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The Dot in .mars 150

Posted by michael
from the round-trip-min/avg/max-=-360000/600000/1800000-ms dept.
Skynet writes "CNN has a really cool interview with Chad Edwards, manager of the Mars Network Office, about NASA's desire to improve telecommunications to and from Mars. They plan to get a 1MBps link up by 2007. They also discuss the possibility of multiple Internets spread throughout solar system, all interconnected. Very interesting discussion."
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The Dot in .mars

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  • by Anonymous Coward
    Mars lost its magnetosphere a long, long time ago. The internal dynamo that earth has with molten rock swirling beneath the crust quit working in Mars eons ago. This magnetosphere is only one of the many things that is necessary for a planet to keep a stable atmosphere. Without a magnetosphere, fast moving solar particles can strip the atmosphere faster than Rosie O'Donnell taking on a Thanksgiving turkey. Think before you post.
  • by Anonymous Coward
    They also discuss the possibility of multiple Internets spread throughout solar system, all interconnected. Who's to say that someone somewhere hasn't done it already.
  • I can see it now. Next target for a slashdotting? The big Jupe itself! Big planet, little bandwidth!

    And what happens to the link if one of the martians decides he wants to hop in on a game of Quake? And what're his pings going to look like from almost 49 million miles away?

    U R 0WN3D 3RTHL1NG!

    Chas - The one, the only.
    THANK GOD!!!

  • And what're his pings going to look like from almost 49 million miles away?

    Probably a lot like any AOL user.

    Does this mean they have to use AOL-speak/type too?

    Chas - The one, the only.
    THANK GOD!!!

  • Sure they do. The boiling point of water drops with the pressure. Even in our own atmosphere we can get up to the boiling point. It is somewhere around 15 km up, IIRC.

    Even easier: pump the air out of a container containing water and air. The water will boil eventually.

    You're right about not exploding in space: our skin is strong enaugh to keep us together.
  • by BigZaphod (12942)
    And I'll probably *still* only be able to get a 28.8kbps connection to the Internet right here on *EARTH*. Grrrr....
  • Don't forget!

  • Your eyes and mucous membranes willl probably go, though, and you will probably get pretty good pressure bruises on the surface of your skin. Exploding might be more pleasant :)

  • Never underestimate the bandwidth of a station wagon full of magnetic tape...

    (BTW, to whom should I attribute this? I can't remember where I heard this.)

  • Where else could Napster thrive?
  • Haha, this is great! It's a lot like the ansible technology stolen from the buggers. Although, I don't think electromagnetic radiation is tough enough to wire a solarsystem.

    Although we could probably use our palm pilots on the moon. WAP would finally become standardised! ;) I wonder if there would be any dead zones? Like when the sun passes between you and a digipeater.
  • Perhaps we should use the .ma domain?

    ".MA" is already taken - it's for Morocco.

  • THe important thing here really is that now we can get a game of Network Doom going with machines on Phobos, Demios and Earth.
  • >Personally I vote for ICP/IP
    >(Interplanetary Control Protocol over IP)

    or Insane Clown Posse / Internet Protocol
  • Mars was a name coined by the Romans, therefore it is Latin, Latin is the intenational language for naming things in science. SO .mars is not Americocentric.
  • > THe important thing here really is that now we can get a game of Network Doom going
    > with machines on Phobos, Demios and Earth.

    The six minute ping might make deathmatching a little complicated...

  • by qqaz (33114)
    How come Mars gets a 1Mbps connection, and I'm stuck at 24k? They don't even have any people!
  • Woopeee... guess i can register sex.mars now and make a fortune on it.
  • It's been a while, but that sounds like most of the basics are right. This concept is what Orson Scott Card used in the Ender books. They had some whatsit doohickey that carried split particles around the universe. However, that device was able to influence the spin of the particles, and it also assumed that the spin of on particle would affect the spin of the article on the other end. It's still cool.
  • Sounds good to me, an Internet spread through the cosmos would be great.
  • All your... []
  • Umm .. dunno if I've missed something here, but there isn't anybody living on mars ?

    so the other end of this link isn't going to be all that interesting to talk to

    Every ship and probe that goes out there has its own transmitter to Earth, so the only difference that this 'link' has is that it will use tcp/ip instead of whatever other protocol they were using.

    And some script kiddie will DDoS it 24/7 just so that they can say they ddossed mars..

    sounds like a rather silly idea, all things considered
  • Actually, I'm trying not to get pissed that robots on Mars will have broadband before I can get a reliable 28.8 to my house.

