After being born and raised in the Viking capital Stockholm and abandoning my parents and my brother to go do a Ph.D. in Berzerkeley and postdocs in Munich/Garching and Princeton, I moved to Narberth and this infinite corridor at Penn. I then moved to this even more infinite corridor. Here's my photo album.

Mouse versus Max
Latest score: Mouse 3, Max 0

According to the authoritative text on the subject, The Hitchhiker's Guide to the Galaxy, humans are the 3rd most intelligent species on Earth, superseded not only by dolphins but also by mice. This page provides evidence supporting that hypothesis, although it can be debated whether it mainly demonstrates the intelligence of mice or my own lack thereof.

Houdini the Mouse
Here's our little friend posing for my surveillance camera, enjoying a piece of cheese while evading two mouse traps. It is standing right in front of its house, the empty space behind the baseboard under a cabinet in our kitchen in Winchester, Massachusetts. Philip, Alexander and I think it's cute, but Angelica has given me a grim ultimatum: catch it my way or she'll deal with it her way - Brazilian women aren't known for their compassionate love of furry little rodents...

In the past, the kids and I have successfully caught mice with the Victor Tin Cat trap (the one our friend is standing on in the picture) and let them loose in a far-away forest (the mouse equivalent of being deported to Siberia). But this time, no luck. The trap remained empty every morning even though the mouse was clearly around (a piece of cheese on top of the trap would invariably disappear and Angelica would curse over mouse droppings in the pantry, in the sink, etc.).

The Mousecam

Faced with Angelica's ultimatum, all resources were mobilized. I unleashed my inner geek and rigged up a webcam-equipped laptop (right) with the $25 EvoCam video surveillance software to find out what was going on. I set it up to record a 15 second movie each time it detected motion, as well as to take a frame each second just in case (our friend sometimes eluded the motion sensor, which seemed to be optimized with larger intruders in mind).

June 12, 2005
First deployment of the mousecam. As we all gather around the breakfast table to inspect the findings, I'm the laughing stock, publically humiliated by the mouse. It appears to be either too large or too smart to enter the trap. As you can see in the movie, it's figured out that it can lie on its side and help itself to the peanut butter by sticking its right paw through the air vent, without ever entering the trap. So all these nights, I've simply been feeding it!

In desperation, I order a larger trap: the Ranger rat/squirrel trap, after a friendly sales rep named Kevin told me he thought the wire grid was fine enough to keep our mouse inside.

July 1, 2005
We're back from vacation in Sweden and Iceland, and the new trap has arrived. It's now or never! Tonight's menu: a cheese aperetif followed by peanut butter for the main course and an Atkins chocolate bar for desert - something Angelica discovered he'd secretely feasted on in the pantry. I cover the new trap with cloth to make it look more cozy and mouse-friendly - something Kevin had suggested.

I wake up early the next morning, full of anticipation. The cheese is gone and the trap door is down! I remove the cloth and my heart sinks: no mouse. I check the surveillance results. Here is a movie of the appetizer being eaten. Houdini looks like he's slimmed down while we were away! The motion sensor missed the main action, but the second-by-second time lapse movie didn't (left). The mouse enters, heads for the peanut butter on the trigger and the chocolate on the far side and the trap door slams shut. But not many seconds later, Houdini the Mouse is seen leaving again! How on Earth could he get out?

July 2, 2005
After once again being ridiculed at the breakfast table, it was back to work. I bent the trap frame to shrink the opening around the trap door, and closed off a slight gap with steel wire. I pulled back the cloth a bit so that if Houdini did another breakout stunt, at least I'd be able to see where and how. I sat in the living room reading for an hour, prepared to rapidly place the whole trap in a more Houdini-proof container as soon as I heard the trap door close. But no luck. When I peered into the kitchen, Houdini had announced his arrival by eating the cheese aperetif, but s/he cleverly stayed out of the trap itself until I'd gone to bed.

