Tagged with “long now” (65)
The darkness of dark matter and dark energy
All that we know of the universe we get from observing photons, Natarajan pointed out.
But dark matter, which makes up 90 percent of the total mass in the universe, is called dark because it neither emits nor reflects photons—and because of our ignorance of what it is!
It is conjectured to be made up of still-unidentified exotic collisionless particles which might weigh about six times more than an electron.
Though some challenge whether dark matter even exists, Natarajan is persuaded that it does because of her research on “the heaviest objects in the universe“—galaxy clusters of more than 1,000 galaxies.
First of all, the rotation of stars within galaxies does not look Keplerian—the outermost stars move far too quickly as discovered in the 1970s.
Their rapid rate of motion only makes sense if there is a vast “halo” of dark matter enclosing each galaxy.
And galaxy clusters have so much mass (90 percent of it dark) that their gravitation bends light, “lenses” it.
A galaxy perfectly aligned on the far side of a galaxy cluster appears to us—via the Hubble Space Telescope—as a set of multiple arc-shaped (distorted) galaxy images.
Studying the precise geometry of those images can reveal some of the nature of dark matter, such as that it appears to be “clumpy.”
When the next-generation of space telescopes - the James Webb Space Telescope that comes online in 2018 and the WFIRST a few years afterward, much more will be learned.
There are also instruments on Earth trying to detect dark-matter particles directly, so far without success.
As for dark energy—the accelerating expansion of the universe—its shocking discovery came from two independent teams in 1998-99.
Dark energy is now understood to constitute 72 percent of the entire contents of the universe.
(Of the remainder, dark matter is 23 percent, and atoms—the part that we know—makes up just 4.6 percent.)
But when the universe was just 380,000 years old (13.7 billion years ago), there was no dark energy.
But now “the universe is expanding at a pretty fast clip.”
Natarajan hopes to use galaxy-cluster lensing as a tool “to trace the geometry of space-time which encodes dark energy.”
These days, she said, data is coming in from the universe faster than theory can keep up with it.
”We are in a golden age of cosmology.”
Feeding the world (and saving nature) in this populous century, Jane Langdale began, depends entirely on agricultural efficiency—the ability to turn a given amount of land and sunlight into ever more food.
And that depends on three forms of efficiency in each crop plant: 1) interception efficiency (collecting sunlight); 2) conversion efficiency (turning sunlight into sugars and starch); and 3) partitioning efficiency (maximizing the edible part).
Of these, after centuries of plant breeding, only conversion efficiency is far short of the theoretical maximum.
Most photosynthesis (called “C3“) is low-grade, poisoning its own process by reacting with oxygen instead of carbon dioxide when environmental conditions are hot and dry.
But some plants, such as corn and sugar cane, have a brilliant workaround.
They separate the photosynthetic process into two adjoining cells.
The outer cell creates a special four-carbon compound (hence “C4“) that is delivered to the oxygen-protected inner cell. In the inner cell, carbon dioxide is released from the C4 compound, enabling drastically more efficient photosynthesis to take place because carbon dioxide is at a much higher concentration than oxygen.
Rice is a C3 plant—which happens to be the staple food for half the world.
If it can be converted to C4 photosynthesis, its yield would increase by 50% while using half the water.
It would also be drought-resistant and need far less fertilizer.
Langdale noted that C4 plants have evolved naturally 60 times in a variety of plant families, all of which provide models of the transition.
“How difficult could it be?” she deadpanned. The engineering begins with reverse-engineering.
For instance, the main leaves in corn are C4, but the husk leaves are C3-like, so the genes that affect the two forms of development can be studied.
Langdale’s research suggests that the needed structural change in rice can be managed with about 12 engineered genes, and previous research by others indicates that the biochemical changes can be achieved with perhaps 10 genes.
How much is needed for the eventual fine tuning will emerge later.
When is later?
