More Science Talk
Welcome to Science Talk, the weekly podcast of Scientific American, for the seven days back dated to February 20th, 2008, because I actually filed on the evening of the February 21st, well, I'm Steve Mirsky by the way. If you have been breathlessly waiting for this week’s podcast I apologize, I was out of town at a couple of conferences and this week's episode features some highlights from one of them and that's the annual meeting of the American Association for the Advancement of Science, the AAAS, which took place last week in the beginning of this current week in Boston. The other conference was inside baseball, was about the future of science journalism, which is going to be good, thankfully. So, this week on the podcast we'll hear from Nobel laureate David Baltimore about HIV research. We also have an interview with the director of the jet propulsion laboratory, Charles Elachi, and in a real coup, we actually managed to get Scientific American editor Mark Fischetti to come on board and make an appearance. First up, David Baltimore, he is the president of the AAAS and professor of biology at Caltech. He shared the 1975 Nobel Prize for the discovery of the reverse transcriptase. I attended his presidential address to the conference and he spent a few minutes reviewing the effort to create an HIV vaccine. Here's what he said.
Baltimore: When I mentioned AIDS I want to comment on how we can ever expect to reverse the spread of this scourge. The background is I'm sure well known to most of you: there is no AIDS vaccine, there is no hopeful candidate AIDS vaccine, HIV—the cause of AIDS—has evolved to be virtually impossible to attack by antibody and without antibody sensitivity it's pretty well uncontrollable by the immune system. This is a huge challenge, because to control HIV immunologically, the scientific community has to beat out nature, has to do something that nature with its advantage of 4 billion years of evolution has not been able to do. Our lack of success may be understandable but it is not acceptable. Thus, calling an AIDS vaccine a grand challenge is not hyperbole. You might ask, "Why is HIV different from most other viruses?"; "Why can vaccines control so many viruses but not HIV?" The answer is buried in the evolution of the virus. HIV managed to evolve to be immunologically protected. Its code is structurally refractory to antibody inactivation and hosts cellular immune system: these responses don't produce durable control. Virtually no other virus has combined these two modes of immune avoidance. If one virus can do it, why not others, why aren't all the viruses that are out there, like HIV? The answer, I think, is that HIV has chosen a lifestyle different from that of all other viruses. Most viruses don't avoid immune attack and they don't really need to. They carry out a generation of their lives and they get passed on to a new host within the week that occurs between the encounter of the immune system with a new virus and its establishment of an immune reaction to that virus. But HIV, by avoiding immune attack, can establish a chronic infection that the body is unable to eliminate. Interestingly, HIV evolved in chimpanzees and for unknown reasons it does not cause disease in chimps. Thus, this lifestyle they start—immune avoidance—is not much of a liability in its natural host. But when HIV jumped to humans, it found a host where it caused a serious degenerative disease. Thus, we are the victims of a diabolical circumstance. HIV, a benign virus in chimpanzees, came into our lives and produced a disaster. Against that background the vaccine community has tried its best. It initially made an attempt to control the virus through antibodies but found that the virus was quite solidly protected against that mode of attack and it switched [to] striking the other arm of immune protection—the cellular immune system that's never been actually mobilised to protect against a virus—and sure enough, a full-scale clinical trial of the first such candidate vaccine gave no protection. [The] community is still trying this route of attack because it is one of the few natural hopes we have. Some are also still trying the antibody route because it's been so successful against a host of other viruses. But the community is depressed because we're seeing no hopeful route to success. I should add that this depression is not halting development activity. Knowing how crucial it is to get a vaccine, the community of vaccine developers are moving ahead, even recognising the long odds against success. I would point out that none of this work could have been done anywhere between the most technologically advanced countries. It involves the most sophisticated concepts and techniques of modern science and even so hasn't worked. Our only hope may rely in inventing new ways of providing antiviral protection, and under the aegis of the Bill and Melinda Gates Foundation, we are attempting that. I don't want to get too technical but we're trying to combine gene therapy, immunologic therapy, and stem-cell therapy to stimulate an immunologic attack on HIV through new routes. This is truly a grand challenge and we hope that we can make some progress. At least we'll give it a try.
Steve: You can hear the entirety of Baltimore's talk with some very pungent political commentary near the end. It's up at the AAAS Web site, www.aaas.org. That is a-a-a-s.org. The AAAS conference is a real beehive. It is pretty crazy there. Thousands of scientists and hundreds of reporters are all running around to dozens of lectures going on at the same time. So I was able to grab a few minutes with Charles Elachi, the director of the NASA Jet Propulsion Laboratory in Pasadena, as we rode an escalator and walked through corridors going from one talk to another one.
