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(Slate)   Say hello to my faint, cool, little friends: Astronomers discover third closest star system just six light years away   (slate.com) divider line 108
    More: Cool, light-years, Alpha Centauri, Atomic Nucleus, NASA's Wide, failed star, Binary Star, metallicity, dwarf star  
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9343 clicks; posted to Main » on 11 Mar 2013 at 1:43 PM (1 year ago)   |  Favorite    |   share:  Share on Twitter share via Email Share on Facebook   more»



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2013-03-11 05:14:26 PM  

PirateKing: So any planet that orbits a brown dwarf would have to be relatively close to be habitable, but aren't most of the extra-solar planets we've detected relatively close to their primaries?

Or is that just sampling bias because it's easier to detect planets that are in close?


As I understand it, our current best technique for detecting extrasolar planets requires us to be able to measure the apparent dimming of a star as a planet passes in between us and the star.  As a result, it's comparatively easy to identify a Jupiter-like gas giant closely orbiting a dwarf star, but identifying an Earth-like planet in the Goldilocks zone of a star like our own sun would still be quite difficult, if it's even possible.
 
2013-03-11 05:24:17 PM  

SnarfVader: Lt. Cheese Weasel: 6 light years?  Might as well be 6 billion light years.  We're never getting off this rock to make that kind of voyage.  EVER.


This assumption is based on beliefs we hold true today.

Tomorrow?

Not so much.

Our current understanding of "space-time" and the "laws" of the universe may be about as accurate as the belief in geocentrism back in the day. With enough time, technology, and curious muldoons asking questions and finding answers, we'll figure it out.

If you can see it, you can get to it...eventually.

Who's with me........
mimg.ugo.com
 
2013-03-11 05:38:11 PM  

SmackLT: Wait, it's a binary star system?

FARK PARTY MOS EISLEY CANTINA 2023


Why not?  It's already a wretched hive of scum and villainy.  Farkers will fit right in.
 
2013-03-11 05:41:15 PM  
Rising_Zan_Samurai_Gunman:  Above 75-80 Mj you start fusing Hydrogen 1 and you have a Red dwarf, which is the lowest level of main sequence star, and the most common in our section of the galaxy.

cache.io9.com
Smoke me a kipper.
 
2013-03-11 05:42:40 PM  

thisispete: So if we have the technology to readily detect brown dwarfs, does that mean we will soon have a yay or nay on the Nemesis hypothesis?


heh
was just reading about extinctions
they have not found the Nemesis body, which is not the same as there isnt a Nemesis body or bodies or effect. Pretty sure that they have ruled out a body of X mass and above. Pretty sure.
 
2013-03-11 05:44:15 PM  

anfrind: PirateKing: So any planet that orbits a brown dwarf would have to be relatively close to be habitable, but aren't most of the extra-solar planets we've detected relatively close to their primaries?

Or is that just sampling bias because it's easier to detect planets that are in close?

As I understand it, our current best technique for detecting extrasolar planets requires us to be able to measure the apparent dimming of a star as a planet passes in between us and the star.  As a result, it's comparatively easy to identify a Jupiter-like gas giant closely orbiting a dwarf star, but identifying an Earth-like planet in the Goldilocks zone of a star like our own sun would still be quite difficult, if it's even possible.


Dimming is one way and gravitational wobble is the other way.  Both work better with big, close planets with extremely short years.  The dimming method only works if the plane of that solar system is parallel to the direction we are observing it from.
 
2013-03-11 05:44:45 PM  

ciberido: Rising_Zan_Samurai_Gunman:  Above 75-80 Mj you start fusing Hydrogen 1 and you have a Red dwarf, which is the lowest level of main sequence star, and the most common in our section of the galaxy.

[cache.io9.com image 460x276]
Smoke me a kipper.


Brown Dwarf is Red Dwarf's cooler sibling.
 
2013-03-11 05:45:05 PM  
Using newer and more powerful infrared telescope technology, able to detect brown dwarfs as cool as 150 kelvins out to a distance of 10 light-years from the Sun,[10] results from the Wide-field Infrared Survey Explorer (WISE survey) have not detected Nemesis.[11][12] In 2011, David Morrison, a senior scientist at NASA known for his work in risk assessment of near Earth objects, has written that there is no confidence in the existence of an object like Nemesis, since it should have been detected in infrared sky surveys.[13][14][11]

unless it is colder than 150K ....
 
2013-03-11 05:49:53 PM  

stonicus: Stone Meadow: zarberg: StrangeQ: Our technology today is several orders of magnitude more advanced than it was 1000, 100 or even 10 years ago.  Give humanity another 1000 years without some sort of global catastrophe and it's really impossible to even imagine what our technology will be like.

