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"The Youngness Paradox" (Weekend's Most Popular)




According to MIT's  Alan Guth , originator of the inflationary universe theory, our Universe is a product of eternal inflation --eternal into the future, but not into the past. An eternally inflating Universe produces an infinite number of pocket universes , which in turn are producing more new universes.  The old, mature universes are vastly outnumbered by universes that have just barely begun to evolve. Guth called it the "Youngness Paradox."

Guth says that "the synchronous gauge probability distribution strongly implies that there is no civilization in the visible Universe more advanced than us. We would conclude, therefore, that it is extraordinarily improbable that there is a civilization in our pocket Universe that is at least one second more advanced than we are. Perhaps this argument explains why SETI has not found any signals from alien civilizations.”

In Guth's view, “nature gets a lot of tries -- the Universe is an experiment that’s repeated over and over again, each time with slightly different physical laws, or even vastly different physical laws,” says MIT physics professor Robert Jaffe.

Some of these universes would collapse instants after forming; in others, the forces between particles would be so weak they could not give rise to atoms or molecules. However, if conditions were suitable, matter would coalesce into galaxies and planets, and if the right elements were present in those worlds, intelligent life could evolve.

Some physicists have theorized that only universes in which the laws of physics are “just so” could support life, and that if things were even a little bit different from our world, intelligent life would be impossible. In that case, our physical laws might be explained “anthropically,” meaning that they are as they are because if they were otherwise, no one would be around to notice them.

MIT's Jaffe and his collaborators felt that this proposed anthropic explanation should be subjected to more careful scrutiny, and decided to explore whether universes with different physical laws could support life.

The MIT physicists have showed that universes quite different from ours still have elements similar to carbon, hydrogen, and oxygen, and could therefore evolve life forms quite similar to us, even when the masses of elementary particles called quarks are dramatically altered.

Jaffe and his collaborators felt that this proposed anthropic explanation should be subjected to more careful scrutiny, so they decided to explore whether universes with different physical laws could support life. Unlike most other studies, in which varying only one constant usually produces an inhospitable universe, they examined more than one constant.

Whether life exists elsewhere in our Universe is a longstanding mystery. But for some scientists, there’s another interesting question: could there be life in a universe significantly different from our own?

In work recently featured in a cover story in Scientific American, Jaffe, former MIT postdoc, Alejandro Jenkins, and recent MIT graduate Itamar Kimchi showed that universes quite different from ours still have elements similar to carbon, hydrogen, and oxygen, and could therefore evolve life forms quite similar to us. Even when the masses of the elementary particles are dramatically altered, life may find a way.

“You could change them by significant amounts without eliminating the possibility of organic chemistry in the Universe,” says Jenkins.

Although bizarre life forms might exist in universes different from ours, Jaffe and his collaborators decided to focus on life based on carbon chemistry. They defined as “congenial to life” those universes in which stable forms of hydrogen, carbon and oxygen would exist.

“If you don’t have a stable entity with the chemistry of hydrogen, you’re not going to have hydrocarbons, or complex carbohydrates, and you’re not going to have life,” says Jaffe. “The same goes for carbon and oxygen. Beyond those three we felt the rest is detail."

They set out to see what might happen to those elements if they altered the masses of elementary particles called quarks. There are six types of quarks, which are the building blocks of protons, neutrons and electrons. The MIT team focused on “up”, “down” and “strange” quarks, the most common and lightest quarks, which join together to form protons and neutrons and closely related particles called “hyperons.”

In our Universe, the down quark is about twice as heavy as the up quark, resulting in neutrons that are 0.1 percent heavier than protons. Jaffe and his colleagues modeled one family of universes in which the down quark was lighter than the up quark, and protons were up to a percent heavier than neutrons. In this scenario, hydrogen would no longer be stable, but its slightly heavier isotopes deuterium or tritium could be. An isotope of carbon known as carbon-14 would also be stable, as would a form of oxygen, so the organic reactions necessary for life would be possible.

