Slashdot Mirror
Farthest Human-Made Object: First Quarter Century
An anonymous reader writes "The NASA Astrobiology Magazine reports today the 25th anniversary of the Voyager I launch, now the farthest human-made object at 93 Sun-Earth distances (93 AU), or 12 light-hours away. Expected battery life to 2020. The fascinating part is that gold record of civilization, which is a strange audio mix of sentimental kisses [wav file, let ET phone home that way] and perhaps the most dated picture of DNA. Some progress there. Voy 1 will likely confuse even modern earthlings-- much less ET. Case in point: In 2002, can we understand that 70's show, when the Polish greeting memorialized as "Welcome, creatures from beyond the outer world"? Unlike those ET creatures we meet daily from the inner world?"
In slightly related news, NASA has lost contact with Contour, the Comet Nucleus Tour probe.
Money for nothing, pix for free
In about 300 years an advanced extraterrestrial civilization will come across it and think "Ha, what a primitive civilization, THIS is the extent of their technology... hey, they have lots of water and nitrogen, let's go conquer them." And when they get here they're met by the Global Planetary Defense System with its neutron shield and highly accurate laser weaponry instead, manned by fourth generation genetically-engineered Warrior Humans who kill without mercy but can be easily controlled.
Wish I was gonna be around to watch all this.
The fact that Voyager is now 12 light *hours* away really puts things into perspective for me. I'm not much of a space nut but I know that the distance from earth to the nearest stars (apart from our sun) is measured in light *years* so it's humbling to realise that even our furthest reach is trivial in the grand scheme of things. We haven't even stepped out of the house yet, nevermind explored the neighbourhood. (That sounds a bit like a put-down but it isn't. I think Voyager is an awesome achievement.)
12 light years would require it to fly at ½ the speed of light, which is not technichally feasible (unfortunately!)
I'm in a Unix state of mind.
considering it was going nowhere near Mars.
Best Slashdot Co
Assessing their key radio-isotope generators that power the on-board battery, Massey evaluates: "We don't run out of electrical power until about 2020", or at least for Voyager I, around 43 years towards its lifetime of some communication with its originating star, Sol, and its home planet, the Earth.
Looks like the isotope's power the battery.
Live web cams
As BBC reported yesterday, in 2012 or so, Voyager 1 is predicted to cross the heliopause, the boundry at which time it *really* will leave our solar system.
Pretty neat for a piece of 1970's technology.
I have a question, why didn't we power the Mars Pathfinder rover by nuclear? Were they afraid that if it crashed into the planet, it would cause some nuclear fall out?
Looks like it was solar/battery http://mars.jpl.nasa.gov/MPF/roverpwr/power.html
Live web cams
Nothing has changed really. If you put this 25 years in perspective, we have not even invented anything important. A couple of wars fought, a few new ways to use old inventions created, escape from trousers that kills your genitals completed (although there are signs of this behaviour is in the air again said MTV when I last watched it a year or so ago). 25 years is nothing.
When eminent biologist and author Lewis Thomas was asked what message he would choose to send from Earth into outer space in the Voyager spacecraft, he answered, "I would send the complete works of Johann Sebastian Bach." After a pause, he added, "But that would be boasting."
...and perhaps the most dated picture of DNA
Huh? Unless something changed recently, all the details illustrated in the DNA diagram are still as valid now as they were in the 70s. Is the story submitter upset because the double helix isn't animated, spinning slowly around, backlit by an offscreen purple fluorescent light source with meaningless reams of genetic code flashing past in the background like in a million bad sci-fi movies?
You'll still find a very similar style of diagram in any molecular biology textbook.
It's got its own radiation source which is used for power generation (ditto the Pioneer craft). Since this is doubtless running continually whether we want it to or not, it's running out. So it's not batteries per se, but a question of the half life of the element in question. Solar power's out of the question at these distances, hence the need for this power source.
PenguiNet: the (shareware) Windows SSH client
The BBC are reporting that they've found the probe orbiting the sun... No comets then ...
Simon
Physicists get Hadrons!
Yes. "The planet" in question being Earth. If a nuclear-powered device explodes on launch, or in low orbit, it's "not a good thing". At the very least you'll get radioactive debris spread over a wide area.
Simon.
Physicists get Hadrons!
Ohh, that's what it means. I understood the whole sentence as the origin of this confusion. IMHO, the whole article was confusing, not the data in voyager.
Pretty neat for a piece of 1970's technology.
Not really. I mean, the journey it made, the navigation around the planets to gain more speed was pretty impressive, but in my view it is not impressive to leave to solar system. You see, on the next Shuttle flight they could bring a 16th century vase, and hurl it into space. Give it a few years, and it will too leave the solar system, but is that neat, or impressive?
