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posted by
martyb
on Wednesday November 14 2018, @10:33PM
from the with-an-oink-oink-here-and-a...oh,-wait dept.
from the with-an-oink-oink-here-and-a...oh,-wait dept.
Exoplanet discovered around neighbouring star
Astronomers have discovered a planet around one of the closest stars to our Sun.
Nearby planets like this are likely to be prime targets in the search for signatures of life, using the next generation of telescopes.
The planet's mass is thought to be more than three times that of our own, placing it in a category of world know as "super-Earths".
It orbits Barnard's star, which sits "just" six light-years away.
Writing in the journal Nature [DOI: 10.1038/s41586-018-0677-y] [DX], Guillem Anglada Escudé and colleagues say this newly discovered world has a mass 3.2 times bigger than the Earth's.
Also at phys.org.
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Exoplanet Detected Around Barnard's Star, 6 Light Years Away
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(Score: 4, Insightful) by bob_super on Wednesday November 14 2018, @10:52PM (25 children)
Instead of fighting all the time because someone expresses a different social, political or religious belief, can we just repurpose our advanced tech and mil budgets to explore the mindbogglingly diverse solar system and nearby stars ?
A bit more curiosity, a lot less anger.
(Score: 2) by PartTimeZombie on Wednesday November 14 2018, @11:12PM
That would be nice. I'm on board.
This is really close too*, if we're ever going to send someone off to have a look, Barnard's Star might be an option.
Not that I expect that to happen in my lifetime.
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.
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* for some values of close.
(Score: 2) by RamiK on Wednesday November 14 2018, @11:48PM
No. Fighting over meaningless values is what gives life meaning exceeding the bare struggle for survival life is otherwise. Any organism can expand its habitat. But it's only humans that can kill each other over spelling mistakes and the correct pronunciation of the one and only Flying Spaghetti Monster.
p.s. I may or may not had Nyango Star's Anpanman Maachi cover [youtube.com] playing in the background.
compiling...
(Score: 0) by Anonymous Coward on Wednesday November 14 2018, @11:54PM (1 child)
> Instead of fighting all the time ...
I've been on board as a pacifist all my life. When a neighborhood bully decided to beat me up for no apparent reason (middle school), I just sat down and he didn't know what to do next. I remember that as a very stressful event, but one with a good outcome (luckily he wasn't so committed that he started beating on me while I was down!)
This isn't any kind of religious pacifism, it's all personal. I've never had anything to do with religion. Point of pride, I've never been to a regularly scheduled church service, parents didn't take me to church.
On the other hand, I've been in a few business conflicts and then I fight hard.
(Score: 2) by MichaelDavidCrawford on Thursday November 15 2018, @01:19AM
I used to get beat up all the time but then I somehow figured out how to knock someone flat with just one punch.
Yes I Have No Bananas. [gofundme.com]
(Score: 3, Interesting) by edIII on Thursday November 15 2018, @12:14AM (14 children)
Unlikely. There are still the tech hurdles to work out, the differences in time, and the impossibility of visiting most super earths. Assuming some tech hurdles are worked out, it will be you launching the vehicle, and your great-great-grandchild inspecting the datastreams once there, and then a great-great-great-great-great-great-grandchild might visit it. Humans are not that generally forward thinking, or sacrificial for the future either. Children are cared about, but the next generation after that is simply to far ahead to give a shit. I blame c-suits myself and their institutionalized short-term thinking.
That, and it takes evolved intellectuals to get excited enough about scientific exploration to find it more worthy than killing the neighbor for wrongthink.
Even then, it sounds like nobody will ever visit a super earth. At least not without permanent residence. IIRC, there were calculations about the amount of power needed for escape velocity from a super earth, and we didn't have any technology or energy density that came even close. In short, you're never getting off the ground again. We're never retrieving samples, and all we will ever have are telemetry coming from devices. We need advanced drive systems that run on pure energy, and the energy densities that can only be obtained with advanced fission/fusion devices. The flying DeLorean has a better chance of getting off the ground with Mr. Fusion and those hybrid tire/thrusters than any of our current tech.
I think at most we can reasonably shoot for mining asteroids, or bringing them into stable orbit with the moon to be mined there. One of the reasons why everyone cannot have an engine that "runs on water", were the requirements of large amounts of platinum. Between the oceans storing carbon for us (carbon nanotubes), and asteroids giving us all the heavy and precious metals we could want, a lot of the ideas to switch us from fossil fuels become economically viable.