I wake up at 5AM and fail to fall back a sleep since I'm wondering whether I've caught Houdini. I get up and find ... another fiasco. The trap door is closed, the peanut butter is all gone, the chocolate bar is full of tooth marks - and the trap is empty. My only consolation is a movie with the full Houdini breakout routine. I'm amazed that someone so large-looking can squeeze through such a narrow opening, but a website I should have read before buying this trap claims that some mice can get through cracks as narrow as a quarter of an inch. Which would explain how Houdini gets under the pantry door.

But that wasn't all. Houdini didn't want to miss an opportunity to humiliate me further: he was so confident in his talents as escape artist that he reentered the closed trap to finish off the peanut butter and have more chocolate dessert! And he did it twice! Here are two movies of Houdini reentering through the rectangular openings in the side grid, near the front and near the back.

Crisis. Angelica is now threatening to take matters into her own hands on Tuesday, the day after tomorrow. And my mother-in-law Dulce has arrived from Brazil, so the feel-sorry-for-the-mouse percentage of the voices in the household has shrunk. Philip suggests we should feed the mouse until it's too fat to be able to escape from the trap... Alexander says that the first trap was too small and the second trap was too big, and that the problem is that the mouse is "too medium-sized", so that we need to buy a medium-sized trap. Indeed, in desperation I've ordered a Havahart "Small Live Trap'' which looks like it has smaller openings, paying $31.50 for shipping just to get it here asap. I've also ordered this cutesy trap as backup. To be continued...

By now, I have a long fine tradition of being humiliated by mice. If you speak Portuguese, here a hilarious description of my previous mouse woes written by my wonderful mother-in-law Dulce. If you email me and say you're interested, I'll translate it to English.

Here's some doggerel that I've scribbled down over the years, most of it around 1990 and in Swedish. If you like any of it and let me know, perhaps I'll translate some more of the short stories into English. To go to the only story I've translated so far, click
In Motion
(Translation of "I Rörelse" by Swedish poet Karin Boye, September 16, 1990)
Days of satisfaction don't rank first.
The greatest days, they are the days of thirst.
Our journey might turn out to be in vain,
But it's the path itself that's worth the pain.
A single goal in life is not the best.
The best of goals is just a night-long rest.
In places where you only spend one night,
you sleep secure and wake up with delight.
Get up! It's time to leave your cozy bed.
Another grand adventure lies ahead.


(August 15, 1990)
The path of life is long and grey
and ends six feet beneath.
The secret is to notice
that there are little flowers growing at the roadside.
(October 17, 1991)
Good Morning.
Good night.
You have been discontinued.


January 1, 1989 (translated April 25, 1996)
So floridly flickering, sparkling and crackling,
so beautiful and such a life-giving thrill.
So negligible in the cosmic expanses,
so hopelessly futile - but beautiful still!


Written in Swedish 1/9-90. Translated 1/25-92.
A urinal.
A well kept East German urinal.
New strangers but the same eyes.
The same somber, indifferent eyes.
The same 10 Pfennig.
The same 10 Pfennig as when she got the job,
38 years ago.
The same eyes.
The same resigned eyes.
A urinal.