Ok, I got off (actually, stayed on) my butt and found this:
Radioisotope Thermoelectric Generators (RTG's)
Three RTG's provide electric power to Voyager. The generators produce about 1800 watts of heat by the radioactive decay of plutonium. The heat is then converted to about 400 watts of electric power by thermocouplers. The RTG's are mounted on a boom to protect the scientific instruments from excess heat and radioactivity.
and this, which discusses RTGs in the context of Cassini and safety.
PenguiNet: the (shareware) Windows SSH client
Doesn't the disc on Voyager feature an introduction by then UN Secretary General Kurt Waldheim giving greetings from Earth?
How odd that the first human voice any aliens who could work the disc will hear is the voice of a former Nazi alleged to have taken part in war crime atrocities in the then Yugoslavia...
"Information wants to be paid"
Often scientists talk about how the universe is expanding. The concept of expansion itself demands that a boundary be present. And boundaries demark two regions, one within and one beyond. Yet nobody dares mention what is beyond the universe.
All these contradictions just tell us one thing. Alot has to be undone about our stake of knowledge before we can begin to truely understand.
Our current state of knowledge is similar to the days before Galeleo, when people thought the world was flat and you could reach the end of the world.
My 0.02
"Fighting terrorists with millitary might is like killing a mosquitor on your Dad's forehead with a rifle."
That's a nice sentence fragment you've written. Try full sentences next time. You might like them.
I don't know about anyone else but I get this quite erie vision of this thing out there with nothing around it for millions of miles.
Avantslash - View Slashdot cleanly on your mobile phone.
Obviously the universe isn't getting any larger. Everything inside of it is getting perportionaly smaller, evenly. That way it looks like the universe is getting bigger, but really not. It's just the size of a softball. really.
Besides, your analogy falls flat. I presume your point was that the age of the technology is irrelevant when it comes to leaving the solar system? Then consider this: what is it that pushed the 1970s technology of the Voyagers out of the solar system? Answer: more 1970s technology. If your 16th century vase were propelled by 16th century rockets, then your analogy would be valid.
Patrick Doyle
I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....
In what way do you perceive some dodgy, non-metric unit like miles as making calculations easier? Why not define it as 319.1 billion rods?
I guess part of the reason for AU is to give the man in the street something to understand in news stories (since so many people *don't* understand light years). I doubt anyone really does any calculation with it.
PenguiNet: the (shareware) Windows SSH client
Bellbottoms are coming back. 'Nuff said.
It's 10 PM. Do you know if you're un-American?
How fast is voyager traveling? Can we launch something that is faster? We've got 4.2 light YEARS to get to Proxima Centauri. 12 light HOURS are not going to cut it....
"Only one thing, is impossible for god: to find any sense in any copyright law on the planet." Mark Twain
The power source on the Voyager I & II spacecrafts, like most other of the time, is called a PTG or plutonium thermoelectric generator. Basically you have a heat source (chunk of plutonium) surrounded by devices similar in construction to modern peltier coolers. The Seebeck effect (opposite of Peltier effect) allows electrical power to be generated by the temperature gradient across the device. Basically you have an electrical power source with no moving parts and a very long life (Plutonium has a decently large halflife). It's a shame that the environmentalists had a hissy fit in the 80's and 90's that blocked this very reliable technology from being used on modern spacecraft.
Why do we put our DNA in space like that? Its fucking stupid!!
What next? Displaying your social security number on the INTERNET? Yeah let all the terrorists and hackers grab your identity?
Well thats what we are doing in space, dumbass Nasa scientists should get their ass kicked seriously.
If you use Linux, please help development of Autopac
If its velocity is constant, when it dies in 2020 Voyager will have travelled less than a light-day from Earth. In the grand scheme of things, unless it really collides with something there is very little chance it will ever be noticed.
I dont care how many degrees you have, anyone ignorant enough to put pictures of us, our DNA, our sound files and everything into space deserves to have their asses kicked.
Its as stupid as me posting my social security number on slashdot, Here 002-32-4840
Here you go, please hiijack my identity, heres my credit card number too! James Spencer 220345035212
If you use Linux, please help development of Autopac
I mean damn of all things you could give a person why give them your DNA?
If aliens decide to take over the world, well theres a map, our DNA so they can change their genes to look exactly like us, some wav files so they can learn how we talk and maybe even our language from the greetings. What the hell are Nasa scientists doing? Where is the government and national security?
I mean damn shouldnt the NSA outlaw us putting DNA into space and maps, I dare the scientist who gave our DNA to aliens to post his social security number and credit card number on the internet in plain text!
If you use Linux, please help development of Autopac
Radio Signals allows them to know theres something going on at Earth. But they'd have to come here physically to see exactly what we were doing, They'd have to physicially land a ship, get out, snatch a few hundred of us of us from all diffrent races and capture our DNA.
