The Living Universe Foundation Board of Directors Meeting of April 9, 2011

Playlist posted on YouTube

The Living Universe Foundation Board of Directors Meeting of April 2, 2011

Playlist posted on YouTube

Living Universe Foundation Board Meeting Held on March 26, 2011

Playlist posted on YouTube

Regarding an article on Stephen Hawking's Warning: Abandon Earth-Or Face Extinction

The website BigThink.com published an article regarding Stephen Hawking's warning that space colonization is the only choice to avoid eventual extinction.  As I (and I'm sure most of the LUF) agrees with this point we applaud the statement from such a renowned scientist.  However, the article then tries to dismiss the argument with some flawed reasoning.  I don't make the claim that my own reasoning is flawless, but I'd like to share where I think the points made went wrong.

The article makes the same mistake we often see with this kind of argument.  It takes current day technology and explains how hard it would be to jump to the equivalent of our Galactia phase while selecting only habitable "Earth-like" planets as possible destinations.  While Hawking's comments are on the mark as far as the need to spread throughout space to extend our (i.e. the Biosphere's) longevity, the commentary that follows makes it sound like a hopelessly extravagant endeavor.  Like we can put a starship on a Saturn V and blast our way to Gliese 581 (e or c, take your pick) through impassable radiation in traveling in time-dilated hyper-sleep.

"The nearest star [to Earth] is Proxima Centauri which is 4.2 light years away," says University of Michigan astrophysicist Katherine Freese, "That means that, if you were traveling at the speed of light the whole time, it would take 4.2 years to get there."

Unfortunately, at the moment we can only travel at about ten thousandth of light speed, which means if man were to use chemical fuel rockets similar to the those used during the Apollo mission to the moon, the journey would take about 50,000 years. Without the use of a science-fiction-like warp drive or cryogenic freezing technology, no human would live long enough to survive the journey. In addition, "the radiation you would encounter alone would kill you, even if you could get a rocket to go anywhere near that fast," says Freese.

Here are some ways that my thinking differs from the article:

• We can increase our odds of survivability right here.
• By learning to adapt to and manage our home ecosystems and taking care of our current environment.  This knowledge increases our chances in space which will reveal more knowledge to use right here.
• Colonizing the oceans can also bring benefits by creating more living space at sea away from prominent ecosystems we can lessen the burden of humanities' footprint on land.
• We can produce food and preserve sea life by creating fish farming and other aqua/poly-culture solutions at sea using nutrients from below and help feed a struggling population.
• By algae farming we can create carbon sinks to draw CO₂ from the air and submerge it below the zone where it can be taken back into the atmosphere...
• I could keep going, but let's move on to
• We are not afraid of space.
• We don't need an Earth like planet in it's habitable zone.
• Near Earth orbit, Geosynchronous orbit, Lagrange points, the Moon, Mars, asteroids, etc., are all useful can be colonized with the right technology.
• Whether in artificial gravity or in micro-gravity, free space stations or colonized asteroids and comets are a far better use of resources than planets.
• Starting with NEOs (Near Earth Objects) and building through the belts to the Kuiper worlds and on throughout the Oort cloud we have a vast number of worlds right in our planetary neighborhood.
• That stretches the biosphere to at least 1 light year without the need for super fast star ships with radiation shielding and "go-fast" racing stripes.
• By extension, these "World ships" could be the first to ship off to nearby stars.  They might not be the first to arrive, but they could be valuable as part of the growing biosphere as each would carry complete living ecosystems through space.
• Asteroids, nuclear war, grey-goo, or whatever localized danger you might be worried about wouldn't be extinction worthy.  The further we go down this path, our odds of success increases tremendously.
• We don't need to wait for the Enterprise to get to our next destination.
• Given the previous points, we can see that we can build up to an interstellar program over the next millennium without draconian economic measures or hyperbolic extrapolations of current technology.
• If the Vostok-1 represents the space age version of the Kitty-Hawk flight, we can almost guarantee that technology can continue to progress past the current point.
• Faster ships will be developed as a matter of course, just to criss cross the Solar system.  Starting with the low energy, erg pinching, sling-shot orbits we use today we will gradually build on propulsion technology to get us where we want to go faster.
• Radiation problems will be solved right here as we venture out into more strident colonies.  From Lunar and Martian lava tubes to hollowed out asteroids we can move to orbital colonies with thick shielding to more exotic protection as the tech matures.
• Faster ships mean that more particles in your path become ionizing radiation.  You may even need stronger shielding to pass through the Sun's atmosphere than the interstellar medium.
• A single country or even the Earth doesn't have to pay for interstellar missions.
• A system-wide economy would be better able to absorb the costs of an interstellar mission.
• With thousands of worlds and mini-worlds contributing to the project over hundreds of years, eventually funding a trip to Alpha Centauri would be like funding a trip for Magellan or Columbus.
• The energy needs of an interstellar voyage will be tremendous.  A system-wide economic system and power generation system would be able to afford the power costs.
• Storing that energy as antimatter or some other compressed storage medium would also require lots of energy and money.
• We don't even have to be human.
• Humanity is an extremely recent development in the history of the biosphere and may have only a brief existence, at least as homo sapiens is concerned.
• As space technology develops, we will adapt space to suit us.  As medical technology develops we will also be adapting to space.
• Clones--while completely human and unique individuals--will give us better understanding of genetic and epigenetic phenomena and what effect changes and manipulations have on us and our environments.
• As our understanding of aging progresses, it is not unthinkable that human maximum lifespan will increase over time.  Long duration space missions could be completed within such elongated generations.
• Exchanges between species and synthetic biologies may lead to sentient plants, animals, fungi, and other forms of life.  We will grow in possibilities in exchange.
• Machines will also grow more intelligent over time and the differences between us and them will converge.  From AI to nanotechnology, machines will to some degree out evolve us.
• Intelligent software and artificial life will further blur distinctions between species--if that word will retain any meaning.
• That doesn't even take into account of exchanging bits of ourselves with machines and vice-versa.  Cyborgs may become more mainstream.
• Only 1%-10% of your cells are actually "human" the rest of your cellular population consists of residents, visitors, immigrants, barbarians, and insurgents (or maybe mutants would be more accurate for that last group).  Plant, animals, humans, microbes, and machines may evolve into a collective that resembles the ecosystem of the human body.
• Colonization of space will be a collective activity and opportunity of much of the biosphere.
• We have no idea what form life will take on Earth after the current mass extinction.
• After a mass-extinction on Earth, it takes about 10-100 million years to replenish the ecosystems.
• In 10-100 million years, the biosphere of a single planet could span the galaxy.
• The above speculations give only a barest glimpse of the possibilities for the Solar system after 10 million years.  Maybe only even the next 1000 years.
• In 20-200 million years, the ecological niche of every planet, moon, asteroid, comet, etc., around every star, brown dwarf, pulsar, nebula, etc., in the galaxy could be filled.
• In 30-300 million years, the globular clusters, our satellite galaxies, and possibly even nearby galaxies like Andromeda could be colonized.
• In 1 billion years, the galaxy would be as different from the one we live in now as Earth is from it's state 1 billion years ago.

I'm not saying that we are on the verge of some "singularity event" that's supposed to be due mid-century or that we are headed for some kind of an omega-point anytime soon.  But, I do see vast possibilities for the future of evolution and the broad expansion of the biosphere throughout space without alarm-ism or pessimism.  All it takes is a little courage, faith, humility, vision, and imagination.

[luf-team] Starships

Added an image to the Galactia phase section of TMP2;

This picture is my rough and speculative illustration of starships of the Galactia phase. They also represent aspects of Solaria era spacecraft, being based on the proposed NanoFoam composition suggested as a common basis of most artifacts of that period and 'grown' instead of 'constructed'. Three forms are shown; a passenger cruiser, an automated colonial seed carrier, and a possibly earlier external propulsion seed carrier/scout based on the Powell-Pellegrino anti-matter towing thruster concept. Note the difference in scales relative to the original Savage vision. Savage assumed pre-settlement based on large slower cargo vessels carrying large amounts of initial settlement supplies. In TMP2 we have the premise that NanoFoam carries integral to it the bulk of the civilization's technical potential and thus the pre-settlement phase is based on NanoFoam seed 'pods' that subsume and convert available local materials into suitable habitats autonomously and without the need for an infrastructure other than that based on NanoFoam itself. So we have a reversal of relative scales with the passenger carrier larger by virtue of more in-flight supplies and the need for a comfortable living space during a decade long flight and direct conversion to orbital habitat on arrival.