The team found a few other congenial universes, including a family where the up and strange quarks have roughly the same mass (in our Universe, strange quarks are much heavier and can only be produced in high-energy collisions), while the down quark would be much lighter. In such a universe, atomic nuclei would be made of neutrons and a hyperon called the “sigma minus,” which would replace protons. They published their findings in the journal Physical Review D last year.

Jaffe and his collaborators focused on quarks because they know enough about quark interactions to predict what will happen when their masses change. However, “any attempt to address the problem in a broader context is going to be very difficult,” says Jaffe, because physicists are limited in their ability to predict the consequences of changing most other physical laws and constants.

A group of researchers at Lawrence Berkeley National Laboratory has done related studies examining whether congenial universes could arise even while lacking one of the four fundamental forces of our Universe -- the weak nuclear force, which enables the reactions that turn neutrons into protons, and vice versa. The researchers showed that tweaking the other three fundamental forces could compensate for the missing weak nuclear force and still allow stable elements to be formed.

That study and the MIT work are different from most other studies in this area in that they examined more than one constant. “Usually people vary one constant and look at the results, which is different than if you vary multiple constants,” says Mark Wise, professor of physics at Caltech, who was not involved in the research. Varying only one constant usually produces an inhospitable universe, which can lead to the erroneous conclusion that any other congenial universes are impossible.

One physical parameter that does appear to be extremely finely tuned is the cosmological constant -- a measure of the pressure exerted by empty space, which causes the universe to expand or contract. When the constant is positive, space expands, when negative, the universe collapses on itself. In our universe, the cosmological constant is positive but very small -- any larger value would cause the universe to expand too rapidly for galaxies to form. However, Wise and his colleagues have shown that it is theoretically possible that changes in primordial cosmological density perturbations could compensate at least for small changes to the value of the cosmological constant.

In the end, there is no way to know for sure what other universes are out there, or what life they may hold. But that will likely not stop physicists from exploring the possibilities, and in the process learning more about our own Universe.

The Daily Galaxy via MIT 

Related Post: 

"Why Isn't the Milky Way Crawling With Mechanical or Biological Life?" --Stephen Hawking's Answer





TDG: Thanks for posting this.

This is brilliant and entertaining--and

almost entirely useless ignorant

speculation--at least with respect to the

question "Are we alone in the Universe?"

Do some of the 'UFO' sightings represent

other, more advanced intelligences?

If you doubt that other intelligences--with a

vastly greater understanding of 'physics'

and 'reality'--have been interacting with our

civilization for decades, and much longer,

then try asking yourself a simple and

obvious question: Do you want to know if

this is true? Or not?

Isn't this a simple and obvious question?

If your answer is 'yes' [we do want to

know], then perhaps you will try asking

your favorite scientists--astrobiologists,

SETI, and NASA--this question.

They can't openly answer this question with

a simple 'yes' or 'no', because it's the

'forbidden question'.

Don't believe it? Then try asking--or even

openly discussing the question...

Here's an explanation:

A man said to the universe:
Sir, I exist!
However, replied the universe,
The fact has not created in me
A sense of obligation. (Stephen Crane poem, 1899)

The above comments are well said: There's not a shred of proof that anything Guth has speculated on has any basis in reality--either in mathematics or actual physics. I mean, what does "the synchronous gauge probability distribution" actually mean here? He says that it "... strongly implies that there is no civilization in the visible Universe more advanced than us." So? What does "strongly implies" mean here? All he--and everyone--is going on here that we haven't found any radio signals from other civilizations (or optical signals of the kind we can recognize as artificial). This article is a waste of anybody's time. It's just another attempt at figuring why "they" haven't contacted us yet. And this business of bubble universes. Give me a break. They're just as theoretical. No empirical proof exists that such universes exist or have existed. It's all blather. I say: Death to Stupid Speculation.

To regard our universe as "anthropic" contradicts Occam's Razor, and I, for one, reject it!

What happened to logic? Given Guth's view of the observable universe as being the pocket universe that we belong to, we still have billions of galaxies with hundreds of billions of stars each. Solar systems with rocky planets, like good old Earth have been possible for about twice the age of our solar system. Therefore intelligent life on planet Earth should be middling in terms of age. To state that a process like evolution progresses at such a deterministic rate that no alien civilization could be even one second older is bizarre, bordering on extreme silliness.

