macroscale motors: >1e15 W/m^3. For comparison, Earth intercepts ~1e17 watts of solar radiation. (Cooling constraints presumably preclude the steady-state operation of a cubic meter of these devices at this power density.) Nanosystems p. 339 It is difficult, even for someone who has been working with these [...]
20 years ago, in the wake of the cold fusion excitement-turned-debacle, I noticed an interesting fact. The people doing the experiments were divided into two classes: The electrochemists who believed that fusion was happening were doing their experiments in plastic tubs and glassware, whereas the physicists who believed that no fusion was really happening were [...]
Jeriaska has made available videos of presentations from Convergence08, held on November 15-16, 2008 in Mountain View, California, to examine the convergence of NBIC (Nano-Bio-Info-Cogno) technologies. Among those of special interest to Nanodot readers: Mapping a Cone of Uncertainty, Paul Saffo Convergence: Artificial Intelligence Panel, Peter Norvig, Steve Omohundro, Ben Goertzel, Barney Pell Convergence: Synthetic [...]
The discovery that nitrogen-doped, metal-free carbon nanotubes make better electrodes than do platinum nanoparticles may open the way for inexpensive nanotech fuel cells.
Canadian scientists have discovered how chemical structure can elicit a quantum state that permits the ultrafast movement of energy along an organic polymer.
A method that eliminates metallic single walled carbon nanotubes from mixtures leaving fully functional semiconducting SWCNTs may open the way for various nanotech applications that require pure semiconducting SWCNTs.
An open-access review article describes how a layer of nanoparticles of different sizes, compositions, and shapes enhances the efficiency of thin-film solar cells.
If you have a proposal on how nanotech could address a critical national and societal need, the National Institute of Standards and Technology (NIST) wants to hear from you.
The following is an edited and revised version of the talk I gave at the Global Catastrophic Risks conference that was held in conjunction with Convergence 08 (and which I reprised for Convergence). I’m posting it here because it seems to me that this is exactly the kind of thing Foresight was founded for: to [...]
A nanostructure called a “gyroid” provides the basis for a more efficient, inexpensive nanotech solar cell.
The publication of a method to mass produce graphene has opened the way to further study of this remarkable nanomaterial.