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How Lonely is Our Planet?
Tech Central Station ^ | 11/12/2003 | Kenneth Silber

Posted on 11/12/2003 10:27:11 AM PST by farmfriend

How Lonely is Our Planet?

By Kenneth Silber

Where are they?

Physicist Enrico Fermi famously posed this question when asked about intelligent extraterrestrials. If such beings exist, why have we (presumably) not been contacted or visited? Fermi's Paradox, as it is now known, is more profound than it may appear. Calculations suggest that if our galaxy has even one extraterrestrial civilization with the interest and ability to colonize new star systems, such a civilization could spread far and wide in a period far shorter than the age of the galaxy.

There are many possible solutions to Fermi's Paradox. Perhaps extraterrestrials have no interest in colonization, or destroy themselves before getting very far (but even a single exception would overthrow such explanations). Perhaps extraterrestrials have visited, in the past or present, while keeping a low profile. Maybe a ruthless galactic exterminator wipes out budding civilizations and is right now on the way here. Or it could be that Earth is the only, or at least the first, planet in our galaxy to harbor life or intelligence.

Planetary scientist David Grinspoon delves into Fermi's Paradox and other questions about extraterrestrial life and intelligence in Lonely Planets: The Natural Philosophy of Alien Life (Ecco/HarperCollins). The book provides a lively and interesting discussion of astrobiology, the scientific study of possible alien life, and of the broader history and culture of thinking about the subject. Grinspoon uses the term "natural philosophy" to emphasize the interdisciplinary and speculative nature of the issues involved.

Grinspoon is an impressively credentialed scientist with a New Age streak and an irreverent tone. He holds positions at the Southwest Research Institute and the University of Colorado, consults for NASA, and is author of Venus Revealed, a valuable overview of the science of Venus. Grinspoon shows a greater affinity than do many scientists for the Gaia Hypothesis, which likens Earth to a living organism. Thus, he thinks Mars is clearly dead, since a living planet would produce a more complex atmosphere. Similarly, he regards Venus and Jupiter's moon Io, which have complex flows of matter and energy, as relatively plausible candidates for life. By contrast, much current astrobiology focuses on worlds that have or had liquid water, such as Mars and Jupiter's moon Europa.

Overall, Grinspoon is an optimist about the possibility of finding alien life somewhere. (Such "optimism," of course, could be a form of extreme pessimism, if one gives much weight to the abovementioned exterminator scenario; but Grinspoon does not.) He notes that the plausibility of alien life is enhanced by the discovery in recent years of dozens of extrasolar planets, or exoplanets, worlds orbiting other stars. He is an enthusiast of the Search for Extraterrestrial Intelligence (SETI), which seeks radio signals or other electromagnetic evidence of intelligent aliens. He places little credence in the Rare Earth Hypothesis, which holds that complex life arose from unusual conditions here and is uncommon in the universe. Rare Earth, he argues, fails to recognize the Gaia insight that life helped shape the amenable conditions on Earth, and furthermore one can imagine planets that would be even more suitable for life.

Could it be that aliens have already arrived? Reports of alien visitations generate widespread skepticism in the scientific community. Grinspoon worries that this response is too dogmatic. He dismisses the "Face on Mars" and sees little merit in conspiracy theories. But he also warns his fellow scientists to be cautious in assuming how aliens would behave. Visiting remote places in the Southwest, Grinspoon watches the sky carefully, hoping but failing to see an alien spacecraft. He sees no reason to think cattle mutilations have an extraterrestrial cause, but regards some of them as quite mysterious.

If intelligent aliens exist, and know of our existence, there are many possible reasons why they may avoid revealing themselves to us. One scenario is the "zoo hypothesis," whereby our planet is something like a wildlife preserve set off limits by advanced aliens. Grinspoon wonders whether we are interesting or important enough to be observed in this way. He notes as an alternative the "seedling hypothesis," in which our planet is akin to one of many seedlings on a forest floor, barely worth a glance from the galactic tourists.