The article does not defend their ridiculous claim that no other civilizations could have surpassed us. It just rambles on about pocket universes. Neat. Still has nothing to do with the headline.

I tell you why they didnt find any Life signals out there...cause those pricks keep it away from the public,,,thats why..and no other reason....

Interesting article.

But I believe the real reason why SETI has not successfully discovered other intelligent life, is most likely due to one of these 3 more plausible reasons:


If you highly encrypt a radio or TV signal, it begins to seem not much more different than just random noise.

This means that if a highly encrypted alien radio signal passed over us, it is NOT realistic to expect that we would recognize it as anything but just random noise.


Radio energy RAPIDLY dissipates as it moves outward into space.

Essentially the further a radio signal travels, the more dramatically weaker the signal becomes.

Just imagine a radio-transmitting tower:

If you are standing next to the tower, you'll get hit with a very concentrated beam of radio energy!

(In fact do NOT stand too close to radar-beacons, such as the ones you find next to airports. If you stand right up against a standard airport radar beacon, you WILL essentially become sterilized and no longer be able to have children/offspring!)

But imagine that radio, or radar, beam of energy radiating and moving out in a rippling circle, across our galaxy.

If you are standing billions, or trillions of miles/kilometers in the distance, you are only getting hit with a VERY TINY, minescule fraction of that radiating circle.

That extremely tiny little fraction of a circle is probably NOT ENOUGH energy for someone else to fully notice the signal, or be able to realistically pick up that signal.

This means, that our radio and TV signals have become GREATLY DISSIPATED as they move ever further into space.

It is NOT REALISTIC to expect a 20th century, or even 21st century civilization to easily pick up those signals.

And so, since we are for now a 20th/21st century type of civilization, we should NOT realistically expect to detect such radio signals either.

3) SIMULATION THEORY (ie: The Matrix)

Finally... if you assume that there MIGHT be hundreds of advanced civilizations in this universe, then that means those hundreds of civilizations are LIKELY running thousands of multiple advanced computer simulations of the Universe.

If they are advanced simulations, then chances are they can run EXTREMELY realistic simulations of the Universe, probably at the quantum-computing level.

So while there MIGHT be hundreds of advanced civilizations...
those civilizations are likely running thousands of Universe simulations.

Ergo the probability that planet Earth exists in the "real Universe" is far less than the probability that Earth exists within a simulation.

In other words, since there are many times more "simulated universes" than the one real universe, the chances are that we exist within a simulation.

Recent theories that the universe appears to behave like a holographic projection could offer support to this "simulation theory". Maybe.

So... maybe we have not detected other alien civilizations, because the current simulated universe we exist within, is only simulating/testing one planet for now. (Earth.)

Why that simulation is running, is unknown.

If this theory is true, then our universe could be a simulation running for scientific research purposes, or perhaps simply as a child's toy video game!

How about, just for a while, everyone ignores pompous speculation about things that no one has the ability to confirm in any manner?

The articles here describing the actual scientific research and new discoveries are nice. The articles allowing stuffed shirts to gaze down from the chairs they've attached 2x4's to the legs to elevate themselves and natter? Not so much.

Or, barring that, at least be journalistic and refrain from fawning over them and actually dissect their meanderings? Pointing out the large holes in their logic would make more interesting reading.

The usual Stupidity that comes from theories based on expanding universes and not based on Steady State Eternal Infinite Universe.

This web site has a very bad habit of quoting scientific papers
without supplying a link for them. I tracked down the paper in which you quoted Guth. In the same paper Guth says,
"Perhaps this argument explains why SETI has not found any signals from alien civilizations, but I find it more plausible that it is merely a symptom that the synchronous gauge
probability distribution is not the right one."

I think it will be Human Arrogance to think that there is NO Truth to UFO and so is the thought that we are the only advanced civilization in the visible Universe.

I think that the second we test a warp drive our planet will be surrounded by alien vessels here to tell us the rules. Until we do we are not worth the time ( or space ) If warp drive is possible - then likely messages are sent that way to.