Steve: Dr. Elachi, thanks for talking to me.
Elachi: It's my pleasure.
Steve: People have all heard about the Jet Propulsion Laboratory. What's the actual role of the JPL today?
Elachi: The JPL is one of the 10 NASA centers, and our focus is mostly on planetary exploration and we do some astrophysics and Earth science, all using robotic spacecrafts.
Steve: Right, this is completely unmanned. The JPL has never...
Elachi: That is correct, that's correct, that's our expertise.
Steve: What are some of the really exciting—other than the Mars rovers that we have done a lot with—what are the some of the exciting missions that are currently going on and what's envisioned for the next few years?
Elachi: Yeah! We have a whole spectrum of missions. Let me give you a couple of examples. One, in the case of Mars, we have a spacecraft heading to Mars which will land close to the North Pole on April 25th and that will be looking, actually trenching in the surface and measuring the composition of the surface. We have a spacecraft that we are planning now to go to Europa and Titan and look for potential, you know, habitable environment—not necessarily humans living there, but really understand the ocean microbes and so on. Some of the particularly exciting missions is are to look at the neighboring few thousands stars and see if there are planets around them. In particular, we are interested to see, are there planets similar to our planets? So, we'll be able to take what we call the family portraits of the planetary systems and then we have a number of missions, which we are planning for Earth studies to allow us to get a better understanding of the global change in the atmosphere or the surface of the oceans and hopefully help policy makers in making decisions about the future of our planet.
Steve: Let's talk about that a little bit; the relationship between the work that people usually consider to be astronomical work and Earth science and environmental science.
Elachi: Yeah! I think with those things, there is a lot of complementarity. Because we develop techniques for doing astronomical or planetary studies and by understanding better how other planets evolved and the technology that we use to observe other planets, we can apply it to our own planet. So, in the case of, for instance, us at JPL, most of our past experience was in planetary exploration but now we spend—almost one quarter of our activities are Earth related and we're using the same techniques that we studied Venus and Mars, we are applying them to Earth.
Steve: Tell me just a little bit, how did you get involved in this whole field?
Elachi: (laughs) Since I was a kid, I used to sit down and watch the stars and get always fascinated by the beauty of the sky, and somehow I liked science and by pure chance I ended [up] going to Caltech in California and as you know JPL was part of Caltech and somehow I went to work while I was a student, you know, and I thought, I'll work for a year, and here 35 years later I'm still there and having great fun.
Steve: Why do you think, I mean every little kid loves looking at the stars or loves looking at dinosaurs, but very few of them become palaeontologists or the director of the JPL. (laughs) Why do you think that you did?
Elachi: Well, I think you really have a…again it depends on what you love doing in your life. I'd say every discipline is exciting. If you are an artist, if you are a philosopher, if you are an engineer, if you are a lawyer it all has its own fun. The key thing is, what do you enjoy doing in life? And for me it turned out, you know, doing exploration is something I enjoy. I look forward everyday to go[ing] to work and I enjoy doing it.
Steve: That's a little nosy, but you really just followed what you love to do until it brought you where you are?
Elachi: That's what I tell everybody is just do the things you love, you know, and you'll do very well at them and...
Steve: And get good at them.
Elachi: That's right., I mean you have to do work hard work but you have to love the things you are doing and there's a role for everybody. It's important to be technologically knowledgeable because we are in a very advanced technological society, but you don't have to be a scientist or an engineer because we need talent across the board.
Steve: Thank you very much for speaking to me, especially under these conditions. I appreciate it. (laughs)
Elachi: Sure, you are welcome.
Steve: We'll have a lot more on the Mars rovers within the next few weeks. The jet propulsion laboratory Web site is www.jpl.nasa.gov
Now it's time to play TOTALL…….Y BOGUS. Here are four science stories, only three are true. See if you know which story is TOTALL…….Y BOGUS.
Story number 1: Researchers have found a fossil of a bat species that was for all intents deaf.
Story number 2: Another fossil story, fossil remains of what may be the smallest frog that ever lived. It would have been about the size of a grain of rice.
Story number 3: A man following the instructions from his onboard GPS unit drove his car onto railroad tracks where it was obliterated by a train.
And story number 4: Altruism and war probably had to evolve together for either to exist.
We'll be back with the answer but first, as I said, there were dozens of lectures happening simultaneously at the AAAS conference, so when I saw that SciAm editor Mark Fischetti was there on Friday, I figured we could get more bang for the buck if I got a brief summary from him about the sessions he had attended.