They wouldnt be able to just hiijack our DNA from space, and come to earth looking just like us.
If you use Linux, please help development of Autopac
All I hear is "Wytajcie, istoty zaswiatu," which would basically mean "Greetings, otherworldly beings," or better, "Greetings to beings from beyond Earth." The "outer world" is at best a rather poetic (or possibly condescending) translation.
I think it would be an equivalent of "Greetings, creatures from Outer Space," but they didn't intone it pretentiously, right before Ed Wood hovers the hubcap from a string and a theremin plays in the background as his boustier intrudes into the picture, as we are wont to do over here.
If you found this record do you think you could play it?
And extract the images from it?
I have the directions http://vraptor.jpl.nasa.gov/voyager/messages/VgrC
and it would still be pretty tricky.
If I didnt have them I dont think I would have any chance of figuring out what this thing was.
-M
I agree.
This would be an interesting experiment to try. Replace the symbols with a consistent set of otherwise meaningless glyphs -- a kind of substitution cipher. Then hand it to a competent biologist and see how long it takes him to come up with a correct interpretation -- probably not more than a few minutes.
You can make it progressively harder, by eliminating certain assumptions about how to represent certain things. For example, you could replace the lines used to indicate chemical bonds with dots; 1 dot for a single bond, 2 for a double, three for a tripple. Also, the alternating 1/2 bond representation of carbon rings is a bit arbitrary; another symbol might be better to represent the nature of the bonds within the ring.
Nonetheless, when looked at by a person who studies organic chemistry, I don't think it would take long for him to figure out.
I think it is very likely that any intelligent life form which encounters Voyager is going to be carbon based; if the civilization has the technology to recover Voyager, it will no doubt have organic chemists. What it will tell them is that we, like they, are carbon based life forms. The exact function of DNA may take them some time to work out, and they may never be sure, but there is a good chance that somebody will conjecture that this is the mechanism by which our genetic inheritance is transferred (assuming they die and leave offspring!). It's a plausible guess, given that if you wanted to give a chemical picture of yourself, the mechanism of genetics would be a high priority.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
First, as has already been pointed out in other replies, miles are also an absurd, arbitrary unit as far as science is concerned. We could get a 'round' unit if we took, say, about .65 AU, as the 'new' astronomical unit--exactly 10^11 m.
But then the AU would be a pretty useless yardstick. Earth's orbit is very nearly circular, which means that over a period of six months, the Earth moves a net distance of (almost) exactly 2 AU. Using this knowledge, it is possible to measure the distance to nearer stars. As the position of earth changes, the apparent positions of nearby stars will also appear to change relative to much more distant stars--a parallax effect. To get a precise measure of this distance, you want to move the Earth as far as possible, to get the maximum apparent shift in position. 2 AU is as far as we can readily move the earth.
There is even a unit of measure that is defined on this basis. The distance at which the apparent parallax shift of a star is equal to one second of arc is defined as one parsec. Parsec measures can be directly obtained from astronomical images taken six months apart, so they are the preferred unit of measure for some types of observational astronomy.
Of course, this also works backwards. If we could see a planet orbiting a star one parsec away (about 3.26 light years--this is a hypothetical case) and its orbital motion was across one apparent second of arc, we would know it orbited its sun at a distance of 1 AU.
~Idarubicin
First cab off the rank is probably the Orion drive. Build a really big plate, attach it with really big springs and dampers to a heavily radiation-shielded spacecraft, and detonate atom bombs behind the plate. The basic technology exists right now, all you need is a pile of cash and be prepared to violate the space weapons treaty. Maximum speed is about 1-2% of the speed of light, so you're still taking a couple of centuries to Proxima Centauri.
Next option is a fusion engine. We can't generate power with controlled fusion yet, but ITER probably will if and when it gets built. ITER is, er, rather large and heavy, and doesn't really produce much net power, so a practical space fusion power plant is a fair bit of engineering development down the road. Anyway, the idea is quite simple. Release the "exhaust" of the reaction out the back of the engine, just like a normal rocket except the exhuast is a hell of a lot hotter and travelling a lot faster. Maximum speed maybe 10-12% of the speed of light.
Alternatively, use a light sail powered by a really big laser. All you need is to scale up laser and telescope technology a crapload (so, again, considerable engineering development required). Maximum speed? Somewhere between 10 and maybe 30% of the speed of light, depending on just how big you can make your mirror (and consequently how far you can keep accelerating).
The other big issue with interstellar spacecraft is the question of how much debris is out there. If there's a lot, as you go faster you'll need one hell of a shield to protect you.
