Accelerating Future

3 Responses »

1. Superconductivity — conducts electricity perfectly, magnetic fields are excluded from the interior of the object (Meissner effect). The soon-to-open Large Hadron Collider will use superconducting magnets to accelerate subatomic particles to 99% the speed of light. In the near future, superconducting materials will decrease the necessary size of large engines, such as those on aircraft carriers, by a factor of 3-4. Some scientists believe that the future discovery of a room-temperature superconductor will launch a new industrial revolution.

2. Superfluidity — zero viscosity, zero entropy, infinite thermal conductivity, “creeps” up surfaces, shows quantum effects at the macroscopic level, such as behaving like a single “superatom”. 645 gallons of superfluid helium were used to cool Gravity Probe B, an orbiter designed to test Einstein’s theories about the curvature of spacetime. When rotated in a canister, a superfluid can only move at certain quantized, discrete speed levels.

3. Superlubricity — practically zero friction observed in eggshell-shaped configurations of crystal. Might be used to create frictionless gears for nanomachines. Has been measured using the extremely sensitive Friction Force Microscope. The phenomenon of superlubricity is very new, only investigated seriously in the last few years. The image below shows regions on a crystal surface displaying superlubricity.

4. Supersonic — faster than sound. “Hypersonic” refers to something traveling more than 5 times faster than sound, or Mach 5. The Earth’s escape velocity is about Mach 24. When a plane or rocket exceeds the speed of sound, it produces the famous “sonic boom”, which may exceed 200 decibels. A team of British engineers wants to build a commercial plane that travels at Mach 5, twice as fast as the Concorde. At that speed, the trip from Brussels to Australia would take less than five hours, passing over the North Pole. Scramjets have a top speed between Mach 12 and Mach 24.

5. Supercriticality — a phase of matter that has properties of both a solid and gas. The picture below shows an aerogel, not a supercritical fluid itself but produced using one. Superfluids have zero surface tension, and are only created at high pressures. By tuning the pressure and temperature of a supercritical fluid, engineers can make it behave more like a liquid or a gas, including manipulating its ability to dissolve other materials. At the surface of Venus, temperature and pressure are sufficient to make the entire atmospheric base a supercritical fluid. Creating superfluid water requires a temperature of 704 °F and a pressure of 218 atmospheres.

6. Superluminal — faster than light. In special relativity, while you cannot accelerate an object to the speed of light — that requires infinite energy input — nothing forbids the existence of something that always moves faster than light. Such a hypothetical particle is called a tachyon, and experiments are underway to find them. According to the theory of cosmic inflation, during the first fraction of a second of the universe’s existence, space itself expanded many times faster than light. This is possible because nothing within space would actually move superluminally, just the spacetime fabric itself. In astronomy, certain phenomena such as relativistic jets appear to move superluminally due to an optical illusion.

Other supers in physics: supergravity, superstrings, supersolids.

One Response »

Below is a list containing various power values and the quantity of water they can boil. Click for the larger version. For the water, the initial temperature is approximately that of the ocean’s surface, 20 °C. The text version may be downloaded here.

Source: Wikipedia - Orders of magnitude (power).

7 Responses »

One of the brilliant young physicists of our age is Scott Aaronson. It’s hard to pick a particular post of his that I like the most, but one I’d like to call your attention to is Mercenary in the String Wars. This guy cracks me up, like the strong force separating from the electroweak force in the first microseconds of the big bang. He sucks me in, like a stable strangelet consuming local baryonic matter. He rocks my world, like… okay I’ll stop. Sorry to ruin it, but I just have to post the end of the blog entry I linked:

I have therefore reached a decision. From this day forward, my allegiances in the String Wars will be open for sale to the highest bidder. Like a cynical arms merchant, I will offer my computational-complexity and humor services to both sides, and publicly espouse the views of whichever side seems more interested in buying them at the moment. Fly me to an exotic enough location, put me up in a swank enough hotel, and the number of spacetime dimensions can be anything you want it to be: 4, 10, 11, or even 172.9+3πi. Is it more important for a quantum gravity theory to connect to the Standard Model, or to build in background-independence from the outset? Can one use the Anthropic Principle to make falsifiable predictions? How much is riding on whether or not the LHC finds supersymmetry? I might have opinions on these topics, but they’re nothing that a cushy job offer or a suitcase full of “reimbursements” couldn’t change.