That's the kicker. We can't even prevent ourselves from starting pointless wars or starving our own populations over greed, not sure how we're gonna not blow up the planet because of it.

Amazing at how much control people have over another is based on religion and religion claims to be so anti-greed.

That reminds me that I meant to reply to StrangeQ: I was surfing the web this morning when I glanced at this article about quantum entanglement occurring at speeds at least "10,000 times the speed of light". If that could be developed into a interstellar drive system, we could travel to the nearest stars in as little as less time than it currently takes to get to the moon (3 days in an Apollo). THAT's the kind of technological change we could conceivably see in the next 1000 years...or less.

/would love to live long enough to see that happen

It's a trap though... at maximum speed, sure a drive system like that could get you to mars and back in 3 days.  Though, it may take you 6 months to a year to safely accelerate a human body to that speed without turning it into spaghetti sauce, and the same goes for slowing down once you get to your destination.  Mars may be too close actually for that sort of technology.  It's like the corner store 2 blocks away.  Car beats bike in speed and acceleration, but it's always going to be just as quick (if not quicker) and easier and cheaper to just ride your bike 2 blocks away than to fire up the car.


What is likely to happen is not that we will invent holy grail drive that travels unbelievably fast, but we will invent a drive that can provide steady thrust over very long periods of time without needing massive quantities of reaction mass (as our current space drives do). Our spacecraft are currently designed to do a quick boost in one direction, then cruise; if we could accelerate halfway, then turn around and decelerate, we'd shave off significant fractions of travel time.

Sustained thrust like that would also be the key to sublight interstellar travel; accelerating at 1 G for a year gets you to a significant fraction of c.
 
2013-03-11 05:51:57 PM  

namatad: Using newer and more powerful infrared telescope technology, able to detect brown dwarfs as cool as 150 kelvins out to a distance of 10 light-years from the Sun,[10] results from the Wide-field Infrared Survey Explorer (WISE survey) have not detected Nemesis.[11][12] In 2011, David Morrison, a senior scientist at NASA known for his work in risk assessment of near Earth objects, has written that there is no confidence in the existence of an object like Nemesis, since it should have been detected in infrared sky surveys.[13][14][11]

unless it is colder than 150K ....


Can't prove a negative -- can't prove the non-existence of Nemesis.

The burden of proof that Nemesis does exist is on those who say that something like Nemesis does exist.
 
2013-03-11 05:52:34 PM  

Atillathepun: Dimming is one way and gravitational wobble is the other way.  Both work better with big, close planets with extremely short years.  The dimming method only works if the plane of that solar system is parallel to the direction we are observing it from.


Given the the massive number of extra-solar planets which we have discovered to date, it would be reasonable to conclude that we have only detected a small fraction of the actual planets out there.
It is funny to review old stories and writings about the rarity of life in the universe. It is rapidly approaching the point where fp has a value of 1 or close to 1.
 
2013-03-11 05:59:41 PM  

StopLurkListen: Can't prove a negative -- can't prove the non-existence of Nemesis.

The burden of proof that Nemesis does exist is on those who say that something like Nemesis does exist.


of course ... what they have proven is that nemesis is cooler than 150k, smaller than some mass (not sure of the value), further out than at least this orbit/mass combo. A small, cool black hole would be a candidate ... but no one has proven nothing at this point.

I enjoy reading about the attempts at explaining different extinction events. Even something which we think would be "easy", whether or not the 26My cycle is statistically significant gets debated on both side.

"that which can be asserted without evidence can be dismissed without evidence "
 
2013-03-11 06:02:19 PM  

stirfrybry: StrangeQ: SnarfVader: Lt. Cheese Weasel: 6 light years?  Might as well be 6 billion light years.  We're never getting off this rock to make that kind of voyage.  EVER.

While it does indeed look bleak right now, who knows what will happen in the next 100 to 1000 years? I'm not giving up yet especially because private companies are now capable of space flight.

Our technology today is several orders of magnitude more advanced than it was 1000, 100 or even 10 years ago.  Give humanity another 1000 years without some sort of global catastrophe and it's really impossible to even imagine what our technology will be like.

Corporations
In
Space


And we all know what that leads to....


upload.wikimedia.org
 
2013-03-11 06:02:26 PM  

SmackLT: Wait, it's a binary star system?

FARK PARTY MOS EISLEY CANTINA 2023


You will never find a more wretched hive of scum and villany.  We must be careful.  But I'll go if I can have my legacy FARK ID back.
 
