Boyle’s interview with Stern comes on the heels of an IAU announcement on June 11, 2008 in Paris that objects like Pluto will henceforth be called plutoids. The suffix oid is often used in the sciences to mean something similar, not necessarily exact, to something else. The IAU says:

Plutoids are celestial bodies in orbit around the Sun at a semimajor axis greater than that of Neptune that have sufficient mass for their self-gravity to overcome rigid body forces so that they assume a hydrostatic equilibrium (near-spherical) shape, and that have not cleared the neighbourhood around their orbit. Satellites of plutoids are not plutoids themselves, even if they are massive enough that their shape is dictated by self-gravity. The two known and named plutoids are Pluto and Eris.

According to this definition, Pluto is similar, not necessary exact … to itself? If IAU scientists had training in language skills, maybe the strange case of Pluto wouldn’t be. But strange it is. According to the IAU’s definition, it’s Pluto’s failure to clear the neighborhood around its orbit that caused it to lose its planet status, and that still has S. Alan Stern steaming. For example, Alan said:

In fact, the IAU definition doesn’t come close to allowing Earth to be a planet …because of the near-Earth objects, the Earth is technically disqualified. But even if you could forgive that … and clear up the language, the issue is that as you go farther and farther away from the sun, the equations that describe the mass required to “clear a zone” show that the objects have to get more and more massive. So Mercury qualifies in Mercury’s orbit, but Mercury would not qualify in Earth’s orbit. Earth might qualify in its current orbit, but if we put the earth where Pluto is - in other words, if Pluto were the mass of the earth - it still wouldn’t qualify.

Food for thought. And to me the image immediately above and right says it all. That’s Pluto at the center of its own planetary system with its large moon and two known smaller moons. As Alan likes to say, if it looks like a dog and barks like a dog, it’s a dog … even if it’s a chihuahua.

Of course, Alan is just one passionate astronomer (and, don’t forget, lead scientist for the first space mission ever to explore Pluto, due to arrive in 2015), but he says other astronomers care as deeply about this issue as he does, and there’s no doubt the public cares. For our part, EarthSky ran a text and chart today focused on Pluto’s annual opposition - when it is opposite the sun from Earth - and viewers have already begun spontaneously commenting on Pluto’s lost planet status.

That’s because, even to us laypeople, the IAU’s decision still rankles. When the IAU took away Pluto’s planet status - thereby reducing the number of planets in our solar system from 9 to 8 - it effectively pulled in our solar system’s outer boundary as seen in the imaginations of most of us. Sure, the solar system is no different than it was before, but school children - and in fact most adults - won’t pick up on that subtlety. The IAU pulled our collective horizon in … and that’s not what astronomy is supposed to do.

What do you think? Should Pluto be re-instated as a planet?

Pluto Believe poster above copyright 2006 mythoslegends.com. Illustration by Pat Rawlings. Used with permission.

Or if you don’t believe the US Census Bureau, you can check out a similar clock that the United Nations produced while marking the global Day of 6 Billion. The UN marked that day on October 12, 1999, and the UN’s population clock is keeping similar time to the clocks of the US Census Bureau.

Of course, neither the US Census Bureau nor the United Nations really knows the number of humans alive today. That number is not knowable. Even the number of humans in the US alone is not truly knowable, although EarthSky participated in the huge fanfare accompanying the arrival of the 300 millionth American in October, 2006. These numbers in the U.S. are determined by good old-fashioned census-taking, plus computer modeling. The last U.S. census was in 2000, and another one is not due until 2010. Do people really tell the truth in a U.S. census? I guess there’s no reason not to, although I can imagine young people - in my daughters’ irreverent generation - not being entirely honest when they enter the ‘number of people in household’ box on a census form.

Of the global numbers displayed on the World POPClock, the Census Bureau says:

(The numbers are) not intended to imply that the population of the world is known to the last person. Rather, the clock is our estimate of the world population size and an indication of how fast it is growing. According to (Census Bureau) estimates, the world population reached 6 billion on July 27, 1999, at about 3:03 AM GMT (July 26 at 11:03 PM EDT). Because of the uncertainties of the estimates, and the fact that we are constantly updating our estimates, the estimate of when 6 billion was hit will change.

There’s also an often-quoted number - 9 billion - predicted as the number of humans on Earth by the year 2050. And there are many many interesting stories related to what happens before and after that 9 billion mark - which we humans are now steadily plodding toward, most of us with our collective heads aimed firmly down at our feet and not at the road ahead. Population movements across Earth’s surface will be one major factor in any given country’s population. Many agree that women entering the workforce in greater numbers - and having greater control over their own bodies and family sizes - will be a major influence on declining fertility rates. Last time I looked, the United Nations was including the possibility of a global pandemic in its population estimates, but few non-experts realize how little even a large pandemic would slow us from reaching that 9 billion mark by mid-century.

