October 27, 2004

Human dwarf species uncovered

"It is arguably the most significant discovery concerning our own genus in my lifetime." -- Bernard Wood, George Washington University.

It now appears that the Neanderthals weren't the only human-like species to co-habit the planet with modern humans in recent evolutionary terms. In fact, a completely different hominid species survived longer than the Neanderthals did (they died out about 28,000 years ago).

Indeed, the discovery of a human dwarf species that lived as recently as 18,000 years ago on the island of Flores is a breathtaking discovery.

The species, named Homo floresiensis, lived marooned for eons on the island of Flores while Homo sapiens rapidly colonized the rest of the planet. Flores was a kind of tropical world populated by giant lizards and miniature elephants.

Homo floresiensis had a grapefruit-sized brain about one-quarter the size of the brain of modern man; it is closer in size with the brains of transitional prehuman species in Africa more than three million years ago. However, evidence suggests that Flores man made stone tools, lit fires and organized group hunts for meat.

It is uncertain if this species ever crossed paths with modern humans. And geologic evidence suggests a massive volcanic eruption sealed its fate 12,000 years ago, along with other unusual species on the island.

October 24, 2004

Did Cybercity Radio show yesterday

I did my first ever live radio interview last night as I was Jack Landman's guest on Cybercity Radio. I believe the show is based out of San Antonio, Texas. The show is reminiscent of Coast to Coast AM with George Noory, and like Coast to Coast has an unhealthy attachment to UFO culture. That being said, Cybercity has its share of credible science. Past guests include Seth Shostak (SETI Astronomer), Alan Guth (Cosmologist), Kary Mullis (Nobel Prize Winner), Neil deGrasse Tyson (Astrophysicist), and Paul Kurtz (Philosophy - Founder CSICOP).

I had a great time doing the interview. Jack opened the show with the theme music to 2001: A Space Odyssey, which I found quite appropriate and dramatic. Consequently, we were immediately engaged in some serious discussions about posthuman possibilities. Other topics we covered included indefinite lifespans, the global brain, technologically enabled telepathy, stem cells and therapeutic cloning, Betterhumans, the World Transhumanist Association, potential dangers in the 21st century (including artificial superintelligence) and molecular nanotechnology.

At the close of the show Jack asked if I would come back to do future shows, an offer to which I graciously accepted.

October 13, 2004

New Transitory Human Column: Death Vs. Hope

My latest column for Betterhumans has been published:

Death vs. Hope
The pace of medical progress should give patients and doctors pause when considering assisted suicide
Clearly, there is an issue here in desperate need of attention. The Canadian government, with its blanket refusal to allow and monitor assisted suicide, has forced desperate people to take desperate measures. Furthermore, the idea that our government can force us to stay alive—regardless of the particulars of our unique situation—is quite frightening and repugnant, especially when we consider how grossly underfunded health care is for the elderly and for palliative care units across the country.

But just because I defend the right to assisted suicide doesn't mean I have to like it. Given the primitiveness of today's technologies relative to what's on the horizon, I have to concede that in some cases it's a necessary evil. But there is the prospect of significantly advanced medical interventions arriving in the near future—interventions that may impact directly on people living with diseases or irreparable injuries today, and particularly those contemplating suicide. So for healthcare practitioners in countries where voluntary euthanasia is legal, and for those considering its legalization, it's time to act accordingly, including full disclosure to patients. Failing to inform patients of all their options is not only irresponsible, it could also mean the difference between someone choosing to live or die.

October 11, 2004

Conversation with Anders Sandberg on antimatter weapons

News that the US Airforce is pursuing an antimatter weapons program hit the media last week. Concerned that this theoretical technology could represent a new existential risk to our species, I opened a dialogue with Anders Sandberg to get his opinions on the subject. Here's our conversation:

I wonder how serious this risk is. I have played around with antimatter weapon scenarios a bit, and they do not seem to be much worse than nuclear weapons. They still ought to be beside them on the list, but they do not seem to do anything truly new.

In the near future they are utterly too expensive to be useful, and they require major installations to build. This places them in the same fairly easily controlled category as nuclear weapons. Since containment is also active, proliferation is unlikely - simply too hard to keep stable.