October 10, 1992
A faithful friend.
A mirror for your mind.
A pillow for your tears.
A hideout for your secrets.
A sharer of your laughter.
A sharer of your past.
A faithful friend
can outlast your boyfriends,
can outlast your girlfriends,
can outlast your marriage,
can outlast you.
Enemy - thy name is greed.
For friendship is frail now that Mammon is God,
with marketing screaming: Buy! Own! Have!
A friend you can't marry is a mere waste of time.
Have to have! Possess! Own!
If you can't own, why stay in touch?
Not a profitable investment.
A faithful friend.
Endangered species?
Another old ideal that's soon extinct?
I still believe in friendship.
Do you?
July 10, 1995. (A surgeon removed a lump in my arm.
Three days later, I found out that it was benign and harmless.)
Tage, Cissi, Mommy, Max
- suddenly I choke.
Every time more close to home,
and sadly it's no joke.
A little lump there in my arm,
so innocently small,
may have the power to destroy
and finish with it all.
All these dreams of wife and kids,
of future love and bliss,
of unveiling reality
may succumb to this.
My dreams of finding evidence
that cosmic birth confirms
may all end within a year,
eaten up by worms.
Just another day in the hospital
April 22, 1995 (I spent a week in the hospital in Munich, having my tonsils taken out, and got bored...)
Every day at half past six
the nurses start to do their tricks.
Although my eyelids feel like lead,
I have to let them make my bed.
I rinse my mouth with Chamomile
and pop my Megacillin pill.
I drink my drops of Novalgin
before the food gets carried in.
Even with this anesthetic,
my eating speed is quite pathetic:
afraid to swallow, I chew and chew
and manage to eat roll or two
in an hour and a half
- it's so absurd it makes me laugh.
Then it's gargle-time again
to cleanse my throat and ease the pain.
I never feel a need to curse,
since it's never so bad it couldn't get worse.
Take the Italian and his woes:
he has these tampons up his nose.
He's in the bed across from me.
Like a Walrus looketh he.
And Herr Fisher, on my right,
must surely feel a certain fright.
Next week he'll receive his answer
from the lab - it may be cancer.
I'm better off than my own brother,
now back to being nursed by mother.
Compared to him I'm doing fine.
His food's even more fluid than mine.
And he must suck his through a straw
to get it past his broken jaw.
At ten o'clock the ache's all gone
because I took a Ben-u-ron.
The sun is out, the sky is blue,
and in our room there's little to do.
So I take my book and find
myself a spot on the porch behind
one of the pillars, in the shade.
Why? Because the doctor forbade
me from sitting in the sun.
The book I'm reading is quite fun;
a novel called "The Golden Gate",
perhaps the strangest I've red to date.
300 pages can't be called terse,
yet the whole thing is written in verse!
Vikram Seth must have plenty of time:
he wrote even the table of contents in rhyme.
The pages turn, the day progresses,
and in the sky the sun precesses.
Every ten minutes I move my chair
to stay clear of the sun and its glare.
My lunch arrives, a la "no frills",
with the obligatory pills.
I take my tray outside again
to the best weather since who knows when.
I eat mashed potatoes with a spoon
and soon it's become afternoon.
But it's worlds apart from my breakfast stunt:
it's now all quiet on the oral front.
Later in the day I hear
a friendly and familiar cheer.
Angelica has come and brought
some ice-cream and - who would have thought! -
the illustrious Bhuvnesh Jain,
master of the deeply non-linear domain.
(He's the one who was so kind
as to lend me this food for the mind.
And it was in turn this book that made
me write these lines there in the shade.)
They talk, they converse, they discuss and they stay
until my hoarse voice has faded away.
Finally it's time for bed.
This is the time of day I dread.
Because it's when the sky is black
that the tonsil ghosts come back.
The evil demons set to work
and in my throat they go berserk.
I take a night-cap Novalgin and try
to get some sleep but cannot - why?
'cause the Walrus is watching "Temple of Doom"
and has put his TV set right there in our room.
I insert these ultimate earplugs of wax,
but the volume seems to be turned up to max.
To my poor ears this is pure vermin:
American turkeys dubbed into German.
I finally slumber, but not very deep,
for after just an hour of sleep
I'm suddenly woken up with a jolt
by something that sounds like a thunderbolt.
I understand when I hear the encore:
that's what it sounds like when walruses snore.
Now my throat is throbbing with pain
and I fail to fall back asleep again.
I can't go to the night-nurse and plea
for another Novalgin to make me pain-free
because the rules say that four hours must pass
until I'm allowed to have one more glass.
So I fumble in the darkness until
I find that blessed white round pill,
the Ben-u-ron that on a hunch
I secretly stowed away at lunch.
Two hours later I wake up anew
and go to the night-nurse for her magic brew.
The story repeats throughout the night
until at six-thirty they turn on the light.
Oh, Romania...
(Song written July 4 1990, during visit to Romania. Melody: Clementine)