2013-03-11 06:06:03 PM  

StrangeQ: Give humanity another 1000 years without some sort of global catastrophe and it's really impossible to even imagine what our technology will be like.


Why did Zager and Evans just pop into my head?

/some machines doing that for you.......in the year 2525, if man is still alive.....nevermind........
 
2013-03-11 06:08:29 PM  
qorkfiend: ... Sustained thrust like that would also be the key to sublight interstellar travel; accelerating at 1 G for a year gets you to a significant fraction of c

True, but I wasn't even really thinking about a real "drive", per se. Rather, I was reinforcing the comment that there are a large number of unknown-unknowns facing us in the coming centuries. We can't even begin to predict coming developments more than a few years out already...much less centuries or even decades from now.

Cool beans, eh?
 
2013-03-11 06:09:42 PM  
qorkfiend: What is likely to happen is not that we will invent holy grail drive that travels unbelievably fast, but we will invent a drive that can provide steady thrust over very long periods of time without needing massive quantities of reaction mass (as our current space drives do). Our spacecraft are currently designed to do a quick boost in one direction, then cruise; if we could accelerate halfway, then turn around and decelerate, we'd shave off significant fractions of travel time.

Sustained thrust like that would also be the key to sublight interstellar travel; accelerating at 1 G for a year gets you to a significant fraction ofc.


I feel like I just read a BattleTech book.

/that's a good thing.
 
2013-03-11 06:19:32 PM  

stirfrybry: StrangeQ: SnarfVader: Lt. Cheese Weasel: 6 light years?  Might as well be 6 billion light years.  We're never getting off this rock to make that kind of voyage.  EVER.

While it does indeed look bleak right now, who knows what will happen in the next 100 to 1000 years? I'm not giving up yet especially because private companies are now capable of space flight.

Our technology today is several orders of magnitude more advanced than it was 1000, 100 or even 10 years ago.  Give humanity another 1000 years without some sort of global catastrophe and it's really impossible to even imagine what our technology will be like.

Corporations
In
Space


Yes it will be awesome when they purchase some mineral right and create a shade panel ala simpsons mr burns.  So we have to pay for sunlight.

Only 1/2 kidding.  I think a lot of people grossly overestimate how deep corps are interested in going into their pockets without an extreme profit potential.

It will have to be a collective of the people and governments if it were ever to happen the ROI is too much of a risk for a for profit company to endure.
 
2013-03-11 06:22:16 PM  

SnarfVader: Lt. Cheese Weasel: 6 light years?  Might as well be 6 billion light years.  We're never getting off this rock to make that kind of voyage.  EVER.

While it does indeed look bleak right now, who knows what will happen in the next 20 to 100 years? I'm not giving up yet especially because private companies are now capable of space flight.


Low Earth orbit is not space, at all. They're still being protected by the various fields around the planet. Actual space is extremely hazardous to us.

And beyond those hazards, we've evolved specifically for the conditions on Earth. Aside from gravity, the sun at this particular distance regulates our hormones to keep us healthy and allow us to reproduce. We can't just up and leave.
 
2013-03-11 06:23:21 PM  

qorkfiend: stonicus: Stone Meadow: zarberg: StrangeQ: Our technology today is several orders of magnitude more advanced than it was 1000, 100 or even 10 years ago.  Give humanity another 1000 years without some sort of global catastrophe and it's really impossible to even imagine what our technology will be like.

That's the kicker. We can't even prevent ourselves from starting pointless wars or starving our own populations over greed, not sure how we're gonna not blow up the planet because of it.

Amazing at how much control people have over another is based on religion and religion claims to be so anti-greed.

That reminds me that I meant to reply to StrangeQ: I was surfing the web this morning when I glanced at this article about quantum entanglement occurring at speeds at least "10,000 times the speed of light". If that could be developed into a interstellar drive system, we could travel to the nearest stars in as little as less time than it currently takes to get to the moon (3 days in an Apollo). THAT's the kind of technological change we could conceivably see in the next 1000 years...or less.

/would love to live long enough to see that happen

It's a trap though... at maximum speed, sure a drive system like that could get you to mars and back in 3 days.  Though, it may take you 6 months to a year to safely accelerate a human body to that speed without turning it into spaghetti sauce, and the same goes for slowing down once you get to your destination.  Mars may be too close actually for that sort of technology.  It's like the corner store 2 blocks away.  Car beats bike in speed and acceleration, but it's always going to be just as quick (if not quicker) and easier and cheaper to just ride your bike 2 blocks away than to fire up the car.