Someday, perhaps, a dramatic new experimental finding or theoretical breakthrough will change the situation vis-à-vis string theory and its competitors. Until then, I shall answer to no quantum-gravity research program, but rather seek to profit from them all.

On his post on getting a real job, after presenting his research statement, teaching statement, and CV, he writes:

In your offer letter, make sure to specify starting salary, teaching load, and the number of dimensions you’d like spacetime to have.

As I’m currently reading Lee Smolin’s The Trouble With Physics, I find Aaronson’s cynicism funny - and relevant.

3 Responses »

A couple of videos demonstrating cymatic phenomena.

The last part of the final video is the most unusual of all.

9 Responses »

There’s so much relevant news from the past week, I can’t just focus on any one thing… so here are five of the most significant things to hit my radar in past week:

In ascending order of importance.

5. On Marginal Revolution: What are some unknown but incredibly important inventors? Why can’t we get rid of the penny? And what is the moral basis of capitalism?

4. Lawrence Berkeley lab and Oxford University researchers developed a particle accelerator that takes electron beams and powers them up to a billion electron volts (1 GeV) in only 3.3 centimeters using a technology called laser wakefield acceleration. If these particle accelerators become popular and start to edge out conventional accelerators, then we’ll both learn a lot more about particle physics, and put ourselves at greater risk for creating a stable strangelet. Doing a risk/benefit calculation is difficult because of uncertainty in the probabilities involved.

3. If all goes well, we may start running our automobiles on ceramic ultracapacitors which take us 500 miles on only $9 worth of electricity using a battery that recharges in 5 minutes. Eric from Digital Crusader did a few basic calculations and found that transferring that amount of energy would require a rate of 1.2 megawatts, much greater than anything seen in current home electronics systems. The inventors of this technology claim that one day it will completely replace the internal combustion engine.

2. The mouse brain has been mapped down to individual cells. It only cost $41 million to do. A 3D atlas of the common lab mouse brain can be found here. If we had computers a couple orders of magnitude more powerful than today, we could start trying to simulate that mouse’s brain in a virtual environment. The success of the mouse brain mapping project is also a testimony to the success of high-level philanthropy. Paul Allen, co-founder of Microsoft, contributed $50 million to the project, more than it even needed. This Merkle paper is relevant as background.

1. Chris Phoenix proposes the creation of cubic micron DNA structures. Specifically, Chris proposed “solid molecular constructions, using DNA as a backbone, plus other arbitrary molecules precisely positioned within the volume. ” He estimates that it would be possible to design one for $10 million to $100 million once the entire process is automated. The idea came out of a thought experiment about what would be possible with today’s technology and only a “moderate amount of engineering”.

The idea would be to build bricks that can independently manufacture other bricks, to produce a rudimentary DNA nanofactory. Less ambitiously, you could design bricks that perform specialized tasks, like breaking down garbage efficiently, and then mass-produce the bricks to perform that function. The power of the approach is that, with current technology, you can precisely specify the DNA structure within a cubic micron volume, making it possible to eventually build any structure that can be designed. Because the density of DNA is about 1.3 nm^3 per base pair, it would take about 500 million base pairs worth of DNA to fill a cubic micron space. At current DNA synthesis prices ($0.10 if it’s your machine) that works out to $50 million/block, but the cost is rapidly falling.

Chris expounds a bit more on the concept here. Meanwhile, CRN argues “yes, it’s coming soon“.