Finally, there's there's also the possibility of using antimatter-matter reactions to power a ship. Antimatter is kinda powerful stuff to have around, and you could theoretically use it to power a ship to near the speed of light. However, there is no known natural source, and manufacturing it requires milllions of times more energy put in than you get back when you "burn" it. It, therefore, is a really long-term option from when humanity has such astounding energy generation capacity it can afford to use it to power antimatter-powered spaceships.
All in all, there are some possibilities, but most are still a fair bit of technological development away. Let's get to the rest of the solar system first :)
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
Is the Voyager really going fast enough to make it to another star, even if it was pointed at one? A lot of these posts and articles similar to this seem to imagine the thing just sailing on forever, not in a particularly long orbit around our sun.
If I'm plugging in the equation right, taking into account the 93 AU that the Voyager has already reached, and the present speed (39,000 miles an hour, assuming none of that's tangential velocity), I get a required speed of 4000 km/s, and the Voyager is going far slower.
So as far as I can tell, really the gold record, etc. on board are more of a time capsule for when the craft swings back around on its comet-like trajectory, rather than for contacting aliens. I think the nasa people and popular science writers like to preserve the more romantic notion of an unintentional first instellar voyage, though my calculations could be wrong.
It was best said on "Jackie Chan Adventures" when Jade got sucked through a time warp. She gets sent back to 1976: Jade: "Where am I?" "What is going on?" "BellBottoms?! That is soooo 90's"
The emacs religion: to be saved, control excess.
Fully updated with ion or solar sail propulsion to get it out there quicker with a nice AOLesque "VERSION 3.0" stamped on the side so they know its the latest.
On board we also include a copy of Lord of the Rings in DivX format and Mp3's of Britney Spears. That way if the aliens invade, we can tell the RIAA and MPAA they have pirated movies and music and watch the aliens recoil and flee under the unsuing crush of lawyers and DMCA threat letters.
If that doesn't work, we trick them into installing the cracked copy of WinXP convieniently on stowed board and watch their ships fail in horrible and astonishing ways.
Now if that fails, then we trick them into installing AOL and logging onto it. After all nothing can withstand humankinds most powerful weapon... Pure stupidity.
--Won't that be grand? Computers and the programs will start thinking and the people will stop. - Dr. Walter Gibbs
I don't understand this embarecement to be seen as a baby. Don't we all were babys once? Everyone loves to se babies but get embareced when people see themselves as a baby. I used to have a picture of my self as a baby in my wallet, it was a funny one cause I was doing some "dirt" gestures. Actualy my hands were caugth in a random position that casualy looks like an "ok" for american, but in Brasil it stands for "asshole".
[]'s Victor Bogado da Silva Lins
^[:wq
realize that the article was submitted a day before it was posted to the main page, so "today" actually refers to August 20th.
"Project Thunderwell was the inspiration of astrophysicist Bob Brownlee, who in the summer of 1957 was faced with the problem of containing underground an explosion, expected to be equivalent to a few hundred tons of dynamite. Brownlee put the bomb at the bottom of a 500-foot vertical tunnel in the Nevada desert, sealing the opening with a four-inch thick steel plate weighing several hundred pounds. He knew the lid would be blown off; he didn't know exactly how fast. High-speed cameras caught the giant manhole cover as it began its unscheduled flight into history. Based upon his calculations and the evidence from the cameras, Brownlee estimated that the steel plate was traveling at a velocity six times that needed to escape Earth's gravity when it soared into the flawless blue Neavada sky. 'We never found it. It was gone,' Brownlee says, a touch of awe in his voice almost 35 years later.
http://www.geocities.com/CapeCanaveral/Hall/189
----------------------------------- My Other Sig Is Hilarious -----------------------------------
I really hate signatures, but go to my website.
The heliopause is not a gravitational feature. It is a feature of matter.
The sun emits a flood of mostly-charged particles that make up the "solar wind." The earth is shielded by its magnetic fields, but the interplanetary environment is quite harsh.
The heliopause is where this outward flow of solar matter becomes less than the general flow of matter through the galaxy. There isn't any good way to observe this from earth, which is why having a Voyager pass through the area is a good thing. Our current picture of the heliopause is based on physical modeling and simulation. Having any observational data to check these models against would be a major step forward.
It should be, "Greetings, creatures from beyond Earth."
mmm... yeah... You see, we're putting the cover sheets on all TPS reports now before they go out...
Even without believing tinfoilhat stuff, isn't it more accurate to call this the farthest known manmade object?
How impossible is it that a pottery shard was included in some ejectile material 25,000 years ago... and given the likely orbits of something like that, how far could it have gone?
Just because the nearest star is really far away, it doesn't make it disappointing. We'll get there some day, it may take time and it may not be easy to phone home, but does it matter.
1000 years ago, it took years to go or communicate from one end of the known world to the other.