What is likely to happen is not that we will invent holy grail drive that travels unbelievably fast, but we will invent a drive that can provide steady thrust over very long periods of time without needing massive quantities of reaction mass (as our current space drives do). Our spacecraft are currently designed to do a quick boost in one direction, then cruise; if we could accelerate halfway, then turn around and decelerate, we'd shave off significant fractions of travel time.

Sustained thrust like that would also be the key to sublight interstellar travel; accelerating at 1 G for a year gets you to a significant fraction of c.


Unfortunately, all of our drive technology really does amount to throwing mass in the other direction (solar sails being the exception, but not helpful between systems). Unless you think Blinsight's quantum ion teleporter is doable, we're stuck with massive amounts of fuel.
 
2013-03-11 06:25:07 PM  

Stone Meadow: We can't even begin to predict coming developments more than a few years out already...much less centuries or even decades from now.


I can.  Current oceanic pollution rates mean algae blooms will stop growing = most of the oxygen production on this miserable rock will be gone.  When the algae is gone, krill and most small lifeforms die including plankton. It balloons up the food chain exponentially. Oceans will be void of significant fisheries and life.

Bees will be gone (unless colony collapse is solved.)  No pollinators means grain stocks depleted = most animals we raise for protein are dead. Imagine a world with no wheat, soy beans or rice. Fruit/vegetables will only be grown on very low scale manually pollinated farms....like Japan does.  We'll fight over those first once the panic hits.

We'll be eating each other inside 100 years.

Feeling very doomish today.  You'll get over it.  Have a beer.
 
2013-03-11 06:43:27 PM  

Lt. Cheese Weasel: Stone Meadow: We can't even begin to predict coming developments more than a few years out already...much less centuries or even decades from now.

I can.  Current oceanic pollution rates mean algae blooms will stop growing = most of the oxygen production on this miserable rock will be gone.  When the algae is gone, krill and most small lifeforms die including plankton. It balloons up the food chain exponentially. Oceans will be void of significant fisheries and life.

Bees will be gone (unless colony collapse is solved.)  No pollinators means grain stocks depleted = most animals we raise for protein are dead. Imagine a world with no wheat, soy beans or rice. Fruit/vegetables will only be grown on very low scale manually pollinated farms....like Japan does.  We'll fight over those first once the panic hits.

We'll be eating each other inside 100 years.

Feeling very doomish today.  You'll get over it.  Have a beer.


What?  But I just watched a lesbian porn.
 
2013-03-11 06:45:56 PM  

J. Frank Parnell: And beyond those hazards, we've evolved specifically for the conditions on Earth. Aside from gravity, the sun at this particular distance regulates our hormones to keep us healthy and allow us to reproduce. We can't just up and leave.


Radiation in space is not friendly to meatbags in even short term exposures.  So even if the sustained thrust thingy is done, and you figure out how to protect the body it will still take a VERY long time to go 3+ light years to Alpha Centauri or 6 to the star in this farticle. We're not going to be bending space or going faster than light. How many generations do you think it would take on some platform if it headed to Alpha Centauri? 10?  20? 200? 20000? Someone do the math, I'm getting drunk.  Hint:  don't bother, get drunk and pork your bosses wife instead.
 
2013-03-11 06:46:03 PM  

StrangeQ: SnarfVader: Lt. Cheese Weasel: 6 light years?  Might as well be 6 billion light years.  We're never getting off this rock to make that kind of voyage.  EVER.

While it does indeed look bleak right now, who knows what will happen in the next 100 to 1000 years? I'm not giving up yet especially because private companies are now capable of space flight.

Our technology today is several orders of magnitude more advanced than it was 1000, 100 or even 10 years ago.  Give humanity another 1000 years without some sort of global catastrophe and it's really impossible to even imagine what our technology will be like.


Yeah that aint gonna happen, well before 1,000 years from now we are gonna have peak fresh water where farking water costs more than gasoline because there is too many of us parasites on the planet, then things go full retard after you have war, famine, pestilence, and death everywhere and it ends up going full Nuclear retard.

Our future will be more like Planet of the Apes than Star Trek.
 
2013-03-11 06:46:04 PM  

namatad: do they make up close to enough of the needed mass to explain the rotation of the galaxy?


Nope.  They're massive compared to the Earth, but they're like ants to stars.  Most likely there are hundreds of billions of them out there, but that doesn't change the equation much.

IIRC someone calculated how much mass in the form of non-fusing objects (rogue planets, brown dwarfs, etc.) would be needed to make up "dark matter" in spiral galaxies, and it came out to be so much that most of the stars in the sky would be blotted out by the traffic, like headlights on the other side of a busy crosswalk.  Which makes sense; these things are a tiny fraction of the Sun's mass, and if they were dark matter they'd make up the vast majority of the galaxy's mass.  There would need to be an absolutely staggering number of them.
 