By the way, EarthSky is working behind the scenes now toward making podcasts featuring scientists speaking about population issues. We have a terrific partner in this proposed project, the Population Reference Bureau, whose website already has much to offer on the movement and increase of Earth’s humans. Population is a favorite subject of EarthSky’s, since spending some years in the early part of this century grappling with the concept of a human world and with the 21st century scientific revelation that humans and Earth are coupled in a very profound way.

To me, sitting in my editor’s chair at this website, it sometimes seems as if we humans are in a race. The race is between our own burgeoning population numbers, and our political and technological will to solve the problems that come with increasing population. Will we as a species come to recognize our connection to nature and learn to live in a way that’s sustainable? I wonder how my two daughters - still childless, but both now firmly in their childbearing years - feel about bringing children into such an uncertain world.

In case you haven’t been watching, here are the population estimates since July of 2007, according to the world POPClock.

07/01/07 6,600,411,051
08/01/07 6,606,949,106
09/01/07 6,613,487,162
10/01/07 6,619,814,313
11/01/07 6,626,352,369
12/01/07 6,632,679,520
01/01/08 6,639,217,576
02/01/08 6,645,755,632
03/01/08 6,651,871,878
04/01/08 6,658,409,934
05/01/08 6,664,737,085
06/01/08 6,671,275,141
07/01/08 6,677,602,292

The photo at left is from TheAlieness GiselaGiardino²³’s photostream. It’s called Praying for Time.

The photo in the middle of this post is called The Road Ahead. It’s from advencap’s photostream.

“It’s not all bad,” I piped up, which caused the friend to turn in my direction for the first time. “Of course it is,” he said and began talking about a speech made a few days ago by UN Secretary-General Ban Ki-moon at last week’s United Nations’ Food Summit in Rome, calling for a sense of urgency in the fight against global hunger. The friend mentioned the World Bank’s definition of extreme poverty as living on less than U.S. (PPP) $1 per day, and moderate poverty as less than $2 a day. Half the world lives on less than $2 a day. There have been news stories about recent food riots, like the one pictured here in Bangladesh. There have been stories - even here in the U.S., one of the world’s most food secure nations - asking whether we could really run out of food.

And food is just one of the many pressing issues facing our world. Yet … it’s clear to me, every day, that some of the smartest people in the world are working hard to solve the very difficult issues facing us here at the beginning of the 21st century. Around here, we spend our days listening to some of these great minds, people of goodwill, talking about their work on global problems: eliminating poverty, securing food and fresh water for all 6.7 billion of us, exploring alternative energy sources, preserving global health and biodiversity.

In the 1960s, when people my age were young, there were half as many people on Earth as today. Back then, we knew of course that global population was growing rapidly, and it was a bit of a scary thought. But we used to say, “Well, sure, there will be lots more people … but there will be lots more smart people, too.”

That has turned out to be true, and hearing them talk about their work is what continues to give me hope for the future.

The picture at the top is from Aussiegall.

EarthSky’s core purpose is to be a clear voice for science. But in my three decades of doing this work, I’ve watched science move from a more central place in society to a place at society’s fringes. Is global warming real? Are genetically modified foods bad for us? Did evolution happen, and is it still happening? How will our energy needs for the future be met? Will there be enough food and fresh water? In the past, when scientists answered these questions, people seemed more likely to believe them.

Now - while pressing questions like the ones above loom - many trends are contributing to a modern misunderstanding of science, with perhaps none so great as the outcome of scientific research itself, which is simply a better life for all of us. Overall, the standard of living around the world in the past decades has increased, and with that increase has come more freedom across every sector of society, more choices, and more niches filled with people pursuing their interests among others who are like-minded. Media has fragmented and evolved. There’s an Internet, with its many voices. More than ever, the voice of science has to speak loudly to be heard.

That’s what we do, here at EarthSky. Our aim is to use new media to shine a light on scientific activities that lie close to the heart of humanity’s ability to sustain itself on Earth. High falutin’ words, but I really believe that we need the tools of science to navigate the perils of this century. Do you agree?

If it’s true that the tools of science are necessary for humanity, then why has science moved from society’s center to its fringe?

What EarthSky does is produce podcasts - both long and short audio podcasts - featuring the voices of scientists themselves. We’ve interviewed and presented the voices of literally thousands of scientists since 1991, and many have continued to work with us as global science advisors. We also have a a large distribution network - with our podcasts heard some 12 million times each day. And … that number is growing.