250 years ago, we reach the new world. But it still took most of a year, and the danger of shipwreck to get there.
In 100 years from now we may have very fast ships. Lets say 10% of light speed. This would put us on the nearest star in 40 years. People who go on that mission will be expecting it to be so. Civilization is not a one mans cause; it's the perspective of generations.
-:) Oh no - not again.
www.rednebula.com
I'm sure it must be mentioned elsewhere, but I don't see it... It isn't an issue of the half life of the element, but rather the lifespan of the thermocouples. The half life of plutonium could probably power this craft for quite a few years past 2020. The thermocouples, however, have a known degradation rate and therefore their failure rate (or point at which their power production falls below that required to run the craft) is known and can be fixed at 2020. (Roughly, at least.)
The point is that parallax measurements of distances to stellar or planetary objects are based on the Earth's motion around the sun. The measurements *inherently* give you an answer in AU.
1) Why apply a conversion factor just to express it in meters?
2) The proper conversion factor depends on other measurements (I'm actually not sure how the mean earth-solar distance would be measured), so it can't be defined arbitrarily. If you made the Earth 0.93 AU, you'd have to multiply all your parallax measurements by 0.93 to get the distance in your "new AU" anyway. Pointless effort for no gain.
There is a reason for proliferation of auxiliary units. The interatomic spacing of Si atoms in a crystal is used as a basis for diffraction measurements; the "amu" is the basis for atomic mass measurements; the "mol" is used as a measure of quantity, etc.
In all of these cases, the measurements based on the unit are more (or just slightly less) precise than the basic unit can be measured by other techniques. It is most convenient to express your results that best preserves the original accuracy.
"Also, the alternating 1/2 bond representation of carbon rings is a bit arbitrary; another symbol might be better to represent the nature of the bonds within the ring."
It is a bit arbitrary, but it would be difficult accurately to depict the real nature of the bonding in a fused heterocyclic aromatic system in any simple way. A common convention is to draw a six-electron aromatic ring (e.g. benzene, thiophene, tropylium) with a circle in the center. One organic chemistry text, March's _Advanced Organic Chemistry_, adopts this convention for single rings but does _not_ use it for fused systems, for a good reason: if you drew (say) naphthalene with a circle in the center of each ring, you would inaccurately give the impression that napthalene was a system of two independent six-electron rings, and not a fused system of ten electrons with a certain amount of bond fixation.
hyacinthus.
I don't think they will get so much info from that simple picture. No reason to be worried there. If they would figure out *what* it is, they have to figure out *where* in our DNA it is, and even then they have no clue about nearly anything regarding our DNA... let alone creating humans.
Will work for bandwidth
The on-again off-again 2006 Pluto probe (launch date) relies on favorable planetary configurations as Voyager did. If it isn't launched in 2006 then its something like 40 years before another favorable Pluto configuration occurs.
How quickly could we catch up with Voyager using 2002 technology?
It's a shame that the environmentalists had a hissy fit in the 80's and 90's that blocked this very reliable technology from being used on modern spacecraft.
Not really. The problem is that in order to make one of these generators safe, it needs to be protected from the launch rocket exploding on take-off. It doesn't matter whether you're an environmentalist or not - if a couple of kilos of plutonium gets vaporised and spread to the four winds on the launch pad, you've just made enormous chunks of the US's only major space launch site unusable until it can be cleaned up. You can stick your head in the sand about it, but that doesn't make the radiation go away. Needless to say, the clean-up operation and interruption to US space activities would cost tens of billions of dollars - and quite possibly a lot more.
It's perfectly possible to protect these generators from the explosive force caused by a rocket blowing up on the launch pad - it's just a simple engineering problem. The problem is that it costs weight - lots of it, and the number one thing you want to avoid on a rocket launch is extra weight. Every extra kilogram costs you hundreds of thousands of dollars, or costs you one or two or three valuable scientific instruments.
So unless you absolutely need a radioisotope thermoelectric generator, you don't use one. Solar panels are lighter (because they don't need explosion protection) and, therefore, cheaper to launch (which is the only really major cost consideration - the cost of the space vehicle itself pales in comparison). Modern solar panels are good out to nearly Jupiter. Beyond that you need an RTG. I can only think of one mission that NASA has launched since the Voyagers that has gone out that far - Galileo, which was launched in 1989 - and yes, it had an RTG on-board despite the protests.
Honestly, NASA - at least the engineers - couldn't give a damn about the environmental issues involved with RTGs. Because as long as their containment engineering is up to scratch - and I rather suspect it is - there simply are no environmental issues. Instead, it comes down to economics - and for most missions that NASA undertakes, which go no further out than Mars, thermoelectric generators lose out badly to solar panels.