8 Responses »

And this is the Rice dwarf virus of the family Reoviridae. The Reoviridae family is a family of viruses that attack the gastrointestinal system. What you see is a computer model built using X-ray crystallography techniques to image the virus atom-by-atom.

What is fascinating is their similarity in appearance. Parallels between objects at such vastly different scales points to the fact that we live in a low-entropy, fractal universe. This allows us to make inferences about new objects using metaphor and metonymy, and actually have a chance that those inferences are correct. If our universe consisted of radically diverse objects, past experience would be far less useful in predicting the future - in fact it would have been difficult for any form of intelligence to emerge.

Contemporary physics theories assert that our observable universe is only a small part of a much larger region called the multiverse. The multiverse is infinite for all practical purposes, and contains universes of every size and with every conceivable set of natural laws, including those with greater or fewer spacetime dimensions.

Most of these universes lack the conditions necessary to foster life - for example, if the strong force in the atomic nucleus were slightly weaker than it is here, stable atoms would be impossible, and all the matter in the universe would be a diffuse fog. But finding ourselves in a universe fine-tuned to support life should be no surprise. After all, how could our species have popped up anywhere else?

Specific complexity requires order. Our universe has orderly natural laws that allow complexity to accrete without the interference of chaos. It even looks like the product of an evolutionary selection process that favors the existence of life.

The multiverse hypothesis comes from quantum mechanics. In quantum mechanics, everything is a chaotic foam at the lowest level, involving random tunneling effects and principles of uncertainty.

If every universe in the multiverse is part of a huge, randomized quantum manifold (as our evidence suggests), then we should expect disorderly universes to be more common than orderly universes. This “universal majority” is far too chaotic and disorganized to harbor intelligent observers. In the same way that SETI scientists specify a planetary “habitable zone” at a certain distance away from a central star, there is a multiversal “habitable zone” where all conscious beings live.

Think of a cellular automata grid like the Game of Life. The simple, disorganized structures are the first to emerge. For the longest time these are the only structures visible. Then, simple, progressively more organized structures can be seen. Eventually, a self-replicator is able to emerge from the fray - the simplest structure capable of reliably copying its own design. If there is a random component to the self-replication process, then evolution and variation may cause this simple replicator to get more complex over time.

When it comes to universes, structures which apparently can be described by just a few parameters, such as starting mass, dimensions, and fundamental forces, simple is more common. We just can’t see all the simple universes because they are too simple to support life. And of course, by definition, we can receive no information from universes outside our own, even though we know they exist. When it comes to structures built by random processes, simplicity rules.

Move up the complexity ladder for universes, and surely they get rarer. (Unless there is a specific force manufacturing complex universes, which looks extremely unlikely. The underlying mechanism of universe creation is quantum and therefore random.) These complex universes may be rare objectively, but they are not rare to observers, who make them their home. Observers only find themselves within universes past a certain complexity level - that threshold necessary to support the emergence and flourishing of life.

There definitely exist universes more complex than our own, and we have to ask - do they contain life? In a universe with more than four dimensions, the interactions between objects would be so complex that a self-replicator would need to be fundamentally more sophisticated to launch itself, and therefore take much longer to come about by random collisions. These complex universes also must be rarer to begin with, so it seems less likely for any given intelligent observer to find him or herself within one.

This is our anthropic landscape. As typical conscious observers, we should expect to live in a universe that is simple, but not so simple that it can’t contain life. This squares nicely with our observations.

The universe’s fundamental simplicity doesn’t signify that complex forms can’t emerge within it. The human brain is coded by a portion of the genome that has less information content than Microsoft Word, but the self-similar, fractal nature of neural architecture means that an adult brain is many orders of magnitude more complex than the genome that built it.

In the same way, even if the universe in fact contains almost no information, it doesn’t mean that we can’t build things or have experiences within it that look complex to us.

For a little more on anthropics, see my October post on the self-sampling assumption, or George Dvorsky’s post from last month on the topic.

4 Responses »