Collected Essays (26 page)

What is a little hard to grasp is that the two pictures represent the same thing. The peaks in the one image correspond to the bubbles in the other image. A peak that rises on top of a peak is like a bubble that swells out from the side of a bubble.

RR:
Can we go to the other bubbles of our fractal universe?

AL:
Far in the future, our sky will start looking a lot different, as our stars start dying. And then we will see into the different parts of universe, some parts with different laws of physics.

Can we use the energy in our bubble which has cooled off, can we fly to the other tips of the fractal, can we go there and live comfortably? The theory of such cosmic flights suggests that even if you travel at the speed of light, you lose so much time that when you get to another part of the universe, it will already be cold and empty there.

RR:
You say that some of the different bubble-universes have different laws of physics—how does that work?

AL:
We’ve talked about one scalar field that is responsible for the universe’s expansion. It seems that there may also be a second scalar field which makes different kinds of physics in different regions of the universe. There is one overall law of physics for the whole universe, but the scalar fields make for different realizations of this law. It is like water with many different phases. For those who live in water it is very essential that the water be a liquid and not a solid or a gas.

RR:
What if I could somehow fly up to the edge of a region of the universe with different physics? How would it look?

AL:
Between the different regions of the universe, there are boundaries called “domain walls.” There is a tendency of the domain walls to straighten up, and also to move one way or the other with a speed approaching the speed of light.

So first of all it would be very difficult for you to reach a domain wall if it is moving away from you. And if it is moving towards you, it will be very difficult to run from it. In fact, if a wall moves towards you at the speed of light, then you first see it only at the moment it hits you.

But we don’t need to worry too much; the typical estimates in these theories give you a distance from us to this next domain wall which is much much greater than ten billion light years, so we may live for now.

RR:
Might we say that the regions with different physics are competing with each other?

AL:
I think about the moving boundaries of the regions as perhaps like a Darwinian fitness. Should we discriminate and say those with greater volume are winners? There is a lot of place for losers as well, everything which can exist tends to have room for its existence in the self-reproducing inflationary universe. We can think of a Darwinian process without hate and killing, a process that produces all possible species.

RR:
How did the whole process begin?

AL:
Maybe the universe didn’t have a beginning. There are some philosophical problems with the idea of the universe having a beginning. When the universe was just created, then where were the laws of physics written? Where were the laws of physics written if there was no space and no time to write them? Maybe the universe was created without obeying any laws, but then I don’t understand. Well, maybe the laws and the universe came into existence simultaneously? Quantum mechanics might say our universe together with its physical laws appeared as a quantum fluctuation, but then where were the laws of quantum mechanics written before creation?

RR:
In one of your papers you talk about relating the nature of our consciousness to our universe. What do you mean?

AL:
For me, the investigation of the universe is mainly a tool for understanding ourselves. The universe is our cosmic home. You look around the house of your friend and imagine you may learn something about your friend by looking at how his house is built. My final purpose is not to understand the universe, but to understand life.

An example of this is the question of why we humans see time as passing. According to the branch of physics called “quantum cosmology,” the universe is best represented as a pattern called a “wave function” which does not depend on time. But then why do I see the universe evolving in time?

The answer may be that as long as I am observing the universe, the universe breaks into two pieces: me and the-rest-of-the-universe. And it turns out that the wave function for each of these separate pieces does depend on time. But if I merge with the universe then my time stops.

RR:
How do you feel about having left Moscow to live and work in the U.S? What are some things that strike you about American culture?

AL:
Visiting different countries is one thing, living in different countries is another. People are similar. They are kind here, they are kind there; they are friendly here, they are friendly there. But the laws of society are different in sometimes a very unexpected way. The U.S. bureaucracy is much more complicated. In Russia I was unable to do many things. But for the things that were allowed, there were not so many rules. Here in U.S. you have more opportunities, but each opportunity is well classified; if you want to know how to use the opportunities you have to know many laws.

RR:
You like to use computers to simulate solutions to your equations. How do you program them?

AL:
I am almost computer-illiterate. All the calculations are made by my son Dmitri. I was begging him to do it when we moved here in 1990, and in the beginning he was not very interested, but then I said what if I got a really good computer for this work? And indeed we got one from Silicon Graphics, and it was a lot of fun to work on it.

Dmitri is majoring in Physics at Caltech; we’ve written six or seven papers together. Sometimes we get results by looking at computer simulations. The simulation shows a physical effect that is unusual. We study and check, and again see something strange. I shout, “You have an error in your program,” and he checks and there is no error and then I understand something new. The simulation really helps us to discover, it’s not only a tool to illustrate and to calculate; when you make it visual, you see something and understand it better.

RR:
You’ve suggested that it might be possible to create a universe in the laboratory by violently compressing some matter, that one milligram of matter may initiate an eternal self-reproducing universe. How would this work?

AL:
We don’t have a no-go theorem which says it is impossible. But it is very difficult. You have to do more than just compress the matter, but with high temperatures and by quantum effects there is a chance of creating a universe. Our estimates indicate that you would need a very good laboratory indeed. And it is not very dangerous to try. This new universe would not hurt our universe, it will only expand within itself.

RR:
Can you imagine there being any kind of economic or spiritual gain from creating new universes? Might this lead to a Silicon Valley industry or to a cosmological cult?

AL:
The question is: Is it interesting to create a universe? Would you have a profit or benefit? What would be the use?

Suppose life in our universe is dying, and we make a small private universe we can jump into so we have a place to live. But it’s not easy to jump, when we create a universe it is connected to our universe by a very narrow bridge of space, we can’t jump through it, and the new universe will repel us because it is expanding.