Now, perhaps environmentalist fears are preventing NASA from sending more probes beyond Jupiter because they need an RTG, but that's a different matter entirely. Maybe they need to publicly blow up a few rockets with the generator containers on-board to prove their point.
I can only think of one mission that NASA has launched since the Voyagers that has gone out that far - Galileo
Cassini, as well. Which, surprise surprise, also has an RTG on-board.
I noticed that a drawing of a circle is copyrighted. It's a the top of the list on NASA's webpage on the Voyager photograpic recordings. Makes me wonder, will extraterrestrials be sued under DMCA?
The reason why there is a RTG (radioisotope thermoelectric generators...it generates power on the heat) on all deep robotic probes (Pioneer 10,11, Voyager 1, 2, Galielo, Cassini etc.) is because of the good old inverse square law.
:-) The power a probe would receive from panels around Earth would now be 0.01 times as strong around Saturn. Needless to say you aren't going to get the 200 or so Watts needed to power critical equipment on Voyager 1 out of solar panels at the place it is flying right now(I suppose you could attach monsterous solar panels but that is mass a spacecraft doesn't need).
Lets say that the power collected from standard set of solar panels for an object around Earth is suffient to power the electrontrics. The problem is space is big...really big! For instance...
Mars is about 1.5 times as far from the Sun as Earth....
Jupiter is about 5.25 times as far away...
Saturn is about 9.5 times as far away...
I won't go farther.
Of course the idea of radio active material on space probes sends some people into a fit but it really isn't that much material. It also ignores the fact that if we want to do distant science there is no better powersource built yet.
If a nuclear-powered device explodes on launch, or in low orbit, it's "not a good thing". At the very least you'll get radioactive debris spread over a wide area.
You actually think NASA would be dumb enough to send up a nuclear-powered device without adequate containment against explosion and re-entry?
NASA may be huge, inefficient, wasteful and sluggish, but they're not stupid.
We're giving out thousands of times more info through Discovery and other such channels and so on. The difference is, though it's difficult, it's possible to stop this probe. Our radio and TV transmissions are impossible to stop. Should we stop this too and use only wiretechnology for information exchange? For how long have we had TV broadcasting, like 60 years or so? By now there's a lot of information for anyone within a 60 light year radius from us, even further if they pick up our radio signals. If they can understand our TV programmes, they should know by now that we can't even unite as a species but instead we choose to kill each other every now and then. They also know some of our technology; if they are 30 lightyears ago they're aware that we have the ability of interplanetary travel. Will they be worried about this? Or will we be considered too primitive for them to establish contact? Are we a threat to others? Or will they realize that we have many good sides too, and that that would make them think we're worthy of contact with them?
Whether it is right or wrong to give out information about us, I don't know. There is a possibility someone will try to benefit from this, in one way or another. In case of contact, it could give them an unfair advantage.
However, I don't think we should stay quiet all the time. Actually I think we should more actively send out radiomessages for *their* SETI-scientists to detect and maybe send back an answer to us. As I see it, if we establish contact by the means of radio signals, the chance is great that they are more advanced than us. Why? Becuase basically, we discovered radio yesterday. We might find civilizations that are new to radio too, but chances are they have advanced much more than that. Somehow I like to think that they would therefor be peaceful, because they have survived longer than we as a technological civilization, and therefor would pose no threat to us.
Will work for bandwidth
As I understand it, the heliopause is the point at which the solar wind (particles coming from the sun) can no longer expand due to the pressure of particles coming the other way.
:)
Think of it like this: Say you have a very large fan blowing air in one direction, and a long way away you have a lot of small fans blowing the opposite way. At some point, the wind from the large fan will exactly balance the wind from the small fans. That would be the... aeropause, or something.
If there is an Interstellar Criminal Court, you sir are in big trouble. :-)
there is entirely too little experimental and experiental data for any strong claims about the safety of RTG containment to be made
Rubbish. NASA RTG containment systems have been tested in real-life missions on re-entry twice, once in 1968 from a failed meteorological satellite, and once in 1970 from the remains of Apollo 13. On both occasions the RTG containment worked fine. Lab studies on both the re-entry and the explosion-on-launch scenarios have been extensive, and NASA's RTG systems have been tested to and survived nearly 4x the pressure produced from a rocket explosion on a Shuttle-type spacecraft.
The physics and engineering behind an effective RTG containment system are quite simple. Frankly, a good Victorian-era engineer could have done it (although it would certainly have been a lot heavier than modern systems).
NASA has a nice little piece on RTG safety that they wrote for people concerned about Galileo's power system. It's available here.
Of course, you are free to disagree with NASA's findings, but it seems like good enough evidence to me.