That's after the platinum market crashes the same way the aluminum market did when the Bayer and Hall-Héroult processes were starting to be used :) Could you imagine what it would be possible to build with super cheap platinum, gold, silver, etc?
Realistically, we should shoot for colonies on the moon and mars, and start asteroid mining as soon as possible to gain access to the resources.
Technically, lunchtime is at any moment. It's just a wave function.
(Score: 2) by MichaelDavidCrawford on Thursday November 15 2018, @01:22AM (13 children)
Antimatter drives are no science fiction: CERN is actively working on them. So far they can hold a few highly-cooled (slow) antiprotons in a magnetic bottle for a very brief time.
It's not the gas, it's the gas tank: if antimatter comes into contact with regular matter you set your starship up The Bomb.
Yes I Have No Bananas. [gofundme.com]
(Score: 2) by RandomFactor on Thursday November 15 2018, @02:52AM (2 children)
It's both really.
Yes, antimatter makes CIF3 look noble, however the fuel itself is also crazy difficult and expensive to manufacture as well.
Still....want antimatter drive NOW!
В «Правде» нет известий, в «Известиях» нет правды
(Score: 3, Funny) by MichaelDavidCrawford on Thursday November 15 2018, @03:34AM (1 child)
-t.
Some of them have pointy ears. All the pointy-eared ones are also wearing green facepaint.
As they approach you can see that their holding up brightly hand-painted signs. Then you can hear them shouting. From a distance at first, but when two blocks away you can just make it out:
"WHAT DO WE WANT?"
"WARP DRIVE!"
"WHEN DO WE WANT IT?"
"NOW!"
Yes I Have No Bananas. [gofundme.com]
(Score: 1, Touché) by Anonymous Coward on Thursday November 15 2018, @11:28AM
Every self-respecting Trekkie knowns that the Warp drive will be invented in the 2060s by Zefram Cochrane.
(Score: 4, Interesting) by edIII on Thursday November 15 2018, @04:17AM (8 children)
Which makes them too dangerous to use. At least not without putting the engine really really realllly far behind or in front of the main part of the ship. How big is the blast wave from one of these antimatter storage pods? You need to be at least that far away.
Star Trek science sounds great and all, but I think the risk assessment of antimatter drives makes them unusable in a typical starship.
What if you merged antimatter engines with space elevators? 100k feet of multiple carbon nanotube ropes attached to engines, with thrusters on the main ship, could keep it taught and allow the main part of the ship to be dragged like a sled. You could then drag multiple backup engines behind, and even use them to slow down. Like a two-way bullet train through space.
The added benefit to such a design would be using the ship and engines as counterweights, and then lower carbon nanotube ropes down to the surface of the super earth. Portable space elevator. You could make it possible to load up whatever cargo from the surface you want, then attach it to an antimatter engine in space and pull it straight off the planet :)
At least, that's the only way I would use such things. Star Trek is a TV show. I highly doubt that they could make such antimatter storage pods safe enough to live around.
Technically, lunchtime is at any moment. It's just a wave function.
(Score: 2) by bob_super on Thursday November 15 2018, @05:33AM
Shockwaves in space go down in intensity with the square of the distance.
Shockwaves propagating through the superstructure don't.
Shrapnel will hit you at full speed regardless of distance, but shrapnel density also goes down with the square of the distance.
You gotta need a bigger ship. With a huge soft shield in the middle.
(Score: 3, Informative) by Immerman on Thursday November 15 2018, @04:54PM (6 children)
Not really - if the fuel tank explodes, everybody's dead anyway - doesn't really make much difference if it's instantly or after they run out of supplies. Earth (or anywhere a rescue ship could reach in time) is a special case - anywhere else your long-term survival depends on that fuel, so all other design decisions can be based on the assumption that the fuel tanks won't explode.
As for your "towing engines" - there's a few big problems:
#1: 100k feet of carbon fiber is heavy, radically increasing the mass of the ship, and thus reducing acceleration.
#2: Carbon fiber is flammable - fire up your engines and it will be rapidly incinerated by the exhaust and leave you behind.
#3: Shorter, heavier, flame-proof cables mean your ship is blocking a lot of the exhaust, neutralizing its thrust.
#4: Tilting multiple engines outward so that your rope and ship aren't in the exhaust means a percentage of the thrust is working against itself, so you're wasting acceleration potential.