Posted to luf-team by: Eric Hunting, Tue Jun 29, 2010 7:02 pm

Welcome to the LUF's First Wave!

Sadly, Google has determined that Google Wave isn't worth their trouble. Our work here will remain until Google shuts down its service. However, the work will be imported into the new wiki that is now under development.

Collaborative Space Travel and Research Team (CSTART)

"Looks like the concept of Open Source space programs is starting to snowball." — Eric Hunting

Space exploration, by anyone, for everyone

We are a non-government, non-profit, collaborative space agency engaged in research and exploration of the solar system. We are based on an open model, and depend on the collaboration of volunteers located around the world. You can read more about us or just get involved in the project and help us reach the moon!

This looks like the sort of group that we should keep our eyes on. We share common goals and interests. We could also assist in their work and they may me interested in assisting us in ours. So hear is a link to their RSS feed if anyone is interested in tracking their progress: CSTART feed.

Next Gen Fabber May Go to Space Station

It is expected that Lunar and Martian explorers will build tools and parts as needed while traveling or using local resources. NASA scientists are interested in testing electron beam freeform fabrication EBF3 on the International Space Station. Such a device could build certified aerospace parts cheaper and using less material than conventional manufacturing methods.

in reference to: http://www.space.com/businesstechnology/091104-tw-3d-replicator.html (view on Google Sidewiki)

NASA may use Soviet technology for new shuttles

Russia's canceled Buran space shuttle could be a stepping stone to NASA's new space transportation system.

The Soviet-era Buran space programme, mothballed 20 years ago, may be revived. With NASA about to retire its ageing fleet of space shuttles, there is a pressing need for viable space transport.

Two decades ago the Soviet space shuttle Buran blasted off on its first and only orbital flight. Just a few years later, with the collapse of the Soviet Union, the programme was shelved.

The Buran was the Soviet Union's answer to NASA’s space shuttle programme. On November 15, 1988, the shuttle was propelled out of the Earth’s atmosphere by the specially designed Energia booster rocket from the Baikonur launch pad in Kazakhstan. (cont'd)

LUF Revival

If you haven't checked in on LUF-Team for a while, you might like to know that a revival of activity is underway.

For the past few months activity has focused on :

• Re-establishing the LUF as a corporate entity,
• Completing and adding media to TMP2,
• Developing a new website to organize knowledge and members, and
• Determining the steps needed to establish the Foundation Phase of TMP.

This could be considered a reboot. We are basically starting from scratch with the new TMP2, some old timers as well as some new blood and trying to make a different kind of organization. Come check it out!

Open Source hardware - Sustainable development

Something which is often discussed on the LUF Blog is new and interesting uses of the open source way of collaborating with each other. For the last year I have been working on an open source project which brings together hardware designs, software and knowledge, all under an open source umbrella. The project is called Akvo and is about bringing knowledge about sustainable water and sanitation solutions to people who are trying to realize water and sanitation for those that have none.

Why is this important? About 1 billion people do not have access to safe water to drink and more than 2.5 billion people do not have adequate sanitation facilities. This causes huge problems and massive suffering. Millions of children die every year to curable diseases like diarrhea, which happen because of poor access to water and sanitation.

The Fab Flashlight

Using a Fab@Home machine, a flashlight has been fabbed. From this CAD conception...













...came this flashlight.

Awesome isn't it?

TMP 2.0

If you have read the original book and were inspired in any way by it, there is very good news. Eric Hunting has begun a new The Millennial Project 2.0 Wiki. It won't be the same as the original book, as the information within it, and the medium upon which it will be hosted will be updated using cutting edge science, technology, and ideas. A lot has happened in those 15 years since the original book was written, and the vision and plan need to be updated for the 21st century.

http://tmp2.wikia.com/wiki/Main_Page

"Twilight Zone" effect

Carbon dropped into the oceans is not automatically stored away for millennia. Instead, microorganisms living in the "twilight zone" captures much of the carbon and returns it to the biosphere. This is important for OTEC schemes that plan to sequester carbon by locking it up in algae and sinking it to the ocean bottom. From this study, it looks as if the material needs to be deposited at least 1000 meters down to get a maximum impact.