Infinite number of "universe" produced by a single finite universe? Hold on! Let me put on a scuba gear cause this BS is deep. This theory will go down into eternal history as did the Flat Earth Theory, "The wold she is a flat; like your head is flat." First we way that light curves back around itself to the point that one could see the back of one's head. The universe is expanding into infinity. Now the universe is eternally inflating into the future; not eternally inflating (deflating) into the past; tire rotating anyone? Why we have not detected any signs of alien life; we are the crown of creation and life begins with us. It seems that science is being displaced by a new myths of self righteous me-ism,or just plain narcissism.

I have a theory. Opinions are like anuses;everyone has one. My theory is that space is infinite. Time is infinite. Matter is infinite, but the universe is finite. Time had no beginning and time will have no end. The number of universes in existence is infinite, but the mass of any universe is finite. There is no such thing as time; it being a human construct. Since galaxies cluster together (the lumpy cream of wheat theory), I propose that universes cluster together. We may be a dwarf universe and we are being cannibalized by a much larger universe (we are being absorbed; not self absorbed). Life has always existed in the cosmos; and life will always exist for eternity. We are a thread in the fabric of life; we are not life itself. We should get over ourselves.

Considering the last paragraph of your article, why isn't it a reasonable thing to conclude that what these physicists and cosmologists are doing is writing science fiction in equations? I was brought up to have great respect for science but when you can't verify speculations such as these any "science" being done is inevitably abortive since it can't be held up against reality to check it.

Somehow I think the fight to deal with man-made global warming is entirely more worthy of funding and respect than this kind of stuff. I know, how could anyone think that saving life on Earth could be more important than the high church of theoretical cosmology.

I think this is just about as arrogant as claiming life doesn't exist anywhere other than on Earth and that the Earth is the center of everything. It's really sad when people make these claims. First of all there are things we don't know about in the universe that could easily be true. Take transmissions for example, the theory of subspace could very well be true, it could be the transmissions we can't detect yet and I know I'm using scifi (which ironically has been a great guide so far as to the possibilities in some circles) but I'm not claiming that mankind has discovered the end all be all of everything in the universe so therefore we're the most advanced most centered best ever race in the galaxy. I think this is really narrow minded honestly.

Gee, I read the whole article, and was going to comment on it ........, but when I went to the comment section I found I had already given that same answer the first time this article came out!

At least I'm consistent

(I wonder if this is Al's Heimers?)

Me thinks singularity used by current cosmologists means space to be nothing, absolutely nothing, no space and time. They came into existence with a little old bad bang that didn’t follow any currently known rules of physics. However, anything can be done with the magic of math.

Currently there are lab studies that provide another basis for the redshift called PIR, plasma induced redshift that is remarkably similar to the spectral shifts seen in red shifted light. Therefore, when the notion of an expanding universe is replaced due to eventually finding objects well beyond 13.8 billion Lys, all these silly things about bubble universes will all burst as well.

Thank you very much for publishing this kind of article. I like your article very much. More space and technology related material exists at This site is also more resourceful with science, nanotechnology, biotechnology, space and astronomy related latest inventions and news.

"I think that the second we test a warp drive our planet will be surrounded by alien vessels here to tell us the rules. Until we do we are not worth the time ( or space ) If warp drive is possible - then likely messages are sent that way to."
Good Comment I think, a real Star Trek scenario.

Globular clusters are objects from more older "meta-universe."

I think the arguments of the origins of our universe and whether there are any other universes, or life in our universe is so pointless. Why? Because I believe the physical world is a mental construct of the human mind. It all exists in our head. When we die there is no universe, there is nothing. Can you remember what happened before you were born? Nothing.

As a budding science fiction writer I love all the "techno-speak" tax payer fueled musings from cosmologists.

As a taxpayer I'd prefer a little more science with their fiction.

The next thing you know they'll start talking about unknowable particles of Dark Matter being more abundant in the universe than visable matter.



Give a cosmologist a joint and an unlimited budget and this is what you get. I'm writing off any cosmological theories that originate from anyone working in Colorado, Oregon and anywhere south of San Diego.

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