Things change a bit if we move to space. There one can build "antimatter distilleries" orbiting the sun, accumulating antimatter or producing it through solar-powered accelerators. Everything scales up, and now one can make sizeable amounts. Production is still very visible, and fairly easily disrupted.

Antimatter becomes a serious problem if a stable (especially a passive) containment is constructed (or it can be produced in such a form). Penning traps are too small to be a threat, but once you have stably magnetically levitated anti-hydrogen or heavier, you have a potential problem with proliferation. Amat bombs could (if the containment is small) be sneaked around relatively easily and be hard to keep track of. Again, I don't think this is worse than suitcase nuclear proliferation. You get a very unstable and risky situation, but not the end of the world (Charles Stross description of the situation on the post-singularity Earth in his latest novels comes to mind).

Big antimatter detonations could be used to sterlize planetary surfaces if spread across the atmosphere. The ambiplasma fireball is going to radiate a very nasty blackbody spectrum over a sustained amount of time (minutes?) and likely produce lots of short-lived biologically active isotopes. But this kind of sterilization seems to require plenty of preparation (making the antimatter in significant amounts) and deliberate use, not just accidents. Most likely a Shriek rather than an accidental Bang.

Just some thoughts.
Thanks for the clarification and insight, Anders. It certainly doesn't seem like the kind of weapon that would be utilized by nihilist groups/individuals or even aggressive state actors.
Maybe aggressive states would find uses for it, but beyond a certain size bigger explosions are not more destructive (most of the explosive power ends up in space). Maybe antimatter would be good for secretive space warfare or redirecting asteroids at enemies, but that seems a relatively low-level nastiness.
That being said, could a catastrophic accident arise from the development of such a weapon or fuel source (e.g. antimatter catalyzed nuclear pulse propulsion)?
I'm thinking possibly, but only in the form a localized disaster. A Shriek at Worst.

Hmm, to accelerate a starship to 0.3 c you need about 2.5% antimatter if you have perfect conversion of energy into kinetic energy. A million ton ship would need 25,000 ton antimatter, which would indeed be a bad day if it all blew up. About 976,000 gigatons bad. (assuming I calculated right). This kind of space opera starship would indeed be a dinosaur killer.

Going down to a mere 0.1 c gives a requirement of just 0.25% antimatter, and 0.01 c 2.5e-3% - much safer.
Although, how do you know how long the ambiplasma burst will linger? It's my understanding that they can be relatively long-lived, as the component particles and antiparticles are too hot and too low-density to annihilate with each other rapidly. If the ambiplasma fireball lingered for a protracted period, that could be bad.
I tried to calculate this during my recent trip to Brussels, as I thought my earlier answer was a bit too handwavy, but the exact answer seems hard. The mean free path depends on the density, but the density will depend on how the initial fireball expands. This will in turn depend on how opaque to gamma rays the air is and how it is heated; my general impression is that there will be a high density shockwave accelerating outwards with much antimatter reactions (as fast moving antimatter reaches it from inside) and driven by internal gamma-rays and a low density ambiplasma with more antimatter inside. Given that average particle speeds will be hundreds of km/s scattering will be very intense unless the gas is very dilute. See this article.

But to do this correctly I would likely need a nuclear fireball simulator. Maybe we should ask Sandia labs :-)

Given these ponderings, I'm revising my estimates of ambiplasma longevity in an atmosphere downwards. You get a nasty fireball, but it won't last *much* longer than a nuclear one.
Don't antimatter explosions produce copious amounts of gamma rays?
Yup. That is the primary effect of quark-antiquark and lepton-antilepton interactions. But don't forget that the reactions also cause cascades of very hot nuclei, protons, neutrons and leptons - you get all kinds of rays.
Gamma rays are very dangerous and are the primary source of the radioactive fallout of nuclear weapons. I recognize that the effects would be immediate (unlike radioactive isotopes which persist), but I wonder what the effect of that would be on biological organisms.
Gamma rays in themselves do not cause fallout. They just hurt organic matter, but have to be very strong to disrupt atomic nuclei. In this case they will mainly heat up the fireball, and get scattered into (still dangerous) x-rays.

