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#11
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On May 19, 8:56*am, wrote:
"A team of astronomers has identified a novel new kind of galactic wanderer - lone, Jupiter-sized planets expelled from forming solar systems and drifting in the empty void between the stars. The researchers, led by Takahiro Sumi of Japan's Osaka University, spotted 10 such free-floating "orphan planets" in data from a 2006-7 microlensing survey of our galaxy's centre, which searched for the tell-tale sign of transiting bodies' gravitational fields distorting light from distant stars. Team member David Bennett, of the University of Notre Dame in Indiana, explained that this first sighting in a small portion of the Milky Way points to enormous numbers of orphans. He said: "Our survey is like a population census. We sampled a portion of the galaxy, and based on these data, can estimate overall numbers in the galaxy."" See: http://www.theregister.co.uk/2011/05/19/orphan_planets/ Future space travels at any significant velocity are going to become interesting, whereas even at 0.1c (30,000 km/sec) is going to represent a highly speculative gamble, even if the very pointy nose of the interstellar craft were made of solid titanium and coated with a thick sacrificial layer of carbonado (Russians use solid blocks of extremely high density energy as an explosive coating for their initial tank armor). For interstellar treks, it looks as though we'll need some really good bumpers on our fusion and ion rocket driven spacecrafts. Obviously sending a small fleet of radar equipped probes way ahead in order to chart a viable course that would not involve encountering wandering/ rogue items of even a m3, would be imperative (detecting each and every cm3 or larger item seems wise). At even 0.1c velocity, having a fleet of those scout probes with radars looking in all critical directions, say five probes positioned perhaps at least .001 ly ahead and out to either side, top and bottom would give sufficient .365 day (8.76 hour) warnings of any potential encounters, so that evasive maneuvers could be taken or multiple laser cannons fired at the pending threat. http://www.wanttoknow.info/ http://translate.google.com/# Brad Guth, Brad_Guth, Brad.Guth, BradGuth, BG / “Guth Usenet” |
#12
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On May 19, 4:58*pm, Pat Flannery wrote:
On 5/19/2011 8:21 AM, David Spain wrote: Well brother, just the news we need. So much for navigating through interstellar space on Warp Drive. At least until we've charted all these guys... That probably wouldn't be a problem; although there may be a lot of them flying around out there, interstellar space is so large that physically running into one would be a very unlikely event. I'd worry more about hitting something in a star's Oort cloud as one approached a solar system, although that's probably fairly unlikely also. Fun to know if these things have moons around them. Pat Considering that the Earth hasn't been knocked out of it's orbit by a close encounter with one of these sometime during it's multi-billion year history, they might be rare in our neck of the galactic woods. |
#13
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Pat Flannery wrote:
Orval Fairbairn wrote: Of course, blindly setting off at relatavistic speeds is a recipe for sure disaster! hitting even a pea-sized mass at that speed would release the energy equivalent of an atomic bomb. So, unless you have some kind of shielding or space-warping techniques, brute force interstellar would be a minefield. Looking across space it looks empty. That means the objects are very sparse. Whether that means they are sparse enough to be a danger is something that only some interstellar trips can really determine. But if there are a lot of them they might still be useful as resources for people who live way out there and are in no hurry to get from one to another. They never seem to discuss how the starship slows down at the end of its trip so it can get more than a few hours glimpse of the target solar system as it moves through it at near light speed. It slows down the same way it speeds up. Using its impressive space drive. Whatever that is. Could be anything from a Bussard ramjet though a warp drive. |
#14
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Pat Flannery wrote:
Doug Freyburger wrote: The question becomes one of estimated densities by size. How many Trans-Neptunian Objects in the Kuiper belt are how big? How large is the Oort cloud and how much does it overlap with the clouds of other stars? How many planet sized objects are alone out there? How many large objects have entire dark moon systems out there? The list of questions only gets easy to answer once the objects are big enough to acheive ignition and shine from their own fusion. Even with M class stars they are too dim to be accurately surveyed beyond 20-30 light years. If there are objects of Jupiter size hanging out in the Kuiper belt they should be detectable as they eclipse distant stars. True. Objects of Pluto size are still being discovered. There may be several of them in that size range, and vast numbers a kilometer or a few kilometers in diameter. Farther out in the Oort cloud they would get harder and harder to detect. Consider the theory of "Nemesis" the brown dwarf on a long elipse that has never been disproved. |