Lonely Planets is written in a colloquial style, replete with anecdotes and asides. Often this works well. A particularly amusing passage involves Grinspoon learning about the finding of suspected fossils in a Martian meteorite several years ago. But at times the tone becomes irritating, as Grinspoon displays his credentials as cultural hipster and political progressive. There is a gratuitous swipe against "a few Flat Earthers and Republican senators," for instance, and a suggestion that interstellar travel should involve "good weed." Also, Grinspoon's discussion of skepticism would be more convincing if he didn't repeatedly misspell the name of the magazine Skeptical Inquirer.

Grinspoon's optimism about extraterrestrials extends to a belief that they are probably wise and benevolent. He writes about how advanced beings would have transcended the dangers of self-destruction by developing their compassion and environmental awareness. But here Grinspoon disregards his own advice about assuming too much about aliens. For all we know, extraterrestrial wisdom includes advocacy of a strong defense and free-market economics. Maybe Republican senators do well in galaxy-wide elections.


TOPICS: Culture/Society; Extended News; News/Current Events
KEYWORDS: aliens; planets; space; xplanets
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For real time political chat - Radio Free Republic chat room
1 posted on 11/12/2003 10:27:12 AM PST by farmfriend
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To: Sabertooth; petuniasevan; RadioAstronomer
ping
2 posted on 11/12/2003 10:29:30 AM PST by farmfriend ( Isaiah 55:10,11)
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To: msdrby
ping
3 posted on 11/12/2003 10:32:54 AM PST by Prof Engineer (This is NOT the government the Founders intended. ~ Golden Corral supports troops and veterans)
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To: farmfriend
Given the best estimation of the age of the universe, the amount of time it took the earliest solar systems to form, the amount of time it took life to develop on Earth, the apparent rarity of even the conditions under which life might develop, and the complete absence of any sign of intelligent life elsewhere, it is plausible to suggest that we might be the first intelligent life in the universe, or in the galaxy. Maybe this is hubris, but it has to be admitted that conscious thought and intelligence is a remarkable development that does not easily occur.
4 posted on 11/12/2003 10:36:14 AM PST by thoughtomator ("A republic, if you can keep it.")
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To: thoughtomator
re: "it has to be admitted that conscious thought and intelligence is a remarkable development that does not easily occur."

Rather bold statement. What do we REALLY KNOW???

There has been so much learned in the last century, the last decade, and within the last year, that we just can't know such things yet, is my opinion.

5 posted on 11/12/2003 10:44:00 AM PST by RonHolzwarth
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To: RonHolzwarth
We know that there is an absence of signs that are perceptible to us of intelligent life elsewhere. Our "eyes" are decent, and have a substantial range, but no matter how hard we search we can find no sign of intelligent life.

It could be that we have already found signs of intelligent life but failed to comprehend them or realize their significance.

But if intelligent life were reasonably common, given the size of the universe, doesn't the probability indicate that at least one would be persistently sending out signals to contact other civilizations as we do?

Granted, it's all speculation. We "know" very little. But Occam's Razor indicates that the simplest explanation - that we are the only ones - is the best working theory, until there is evidence otherwise. If you're going to discard Occam's Razor, then we can ask, are there fairies in the 5th-7th dimensions that prance about and cause people to fall in love?... and other similarly ridiculous questions, that would be equally plausible under the assumption that what we do not know might be true.
6 posted on 11/12/2003 10:54:37 AM PST by thoughtomator ("A republic, if you can keep it.")
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To: farmfriend
How Lonely is Our Planet?

Lonely enough to moon over Miami?

7 posted on 11/12/2003 10:55:40 AM PST by talleyman (I calls 'em as I sees 'em)
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To: thoughtomator
Adding to that, there is no reason to believe that high intellegence is an evolutionary step upwards; more like a sidestep.

Are grasses less evolved than trees?

Are sharks less evolved than primates?

Is complexity a desirable trait and simplicity undesireable, in the grand scheme of things?

8 posted on 11/12/2003 10:56:03 AM PST by Cobra Scott
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To: thoughtomator
Our "eyes" are decent, and have a substantial range, but no matter how hard we search we can find no sign of intelligent life.

How hard have we searched?

9 posted on 11/12/2003 11:05:22 AM PST by RadioAstronomer
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To: farmfriend
Maybe a ruthless galactic exterminator wipes out budding civilizations...

Liberalism???