Actually, an antimatter bomb would be dirty since any atom getting hit by the antimatter would be transmuted. In air that would likely mean that you got lots of light nuclei. This isn't that bad, because most of them decay fairly quickly before they can get integrated into an organism - but *lots* of C14 and tritium could be troublesome. Unfortunately, a lot of highly accelerated alpha particles and others will slam into heavier nuclei and leave behind nastier isotopes, especially if it is a ground-burst.
Oh, one final thought, is there any connection between gamma ray bursters and antimatter explosions? Do antimatter explosions happen naturally in the Universe?
Not to my knowledge. Antimatter detonations would have a characteristic spectrum (like at 0.5 MeV for electron-positron annihilation), and it is not seen in GRBs or elsewhere. No risk for antimatter rocks hitting us.

October 7, 2004

New book about Fermi

Fermi acceleration. Fermi liquid. Fermi pressure. Fermi gas. The Fermi paradox. Fermi questions. The Fermi-Thomas model of the atom. The Fermi-Turkevich gap. Fermium and fermions. Enrico Fermi High School in Enfield. Conn. The Fermi National Accelerator in Batavia, Ill. The Enrico Fermi Institute at the University.

Okay, so this guy did something with his life.

James W. Cronin, a University of Chicago physicist and Nobel laureate, has brought together an impressive array of writers and scientists in a tribute to one of the greatest scientists of the twentieth century, Enrico Fermi. The book, titled Fermi Remembered, describes the multi-faceted scientific legacy of Fermi, who made significant contributions to 20th-century physics.

In a review of the book, Steve Koppes writes:
Albert Einstein’s relativity theory and the quantum mechanics developed by Werner Heisenberg and Erwin Schrodinger are often cited as milestones in 20th-century physics. But for sheer breadth of achievement, Fermi left a unique signature on modern physics.

“He gave to science all he had, and with him disappeared the last universal physicist in the tradition of the great men of the 19th century, when it was still possible for a single person to reach the highest summits, both in theory and experiment, and to dominate all fields of physics,” wrote the late Nobel laureate Emilio Segre of Fermi in 1962.

Although not a biography, the book contains reminiscences of Fermi from 25 scientists who knew him, as well as material from his research notebooks, correspondence, speech outlines and teaching.

Among Fermi’s early accomplishments was to apply quantum mechanics, which explains the behavior of atoms and subatomic particles, to the physics of solids and gases, Cronin said. In the 1920s, he built on quantum theory by formulating concepts called Fermi energy and, with Paul Dirac, Fermi-Dirac statistics. These concepts later became vital to the development of semiconductors and other electronic devices.

Fermi went on to earn the Nobel Prize in 1938 for his discovery of new radioactive elements produced by the addition of neutrons to the cores of other atoms, and for the discovery of nuclear reactions brought about by slowly moving neutrons. He also directed construction of the first nuclear reactor at the University during World War II as part of the effort to develop the atomic bomb. But he turned his attention to an entirely new topic after the war.

While researching the book, Cronin discovered a 1945 letter from Fermi outlining his vision for the newly formed research institute that now bears his name at the University. “That was to do high-energy physics, not nuclear physics, not following up what he had done with the bomb,” Cronin said. “He was looking far, far ahead of that.”
In addition to his remarkable work as a physicist, Fermi also contributed to cosmological and metaphysical discussions by introducing the (in)famous Fermi Paradox, in which he contemplated the unexplained 'Great Silence' from other possible intelligent life-forms in the Universe.

October 5, 2004

Caplan: Stem-cell research a pawn in election politics

The more I read Art Caplan's work the more I like him.

His recent OpEd, "Stem-cell research a pawn in election politics," is an excellent critique of Bush's confused and misguided stem cell policy. Bush's policy, says Caplan, makes a mockery of the moral issues involved:
Not only is the president’s compromise nothing of the sort, his moral reasoning, and that of his defenders, is at best obtuse. Consider these points:

* The president says that embryo destruction is wrong, but still allows research on embryos destroyed before August 2001. Huh?

* The president says that embryo destruction is wrong, but does absolutely nothing to prevent the daily destruction of embryos in fertility clinics across the United States. What?