2013-03-11 06:47:50 PM  

IRQ12:

It will have to be a collective of the people and governments if it were ever to happen the ROI is too much of a risk for a for profit company to endure.
Nah...  Study your history.  Specifically, look at how the development of insurance companies boosted world trade. When ONE successful mission can bring in enough money to pay for several failed missions, people can -- and will -- do it.
 
2013-03-11 06:51:44 PM  

Lt. Cheese Weasel: 6 light years?  Might as well be 6 billion light years.  We're never getting off this rock to make that kind of voyage.  EVER.


upload.wikimedia.org
 
2013-03-11 06:53:01 PM  

Oldiron_79: Our future will be more like Planet of the Apes than Star Trek.


billstermiteco.com
Only the roaches will win in the end.
 
2013-03-11 06:58:57 PM  

dragonchild: namatad: do they make up close to enough of the needed mass to explain the rotation of the galaxy?

Nope.  They're massive compared to the Earth, but they're like ants to stars.  Most likely there are hundreds of billions of them out there, but that doesn't change the equation much.

IIRC someone calculated how much mass in the form of non-fusing objects (rogue planets, brown dwarfs, etc.) would be needed to make up "dark matter" in spiral galaxies, and it came out to be so much that most of the stars in the sky would be blotted out by the traffic, like headlights on the other side of a busy crosswalk.  Which makes sense; these things are a tiny fraction of the Sun's mass, and if they were dark matter they'd make up the vast majority of the galaxy's mass.  There would need to be an absolutely staggering number of them.


that was my first sideways guess
on the other hand, I just read the article about the millions of black holes which were discovered.
how many black holes would be needed to explain the halo?
I am sure that they have answered that question. I just havent read about it.

dark matter has always felt like a kludge. esp when you think about occam's razor.
/what do I know ... I only have a ba in physics
 
2013-03-11 07:02:10 PM  

GeneralJim:

When ONE successful mission can bring in enough money to pay for several failed missions, people can -- and will -- do it.
Please note that what I am saying here is that the ECONOMIC problems of space flight are relatively simply solved.  On the other hand, the technical problems are a total biatch.  We have to develop a drive that can produce a constant 1 G acceleration for decades at a time, and with little if any carried fuel.  We have to be able to produce, in space, nutrition which is as complete as that found on Earth.  We have to be able to shield the craft from the radiation from which Earth is protected.  And all of this has to take place in an environment in which a single problem is very likely to cause death -- and it has to run without any serious problem, again for decades.  And, yeah, if I were writing a science fiction story, I'd arrange for a propulsion system based on some sort of wormhole drive, but reality is not as easy to alter as a script or a novel.  If we DO develop such a drive, and can, for example, go from one planet to a planet in another star system, THEN we re-evaluate.  People have a hard time visualizing how frigging FAR AWAY other stars are.  It's not really a concept that fits well in the human mind -- and that should be a clue.
 
2013-03-11 07:03:17 PM  

enik: Lt. Cheese Weasel: 6 light years?  Might as well be 6 billion light years.  We're never getting off this rock to make that kind of voyage.  EVER.

[upload.wikimedia.org image 200x166]



meganproctor.files.wordpress.com
I'd love it if some uber advanced  life form found us and saved us from ourselves.  I really would. But why would they bother?  We're a despicable dirty life form. Virus. Humans V2.0 might be better.  This petri dish is just about finished.
 
2013-03-11 07:41:02 PM  

namatad:

dark matter has always felt like a kludge. esp when you think about occam's razor.
/what do I know ... I only have a ba in physics

This is a common misconception, especially among snarky snobs -- that one must be a highly trained professional to make a wild-ass guess.  Such guesses are a necessary part of science: one needs a hypothesis to attempt to falsify, thus suggesting better ideas.  In point of fact, MANY times those same "professionals" are not suited to deal with some part of their science, because that part uses another specialty.  For example, in the field of climatology, proper analysis of many of the claims, and of the data themselves, is better handled by someone with a deep understanding of accounting, auditing, and statistics, than a climatologist.  That's why the exposure of the "hockey stick" fraud, and others, was done by outside auditors, rather than climate scientists.

And, while perfectly valid as an initial hypothesis, both the Anthropogenic Global Warming hypothesis, AGW, and the "dark matter" hypothesis are both hypotheses of back-filled ignorance.  In climate, the amount of insolation the planet was receiving was well known, and reasonably accounted for, and the planet was warming up more than appropriate.  As a first guess, "the extra warming is due to increased carbon dioxide" made good sense.  But, to this day, the rationale behind that is "we don't know of anything else it could be" rather than supporting it on its own merits.  The "dark matter" hypothesis is much the same:  "Our equations, which we like a LOT, only work if we assume that we don't know about around 84% of the matter in the universe.  Therefore, it must exist, although we can't see it."  Well, again, it's a good starting point.  However, "I don't know what else it could be" isn't very reassuring.