10 posted on 11/12/2003 11:14:52 AM PST by Onelifetogive
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To: Cobra Scott
Is complexity a desirable trait and simplicity undesireable, in the grand scheme of things?

Cockroaches are the pinnacle of evolution

11 posted on 11/12/2003 11:14:56 AM PST by WackyKat
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To: thoughtomator
We "know" very little. But Occam's Razor indicates that the simplest explanation - that we are the only ones - is the best working theory, until there is evidence otherwise.

That would effectively "prove" that God created us.....

12 posted on 11/12/2003 11:17:40 AM PST by Onelifetogive
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To: farmfriend
"One scenario is the "zoo hypothesis," whereby our planet is something like a wildlife preserve set off limits by advanced aliens."

Or it could be because we're one big sitcom...


13 posted on 11/12/2003 11:19:30 AM PST by KantianBurke (Don't Tread on Me)
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To: thoughtomator
But Occam's Razor indicates that the simplest explanation - that we are the only ones - is the best working theory

Are you sure that is the simplest explanation?

14 posted on 11/12/2003 11:19:34 AM PST by RadioAstronomer
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To: farmfriend
>> Or it could be that Earth is the only, or at least the first, planet in our galaxy to harbor life or intelligence.

IMO, that is the most likely scenerio based on my understanding of the Bible. However, since God created all things for his pleasure (Rev 4:11, KJV), he could have created other "earths" in other solar systems, also for his pleasure. Assuming the latter is true, they why no contact? The most likely scenerio in this case is the inability to achieve a speed fast enough to perform inter-galactic travel. For example, at the rate of 25,000 miles per hour it would take over 25,000 years to travel a distance of 1 light year (1 light year = 186,000 miles/sec * 60 sec/min * 60 min/hr* 24 hr/day * 365 days/year = 5,865,696,000,000 miles = over 5.8 trillion miles). To reach the nearest star (other than the sun) it would take over 100 thousand years. Assume there is another "earth" in our galaxy, but it is on the other side of the galaxy. Since our galaxy is approximately 100,000 light years across, the nearest "earth" would be about 50,000 light years away, requiring over 1 billion years of travel at 25,000 MPH. Assume there is only one "earth" in each galaxy. One of our neighboring "companion" galaxies, Andromeda, is approximately 2 million light years away. To reach that galaxy it would take 2 million years traveling at the speed of light, and over 50 billion years traveling at 25,000 MPH (you might want to check my math).

The sheer vastness of our universe makes me believe that God wanted us isolated, if indeed there are other "earths" in our universe.



15 posted on 11/12/2003 11:23:27 AM PST by PhilipFreneau
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To: RadioAstronomer
The simplest explanation, I would suppose, is that we are simply ignorant and don't know. But that doesn't help at all in the search for truth, does it? Not being content not to know, theories must be proposed and examined to determine what is and is not truth.
16 posted on 11/12/2003 11:30:48 AM PST by thoughtomator ("A republic, if you can keep it.")
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To: farmfriend
My hypothesis is that any sufficiently advanced civilization will make discoveries and expand its capabilities at an ever-increasing rate, until it finds it necessary to transfer its mind(s) to ever smaller, ever faster nonliving substrates.

As they bind themselves in a nutshell, and count themselves kings of infinite space, a cosmic irony arises. They master every technology they would need to make a successful interstellar journey, but the scale of the resources required, and the distance and timescale involved become subjectively infinite. And in any case, there are always more interesting and important adventures and discoveries to be found at the next level downward.

17 posted on 11/12/2003 11:31:26 AM PST by Physicist
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Comment #18 Removed by Moderator

To: thoughtomator
Not being content not to know, theories must be proposed and examined to determine what is and is not truth.

Actually at this point there are searches underway to determine this very thing.