Of course if your nuclear/antimatter/whatever drives have enough specific impulse to waste a fair percentage some, then #1 and #4 can be solved with more money, and it could work.
As for a space elevator - that's actually a great idea for visiting super Earths. *IF* we could develop a material with enough tensile strength to support it's own weight. Sadly, multiwalled carbon nanotubes, the strongest material we know of, are only barely strong enough to work on Earth, with safety margins that would make any responsible engineer run screaming for the hills. Even more sadly, there's reason to believe they're approaching the maximum strength-to-weight ratio of any material that could exist - C-C molecular bonds are (among?) the strongest known, and bonds generally get weaker as you move up the periodic table, while density increases considerably more quickly, so there's not even much hope of eventually finding some sort of exotic element that could do the job better.
Also, you'd probably need a LOT more than 100k feet, though that depends on the rotational speed of the planet. On Earth, you need 22,236 mi (~12 million feet) to reach geostationary orbit.
Of course, that only applies if we're talking about a traditional "beanstalk" elevator. If instead we used a "tumbling cable" skyhook in low orbit, you could use a much shorter and weaker cable tumbling fast enough that the lower end neutralized most of the low-orbit velocity while just skimming the atmopshere, while your landing craft could be a high-speed rocket-plane that could make up the difference and rendezvous with the cable at negligible relative speed.
(Score: 2) by edIII on Thursday November 15 2018, @10:00PM (5 children)
Too much risk that a fuel tank will explode, and like you say, you are very very far away from supplies. I was thinking multiple engines and fuel tanks though, all kept far away from the main ship. One engine tows you from the front, and the trailing engines are towed behind you. If those trailing engines are oriented to fire backwards, you could use it as a way to slow down too. Although, calculating orbits is much less fuel intensive for sure.
As for #2, I was imagining a wing like structure in the towing engine such that the tips have the cables, the center has the engine, and the ship itself is a torus. The thrust could be channeled through the center of the ship, with nothing blocking its path. With the torus, you could spin the inside for gravity, but also have the ability to twist to compensate for the thrust.
#4 doesn't apply, because the engines are not tilted. Straight backwards towards a center point.
#1 is a very good point. I thought we would have breakthroughs to make it stronger still, but your observation that we may be at the theoretical limits is sobering. My idea only works with cables that have the kind of strength and durability required, and hopefully, the ability to be manufactured out in space.
Your last idea about the skyhook sounds very interesting, but isn't the problem of a super earth that any landing craft lack the ability to reach escape velocity? I would assume that would make it difficult as well to reach the upper atmospheres, unless you factor in much denser air. If the latter, a high speed rocket plane might best be replaced with a hybrid dirigible.
Of course the whole idea centers around light and strong cabling that you kinda shot down, so not sure it is workable as I thought.
Technically, lunchtime is at any moment. It's just a wave function.
(Score: 2) by Immerman on Friday November 16 2018, @02:21AM (4 children)
So where do you put the second fuel tank so that it's not destroyed when the first tank explodes? Not to mention, even if you can pull that off you almost certainly need ALL that fuel to make it home, so destroying one tank is just as deadly as destroying all of them.
That would have to be a phenomenally large torus, as the exhaust plume expands rapidly thanks to being at higher pressure than the surrounding vacuum.
The beauty of a skyhook is that you don't *need* to reach escape velocity (or more accurately, orbital velocity - once you're in orbit reaching escape velocity is relatively simple). Picture the cable as one pair of spokes describing a line through the center of a wheel. A wheel which is spinning at just the right speed so that the lowest point on the rim perfectly matches speed with the top of the atmosphere. Essentially you get a wheel rolling across the top of the atmosphere. And if you're in, say, a stationary hot air balloon directly beneath it you'll see a point on the rim come almost straight down above you, stop, and go back up again. Like this, only the wheel would be rolling around a circle, rather than along a flat plane: https://en.wikipedia.org/wiki/Cycloid [wikipedia.org]
So, you're sitting in your hot air balloon (which does indeed work even better in the dense atmosphere likely on a Super-Earth), floating at the top of the atmosphere. And when that cable tip comes down and momentarily stops right above you - you grab it. You can then ride the "wheel" up to the top of the arc, at which point you'll be traveling at over twice orbital speed. For a skyhook in low Earth orbit (~8km/s) , it that means you'd be traveling at ~16km/s, about 5km/s faster than escape velocity from orbit (escape velocity from orbit is sqrt(2) times the circular orbital speed), more than fast enough to reach the orbits of Pluto or Mercury without any further propulsion. So probably you want to let go before you reach the top.