Radiation Protection In Space

Radiation is a major hazard for anyone venturing into space. The commonly proposed way to deal with space radiation (particularly for settlements on planetary surfaces such as Luna and Mars) is to either build underground or to use a very thick wall of regolith to shield the settlers. But when you are in outer space (in an orbital settlement or a traveling ship, for instance) such radiation shields will be massive, with significant costs for transport.

A blog entry at Colony Worlds describes this problem, and a possible solution, which is to use artificial magnetic fields for settlements. This idea is not new. Other than providing extremely fast transport through the solar system, the M2P2 drive is designed to shield the passengers of a space ship from radiation. Such an drive would give potential settlers much easier access to places such as the inner moons of Jupiter (Io and European in particular).

The idea seems to be catching on as scientists are about to test a new "deflector shield" which creates an artificial magnetic field to deflect harmful radiation.

Now scientists at the Rutherford Appleton Laboratory in Oxfordshire plan to mimic nature. They will build a miniature magnetosphere in a laboratory to see if a deflector shield can be used to protect humans living on space craft and in bases on the Moon or Mars.

In order to work, an artificial mini-magnetosphere on a space craft will need to utilise many cutting edge technologies, such as superconductors and the magnetic confinement techniques used in nuclear fusion.

Thus science is following science fiction once again. The writers of Star Trek realised that any space craft containing humans would need protection from the hazardous effects of cosmic radiation. They envisioned a 'deflector shield" spreading out from the Starship Enterprise that the radiation would bounce off. These experiments will help to establish whether this idea could one day become a practical reality.

Another option is the transhumanist one, which is to modify the human body itself to withstand radiation.

Rebel with a Cause: The Optimistic Scientist

The TCSDaily recently conducted an interview with Freeman Dyson. Here are some of the highlights of the interview:

Benny Peiser: In your book "Infinite in all Directions" (1988) you discuss eschatological questions surrounding the theoretical issue of the end of the universe. As one of a very small number of optimistic cosmologists, you have developed a scientific theory of infinity. You write: "I have found a universe growing without limit in richness and complexity, a universe of life surviving forever and making itself known to its neighbors across unimaginable gulfs of space and time." This hopeful cosmology contrasts sharply with the apocalyptic Zeitgeist. What would you say are the most important intellectual principles and ideas that have sustained your optimism?

Freeman Dyson: My optimism about the long-term survival of life comes mainly from imagining what will happen when life escapes from this planet and becomes adapted to living in vacuum. There is then no real barrier to stop life from spreading through the universe. Hopping from one world to another will be about as easy as hopping from one island in the Pacific to another. And then life will diversify to fill the infinite variety of ecological niches in the universe, as it has done already on this planet.

If you want an intellectual principle to give this picture a philosophical name, you can call it "The Principle of Maximum Diversity." The principle of maximum diversity says that life evolves to make the universe as interesting as possible. A rain-forest contains a huge number of diverse species because specialization is cost-effective, just as Adam Smith observed in human societies. But I am impressed more by the visible examples of diversity in rain-forests and coral-reefs and human cultures than by any abstract philosophical principles.

Benny Peiser: In the first chapter of your new book, "The Scientist as Rebel," you write that the common element of the scientific vision "is rebellion against the restrictions imposed by the locally prevailing culture," and that scientists "should be artists and rebels, obeying their own instincts rather than social demands or philosophical principles."

Contrary to this liberal if not libertarian concept of scientific open-mindedness, there has been growing pressure on scientists to toe the line and endorse what is nowadays called the 'scientific consensus' - on numerous contentious issues. Dissenting scientists frequently face ostracism and denunciation when they dare to go against the current. Has Western science become more authoritarian in recent years or have rebellious scientists always had to face similar condemnation and resentment? And how can young scientists develop intellectual independence and autonomy in a bureaucratic world of funding dependency?

Freeman Dyson: Certainly the growing rigidity of scientific organizations is a real and serious problem. I like to remind young scientists of examples in the recent past when people without paper qualifications made great contributions. Two of my favorites are: Milton Humason, who drove mules carrying material up the mountain trail to build the Mount Wilson Observatory, and then when the observatory was built got a job as a janitor, and ended up as a staff astronomer second-in-command to Hubble. Bernhardt Schmidt, the inventor of the Schmidt telescope which revolutionized optical astronomy, who worked independently as a lens-grinder and beat the big optical companies at their own game. I tell young people that the new technologies of computing, telecommunication, optical detection and microchemistry actually empower the amateur to do things that only professionals could do before.