19 posted on 11/12/2003 11:32:39 AM PST by RadioAstronomer
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To: KantianBurke
Perhaps they have never heard of the Prime Directive
20 posted on 11/12/2003 11:36:14 AM PST by AxelPaulsenJr ( Since 1999)
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To: farmfriend
Seems to me any civilization advanced enough to traverse interstellar space would be advanced enough to observe us undetected. Cloaking device on, Captain!
21 posted on 11/12/2003 11:40:08 AM PST by GodBlessRonaldReagan (where is Count Petofi when we need him most?)
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To: farmfriend
I believe it was Bill Watterson of "Calvin and Hobbes" fame who put these words in the mouth of Calvin's feline friend: "The surest sign that intelligent life exists elsewhere in the universe is that it has never tried to contact us."
22 posted on 11/12/2003 11:40:46 AM PST by aardvark1
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To: KantianBurke
Schnozzy & Wozzy having lunch! Grubbies,
Lizard & Sea Urchins on the menu today!
23 posted on 11/12/2003 11:48:03 AM PST by Twinkie
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To: RadioAstronomer
Our "eyes" are decent, and have a substantial range, but no matter how hard we search we can find no sign of intelligent life.

How hard have we searched?

If there are civilizations more advanced than our own, why wouldn't they make themselves easier to find. Keep in mind, they would certainly know that we are here.

24 posted on 11/12/2003 12:00:57 PM PST by Moonman62
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To: Moonman62
Keep in mind, they would certainly know that we are here.

How? Our radio signals have only gone about 50 light years.

25 posted on 11/12/2003 12:03:06 PM PST by RadioAstronomer
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To: RadioAstronomer
They would have known that life was here for quite a long time by observing the spectral lines in our atmosphere.
26 posted on 11/12/2003 12:36:42 PM PST by Moonman62
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To: Cobra Scott
...Are sharks less evolved than primates?

Is complexity a desirable trait and simplicity undesireable, in the grand scheme of things?

Apparently not, until one species happens to pass a certain threshold of intelligence. At that point, history tells us that it became very desirable for us. So I guess one species has to first stumble onto that one developmental pathway & reach that threshold level where more intelligence is better. Up until that point, a runaway evolution of increasing intelligence is not necessarily desirable at all.
27 posted on 11/12/2003 12:40:37 PM PST by jennyp (http://crevo.bestmessageboard.com)
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To: WackyKat
Cockroaches are the pinnacle of evolution

As I understand it, bacteria still make up the bulk of the biomass on Earth! However, we're the only species who will ever know this.

28 posted on 11/12/2003 12:42:16 PM PST by jennyp (http://crevo.bestmessageboard.com)
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To: farmfriend
We could be monitored up the ying-yang and not know it with sub-atomic sized probes reporting back our relative primitiveness.
29 posted on 11/12/2003 12:45:39 PM PST by Semper Paratus
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To: Moonman62
Life yes. Tool making life? Not sure if you could tell that way. Will have to think about that. :-)
30 posted on 11/12/2003 12:48:16 PM PST by RadioAstronomer
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To: farmfriend
It's the old non-interference-prime-directive thing.
31 posted on 11/12/2003 12:52:20 PM PST by Consort
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To: KantianBurke
"But this doesn't make much Marklar when you consider that these Marklar are nothing like the Marklar that were Marklared on the earlier Marklar."
32 posted on 11/12/2003 12:53:12 PM PST by beezdotcom ("Where there's smoke, there's an anti-smoking lobby...")
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To: RadioAstronomer
Our radio signals have only gone about 50 light years.

Is that all? Wow. That doesn't get us very far does it.

33 posted on 11/12/2003 12:56:27 PM PST by farmfriend ( Isaiah 55:10,11)
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To: beezdotcom

Detective Marsh says for you to quit mixing up episode quotes! :>

34 posted on 11/12/2003 12:58:04 PM PST by KantianBurke (Don't Tread on Me)
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To: Consort
It's the old non-interference-prime-directive thing.

They are waiting for us to develope warp drive. Course they will have to be passing by at just the right moment.

35 posted on 11/12/2003 12:58:10 PM PST by farmfriend ( Isaiah 55:10,11)
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To: beezdotcom
and Kenny's a poor piece of crap.
36 posted on 11/12/2003 12:58:26 PM PST by KantianBurke (Don't Tread on Me)
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To: farmfriend



37 posted on 11/12/2003 1:03:27 PM PST by paulklenk (DEPORT HILLARY!)
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To: paulklenk
Hahaha, It's a cook book!!!!
38 posted on 11/12/2003 1:04:15 PM PST by farmfriend ( Isaiah 55:10,11)
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To: cateizgr8
I want to believe.
39 posted on 11/12/2003 1:44:25 PM PST by Britton J Wingfield (TANSTAAFL)
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To: Semper Paratus; All
"We could be monitored up the ying-yang and not know it with sub-atomic sized probes reporting back our relative primitiveness."