I recall a conversation with a physicist friend of mine.  In it, I was trolling him about dark matter.  After he explained his ideas, I said  "It's not dark matter, it's the spiritual universe - and humans cannot see spiritual matter, nor measure spiritual energy.  We therefore call them "dark," although they are, in reality, the actual reality of which physical matter is a shadow."  He was offended "You can't just make up a whole new type of matter, and pretend it exists!" he fumed.  "Why not?  You started it."  They are both essentially the same hypothesis, just with different names.

In climatology, we now know what it is that we were missing -- the Sun's magnetic energy, when it increases, makes a bigger shield to cosmic rays for Earth, and cosmic rays help generate clouds, which increases the albedo of the Earth, thus reflecting energy back into space.  So, more magnetic energy means fewer clouds, which means higher temperatures.  So, indirectly, the Sun's magnetic energy heats Earth as does the insolation.  (Why this is NOT a feedback is left as an exercise for the reader.)  Magnetic activity amplifies the effects of insolation, so solar activity warms the planet more than is accounted for by the insolation.  This extra warming was, previously, assigned to carbon dioxide, and all sorts of things were reverse-engineered from that assumption.  Now that it has proven incorrect, all the numbers about carbon dioxide need to be revisited, and the models programmed with this new understanding of the process.  But that is not feasible, as politicians LOVE the idea that burning anything is damaging, and needs to be controlled.

So far, there's no equivalent of Svensmark's work with cosmic rays to show where we missed the boat on the mass of the universe, etc.  In other words, we have not yet falsified the "dark matter" hypothesis the way we have AGW.  Who knows, though?   It might be right.  It just seems unlikely that a scientific fudge factor just happens to nail reality precisely.  So, we let people do their research, and we wait...

 
2013-03-11 07:43:26 PM  
Look, even a trip to Mars is arguably a one way ticket, based on todays tech.  Great, so we send some brave souls out, they plant a flag and we get a picture. They might even make it back. Good, uplifting and all that rot, but really....will Mars rocks be any more valuable than moon rocks?  IF there was life on Mars, it died a long time ago.

Our best hope, if there is any, is machines with a constant accelerated drive and massive fuel tank/supply, sent towards Alpha Centauri etc and we get lucky. (yes, I do think there are others out there.) Still not sure why they would give a damn about us or if they are in any better evolution phase to help us.

Voyager has almost left this solar system (another argument goes here)...how long has that taken? 35+ years? Half a generation just to reach the door that says 'this way out'.  Sorry. The scale is beyond our capacity to attack it technically.
 
2013-03-11 08:09:55 PM  

namatad: so how many brown dwarfs are there?


www.millionaireplayboy.com
 
2013-03-11 08:15:43 PM  
Third closest?  Yet discovered or what?  Because well, there was obviously a third closest like a zillion years ago.
 
2013-03-11 08:35:22 PM  

Lt. Cheese Weasel: 6 light years?  Might as well be 6 billion light years.  We're never getting off this rock to make that kind of voyage.  EVER.


Doesn't mean we can't look at it from here.  Being only six light years away makes that a hell of a lot easier.
 
2013-03-11 08:46:42 PM  

namatad: Using newer and more powerful infrared telescope technology, able to detect brown dwarfs as cool as 150 kelvins out to a distance of 10 light-years from the Sun,[10] results from the Wide-field Infrared Survey Explorer (WISE survey) have not detected Nemesis.[11][12] In 2011, David Morrison, a senior scientist at NASA known for his work in risk assessment of near Earth objects, has written that there is no confidence in the existence of an object like Nemesis, since it should have been detected in infrared sky surveys.[13][14][11]

unless it is colder than 150K ....


If it's really, really cold, it wouldn't have an atmosphere. If it were dark, it would be hard to spot.
 
2013-03-11 08:48:39 PM  

GeneralJim: one must be a highly trained professional to make a wild-ass guess.


Of course, most people like that just look it up in the Urantia Book.
 