I wrote that post during a brief moment when I thought there was an advantage to convincing the world that I am a sub-literate non-native English writer. Surely you've seen how people can act when they have a dream. Yes, a dream: to become a /. editor. Have some compassion; don't laugh at my hopeless ambitions.
As copyright owner of this comment, I authorize everyone to defeat any technological measure which limits access to it.
(* I have a question, why didn't we power the Mars Pathfinder rover by nuclear? Were they afraid that if it crashed into the planet, it would cause some nuclear fall out? *)
Probably because of fears of protests. The Mars Viking landers of the 1970's used the nuclear approach, and lasted years.
The protests don't stop NASA from using nuke stuff, but it makes them hesitant, and Mars is a grey-area WRT solar-power.
The Pathfinder mission was slated to only last a few weeks because it was experimental, so that is what the design was for. If they had a longer target, then there are probably ways to not have to rely on recharge-diminishing batteries as much as they did.
Table-ized A.I.
Pretty neat for a piece of 1970's technology.
It's nothing compared to my lite-brite! Oooh, the colors!
Don't trust a bull's horn, a doberman's tooth, a runaway horse or me.
But, I want to take a crap all over NASA and the utter inability to best Voyager in the 25 years of innovation since. Is it just me or is the space industry in a completely different reality than the rest of our technology sectors?
:-)
What exactly are you expecting?
Note that the radiation of space limits the miniturization of many electronic parts. Thus, things can only be shrank so much up there.
I mean really though, think... the space shuttle was in the 80's, 20 years ago and we're still there!
Well, chemical propellants are still the most viable launch technology, so the shuttles still do what they do. It would be nice if there were better/cheaper ways to get into space and move fast, but nobody has found the magic formula for that. Trek's Cockrin has not been born yet
Table-ized A.I.
(* Am I the only one who thinks it's a bad idea to give aliens our DNA? Surely any civilization capable of interstellar travel would also be able to use our "blueprints," as it were, to quickly whip up a few fake humans, or even develop biological or genetic weaponry. *)
The Voyager version was only an example, not the complete DNA. Besides, I don't think the entire genetic code is enough to make a person without references to how Earth biology works. It would be like giving machine code of a program. Without knowing the OS and the chip's language/archetecture, it may be nearly useless.
Table-ized A.I.
(* So what, they still don't last forever. *)
My understanding is that the problem is not so much the half-life dwindling of radioactivity, but the connectors and/or gatherers of the energy within the power cells. They tend to corrode over time and diminish the power returned.
Plus, as the probes get further and further the signal is also weaker and weaker. Thus, there are 3 factors diminishing communications power:
1. Regular "half-life" diminishing of the radioactive material's power.
2. Corrosion of the power-gathering terminals
3. Increasing distance from Earth
4. Alien babys playing with probe
(Okay, #4 is a little speculative)
Table-ized A.I.
Looks like the isotope's power the battery.
Bob would like a word with you, please.
It's all about weight. Dragging around an RTG on wheels isn't exactly easy work. Remember that the Sojourner was carried on Pathfinder, which itself was carried another stage.
What would have been a better question would be: Why wasn't the Pathfinder lander powered by an RTG and then Sojourner recharged via a docking station?
1) Radiothermoelectric Generators - RTGs. A chunk of plutonium is warm, like a puppy. Space is cold, like a puppy dipped in liquid nitrogen.
A Peltier-effect CPU cooler exploits a difference in electrical potential (power to the cooler) to create a temperature gradient (hot fins, cool CPU). The effect works in reverse -- Voyager uses the temperature gradient between cold space and warm radioactives to generate an electrical current. No moving parts, so you have 100% reliability, and it can last as long as the radioactives are sufficiently "hot" -- which is often decades.
2) No. Solar is pretty impractical at Jupiter-range distances, and you can forget about Saturn and beyond. That's why Cassini used RTGs. That's why if you want to get to the outer planets quickly, an ion engine plus an RTG is a really cool idea. (That's why I hate enviro-nuts who go apeshit at anything with the word "nukular", but that's another /. thread.)
4) Yes :)
3) To transmit the signals in #4. (And to run the computers to receive signals from Earth.) It's mainly a "where are you now?" and "what's it like out there?" kind of conversation, but there's still some useful data coming back. These long-range probes are how we'll find out if our theories of gravitation are OK or not, and once past the heliopause, give us an idea of what near-interstellar space is like.
What a stupid comment. Just how does the 4000 bc brick gain enough velocity to escape the gravity of the solar system (let alone the earth)?
By bouncing off the forehead of a numbskull
Table-ized A.I.
(* What about the Oort Cloud? Shouldn't that count as part of the solar system? *)
But that boundary is also "nebulous". The Sun's gravity extends the entire universe in theory (except maybe for far-off portions moving away faster than the speed of light from our perspective.)