The C4 Rice project began in 2006 at the International Rice Research Institute in the Philippines, funded by the Bill & Melinda Gates Foundation.
The research is on schedule, and engineering should begin in 2019, with the expectation that breeding of delicious, fiercely efficient C4 rice could be complete by 2039.
It is the kind of thing that highly focussed multi-generation science can accomplish.
“We are uniquely fire creatures,” Pyne began, “on a uniquely fire planet.”
Life itself is a form of slow metabolic combustion—which eventually created oxygen and burnable vegetation that allowed fast combustion, ignited by lightning.
Humans came along and mastered fire for warmth, food preparation, and managing the landscape, and that made us a keystone species.
Humanity’s ecological signature on the world is fire.
Then we made fire the all-purpose catalyst for craft (clay, glass, metal) and eventually industry, shifting to the vast geological resource of fossil fuels.
That “pyric transition” made humans dominant on the earth, even to the point of affecting climate.
We used fire to clear much of the world’s forest for agriculture.
Then came a century of misdirection about wildfire.
The forests of Europe are mostly too wet to burn, but by the late 19th century the leading foresters in world came from there and taught their ignorance to foresters in North America and India, where the land depends on seasonal fire for ecological health.
National governments set about suppressing all wildfire, with catastrophic success.
In the absence of the usual occasional local fires, massive fuel loads built up, and destructive megafires became the norm.
There was an alternative theory of a “restoration strategy” to manage wildfire in way that would emulate how lightning and native American burning kept the landscape ecologically healthy, but it has been applied haltingly and fractionally, and megafires still rule.
“The real argument for fire is that it does ecological work that nothing else does,” Pyne concluded.
“Charismatic megaflora” like redwoods need fire.
An ecologically rich mosaic of forest, savannah, and meadows needs fire.
Healthy prairie needs fire or it gets taken over by invasive woody plants.
People trained only as foresters are blind to all that.
Wildfire practice now works best when it is guided by wildlife biologists who insist that red cockaded woodpeckers need fire-dependent longleaf pines, that grizzly bears need the berries that grow in recent burns, that pheasants need grassland burned free of invasive eastern red cedar.
The techniques for prescribed burns for a bioabundant natural landscape are now well honed.
They need to be applied much more widely.
When in doubt how to proceed, ask the ecologists, who will ask the animals.
All it takes to improve forecasting is KEEP SCORE
Will Syria’s President Assad still be in power at the end of next year?
Will Russia and China hold joint naval exercises in the Mediterranean in the next six months?
Will the Oil Volatility Index fall below 25 in 2016?
Will the Arctic sea ice mass be lower next summer than it was last summer?
Five hundred such questions of geopolitical import were posed in tournament mode to thousands of amateur forecasters by IARPA—the Intelligence Advanced Research Projects Activity—between 2011 and 2015.
(Tetlock mentioned that senior US intelligence officials opposed the project, but younger-generation staff were able to push it through.)
Extremely careful score was kept, and before long the most adept amateur “superforecasters” were doing 30 percent better than professional intelligence officers with access to classified information.
They were also better than prediction markets and drastically better than famous pundits and politicians, who Tetlock described as engaging in deliberately vague “ideological kabuki dance."
What made the amateurs so powerful was Tetlock’s insistence that they score geopolitical predictions the way meteorologists score weather predictions and then learn how to improve their scores accordingly.
Meteorologists predict in percentages—“there is a 70 percent chance of rain on Thursday.”
It takes time and statistics to find out how good a particular meteorologist is.
If 7 out of 10 such times it in fact rained, the meteorologist gets a high score for calibration (the right percentage) and for resolution (it mostly did rain).
Superforecasters, remarkably, assigned probability estimates of 72-76 percent to things that happened and 24-28 percent to things that didn’t.
How did they do that?
They learned, Tetlock said, to avoid falling for the “gambler’s fallacy”—detecting nonexistent patterns.