Oh Romania, oh Romania,
getting better every day.
Soon we're better than Albania,
'cause socialism is here to stay!
If you disliked Ceaucescu,
you might one day be found dead.
It's much better with Iliescu:
the miners only bash your head.
Oh the miners, they are glorious,
smashing microscopes with delight.
Thanks to their stupor they are notorious.
Thanks to theys clubs they're always right.
But the students, they are rabble,
worthless parasites on the state.
They make no bread, they make only trouble,
so let the miners decide their fate!
With Ceaucescu's Securitate,
print a newspaper and you're gone.
With Iliescu's "libertate"
you get no paper to print it on.
We work a month using muscle power
and we get two thousand Lei.
A Swede would earn that every hour,
but we're happier than they!
'Cause in Romania life is funny:
we can laugh when we get our pay.
And besides, we need no money
- the stores are empty anyway...
Oh Romania, oh Romania,
getting better every day.
Soon we're better than Albania,
'cause socialism is here to stay!
* * *
Overheard by a man in Bucarest 1990 (true):
"Come Mom, let's run!"
"Ouch, what happened?"


Signe Tegmark, 1902-2004

Kära Mormor,

Du har lämnat oss, men hos mig finns du alltid kvar. När jag blundar ser jag hur vi åker spark tillsammans på den vitgnistrande Övermovägen för att möta jultomten. Jag känner lukten av din gamla Opel när vi kör till Falun för att möta min nya bror. Vi badar tillsammans in Styrsjön. Pappa och jag skidar hungriga hem genom Moskogen, och när jag öppnar dörren möts jag av doften av dina oemotståndliga köttbullar. För mig kommer sommar alltid att dofta som dina syrener och att smaka som din saft och dina bullar i din hammock.

Mormor, tack för allt du gett mig. Tack för en så stor del av min barndom. Tack också för förebilden mina barnaögon aldrig såg. Pålitlighet, ärlighet, nit, flit och oändlig generositet. När mina äldre ögon nu blickar ut bortom Dalälven ser jag att vår planet skulle vara ett bättre ställe om fler var som du.

We all believe in relativity
(Sung during my December 5 2006 relativity lecture (MIT course 8.033) together with Enectali Figueroa, who also provided guitar accompaniment. Here's the YouTube version. With its seven embedded equations, this song aims for new depths in geekdom. Melody: Yellow Submarine, with italicized lines going like the chorus.)

Römer measured the speed of light,
and something basic just wasn't right.
because Michaelson and Morley
showed that aether fit data poorly.

We jump to 1905.
In Einstein's brain, ideas thrive:
"The laws of nature must be the same
in every inertial frame."
We all believe in relativity, relativity, relativity.
Yes we all believe in relativity, 8.033, relativity.

Einstein's postulates imply
that planes are shorter when they fly.
Their clocks are slowed by time dilation,
and look warped from aberration.
Cos theta-prime is cos theta minus beta ... over one minus beta cos theta.
Yes we all believe in relativity, 8.033, relativity.

With the Lorentz transformation,
we calculate the relation
between Chris's and Zoe's frame,
but all invariants, they are the same.
Like B dot E and B-squared minus E-squared,
... and the rest mass squared which is E-squared minus p-squared.
'cos we all believe in relativity, 8.033, relativity.

Soon physicists had a proclivity
for using relativity.
But nukes made us all scared
because E=mc2.
Everything is relative, even simultaneity, and soon Einstein's become a de facto physics deity.
'cos we all believe in relativity, 8.033, relativity.

But Einstein had another dream,
and in nineteen sixteen
he made a deep unification
between gravity and acceleration.
He said physics ain't hard at all
as long as you are in free fall,
'cos our laws all stay the same
in a locally inertial frame.
And he called it general relativity, relativity, relativity.
And we all believe in relativity, 8.033, relativity.