* The president says that embryo destruction is wrong, but fails to tell us whether he really believes that an embryo destined to be destroyed at a fertility clinic but now residing in a Petri dish is morally on par with a child suffering from juvenile diabetes or a person who cannot walk due to a spinal-cord injury. Huh?

* And the president says that embryo destruction is wrong, but does not tell us what he proposes to do about American scientists heading overseas to conduct embryonic stem-cell research in South Korea, Britain, China or Singapore, and then publishing the results in American journals and seeking American patents. Why?

Furthermore, consider Bush's position on cloning for stem-cell research. Using the techniques involved in creating Dolly the sheep, it is possible to create cloned human embryos for use as a source of embryonic stem cells. But the president has done nothing but vigorously try to ban this method for getting stem cells. While it otherwise has little time for the United Nations, the Bush administration is currently devoting much energy to trying to persuade the world body to ban cloning for the purposes of stem-cell research.
Caplan concludes by arguing that the Bush administration has painted themselves into a corner:
So what is really going on here? What's going on is that the president’s defenders are in a political pickle that they themselves created.

Bush believes that human life and human rights begin at conception even if conception occurs in a Petri dish. The president and his operatives know that their core base of supporters fervently opposes all forms of abortion and agrees that embryos are people from the moment of conception. They also know that the vast majority of American people do not agree with these views.

So, the Bush administration made a political calculation to use opposition to stem-cell research and cloning as a low-risk stalking horse to advance its anti-abortion agenda and secure support among its most avid anti-abortion constituents.
Interestingly, Caplan ends the piece with a moderately partisan outro in which he says, "Whatever your views about the upcoming presidential election, have no doubt about where the candidates stand on this issue — Bush is opposed to stem-cell research, Sen. John Kerry is not."

Hmmmm. I wonder if he has his sights set on the Chair position for the President's Council on Bioethics. Even from here in Canada, I'd love to see Caplan replace Leon Kass. We can only hope.

October 3, 2004

Building a machine designed by ET: not a good idea

I recently re-watched "Contact," the 1997 film adaptation of Carl Sagan's novel of the same name.

In this film, extra terrestrial contact is made, with the ET's transmitting the blueprints to a massive engineering project—supposedly for us to build. After studying the schematics it is determined that it is the outline for some sort of transportation device for a lone passenger. The exact means of transportation is unknown, as is much of the science behind the radically advanced technology.

There is some debate about the safety of embarking upon such a project, including worries about it being a possible Trojan horse or doomsday device, but ultimately the fears are set aside and the device is built at a cost of a quarter of a trillion dollars. [spoiler follows]Of course, the machine is a success, and our heroine gets to go on the thrill ride of a lifetime [end spoiler].

As I reflect on this film, however, I believe the decision to construct the device was the wrong one. Rather, the precautionary principle should have been invoked big time. In general I'm not a big fan of the PP, but in this case I think it would have been warranted.

Without knowing the nature of the transmitting ETs themselves, or even if conscious entities were actually transmitting the signal, there's no way we could predicted ET's true intentions. It very well could have been a Trojan horse; the device could have been deliberately designed to look like a transportation device to fool us into building it, only to turn out to be something far more nefarious instead—like a doomsday device, for example.

Why would ETs do such a thing? Well, the transmission could have been viral. Imagine a malevolent or paranoid civilization (or group or individual) determined to wipe out intelligent life across the Galaxy. They set up a bunch of beacons across the Galaxy that transmit the evil code.

As precedent that intelligences are capable of such a thing, people write viruses here on Earth for no good reason. Perhaps signals such as these are the ultimate manifestation of computer viruses—one information system finding memetic compatibility with another and infecting it. The trouble with such a scenario, however, is that such a code wouldn't replicate and re-transmit. But if the source transmitter remains intact, it would be the Typhoid Mary of civilizations.

So, rather than build the device on sheer blind faith alone (i.e. Not knowing how the technology works, not knowing exactly what the device is supposed to do, not knowing who transmitted it, not knowing why it was transmitted....), I would have suggested that the extra terrestrial schematics be studied, reverse engineered, and modeled to the point were we felt comfortable enough to predict as much of its effects as possible.

And then we could build it.