2013-03-11 08:52:02 PM  

GeneralJim: namatad: dark matter has always felt like a kludge. esp when you think about occam's razor.
/what do I know ... I only have a ba in physics
This is a common misconception, especially among snarky snobs -- that one must be a highly trained professional to make a wild-ass guess.  Such guesses are a necessary part of science: one needs a hypothesis to attempt to falsify, thus suggesting better ideas.  In point of fact, MANY times those same "professionals" are not suited to deal with some part of their science, because that part uses another specialty.  For example, in the field of climatology, proper analysis of many of the claims, and of the data themselves, is better handled by someone with a deep understanding of accounting, auditing, and statistics, than a climatologist.  That's why the exposure of the "hockey stick" fraud, and others, was done by outside auditors, rather than climate scientists.
And, while perfectly valid as an initial hypothesis, both the Anthropogenic Global Warming hypothesis, AGW, and the "dark matter" hypothesis are both hypotheses of back-filled ignorance.  In climate, the amount of insolation the planet was receiving was well known, and reasonably accounted for, and the planet was warming up more than appropriate.  As a first guess, "the extra warming is due to increased carbon dioxide" made good sense.  But, to this day, the rationale behind that is "we don't know of anything else it could be" rather than supporting it on its own merits.  The "dark matter" hypothesis is much the same:  "Our equations, which we like a LOT, only work if we assume that we don't know about around 84% of the matter in the universe.  Therefore, it must exist, although we can't see it."  Well, again, it's a good starting point.  However, "I don't know what else it could be" isn't very reassuring.I recall a conversation with a physicist friend of mine.  In it, I was trolling him about dark matter.  After he explained his ideas, I said  "It's not dark matter, it's ...


Sometimes the "wild ass, uneducated guess" is the right guess, because it hasn't been indoctrinated into a particular world view.
 
2013-03-11 09:18:10 PM  

Guuberre: I read that as, "Say hello to my taint, cool little friends."


Glad I'm not the only one.
 
2013-03-11 09:59:36 PM  

Lt. Cheese Weasel: 6 light years?  Might as well be 6 billion light years.  We're never getting off this rock to make that kind of voyage.  EVER.


actually, based on some napkin scribbling that's not quite true.

If we could build a ship big enough to support an eco system for life support and food, and this ship housed nuclear reactors to drive ion engines that accelerate at 9.81 m/s; you would reach 3 light years in as little as 16 years.

Probably less as I reflect I didn't do my calculations properly(I scaled 9.81 m/s to Km/year as if it was velocity not acceleration).

Once the ship reaches the half way point, it would turn around and decelerate at the same rate. This solves the gravity problem as 9.81m/s squared is the force the earth exerts on us.

You could conceivably build a ship that could get you there in under 32 years.

Currently we don't have ion engines capable of this scale of thrust, but I feel we are within a few hundred years of having them. Everything else is just having the billions of dollars to build.
 
2013-03-11 10:23:11 PM  

elchupacabra: StopLurkListen: elchupacabra: I wanna find a brown dwarf that's just shy of the mass for sustained fusion and then nuke it.  Just to see the fireworks.

Dunno what you think is going to happen. Explode an almost-star, or start the fusion? If you want to start fusion, just drop matter into it, no "nuke" necessary. (Assuming in our scenario humanity is capable of moving 'Jupiter'-equivalent masses several light years just for lulz)

Nuking it would start fusion that would run out of steam as it would lack critical mass.  But it would last long enough for lulz.


No it wouldn't.
 
2013-03-11 10:58:58 PM  

C_Canuk: Lt. Cheese Weasel: 6 light years?  Might as well be 6 billion light years.  We're never getting off this rock to make that kind of voyage.  EVER.

actually, based on some napkin scribbling that's not quite true.

If we could build a ship big enough to support an eco system for life support and food, and this ship housed nuclear reactors to drive ion engines that accelerate at 9.81 m/s; you would reach 3 light years in as little as 16 years.

Probably less as I reflect I didn't do my calculations properly(I scaled 9.81 m/s to Km/year as if it was velocity not acceleration).

Once the ship reaches the half way point, it would turn around and decelerate at the same rate. This solves the gravity problem as 9.81m/s squared is the force the earth exerts on us.

You could conceivably build a ship that could get you there in under 32 years.

Currently we don't have ion engines capable of this scale of thrust, but I feel we are within a few hundred years of having them. Everything else is just having the billions of dollars to build.


Nope, not even close. There are two problems with your approach. First, ion engines are veeeeeeeeeeeeeeeerrrryyy low thrust. Figure a ten-thousandth of a G acceleration...maybe, but obviously nothing like 9.8 m/s^2. FWIW, the first ion engine to propel a rocket out of earth's orbit needed 13 months to pass the moon, and the nearest star is 81,000 years away at ion drive speeds.