If towards a black hole you fall
tides will make you slim tall,
but your friends won't see you enter
a singularity at the center,
because it will look to them
like you got stuck at radius 2M.
But you get squished, despite this balking,
and then evaporate, says Stephen Hawking.
We all believe in relativity, relativity, relativity.
Yes we all believe in relativity, 8.033, relativity.

We're in an expanding space
with galaxies all over the place,
and we've learned from Edwin Hubble
that twice the distance makes redshift double
We can with confidence converse
about the age of our universe.
Rival theories are now moot
thanks to Penzias, Wilson, Mather & Smoot.
We all live in an expanding universe, expanding universe, expanding universe.
Yes we all live in an expanding universe, expanding universe, expanding universe.

But what's the physics of creation?
There's a theory called inflation
by Alan Guth and his friends,
but the catch is that it never ends,
making a fractal multiverse
which makes some of their colleagues curse.
Yes there's plenty left to figure out
like what reality is all about about.
but at least we believe in relativity, relativity, relativity.
Yes we all believe in relativity, 8.033, relativity.



(Written in Swedish March 5 1990, translated to English June 13 1998)

"But why?" She was on the verge of tears.

He leaned back in his black leather armchair and looked her in the eyes.

"The official reason is that we have to downsize our staff. But if you really want to know, the truth is that you're too ugly. You tarnish our corporate image."

It took a few seconds for the words to sink in. Then she got up with a swiftness that was surprising considering her formidable weight, took the brown envelope with her compensation and scuffled out of the room. She didn't tell the full truth even to her husband.

The next day, it was Günter's turn. He was called to Mr. Müller's office at 10am, and reemerged five minutes later, red in the face and clutching a brown envelope.

"The bastard!" You just can't treat people this way!" Nobody had really liked Günter, and rumor had it that he was gay. Still, nobody discussed sport in the lunchroom that day.

The third day, Müller sacked Mr. Keller, a chubby middle-aged salesman. The following day, two Turkish guest workers from the production department were laid off.

Indeed, Hartmann & Schmidt AG was never to become the same again after Müller took over. All the employees knew about him was that he was born in Zurich, got his MBA at Harvard, had the a degree of Captain in the army, was considered a rising star in the Swiss business world and had made a fortune on the stock market. After his corporate group had acquired the company from Ciba-Geigy, he had surprisingly made himself the CEO.

"He's a fascist." Wolfgang sounded certain.

Dietrich chuckled. With that skinny build and that short black hair, he actually looks a bit like..."

"C'mon, seriously. I mean, he eliminates the weakest ones and counts on the rest of us being too chicken to do anything about it."

"I don't buy that stuff." Dietrich sipped on his beer.

"His only ideology is money. He fires people to increase profits."

"No Dietrich, that doesn't make sense. If it was just about money, then why would he go out of his way to be so downright nasty?"

"Perhaps he's just a nasty guy?", Martin suggested from across the table.

Martin Schultz was hired fairly recently, and was one of the youngest in the marketing department. He had once had certain moral qualms about working for the company in the first place, but now he was rather enjoying it. He found his job stimulating and was quite pleased with his salary - until yesterday, when Müller had cut it by 20%. What had they done to deserve such a curse?

The next day, a group of ten presented themselves at Müller's office. Wolfgang, who was the head of the union local, explained that they would all quit in protest if Müller continued to fire people without first consulting the union.

"Great. Then please sign these." He had had letters of resignation prepared for all union members, with names and all, ready to be signed. Visibly surprised, all but one of them signed.

"Despite all this talk of solidarity, all that you guys really care about is your own skin. We don't need any bleeding heart liberal cowards here", Müller said while filling out a form. He put a packet of 200-Franc bills in an envelope and handed it to the tenth man.

"You're fired. At least you're less stupid than your nine colleagues here, who have just saved me nine compensation payments."

You could say whatever you wanted about the bastard, Martin thought to himself, but he certainly was clever. He seemed to have read every single line of fine print in the labor legislation.

The same afternoon, Müller went to his secretary's office and closed the door behind him.