That is to say - skyhooks can be *insanely* effective. Basically you're transfering angular momentum from the skyhook to the ship, but the skyhook's presumably much greater mass will keep it in orbit, where you can use ion thusters or other slow, high-efficiency propulsion to regain the lost momentum over a much longer time period. Or, you can rendevous incoming ships near the top of the wheel to slow them down and drop them gently into the atmosphere at negligible relative speed, in which case you transfer their angular momentum to the skyhook. A 100% efficient atmosphere-to-orbit momentum transfer bank with no moving parts.
As for launching from super-Earths, the big problem is that the superlinear rocket equation gets worse much faster, to the point that you just can't carry enough chemical propellant to reach orbit with a "simple" rocket. Nuclear rockets would still do the job nicely, as might some of the more clever and efficient launch systems we've dreamed up. But it means a civilization that started out on the surface of a planet would have to develop powerful nuclear rockets before they could reach orbit. If you start in orbit though, where you can build orbital space elevators of various types, then you simplify things immensely (for sufficiently obtuse definitions of "simplify" - we were building nuclear rockets within decades of our first orbital chemical rockets - while we're still nowhere close to building a skyhook. Theoretically we have the basic materials and technology to do it easily, but the cost and details of attempting an orbital project of that scale have kept us from doing so.
(Score: 2) by edIII on Friday November 16 2018, @05:48AM (3 children)
You really got me thinking about the viability of this. Fun to think about.
Think of an engine as a module that contains a thruster, antimatter storage pod, and then whatever matter we are mixing with (Deuterium?). The modules are separated. I do imagine the module can split in half with smaller thrusters to allow it to come apart and navigate back to the rear of the ship keeping maximum distance while rotating backwards, being dragged in half at the rear. Antimatter on one side, Deuterium on another.
You got me there. It would need to turn into a super structure at 100k feet behind if the plume expands that rapidly. Although, that also makes me wonder just how much heat is actually experienced along the surface area of the torus? The ineffiency you mentioned of being directly behind was blocking some of it right? A torus, or series of them, should allow most of it to pass right around them. Which brings up an interesting idea depending on the level of heat, and that is directly feeding off it for greenhouses and other needs. You would have backups, but imagine the steam baths.
I do imagine the torus would be as large as possible. Resources are difficult to get in the middle of nowhere, so I was assuming a ship that was more of a biodome. I would imagine several miles in diameter, and as many as we could reasonably tow while still being nimble enough to get around safely. The inside of the torus could be hundreds of feet in diameter. I'm thinking a generational ship since nobody mentioned we were escaping the speed of light, just using thrusters with a lot of energy. Even at a reasonable fraction of C, it would be several generations to get to this star and back.
The skyhook on a cycloid sounds pretty damn neat too. It would be one hell of an interesting ship if it could be built.
Technically, lunchtime is at any moment. It's just a wave function.
(Score: 2) by Immerman on Friday November 16 2018, @03:23PM (2 children)
I think keeping your antimatter and hydrogen (no benefit to deutrium outside of fusion, and it's a lot rarer) separate is fairly pointless. After all, the antimatter containment system, engine, ship, etc. is after all made entirely out of matter that will react just as strongly as the hydrogen would. In fact, a dense liquid or powder would likely be a much better choice than hydrogen since it's only the mass that matters, and the denser it is, the easier it is to store the same amount of mass.
As for the temperature of the exhaust - it's going to be high - ridiculously high. You'll probably be using the antimatter annihilation to power an ion drive since the matter-antimatter reaction will leave you with only massless photons, mostly gamma radiation, and photon drives suck. (Also, you *really* don't want to stand in an exhaust stream composed primarily of gamma radiation) When you get right down to it temperature is a measure of average molecular speed - and the entire point of an antimatter powered drive is that it can expel the reaction mass at a much higher speed than is possible with chemical propellant. The faster (hotter) the exhaust when it leaves the rocket, the more momentum it has, and thus the more it causes your ship to accelerate for the same amount of reaction mass. For reference, the exhaust temperature of a Merlin engine is apparently 1500C, or 3km/s - and you probably want the ion drive exhaust to be at least 10-100x higher than that. The VASMIR ion drive in comparison has an exhaust speed of about 50km/s. Not sure how that translates to temperature - it's not a straightforward conversion, and depends on the mass of the molecules involved.