Second, in spite of their high specific impulse, ion engines are still reaction engines, and NASA calculates that for a "real space ship" even a nuclear powered ion drive would take 4 days to go from zero to 60 mph...and their maximum speed would be about 321,000 km/h. That's great for low priority cargo moving around the solar system, but won't do for interstellar travel. Sorry man, but we gotta find a better technology. :)
 
2013-03-11 11:05:45 PM  

Stone Meadow: C_Canuk: Lt. Cheese Weasel: 6 light years?  Might as well be 6 billion light years.  We're never getting off this rock to make that kind of voyage.  EVER.

actually, based on some napkin scribbling that's not quite true.

If we could build a ship big enough to support an eco system for life support and food, and this ship housed nuclear reactors to drive ion engines that accelerate at 9.81 m/s; you would reach 3 light years in as little as 16 years.

Probably less as I reflect I didn't do my calculations properly(I scaled 9.81 m/s to Km/year as if it was velocity not acceleration).

Once the ship reaches the half way point, it would turn around and decelerate at the same rate. This solves the gravity problem as 9.81m/s squared is the force the earth exerts on us.

You could conceivably build a ship that could get you there in under 32 years.

Currently we don't have ion engines capable of this scale of thrust, but I feel we are within a few hundred years of having them. Everything else is just having the billions of dollars to build.

Nope, not even close. There are two problems with your approach. First, ion engines are veeeeeeeeeeeeeeeerrrryyy low thrust. Figure a ten-thousandth of a G acceleration...maybe, but obviously nothing like 9.8 m/s^2. FWIW, the first ion engine to propel a rocket out of earth's orbit needed 13 months to pass the moon, and the nearest star is 81,000 years away at ion drive speeds.

Second, in spite of their high specific impulse, ion engines are still reaction engines, and NASA calculates that for a "real space ship" even a nuclear powered ion drive would take 4 days to go from zero to 60 mph...and their maximum speed would be about 321,000 km/h. That's great for low priority cargo moving around the solar system, but won't do for interstellar travel. Sorry man, but we gotta find a better technology. :)


What would be creating that maximum speed barrier?
 
2013-03-11 11:12:39 PM  
Link
Project Longshot would have been cool.
 
2013-03-11 11:18:09 PM  
The speed of the reaction mass, no?

One thing a lot of people seem to forget is time dilation.  That 16 year trip would feel a lot shorter to the occupants.
 
2013-03-11 11:45:47 PM  

BafflerMeal: What would be creating that maximum speed barrier?


Two things...first, the laws of motion (and real world experience) dictate that on object's motion cannot exceed the velocity of the mass thrown in the opposite direction. This holds true for propeller-driven airplanes, fighter jets...and interstellar rockets.

And second, just as when you stick your hand out the window of your car and feel the drag of the wind on your arm and hand, even in deep interstellar space there is about one hydrogen atom per cubic centimeter that contributes to drag on a space ship...enough to hold its terminal velocity with an ion engine down to about 321,000 kph given the thrust available.

Hope that helps!
 
2013-03-12 12:12:08 AM  

Stone Meadow: BafflerMeal: What would be creating that maximum speed barrier?

Two things...first, the laws of motion (and real world experience) dictate that on object's motion cannot exceed the velocity of the mass thrown in the opposite direction. This holds true for propeller-driven airplanes, fighter jets...and interstellar rockets.

And second, just as when you stick your hand out the window of your car and feel the drag of the wind on your arm and hand, even in deep interstellar space there is about one hydrogen atom per cubic centimeter that contributes to drag on a space ship...enough to hold its terminal velocity with an ion engine down to about 321,000 kph given the thrust available.

Hope that helps!


yep.  thanks.  had glossed over those two in my head.
 
2013-03-12 02:23:21 AM  
At significant fractions of light speed, colliding with a spec of dist could do serious damage to a spaceship.

Accelerating (linerarly) at 1 g for 16 years?  Yeah, by the time you get to your destination hundreds or thousands of years would have passed.  That's kind of stupid, though.  A 1 g it would take on the order of a year to get to 99% the speed of light, after which time more acceleration wouldn't help much.  You'd only dilate time more and waste energy.
 
2013-03-12 05:32:47 AM  

aerojockey: At significant fractions of light speed, colliding with a spec of dist could do serious damage to a spaceship.

Accelerating (linerarly) at 1 g for 16 years?  Yeah, by the time you get to your destination hundreds or thousands of years would have passed.  That's kind of stupid, though.  A 1 g it would take on the order of a year to get to 99% the speed of light, after which time more acceleration wouldn't help much.  You'd only dilate time more and waste energy.


Unless your goal was more time dilation to allow for limited mission endurance (IE human lifespans/food/etc)
 
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