"Irene, there's something I need to discuss with you."

She brushed her hair back with her hand.


"It's about your job. We need to downsize our administration, and there are two options. Either you'll have to leave the company, or you'll get a pay raise in return for a slight extension of your office duties." He slowly walked around her desk and stopped behind her. "It depends on whether..."

He started playing with her long blonde hair, tentatively at first. Once it was clear that she wasn't protesting, he let his hands slide down onto her shoulders. She wore a thin white blouse with a rather deep cut, and he slowly began to massage her bare shoulders. She rapidly found herself in this new situation, but the next morning she found herself fired. "You're too bad in bed", was his only remark. She didn't even get a brown envelope - he knew exactly how far he could push people.

It was eerie how shrewd he was, Martin though to himself.

Six weeks after Müller took over as CEO, the number of employees had dropped from 206 to 120. He had sold all corporate cars and spun off both the corporate conference center and the four tennis courts. Furthermore, nobody seemed to have been fired in an amicable fashion. Some female employees had even been seen crying as they emerged from Müller's office.

Martin walked towards the lunchroom. He was furious, but what could he do? He had never realized how cowardly his colleagues were, but it seemed as though Müller had. They outdid each other in badmouthing him behind his back, but when push came to shove, they worked on as usual to save their own skin.

The topic of conversation over lunch was fresh gossip about Müller. Apparently, he had had a wife who had recently committed suicide.

"I can see why", Martin said.

She had apparently had manic-depressive tendencies and been a bit neurotic in recent years, but Müller had felt that she simply needed a family and some stability.

"Müller the Besserwisser... He could use some psychiatric treatment himself."

Müller's next step was to summon the head of marketing for a discussion about the company's exports.

"Isn't it the case that Africa provides 80% of our exports but only 20% of our profits, since the Africans lack payment capacity?"

"Ehrm, well, yes, I guess that would be a blunt way of putting it."

"So shouldn't we launch some of our best selling products in France, where there's a solid market? Neocomp, for instance?"

"I think that would be risky."

"Why? Haven't our studies shown that the risk of birth defects is minimal? Should Frenchmen be more susceptible than Africans?"

"Eh, no, of course not, but the legal system is troublesome in Western Europe. And Neocomp contains Thalidomide, as you know."

"But surely you can get around such legal technicalities?"

"Yes, but it it's more difficult in Europe, with the media constantly looking for petty stuff like this to blow out of proportion."

"So you don't want to go for France?"

"No, I'm afraid of losing my good reputation."

Müller leaned back in his chair and looked him in the eyes for a few seconds, tapping his forefinger against the mahogany desktop.

"You won't lose your reputation - only your job."

Ten weeks later, Hartmann & Schmidt AG had ceased to exist. The factory buildings had been sold to a firm manufacturing paints and a computer company now used the office suites.

Martin was one of the last to be laid off, and still hadn't found a new job. Which he had discovered to be easier said than done without a reference letter. He felt increasingly flustered as the days went by, and it finally got to the point that he drove out to Müller's villa, without quite knowing why.

The house was quite inconspicuous for belonging to a multi-millionaire, he thought to himself as he walked up the stairs to the front door and rang the doorbell. After quite a long wait, the door was opened by Müller himself.

"What do you want, Martin Schultz?"

" Most of all, I'd like to bash your brains out."

Müller didn't look particularly worried. "What's so strange about hurting people for money? You've been to Harvard yourself, haven't you?"

Müller was fairly short and far from muscular, and Martin really did feel a desire to punch him in the face.

"But you can't have done this just for money."

"What brings you to that conclusion?"

"Because it isn't profitable to crush your employees psychologically. You seemed to hate the whole company, with employees and all."

"And what if I did?"

"Then you're just as loony as your wife was."

Müller suddenly got a strange wild look in his eyes.

"Come here!"

He went inside.

"I'll introduce you to Andreas, my only child. He turned six months yesterday.