Amateurs and small companies will have a growing role in the future of science. This will compensate for the increasing bureaucratization of the big organizations. Bright young people will start their own companies and do their own science.

Benny Peiser: One of your most influential lectures is re-published in your new book. I am talking about your Bernal Lecture which you delivered in London in 1972, one year after Desmond Bernal's death. As you point out, the lecture provided the foundation for much of your writing in later years. What strikes me about your remarkably optimistic lecture is its almost religious tone. It was delivered at a time, similar to the period after World War I, when a new age of techno-pessimism came to the fore, reinforced by Hiroshima and Vietnam.

It is in this atmosphere of entrenched techno-scepticism and environmental anxiety that you advanced biological, genetic and geo-engineering as industrial trappings of social progress and environmental protection. At the height of ecological anxiety, in the same year as the Club of Rome proclaimed the "Limits to Growth," you envisaged endless technological advancement, terrestrial progress and the greening of the galaxy, famously predicting that "we shall learn to grow trees on comets."

At one point towards the end of your lecture, you christen your speech a "sermon." Indeed, your entire lecture reads as if it was written for a tormented audience searching for a glimmer of hope. In his book "The Religion of Technology", David Noble claims that the whole history of technological innovation and advancement has been primarily a religious endeavour. Noble claims that even today your ideas of technological solutions to terrestrial problems constitute in essence a religious conviction. How much of your cosmological view of the world has indeed been shaped by Judeo-Christian traditions? And do you see that there is an inherent link between your religious and your philosophical optimism?

Freeman Dyson: It is true that the tradition of Judeo-Christian religion is strongly coupled with philosophical optimism. Hope is high on the list of virtues. God did not put us here on earth to moan and groan. As my mother used to say, "God helps those who help themselves."

I am generally optimistic because our human heritage seems to have equipped us very well for dealing with challenges, from ice-ages and cave-bears to diseases and over-population. The whole species did cooperate to eliminate small-pox, and the women of Mexico did reduce their average family size from seven to two and a half in fifty years. Science has helped us to understand challenges and also to defeat them.

I am especially optimistic just now because of a seminal discovery that was made recently by comparing genomes of different species. David Haussler and his colleagues at UC Santa Cruz discovered a small patch of DNA which they call HAR1, short for Human Accelerated Region 1. This patch appears to be strictly conserved in the genomes of mouse, rat, chicken and chimpanzee, which means that it must have been performing an essential function that was unchanged for about three hundred million years from the last common ancestor of birds and mammals until today.

But the same patch appears grossly modified with eighteen mutations in the human genome, which means that it must have changed its function in the last six million years from the common ancestor of chimps and humans to modern humans. Somehow, that little patch of DNA expresses an essential difference between humans and other mammals. We know two other significant facts about HAR1. First, it does not code for a protein but codes for RNA. Second, the RNA for which it codes is active in the cortex of the human embryonic brain during the second trimester of pregnancy. It is likely that the rapid evolution of HAR1 has something to do with the rapid evolution of the human brain during the last six million years.

I am optimistic because I see the discovery of HAR1 as a seminal event in the history of science, marking the beginning of a new understanding of human evolution and human nature. I see it as a big step toward the fulfilment of the dream described in 1929 by Desmond Bernal, one of the pioneers of molecular biology, in his little book, "The World, the Flesh and the Devil: An Enquiry into the Future of the Three Enemies of the Rational Soul". Bernal saw science as our best tool for defeating the three enemies. The World means floods and famines and climate changes. The Flesh means diseases and senile infirmities. The Devil means the dark irrational passions that lead otherwise rational beings into strife and destruction. I am optimistic because I see HAR1 as a new tool leading us toward a deep understanding of human nature and toward the ultimate defeat of our last enemy.

Open Source Hardware

Do you have your fabber yet? I don't have mine just yet, but hopefully soon.

If so, then you can seel the products you make with it at an "open-source hardware marketplace" at MFGx. SpendMatters referred to the website as the MySpace for the Manufacturing Set.