With this large broadcast network - built bit by bit over the past 17 years and reaching millions each day - EarthSky is trying to help ensure that the scientific perspective remains part of the human conversation.

So how are we doing? Do you think EarthSky’s core purpose - being a clear voice for science - is worthwhile? Do you like hearing from scientists directly? What do you think about the role of science in the world today? Why do you think science has moved from the center to the fringes of human culture? Please share your thoughts below.

Btw, the photo at right is called Stopping to Think. It’s from Envios‘ photostream.

The photo at top is called Do You Believe in Change? It’s from Carf’s photostream.

Earth was 88 million miles from Mars - nowhere near the closest possible distance between our two worlds - when the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter took this image.

Notice the clouds on the Earth image. NASA scientists say they could make out the west coast outline of South America at lower right, but I couldn’t see it. These scientists also pointed out that Earth’s clouds are so bright, in contrast to our dull gray moon, that the color image of Earth required a fair amount of processing to make a nice-looking release. The moon image has been brightened relative to Earth for this composite.

So that’s the Earth and moon from Mars. Want to see Mars with your own eyes from Earth? Try this chart.

Image credit: NASA/JPL-Caltech/University of Arizona

Original source: Earth and moon seen from Mars from NASA

So says the United Kingdom’s World Cancer Research Fund, whose website carries the tagline “pioneers in cancer prevention.”

The WCRF UK examined 7,000 existing studies over six years to create what they call “the most comprehensive investigation ever into the risks of certain lifestyle choices.”

The result? According to the WCRF UK, everyone should aim to be as thin as possible without becoming underweight, in order to decrease the risk of cancer.

The Body Mass Index (BMI) is a calculation which takes into account height and weight. A BMI of between 18.5 and 25 has been considered a “healthy” weight range. But the new report says that risk increases as an individual heads towards the 25 mark, and that “everyone should try to be as close to the lower end as possible.”

The WCRF UK report includes more specific recommendations for cancer prevention.

Limit red meat
Limit alcohol
Avoid bacon, ham, and other processed meats
No sugary drinks
No weight gain after 21
Exercise every day
Breastfeed children
Do not take dietary supplements to cut cancer

These are recommendations, say the report’s author’s, not commandments. For the most part, I like them and agree with them. They sound sensible. We all know that it isn’t healthy to be overweight, and, unless you’ve been living on the moon, you know that obesity has become a critical public health problem in the U.S. and the rest of the developed world.

But no weight gain after 21? Right.

I have to wonder if this report took the difference between male and female physiology into account. To me, older women look better - healthier - when they are a little heavier. I know I feel in many ways stronger now - with a few extra pounds - than I did when I was my daughters’ ages (24 and 27) and very thin. I have a BMI of 24.2, by the way. Getting down “as close as possible” to a BMI of 18.5 would require me to go back to the weight I had at age 12.

What’s more, thinness is a risk factor for osteoporosis, the disease in which the bones of older women (and men) become less dense and break more easily. My grandmother was one of many women of her generation who died after breaking a hip and, essentially, never getting up again. According to the National Osteoporosis Foundation website, bone structure and body weight do play a role in osteoporosis, with “small-boned and thin women (under 127 pounds) … at greater risk.” Plus, we older women like to remind each other that fat cells hold a little estrogen, with its ability not only to protect the bones but also to relieve menopausal symptoms.

As the BBC article points out, many cancers are not thought to be related to lifestyle. But the report’s authors say that - of the 10 million cases of cancer diagnosed across the world each year - perhaps three million could be prevented if the recommendations were followed. Saving three million lives would be a good thing. On the other hand, you could always deny yourself red meat, alcohol and so on, become very thin … and still get cancer.

The WCRF UK study is interesting. But, knowing a bit about Asian thought, I’ll stick to the advice of the ancient Chinese philosophers: practice moderation.

Read the BBC article: Be thin to cut cancer, study says

Read the full report from the United Kingdom’s World Cancer Research Fund

Photo credit: Thou Shalt Have No Other Food Before Me image by Flickr user Frengo. Used with permission.

And he’s off to a great start, with an interesting turn of phrase, a new way of thinking about global population, in a post that he calls the population cluster bomb. The idea is that Earth’s population isn’t moving in the direction suggested by the 1960s book by Paul Ehrlich titled The Population Bomb … which presented the essentially Malthusian idea that world population would keep growing and growing and GROWING toward catastrophe. I was there in the 1960s, and I remember holding The Population Bomb in my hands and believing it, as many did … but I was wrong.