Thus, in theory something as far away as the further Quasar could still orbit the Sun. What stops it (or interferes/overpowers) is gravity of other stars, and the positions of these change over time.
Thus, if you define the boundary as "the spot where another star's gravity is stronger than the Sun's", then you pin the boundary to something that may not be around the area in a few million years or so.
Something in the Oort cloud may be torn away from its Solar orbit by a passing star, and visa versa.
Table-ized A.I.
(* The heliopause is where this outward flow of solar matter becomes less than the general flow of matter through the galaxy. *)
"It is where the nuclear farts of the Sun are over-powered by the nuclear farts of the rest of the Galaxy and space."
From the yet-to-be-written Bevis and Butthead Encyclopedia. (Any publishers willing to sponsor this, BTW?)
Table-ized A.I.
Wow, I should work for NASA.
taken! (by Davidleeroth) Thanks Bingo Foo!
"Famed as the most remote object ever made by man, Pioneer 10 is now 7.5 billion miles away (Until 17 February 1998, the heliocentric radial distance of Pioneer 10 had been greater than that of any other manmade object. But late on that date Voyager 1's heliocentric radial distance, in the approximate apex direction, equaled that of Pioneer 10 at 69.419 AU. Thereafter, Voyager 1's distance will exceed that of Pioneer 10 at the approximate rate of 1.016 AU per year)."
-Shieldwolf
just = (My)Opinion.toCents();
Anyway, I think something called the AU should be measure something a bit more dinkum Aussie. Like the size of Ian Thorpes feet.
Nerd: Derogatory term typically directed at anybody with a lower Slashdot ID than you.
"mix-up with metric and English units?"
Just nitpicking here, but metric IS english units. The issue was with American Vs. The-rest-of-the-world units.
You can't blame the NASA engineers... I mean, when it comes down to it, they are Yanks after all.
It's always amazed me how Americans have such a facination with whats going on in space, yet don't know, and don't seem to WANT to know whats going on outside their borders on the rest of this planet.
"Some disassembly required"
The magnetron is an extremely high-power wideband 2.4GHz RF transmitter, whose waveguide can be routed to something like a parabolic dish instead of the customary faraday cage with food inside. This is how radar works.
Magnetrons and Klystrons scale to hundreds of kilowatts. For some interesting reading, do a google search on it.
The first part is that I really don't know where to begin in terms of dealing with the poster's question. Infinity is problematic. Aristotle had exactly the same problem that the poster did -- for that reason, Aristotle differentiated between "infinity in extension" and "infinity in division", and disputted the existence of the former. Just as our poster did. In that sense, he's in good company. (Of course, many modern scientists don't see Aristotle as good company.)
On the other hand, I think that incommensurability -- what we call "irrational numbers" (actually, that's what Euclid called them, too) is at least as problematic as infinite extension in terms of violating common sense. The difference is that irrational numbers are indisputable. That's why the Pythagoreans kept them a secret. My point is that just because something violates common sense, doesn't make it false.
Sheesh: particle/wave duality, Heisenberg Uncertainty (properly understood), Relativity -- these all are completely in violation of common sense. Having a background in the history and philosophy of science as I do, I am somewhat sympathetic to objections that contemporary science violates common sense. That's a very interesting question to me. But the fact that this is the case can only come as a surprise to two kinds of people: someone so steeped in contemporary science that they are oblivious to its seeming "absurdities", or someone so oblivious to contemporary science that they're essentially two-thousand years behind the curve.
Both of those people are, in relative terms, unobjectionable. But our poster crosses the line when he (as an example of the second type of person from the paragraph above) asserts that this violation of his common sense indicates that modern science is wrong and that there's a big conspiracy of silence. That's ignorance coupled with arrogance, and that's inexcusable. Which brings me to my second problem.
You see this on Slashdot all the time. I mean, I know this, it's a joke about slashdot. But you get people that work in a technical field, took a few science classes in college, and watch science fiction, and they think they can comment on all sorts of things when, actually, they're just embarassing themselves. I had just had my fill of it yesterday. That's all.
Typing "infinity" and "mathematics" and perhaps "physics" into Google isn't very hard to do. I'm not sure why I should be required to provide a link.
All in all, though, your objection was at least partially valid, and my only defense is to plead annoyance.
Gimme a "T!" Gimme an "R!" Gimme an "O!" Gimme an "L!" Gimme an "L!"
Um, Metric is actually French. English units came to America with the English themselves. We kept using them and find that they work quite nicely, thank you.
Americans...don't seem to WANT to know whats going on outside their borders on the rest of this planet.
If it were filled with brighter people than you, we might care. Half the reason most people hate us so much is that we don't care that they hate us at all.
I spent a year in Iraq looking for WMD and all I found was this lousy sig.