They learned objectivity—the aggressive open-mindedness it takes to set aside personal theories of public events.
They learned to not overcompensate for previous mistakes—the way American intelligence professionals overcompensated for the false negative of 9/11 with the false positive of mass weapons in Saddam’s Iraq.
They learned to analyze from the outside in—Assad is a dictator; most dictators stay in office a very long time; consider any current news out of Syria in that light.
And they learned to balance between over-adjustment to new evidence (“This changes everything”) and under-adjustment (“This is just a blip”), and between overconfidence ("100 percent!”) and over-timidity (“Um, 50 percent”).
“You only win a forecasting tournament,” Tetlock said, “by being decisive—justifiably decisive."
Much of the best forecasting came from teams that learned to collaborate adroitly.
Diversity on the teams helped.
One important trick was to give extra weight to the best individual forecasters.
Another was to “extremize” to compensate for the conservatism of aggregate forecasts—if everyone says the chances are around 66 percent, then the real chances are probably higher.
In the Q & A following his talk Tetlock was asked if the US intelligence community would incorporate the lessons of its forecasting tournament.
He said he is cautiously optimistic.
Pressed for a number, he declared, “Ten years from now I would offer the probability of .7 that there will be ten times more numerical probability estimates in national intelligence estimates than there were in 2005.”
Asked about long-term forecasting, he replied, “Here’s my long-term prediction for Long Now.
When the Long Now audience of 2515 looks back on the audience of 2015, their level of contempt for how we go about judging political debate will be roughly comparable to the level of contempt we have for the 1692 Salem witch trials."
Infrastructure investment tricks
All societies under-invest in their infrastructure—in the systems that allow them to thrive.
There is hardware infrastructure: clean water, paved roads, sewer systems, airports, broadband; and, Fallows suggested, software infrastructure: organizational and cultural practices such as education, safe driving, good accounting, a widening circle of trust.
China, for example, is having an orgy of hard infrastructure construction.
It recently built a hundred airports while America built zero.
But it is lagging in soft infrastructure such as safe driving and political transition.
Infrastructure always looks unattractive to investors because the benefits: 1) are uncertain; 2) are delayed; and 3) go to others—the public, in the future.
And the act of building infrastructure can be highly disruptive in the present.
America for the last forty years has starved its infrastructure, but in our history some highly controversial remarkable infrastructure decisions got through, each apparently by a miracle—the Louisiana Purchase, the Erie Canal, the Gadsden Purchase, the Alaska Purchase, National Parks, Land Grant colleges, the GI Bill that created our middle class after World War II, and the Interstate highway system.
In Fallows’ view, the miracle that enabled the right decision each time was either an emergency (such as World War II or the Depression), stealth (such as all the works that quietly go forward within the military budget or the medical-industrial complex), or a story (such as Manifest Destiny and the Space Race).
Lately, Fallows notes, there is a little noticed infrastructure renaissance going in some mid-sized American cities, where the political process is nonpoisonous and pragmatic compared to the current national-level dysfunction.
By neglecting the long view, Fallows concluded, we overimagine problems with infrastructure projects and underimagine the benefits.
But with the long view, with the new wealth and optimism of our tech successes, and expanding on the innovations in many of our cities, there is compelling story to be told.
It might build on the unfolding emergency with climate change or on the new excitement about space exploration.
Responding to need or to opportunity, we can tell a tale that inspires us to reinvent and build anew the systems that make our society flourish.
Andy Weir’s self-published novel The Martian has become a New York Times bestseller and the #1 movie in America. But it began with a series of blog posts that reflected Andy’s lifelong love of space science and detailed research about traveling to and surviving on the fourth planet in our Solar System.
You can see the film in theaters everywhere, but only at The Interval will you hear Andy skip the fiction and talk about the details of how a real world mission to reach and colonize Mars would work. He’ll discuss his book, too, and answer your questions at this very special event in our Interval salon series.
Page 1 of 7Older