Instead, as Revkin points out:

What (population experts now) depict is more like a dangerous scattering of cluster bombs, as the world splits into two types of countries: those with aging, shrinking populations, like Japan and much of Europe, and those regions, like most of Africa and parts of south Asia, still mired in poverty, disease, illiteracy or government dysfunction with resulting high birth and death rates.

In other words, some countries’ populations are expected to keep increasing, while others decrease. Overall, the rate of population growth - across the entire Earth - continues slowing down so that, by the time our children’s children arrive at the year 2100, the overall number of humans on Earth should be even smaller than now. When I first heard this idea, it surprised me. A shrinking world population? This possible outcome (surely, no one knows what will happen) is something that I - in my teens, reading Ehrlich’s book - never contemplated. World population may stabilize.

The idea of a population cluster bomb (what a great description) means that, despite ourselves, birthrates are already falling in some places on Earth, if not in all. Why not all? Because the key for falling population rates seems to be wealth and urbanization. As nations become wealthier and more urbanized - as people forsake the agricultural lifestyle for cities - they apparently begin to think that two children are enough. Women play a pivotal role, because as women become more educated, become wage-earners, have more power within the family and ultimately take our places alongside men as true equals, most women opt to have fewer children.

Revkin spends most of his blog post on the population cluster bomb speaking with demographer and sociologist Joseph Chamie of the Center for Migration Studies. It’s a fascinating interview. Check it out.

In the meantime, tell me what you think. Do you agree with population experts? Will Earth’s population be able to stabilize by the end of this century? And, if it does, what sort of world will that be?

Photo credit: Thanks to the European Parliament which points out that many people want to have their say.

This comet has become an amazing sight, even in urban skies. The comet is easily visible to the eye alone. I spotted it easily both Friday and Saturday nights this weekend while walking in downtown Austin, Texas, a city of nearly one million inhabitants. How can you recognize it? Unlike some comets, Comet Holmes doesn’t have a tail. It’s a round fuzzball of a comet … distinctly not a star. It’s in the northeast in the evening and, as long as you’re in the northern hemisphere, it’s visible somewhere in the northern sky throughout the night. Just look! Look for the round fuzzy object that doesn’t look like a star.

For more detailed instructions on how to spot it, check out this article: A Halloween comet and a ghoul star.

I’m pretty sure that if I showed this comet to my 24-year-old daughter, Joni, she’d be unimpressed. No long, dramatic comet tail. No explosions. No real-time brightness surges, optimally with sound effects … whaaaaooo, whaaaoooo …

Nothing but a silent fuzzball, bright enough to see in city skies.

And yet to me - maybe to all of us who watch this skies - this is a wonderful event. The sky changes with the seasons, the planets brighten and dim, the moon waxes and wanes on its monthly journey across the heavens. The sky is ever-new to me, but there’s also something changeless about it, a sameness, a familiarity, like an old friend. So when something like this happens - a comet visible to the eye where no comet was before - it tugs at the heart.

People who watch the skies with telescopes see comets all year long. We who watch with just our eyes see them come and go in our skies, with years in between naked-eye comets. Our ancestors saw comets as omens. We know them as mysterious visitors from the deep freeze of the outer solar system, and we send our spacecraft to land on them and probe their icy surfaces. We know they become visible to us only when they swing in toward the sun - some every few years, some only once in thousands of years - and that the characteristic comet tail comes from ices and dust boiling off their fragile surfaces as they draw near the sun.

Most comets are faint. I don’t recall a comet like Holmes that has brightened so much, so fast. Comets tend to brighten gradually as they draw near the sun that binds us and them in orbit. On this return trip near the sun, Comet Holmes had been watched by astronomers with telescopes since July of 2007. Then, on October 24, it just went pop into easy visibility. Now you don’t see it. Now you do.

Don’t miss this one.

Photo credit: Joe Zajac and the Harvard-Smithsonian Center for Astrophysics.

A Halloween comet and a ghoul star

Comet reports and images from the Harvard Smithsonian Center for Astrophysics.

Comet reports and images from Spaceweather.com

17PHolmes from Gary Kronk, comet expert.

Realize that 2 billion is a mind-bogglingly large number. The global population is now about 6.6 billion, with 9 billion expected by 2050.

The question posed by the PRB is whether India will reach a population of 2 billion by 2100 … but realize that by then world population will probably have dropped, with some countries losing as much as 40% of their populations as soon as 2050, according to an earlier PRB study. So if India has a 2 billion population by 2100, does that mean this single land area - only 2.4% of the total land area on Earth - will have more than one-third of Earth’s inhabitants? According to the PRB’s recent report (pdf), India may or may not reach a population of 2 billion by 2100. So, clearly, we’re on speculative ground here. Still, the possibilities are … strange for the future world.