Mitch Free seems like an unlikely person to be part of this whole social / community web-based 2.0 -- some might say 3.0 -- thing. After all, the manufacturing world does not exactly lend itself to online social networking, at least not yet. But Mitch is not one to listen to convention. His latest experiment is a free community site called MFGx which essentially is a custom-built online social networking community for manufacturers, large and small. It's quite cool, and already has some great threads and traffic on it.

One concept that Mitch introduced earlier this week in a discussion thread is fascinating. Mitch writes: "Should certain product manufacturers publish their designs for anyone to download and move towards an open source (hardware not software) model? I think so. Why, because it would leverage the masses to proliferate their low margin hardware platform and allow them to sell the high margin consumables or data content. Take Tivo for example, they will rebate your entire purchase price these days when you purchase a subscription to the Tivo service because they want to sell high margin data subscriptions ... So what if they just made their hardware design open source and allowed anyone to produce a Tivo platform device? It would allow greater proliferation of the platform and get them out of a 'lost leader' business, thus allowing them to sell more high margin subscriptions."

The concept of Open Source manufacturing is quite cool and forward looking. But many of the subjects on MFGx are much more pragmatic (such as containing volatile commodity prices and China sourcing). So even if you know nothing about this whole social networking phenomenon, get yourself over to MFGx and see how online communities can work in a business setting -- and why they're not just for kids on MySpace anymore!

This sort of social network will be essential for the future, especially if you are planning to settle the oceans or to settle space. Compared to those living on Earth, the first space settlers would have to made do with a shortage of many items that they want or need. A simple iPod could be very difficult to ship to a space settlement on Luna. But if you have the designs for an MP3/OGG music player, a fabber, and a store of mined material from Luna, then you could easily design your own.

More on DIY PCBs

I posted an entry on do-it-yourself printed circuit boards earlier today. The MAKE blog has just posted two new entries on the same topic.

• Cheap and east toner for PCB making
• Getting started with EAGLE
  

Will Fabbers Change The World?

It seems inevitable that fabbers will cause an unprecedented revolution that will profoundly change the world. But of course, we should be cautious about making future predictions, given that nuclear fusion, which was 40 years away in 1960, is still 40 years away today. And just recently, I came across an article about the 21 Biggest Technology Flops. As home-based fabbers have only been available in the past 6 months, there are plenty of questions about this technology. One question is whether or not I will be able to fab with heavy metals. Another one is whether or not fabbers will be subject to Moore's Law.

A new Guardian article provides some optimism on the future of home-based fabrication.

Pushing the boundaries beyond simple shapes, Lipson has made a working battery, an electrically-activated polymer muscle and a touch sensor by printing different layers of material. His goal is to make a small robot with limbs, actuators, control circuitry and batteries.

The possibilities are limited by what you can extrude from interchangeable cartridges - quick-hardening plastic is the favourite, but the machine can also handle and layer plaster, Play-Doh, silicone, wax and metals or mixtures with a low melting point such as solder (made of tin and lead). Some users have found chocolate, cheese and cake icing (which may also be used as a temporary soluble support material for hollow structures) rewarding too.

This is plenty of progress in the space of 6 months on the first home-based fabber. Once RepRap demonstrates self-replication using fabbers, prepare for all hell to break loose.

"I think that within 10 years private individuals will be able to make for themselves virtually any manufactured product that is today sold by industry. I sometimes wonder if politicians realise that the entire basis of the human economy is about to undergo the biggest change since the invention of money." -- Adrian Bowyer

What do you want to build with your home-based fabber?

Make Your Own Circuit Board

In the past, I've blogged a lot about fabbers. As such it is no surprise that fabbers are a very exciting technology to me. DIY printed circuit boards (PCBs) are also very exciting. If you want high-powered fabrication, look no further than eMachineShop. If you want to design a good PCB, then Pad2Pad, the sister company of eMachineShop, is a good place to start.

Pad2Pad is the remarkable new way to get the custom printed circuit boards you need. Download our free PCB software, design your board, and click to order - it's that easy! Your boards will be manufactured and delivered at low cost.

Pad2Pad simplifies the whole process of getting circuit boards by up to 80% and open doors to new products and projects. Intelligent design software gives instant exact pricing, expert feedback, and unrivaled convenience. Pad2Pad provides you with a complete PCB solution to quickly move your electronic circuits to the market.

You can also create (and not just design) your own PCB. This MAKE Magazine blog entry shows you just how to create one in your own garage.