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On May 19, 5:17*pm, wrote:
On May 19, 4:58*pm, Pat Flannery wrote: On 5/19/2011 8:21 AM, David Spain wrote: Well brother, just the news we need. So much for navigating through interstellar space on Warp Drive. At least until we've charted all these guys... That probably wouldn't be a problem; although there may be a lot of them flying around out there, interstellar space is so large that physically running into one would be a very unlikely event. I'd worry more about hitting something in a star's Oort cloud as one approached a solar system, although that's probably fairly unlikely also. Fun to know if these things have moons around them. Pat Considering that the Earth hasn't been knocked out of it's orbit by a close encounter with one of these sometime during it's multi-billion year history, they might be rare in our neck of the galactic woods. oh it will pay a visit may 21st 2011 for its first close encounter with earth, and come back for a smashing time december 21st 2012 ![]() sorry this was too good to pass up! |
#16
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On 5/19/2011 8:21 AM, David Spain wrote:
Well brother, just the news we need. So much for navigating through interstellar space on Warp Drive. At least until we've charted all these guys... That probably wouldn't be a problem; although there may be a lot of them flying around out there, interstellar space is so large that physically running into one would be a very unlikely event. I'd worry more about hitting something in a star's Oort cloud as one approached a solar system, although that's probably fairly unlikely also. Fun to know if these things have moons around them. Pat |
#17
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On May 19, 2:17*pm, wrote:
On May 19, 4:58*pm, Pat Flannery wrote: On 5/19/2011 8:21 AM, David Spain wrote: Well brother, just the news we need. So much for navigating through interstellar space on Warp Drive. At least until we've charted all these guys... That probably wouldn't be a problem; although there may be a lot of them flying around out there, interstellar space is so large that physically running into one would be a very unlikely event. I'd worry more about hitting something in a star's Oort cloud as one approached a solar system, although that's probably fairly unlikely also. Fun to know if these things have moons around them. Pat Considering that the Earth hasn't been knocked out of it's orbit by a close encounter with one of these sometime during it's multi-billion year history, they might be rare in our neck of the galactic woods. However somewhat less rare as we get overtaken by the Sirius Oort cloud. http://www.wanttoknow.info/ http://translate.google.com/# Brad Guth, Brad_Guth, Brad.Guth, BradGuth, BG / “Guth Usenet” |
#18
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On 5/19/2011 8:38 AM, jacob navia wrote:
I always thought that warp drives work only in another dimension. Speeding within the Milky Way at almost light speed is impossible anyway since a single wandering dust of 200 grams hitting the spaceship has an energy of an atomic bomb of 1.4937 megatons... That's why you make starships by hollowing out dead white dwarf stars, so you have a couple of hundred miles of diamond between you and outer space for the dust particles to run into. Assuming the shell would support itself, everything inside this literal "star-ship" would be weightless, so you could actually make the concept work...although the hollowing out part of it might be a bit much under its surface gravity field. :-D Pat |
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On 5/19/2011 10:18 AM, Doug Freyburger wrote:
The question becomes one of estimated densities by size. How many Trans-Neptunian Objects in the Kuiper belt are how big? How large is the Oort cloud and how much does it overlap with the clouds of other stars? How many planet sized objects are alone out there? How many large objects have entire dark moon systems out there? The list of questions only gets easy to answer once the objects are big enough to acheive ignition and shine from their own fusion. Even with M class stars they are too dim to be accurately surveyed beyond 20-30 light years. If there are objects of Jupiter size hanging out in the Kuiper belt they should be detectable as they eclipse distant stars. Pat |
#20
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On 5/19/2011 10:34 AM, Orval Fairbairn wrote:
Of course, blindly setting off at relatavistic speeds is a recipe for sure disaster! hitting even a pea-sized mass at that speed would release the energy equivalent of an atomic bomb. So, unless you have some kind of shielding or space-warping techniques, brute force interstellar would be a minefield. Not only that, but the more distant your target star is, the more difficult to know where exactly it will be when you arrive at it. Not only do you have the problem of knowing all the data on its position is already many years old as its light traveled to Earth, but you also have to figure out how its position has changed by gravitational effects of other stars that may have come near it over time, like a three-body problem gone mad. They never seem to discuss how the starship slows down at the end of its trip so it can get more than a few hours glimpse of the target solar system as it moves through it at near light speed. Pat |
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