The CIA World Factbook reports that India has a population of approximately 1,129,866,154 people, according to a July 2007 estimate. It’s already the world’s second-most-populated country next to China. The earlier PRB study - described in this BBC article from 2004 - suggested that India will overtake China in population in this century. That would make India the country on Earth with the biggest population.

The culprits in this impending population boom in India are young Indians alive today, under the age of 15. This group represents something like 30% to 40% of people in India. Imagine them at child-bearing age - and their offspring to come - populating India’s future. In other words … tick, tock.

India now supports about one-sixth of the world’s entire population, and India has 32 cities with a population over 1 million. That’s in contrast to only 9 cities for the U.S. with a population over 1 million. And, again, India’s inhabitants and their cities occupy only 2.4% of the world’s land area, a land area that is hemmed in on top by the mighty Himalayas.

Carl Haub of the Population Reference Bureau answered questions about India’s population online last week. He pointed out that India’s population is being controlled somewhat now, since a population policy instituted in 1952. He said that, in most Indian states, the child-bearing rate for women is now less than 3 children. But there is still a large rural population in India, and Haub said ” … sadly, many women in rural areas have little say on their own childbearing.”

With increasing population, India’s demographics are destined to change. The population should shift increasingly into cities, as has happened elsewhere on Earth. A more urban world is a less populous world, since children are not needed to work on farms.

Among other things, Haub said:

Societies in the south of India are very different from the north.

Son preference is deeply-rooted for reason of support in one’s old age and to officiate at one’s funeral.

Providing really effective reproductive health information and services in the villages, trying to involve men, and providing non-agricultural jobs in certain states should help fertility rates drop.

India’s fertility rate is actually declining now, although slowly.

By the way, don’t forget that India is not far behind China now in having the world’s largest population, with the U.S. is a distant third. India and China both have populations of over a billion already. The U.S. population is just over 300 million. When will India overtake China in leading global population? No one knows, of course, but many online sources seemed to agree it could happen by 2050, or sooner.

The portrait of India’s burgeoning population seems very poignant to me partly because, in recent years, I’ve become a big fan of novels from India. If you haven’t read A Suitable Boy by Vikram Seth or A Fine Balance by Rohinton Mistry, you should. Almost as deeply as if you had visited, these works of fiction reveal an emotional quality to India, a quality of color and tradition, quiet humor and passion, ancient gods, family, a stratified society where rich, middle class and poor people still seem to encounter each other.

Maybe that’s because India is so crowded.

Picture credits: Mosaic and Taj Mahal by Flickr user foxypard4. Population map of India from Wikipedia Commons.

Read more:

Will India’s Population Reach 2 Billion?

World Fact Book entry on India.

“The harm to water quality could be considerable, and water supply problems at the regional and local levels could also arise,” according to the report, which is titled Water Implications of Biofuels Production in the United States. It was written by a committee of the National Research Council that examined policy options and looked at new agricultural techniques and technologies that could help minimize the effects of biofuel production on water resources.

As oil prices have increased, corn ethanol production has expanded dramatically, and there is high interest in further expansion over the next decade, says the report. For example, in the 2007 State of the Union address, President Bush called for the production of 35 billion gallons of ethanol by 2017, which would equal about 15 percent of the U.S. liquid transportation fuels.

The National Research Council committee looked at how shifts in the nation’s agriculture to include more energy crops - and potentially more crops overall as population rises - could affect water management and long-term sustainability of biofuel production.

The committee found, for example, that the quality of groundwater, rivers, and coastal and offshore waters could be impacted by increased fertilizer and pesticide use for biofuels. It also noted that agricultural shifts to growing corn and expanding biofuel crops into regions with little agriculture - especially dry areas - could “change current irrigation practices and greatly increase pressure on water resources in many parts of the United States.” According to the report …

Water demands for drinking, industry, and such uses as hydropower, fish habitat, and recreation could compete with, and in some cases, constrain the use of water for biofuel crops in some regions. Consequently, growing biofuel crops requiring additional irrigation in areas with limited water supplies is a major concern.

As for non-corn ethanol (for example, ethanol made from switchgrass and native grasses), the report noted that there are “fundamental knowledge gaps” that prevent making reliable assessments about those crops’ impact on water resources.

What are the new technologies and techniques that could prevent ethanol production from impacting water quality and availability? While difficult to predict all future technologies, the report mentioned that, for example, genetically modified crops might use less water and/or fewer pesticides.

Read a news release from the National Research Council.

Find the full report.