Martin hesitated for a moment before following Müller, who went on:

"I hated the company as a symbol for what has destroyed my life. And not just the company, but also you and all the other pathetic cowards who worked there. Who never had the guts to say no.

They continued into a bedroom where they were greeted by the cheerful blabber of a baby boy.

"My wife wasn't well during the pregnancy, and had to take tranquilizers."

Martin looked down into the little red cradle. Andreas had big brown eyes and a beautiful face. But he had neither arms nor legs.

Max Tegmark 1989


(Invited essay for EDGE, December 2007)

When gazing up on a clear night, it's easy to feel insignificant. Since our earliest ancestors admired the stars, our human egos have suffered a series of blows. For starters, we're smaller than we thought. Eratosthenes showed that Earth was larger than millions of humans, and his Hellenic compatriots realized that the solar system was thousands of times larger still. Yet for all its grandeur, our Sun turned out to be merely one rather ordinary star among hundreds of billions in a galaxy that in turn is merely one of billions in our observable universe, the spherical region from which light has had time to reach us during the 14 billion years since our big bang. Then there are probably more (perhaps infinitely many) such regions. Our lives are small temporally as well as spatially: if this 14 billion year cosmic history were scaled to one year, then 100,000 years of human history would be 4 minutes and a 100 year life would be 0.2 seconds. Further deflating our hubris, we've learned that we're not that special either. Darwin taught us that we're animals, Freud taught us that we're irrational, machines now outpower us, and just last month, Deep Fritz outsmarted our Chess champion Vladimir Kramnik. Adding insult to injury, cosmologists have found that we're not even made out of the majority substance.

The more I learned about this, the less significant I felt. Yet in recent years, I've suddenly turned more optimistic about our cosmic significance. I've come to believe that advanced evolved life is very rare, yet has huge growth potential, making our place in space and time remarkably significant.

The nature of life and consciousness is of course a hotly debated subject. My guess is that these phenomena can exist much more generally that in the carbon-based examples we know of.

I believe that consciousness is, essentially, the way information feels when being processed. Since matter can be arranged to process information in numerous ways of vastly varying complexity, this implies a rich variety of levels and types of consciousness. The particular type of consciousness that we subjectively know is then a phenomenon that arises in certain highly complex physical systems that input, process, store and output information. Clearly, if atoms can be assembled to make humans, the laws of physics also permit the construction of vastly more advanced forms of sentient life. Yet such advanced beings can probably only come about in a two-step process: first intelligent beings evolve through natural selection, then they choose to pass on the torch of life by building more advanced consciousness that can further improve itself.

Unshackled by the limitations of our human bodies, such advanced life could rise up and eventually inhabit much of our observable universe. Science fiction writers, AI-aficionados and transhumanist thinkers have long explored this idea, and to me the question isn't if it can happen, but if it will happen.

My guess is that evolved life as advanced as ours is very rare. Our universe contains countless other solar systems, many of which are billions of years older than ours. Enrico Fermi pointed out that if advanced civilizations have evolved in many of them, then some have a vast head start on us — so where are they? I don't buy the explanation that they're all choosing to keep a low profile: natural selection operates on all scales, and as soon as one life form adopts expansionism (sending off rogue self-replicating interstellar nanoprobes, say), others can't afford to ignore it. My personal guess is that we're the only life form in our entire observable universe that has advanced to the point of building telescopes, so let's explore that hypothesis. It was the cosmic vastness that made me feel insignificant to start with. Yet those galaxies are visible and beautiful to us — and only us. It is only we who give them any meaning, making our small planet the most significant place in our observable universe.

Moreover, this brief century of ours is arguably the most significant one in the history of our universe: the one when its meaningful future gets decided. We'll have the technology to either self-destruct or to seed our cosmos with life. The situation is so unstable that I doubt that we can dwell at this fork in the road for more than another century. If we end up going the life route rather than the death route, then in a distant future, our cosmos will be teeming with life that all traces back to what we do here and now. I have no idea how we'll be thought of, but I'm sure that we won't be remembered as insignificant.