Zotar and I were just discussing the results of your probed ying-yang, puny earthling!....we predict quite a bit of laughter back at galactic head-quarters!


40 posted on 11/12/2003 1:46:30 PM PST by mdmathis6
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To: farmfriend
Maybe they were already on the way, picked up our Television broadcasts, and turned around when yet another Lucy sitcom premiered.
41 posted on 11/12/2003 1:59:56 PM PST by theDentist (Liberals can sugarcoat sh** all they want. I'm not biting.)
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To: RadioAstronomer
Life yes. Tool making life? Not sure if you could tell that way. Will have to think about that. :-)

That depends on how rare planets with any type of life are. We are probably within a decade or two of having a pretty good answer for that. If there is an advanced civilization in our galaxy, they've probably been studying our planet for quite some time. I don't think it would consume too much of their economic output to keep a light on for us, even if it is for millions of years.

42 posted on 11/12/2003 2:18:58 PM PST by Moonman62
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To: KantianBurke
and Kenny's a poor piece of crap.

I thought he looked just fabulous with his queer makeover a couple of weeks ago. :)

43 posted on 11/12/2003 2:25:18 PM PST by Allegra (CBS has canceled this tagline. It was "not due to controversy." Tom Daschle is disappointed.)
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To: beezdotcom
But that's my point. There is more than one Marklar of Marklar in the Marklar, so maybe the reason no Marklars have Marklared here is they fear that our Marklars aren't Marklar enough to handle the Marklar.

And Kenny *IS* a Marklar peice of Marklar.
44 posted on 11/12/2003 3:02:56 PM PST by beezdotcom ("Where there's Marklar, there's an anti-Marklar Marklar...")
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To: Physicist
"And in any case, there are always more interesting and important adventures and discoveries to be found at the next level downward."

Sounds like my career.

45 posted on 11/12/2003 3:05:53 PM PST by truthandjustice1
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To: beezdotcom

46 posted on 11/12/2003 3:17:58 PM PST by KantianBurke (Don't Tread on Me)
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To: Normal4me; RightWhale; demlosers; Prof Engineer; BlazingArizona; ThreePuttinDude; Brett66; ...
I don't buy this argument that we are alone cause we don't see the aliens yet.. The universe is pretty big. Here are some reason why they may have not visited Earth yet.

1. Advanced civilizations may not want to visit us. They may think we are boring or a waste of time. Heck they may be coming here to conquer us.
2. There are civilizations that is at our level or space technology. Basically no means of FTL (Yes it is possible).
3. There are civilizations that is at the beginning of development.

God created Earth and the Stars. I doubt it he created the planet Earth as the only planet that has life. The universe is big real big.


Space Ping! This is the space ping list! Let me know if you want on or off this list!
47 posted on 11/12/2003 5:35:50 PM PST by KevinDavis (Let the meek inherit the Earth, the rest of us will explore the stars!)
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To: RadioAstronomer
Tool making life at an early 1900's level of development should leave a spectroscopic signature of pollution, right? If they build similar industrial machines as we, that is. The long odds are greatly against us if such a civilization exists, because such a level of development would last for a short time before they discovered better methods of power.

Searching for ET is tough! :)

48 posted on 11/12/2003 5:45:11 PM PST by Brett66
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To: Brett66; RadioAstronomer
Tool making life at an early 1900's level of development should leave a spectroscopic signature of pollution, right?

Ice cores have shown significant amounts of lead from Greek and Roman smelting operations going back 2000 years. Link

49 posted on 11/12/2003 6:12:26 PM PST by Moonman62
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To: Brett66
Searching for ET is going to be tough and dauting task.
50 posted on 11/12/2003 6:32:52 PM PST by KevinDavis (Let the meek inherit the Earth, the rest of us will explore the stars!)
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