Steve: Hi, Mark, how are you?
Fischetti: Hi, Steve, I'm doing well.
Steve: You must be pretty beat. You've spent a full day at sessions here at the AAAS meeting.
Fischetti: Actually, I learnt quite a lot today. I came in expecting to hear mostly discussions about what's going wrong and how things are getting worse with the environment because that seems to be the major focus here. And I did hear plenty of that and some surprising things, but there was good news at the end of the day.
Steve: What was it?
Fischetti: Well, there seems to be real hope amongst people who really study what's going on in Congress [is] that the legislature is actually taking climate change seriously enough that there are quite a number of bills proposed to help mitigate consequences and try to keep down the amounts of greenhouse gases and other pollutants that are being emitted. That's quite a change and they even sort of admitted that's quite a change and I wasn't aware myself how much legislation is actually out there to be considered. The other nod of hope was that the outgoing head of the AAAS was in this session on legislative initiatives and its shaping up now that the four biggest emitters in the world are, U.S. first, China second but by next year China will ride over the U.S., India fifth but they will soon be third and Brazil fourth.
Steve: Brazil? Really?
Steve: Because we hear so many things about Brazil and their automobiles that run on sugarcane.
Fischetti: Right! The first three countries, their great contributions are from burning fossil fuels. However, for Brazil the mass contribution comes from deforestation, burning down the forests. You know, you have a tree's worth of carbon going up in the atmosphere, in our terms, millions. But the good news part was that the head of the AAAS was at the Bali discussions a few weeks ago and the very high elected officials from all those other countries were there and all of them seem to be taking seriously their responsibility for their country to cut emissions, and there's actually been...the president of Brazil and high legislators from India and China all said that they are starting government initiatives to reduce emissions. Now, that's not just happened before. So, that's actually pretty encouraging.
Steve: Right. The fact that people are talking about it at that level is a new thing.
Fischetti: Right. Talking and committing saying, you know, we are just not there recognising the problem, we are going to have a legislation and you know, in these sorts of countries when the head of the country or a high up person says, we are going to have initiatives, they are going to have initiatives. It is a directive, essentially. (laughs) So, that's great.
Steve: So, what other sessions did you attend today?
Fischetti: I started this morning on a session on ocean acidification, which was very sort of smartly titled, subtitled, the other carbon dioxide problem. All the talk about carbon dioxide is in the atmosphere, but roughly half of the carbon that is emitted into the atmosphere is actually sunk into the Ocean, if you want to think of it that way the ocean absorbs. I didn't know that either. Roughly half of all the emissions currently are absorbed by the oceans. Well, what happens is by absorbing that much carbon dioxide, the ocean chemistry changes gradually and the pH of the ocean is starting to lower slightly but it only takes a couple of tenths of a percent drop in pH to significantly alter the entire animal chain in the ocean, if you want to think of it in that way.
Steve: And the flora, the plants as well change.
Fischetti: Right, right. I mean, the corals around the world are already starting to bleach. The numbers are, roughly 8.2 must be the geological pH of the oceans.
Steve: 8.2 pH
Fischetti: Yeah, right. And it's roughly 8.1 now and the models are showing by 2050 or 2100 it could be down to 7.8.
Steve: Wow. I mean, when you consider the volume of water you are talking about to change the pH by even a tenth of a point is really unbelievable to make.
Fischetti: Right. It's significant and that's all it takes to really change the entire food chains essentially and the most interesting thing I learned was, you know, you hear about coral, you hear about fish, but all the microorganisms in the water, there is migration that happens on a daily basis. There is this enormous density of microorganisms at nighttime [that] are down in the deeper water. They migrate up to the surface during the daytime to feed and for better respiration and then they sort of sink down again at night.
Steve: Better respiration because there is more oxygen dissolved in the water.
Fischetti: Yeah, right, more oxygen there. They sort of have this cycle where they need to essentially oxygenate once a day, roughly, and this is to generalise but I had never thought of it but you can visualise this heavy (unclear 17:00) of microorganism kind of flowing up towards the surface and then sinking down at night. So, this one-tenth or two-tenth change in the pH radically changes their metabolism, their ability to metabolize oxygen, which essentially would either force them lower and lower or will just wipe them out and if that happens, then, you know, the entire ocean's life cycle might not sustain.
Steve: So, that was your first session you attended. (laughs) How many sessions did you attend?
Fischetti: Five or six, actually.
Steve: What were some of the other highlights that you did?