Well, maybe you can get energy from the new universe? No, you can’t get energy because of the law of energy conservation. The new universe gets its energy internally, and the energy has to stay inside there.

We can’t get in, we can’t use the energy, but maybe we can do like we do with our children: we teach them and we live on in them. Maybe we can give knowledge and information to the new little universe so that they will think about us with gratitude, like, “Oh God who created us, thank you.”

But it is not so easy to send information inside. Say I wrote a message on the surface of an inflationary universe. But then the letters expand so much, that for billions of years to come each race of people in universe will be living in the corner of just one letter. They will never see the message.

The only way to send information which I have found is strange and unusual. If I create an inflationary universe with a small density, I can prepare the universe in a particular state which corresponds to different laws of physics, masses of particles, interactions, etc. I can imagine a binary code describing all possible laws of physics; this would be quite a long sequence. So if I am preparing a universe in some peculiar state, I can send the message encoded in the laws of physics.

Can I send a long message in this way? Let’s think about our own universe. Let’s imagine that someone made our universe as a message. If our universe were perfect, with all particles having equal masses and charges, then the laws of physics would be trivial, and it would be a very short message. But our particle physics looks weird, and it has a lot of information. We get these strange numbers, there is no harmony. There is information instead of harmony, or to be more precise, the harmony is there, but it is very well-hidden.

To send a long message, you must make a weird universe with complicated laws of physics. It is the only way to send information. The only people who can read this message are physicists. Since we see around us a rather weird universe, does it imply that our universe was created not by God, but a physicist hacker?

I don’t know for sure whether this is a joke or something more. Until it is proven that it is stupid you must pursue some lines of thought. Even if something seems counterintuitive you must be honest and follow the thought line and not be influenced by the common point of view. If you agree with everything which everybody else thinks, you never move. You should try to think for yourself. Even though sometimes in the end you understand they were right.

Note on “Goodbye Big Bang: Cosmologist Andrei Linde”

Written 1995.

Appeared in
Wired
, July/Aug 1995.

For a very short time, I was able to use my
Wired
connection as a carte blanche to meet whoever I wanted to, and I was curious about Linde’s theories. But soon I’d learn that
Wired
had a very short institutional memory—there was a continual turn-over and churn in the editorial staff. The next set of editors had no idea who I was, nor of the articles I’d written for
Wired
in the past. Although I continued to contribute the occasional small squib, “Goodbye Big Bang” would prove to be last commissioned article I was able to sell to
Wired
.

Mr. Nanotech: Eric Drexler

The French word for dwarf is
nain
. A nanometer is one billionth of a meter, which is just a bit larger than the diameter of your average atom. Nanotechnology envisions doing things with individual atoms, one at a time. “You done building that roast beef out of dirt yet, Bob?” “Ten molecules down, ten to the twenty-sixth power to go.”

Of course nature does build cows out of dirt, with some light, water and grass along the way, so maybe we
can
learn how to do it. The dream of nanotechnology is to get lots and lots of little machines to build materials for us.

Present day nanotechnology comes in two flavors: dry and wet.
Dry nanotechnology
is about tiny rods and gears made out of diamond whiskers and the like. The recent discovery that icosahedron-shaped “buckyballs” of carbon can be found in ordinary soot is a big boost for dry nanotechnology. Wonderfully intricate images, some resembling automobile transmissions, have been cranked out by Ralph Merkle of the computational nanotechnology project at Xerox’s Palo Alto Research Center (the legendary “PARC” where Saint Englebart invented windows and the mouse).

No dry nanotechologist has yet been able to assemble the kind of three-dimensional structures that Merkle and others envision. But there is a device known as an STM (for “Scanning Tunneling Microscope) which allows nanohackers to see, pick up, and move around individual atoms on a surface. Quite recently, Don Eigler and a group of at IBM’s Almaden Research Lab managed to use an STM to draw things. First they drew a little man with carbon monoxide molecules on platinum, and then they wrote ‘IBM’ in xenon atoms on nickel. The next big effort will be to assemble a free-standing three-dimensional structure atom-by-atom—how about a six hundred sixty-six-atom model of Danny DeVito?

An ultimate goal of dry nanotechnology is the creation of an “assembler”, a fantastic little nanomachine that can turn out more nanomachines—including copies of itself (an onanistic process known as “self-replication”). You might set an assembler to work making assemblers for awhile, and then somehow signal the godzillion assemblers that now they should switch over to making, say, incredibly strong “club sandwiches” of alternating single-atom sheets of two kinds of metal. The “gray goo” problem crops up here. What if, like the brooms in the tale of the Sorcerer’s Apprentice, the assemblers can’t be turned off? What if they turn everything they can get their nasty little pincers on into more assemblers? The whole planet could end up as a glistering sludge of horny little can-openers. But the nanonauts assure us this won’t happen; it is perhaps comforting that the main nanotechnology group is known as the Foresight Institute.

Wet nanotechnology
proposes that instead of trying to build our own tiny machines, we use a “machine” that nature has already designed: the cellular reproduction apparatus of DNA, RNA, enzymes, and proteins. It’s like finding a way to tell one of your DNA strands something like, “Oh, next time you copy yourself, could you whip up a few million copies of this particular tryptamine molecule for me as well?” It’s all in how you say it, and Gerald Joyce and others at the Scripps Institute are making some slow progress in guiding the “machines” of biological reproduction. But there’s still major obstacles in convincing DNA to do technological things like putting together copper yttrium sandwiches. “No, man, I wanna
fuck
!”