(Score: 2) by edIII on Friday November 16 2018, @10:50PM (1 child)
Thanks for explaining all of this, btw. I'm not very strong in physics at all.
Technically, lunchtime is at any moment. It's just a wave function.
(Score: 2) by Immerman on Saturday November 17 2018, @02:12AM
My pleasure.
(Score: 0) by Anonymous Coward on Thursday November 15 2018, @11:24AM
While containment is indeed one of the problems with antimatter, it is by far not the only one.
For example, when matter and antimatter collide, you get the energy mostly in the form of gamma radiation. Turning undirected gamma radiation into thrust is a non-trivial problem; doing do without killing the crew through radiation is an even harder problem. None of those is worked on at CERN.
And of course we are nowhere near the capability of producing a sufficient amount of antimatter for a spaceship drive.
From CERN: [web.cern.ch]
Also from the same source:
So yes, antimatter drives are science fiction. Note that "science fiction" does not mean "impossible", it just means "not possible in the near future".
(Score: -1, Flamebait) by Anonymous Coward on Thursday November 15 2018, @12:48AM (1 child)
Problem with your plan is we get to those diverse solar systems and then they get invested by Muslim immigrants. Better to fix those problems here on earth first.
(Score: 0) by Anonymous Coward on Thursday November 15 2018, @03:03AM
What's the problem with Muslim investors?
I don't think the Anunnaki would accept investments denominated in Riyals anyway. Gold-pressed latinum is the only way to conduct inter-civilizational trade.
(Score: 0, Troll) by jmorris on Thursday November 15 2018, @02:58AM (3 children)
Not insightful. Dumb.
If you beat your sword into a plowshare you will plow for those who didn't. And in America today, when you have two utterly incompatible philosophies occupying the same territory, peace is not a long term option. Now consider that one side aims to enslave, parasitize and eventually exterminate the other and it is a miracle violence is still being held at bay. That is why, for all that it is now being openly spoken of, separation isn't a viable solution. While my side would be happy to cut the Blue Tribe loose, they can't let us go. The smarter of their leadership understand enough of the reality to know it can't work. They are parasites, without a host they quickly become like every other Socialist experiment, a failed State shithole.
Imagine what would happen if CA split off as a country of its own. Somebody did the math, the remainder of the U.S., after redistributing those Congressional Districts, (and just try to run the math for a Democrat becoming POTUS without the CA Electoral Votes) basically becomes a Red Utopia, we WOULD control our border, expel invaders and build a wall down not only the Mexican border but along the CA border as well to prevent the refugees from fleeing and spreading their disease. Freed from the malice and incompetence of the Socialists we would prosper far beyond what even Trump aspires to. It would be a Golden Age. Meanwhile in CA they would be implementing all the crap they dream of. And we all know how that story ends. Unable to flee back into the U.S. they would collapse into a series of bloody revolutions and counter revolutions. Their leaders would die. Eventually we would take pity on them and readmit them as a Territory, installing a territorial Governor who would rule them back to sanity with an iron fist. And they know these things would happen so they will under no circumstance allow it, they know they must feed from the productive to live in the style they are accustomed to.
(Score: 0) by Anonymous Coward on Thursday November 15 2018, @03:14AM (1 child)
The arrogance and small-mindedness is astounding. As if the successful realization of a world-wide October Revolution would, for reasons only jmorris understands, continue to exist within the context of the antiquated nation-state system!
(Score: 2) by jmorris on Thursday November 15 2018, @04:04AM
A worldwide Socialist Revolution would almost instantly collapse. Read "The Impossibility of Socialist Calculation" by Hayek or "Economic Calculation In The Socialist Commonwealth" by Mises for the proof. Yes proof, in the strict sense. Serious Socialist thinkers have even conceded the point and began furiously redesigning in attempts to work around the problem. None have yet succeeded, even in theory. So no, a worldwide Socialism is literally impossible. Socialists must currently have a free economy to parasitize.
Seriously, in the same topoc as discussion of going to the stars and we still have people denying impossibility of Socialist economics. Stupid monkeys don't deserve the stars. Until we grow up we probably shouldn't be contaminating the rest of the universe with toxic stupidity.
(Score: 2, Touché) by Anonymous Coward on Thursday November 15 2018, @03:30AM
Never been hit by a ploughshare, have you.