Fischetti: Another interesting highlight had to do with climate economics. It gets to be a tough subject but the basic bottom line is, you can propose all you want about what to do with the environment but on a realistic level it is going to make some sort of economic sense, meaning, if you are going to spend tons of money, you have to have some sort of assurance that is going to be worth it and that's where economist get in to play and there's been a lot talk about it in the last year or even two about what economic models to use to inform policies as to when certain investments make sense or not.
Steve: When I was just in a session myself on communicating science to the public and one of presenters made reference to something I had never heard about before but it was pretty funny. He was talking about how President Truman wished he could find a one handed economist.
Fischetti: Right, right. (laughs) Well, he wouldn't have found one here either, I am sorry to say. Well, there was one good piece, I won't use names pro or against on anybody in the panel, but there was one economist in the panel who was trying, and with some success, to kind of convey the bottom line in English and he made one interesting point. The bottom line in the economic models when you understand them is that if you look out to 2050, much less 2100, the models all say you really can't justify doing anything on a major scale because you don't know 50 years from now how much you should use now, what the real effects can be. This is uncertainty, which is the essential ingredient in these models. You can't define what the uncertainty will be because it is too long a period. So, it's hard to say that any economic model whatever makes it seem worthwhile to do anything on a massive scale. So then what? Right, so that led to a lot of pessimism but one economist stood up and said, if you took the best models we have now and went back to 1905 and said, okay we're going to apply these models to what we should do in terms of electrifying the country and in terms of trying to stimulate a real sustainable automobile industry and if you did that in 1905, if you tried to apply them they would have essentially said it's impossible; it's impossible to subsidize an automobile industry and know you are going to succeed. It's impossible to say that then money would cost to electrify United States will be worth it, so don't do it because we can't tell you it's worth doing and let it happen. You know, by 1950 most of the countries were electrified and there were automobiles everywhere. So, as a little bit of levity to say that, at some point he was saying, you know, you sort of go and throw out the economic models and just start doing things.
Steve: That's really good stuff, Mark. Thanks a lot.
Steve: In the coming weeks on the podcast you will hear some of the other interviews I did from the conference about subjects ranging from altruism to baseball statistics to spiders, and the February 15th through 21st episodes of the daily SciAm podcast, 60-Second Science are based on sessions at the AAAS conference and on the Knight Science Fellowship Symposium on the future of science writing. They are all on the podcast page, www.SciAm.com/podcast, and over at iTunes.
Now it's time to see which story was TOTALL…….Y BOGUS. Let's review.
Story number 1: Bats species was deaf.
Story number 2: Frogs species was tiny.
Story number 3: Guy follows car's GPS instructions onto railroad tracks.
Story number 4: Altruism and war co-evolved.
Time is up.
Story number 1 is true. What's now the oldest know bat species probably couldn't navigate by echolocation the way modern bats do. The new oldest bat fossil was described in last week's issue of the journal Nature. So, it looks like bats first took to the air, then evolved the ability to hear their way around.
Story number 4 is true. Computer models show that altruism couldn't evolve without war also becoming entrenched and vice versa. That's according to research published by Jung-Kyoo Choi and Samuel Bowles last fall in the journal Science. Bowles discussed the research at the AAAS conference last week where I learned about it. I interviewed him about it and will play that interview on an upcoming podcast.
Story number 3 is true. Last month, a visitor to the New York metropolitan area trusted his GPS unit when it told him to make a right turn that put him on to a railroad track just north of New York City. He fled on foot in time to escape the total destruction of his car by a Metro North commuter train. That's according to the Westchester Journal News. A spokesman for Garmin, the largest GPS seller in North America, wisely noted that, "GPS is no substitute for common sense".
All of which means that story number 2 about the tiny frog is TOTALL…….Y BOGUS. But what is true is that researchers recently found the fossil remains of a frog that was probably about 16 inches across and weighed 10 pounds, making it probably the biggest frog that ever lived. The find was announced in the Proceedings of the National Academy of Sciences. The fossil was found in Madagascar but appears closely related to other frog species that were found in South America. So, it's also evidence for a long-lost bridge between those land masses. You can find check out illustrations of the frog in the photo gallery at www.SciAm.com. Scientists have dubbed the fossil Beelzebufo ampinga, which translates to an armed frog from hell.
Well, that's it for this edition of the weekly SciAm podcast. You can write to us at podcast@SciAm.com and check out numerous features at www.SciAm.com including slide shows, the hot topics, and the many many many fascinating comments left by your fellow readers and listeners that you can add to. For Science Talk, the weekly podcast of Scientific American, I'm Steve Mirsky. Thanks for clicking on us.