  • If I get there first, I'm calling it Ares. Mostly just to annoy all of the people who would have to rewrite the textbooks.
  • We've been in this situation before - and indeed we still are in some ways. How do you, for example, communicate with a ship at sea whose only access is via satellites that they may or may not be able to reach, depending on the weather? The answer is typically uucp. Admittedly, this doesn't allow for streaming media or web surfing, but email and file transfer work. I suspect that the most likely configuration would be a uucp gateway on each end, with some automation being used to keep servers in sync. So if I am on Mars, and create a VR tour with my handheld camera, I can have it sent to a server on Earth for those on Earth who want to see it. Trying to serve that to Earth from Mars (or vice versa) would be a pain in the neck.
  • If current TCP connection timeouts sit at 1-2 minutes for something that should be negotiated within a few seconds, what will the settings have to be for a Martian link?

    Next thing you know, it will take 2 days for Internet Explorer to detect the nearest proxy server...
  • What kind of error checking would be needed to make sure that not just the bits are accurate but also that the whole packet or message is sent? If there's any error, the packet would need to be resent thus doubling the latency, right? Also, it seems that the moon would be a good place to start the interplanetary since one side is also facing the earth. Sorta like Steve Martin's arrow in the head gag. In one side, go around to the other side, then out. Just thinkin...

    I just picked that IP out of thin air. Kinda scary that I chose a bible thumping site. :P
  • Electricity is 'faster than light' in that, when you turn on a generator, electrons can flow throughout the circuit instantaneously, without 'filling up' the wires with charge.
    Okay, physics lesson.

    One analogy often used for electricity is that of water flowing through a pipe; you open a valve to let the water flow. It's an inaccurate analogy, because it really should be water flowing through two channels, with a pump pulling water out of one and dumping it in the other.

    If the water in the two channels starts out at the same level (same voltage), you can open a valve between the two and no water will flow. To get water to flow, you have to turn on the pump. Not only does it take a finite amount of time to pump the water level (voltage) up to any given level with a pump (generator) of finite capacity, it also takes time for the wave of increasing water level (voltage) to travel from the pump end of the channels to points farther away. In electrical terms, this is known as the propagation delay; the speed of propagation is often referenced to the speed of light, as a "velocity factor" less than 1 (1 = c).

    The best you can do is to have propagation at the speed of light. Whether you're pumping water into a channel or current between two wires, you have to make currents flow and charge stray capacitances. The fastest that these changes can move through any medium is c (possibilities related to suppression of background quantum states notwithstanding), and they usually move slower than that. The typical velocity factor of a coaxial cable using a solid plastic insulator is about 0.6.

    If you turn on a light, you get current flow more or less instantaneously; there is no speed of light delay to the generator and back. This is because there is energy stored in the stray capacitance between the conductors, which supplies energy immediately upon the closure of the circuit.

    Hope this wasn't too muddled.

  • In 2007 you can ;)
  • Would that be a low grav server? :]
  • I can see the scenario, the first sattellite is connected to the internet, there's a post here, it gets slahdotted and falls out of the sky, destroying Dayton, Ohio.
  • as described in the article. Oh well, I guess we can forget about interplanetary Quake games for the time being...
  • Actually I believe it would be multiple intranets.
    Since internet would refer to the entire connected
    network. But still SCHWEET.

  • From the article:
    We don't know of a way today to convey information between Earth and Mars at a speed faster than the speed of light. [It takes light six to eight minutes to travel the round-trip distance.] We don't foresee a way to get rid of the latency in the communications.

    ... there must be some sort of webpage which collects this type of quote somewhere.

  • ... and the question to that bafflingly obvious comment was
    Could there come a day when astronauts or colonies of people living on Mars could communicate with Earth in real-time?
  • by Motor (104119)

    An interplanetary internet...

    I can finally finger Uranus!

    Don't mod me down, I've waited years to make that joke.

  • If you had read the article, you would have seen that they are not aiming to make an extension to the existing internet. They want to build an entire new internet on mars (and also around Jupiter with its moon Europa), and then build "trunk-lines" to communicate between these internets.
  • Er...wrong. If you have a routable IP address, you're connected to the Internet, period. Latency is irrelevant (You Will Be Assimilated).

    Otherwise, I'd be interested to know where you'd draw the line, particularly speaking as someone who started out on a 2400 line 8-)

  • That way, as new technologies come along, we'll be able to make changes to the underlying physical infrastructures without disturbing the protocols that are already in place
    How is this different to the 7 layer model? []
  • Finally scientists have discovered conclusive proof of simple life on Mars with the recent photos of a collection of used AOL CDs buried deep under the Martian soil

    Scientists at NASA are now providing these with broadband capacity to see if they'll troll Slashdot, or if they're actually intelligent.

  • I think the idea is that the probes talk to each other using TCP/IP. What better way for projects developed by seperate governments desiring a high level of secrecy to cooperate?

    I hope they come up with some good hostnames :) pathfinder.nasa.mars or scoperta.esa.mars ... ?

  • Russian, China, Japan or India, name one other country that has a shot in hell of making it to Mars.

    Ergo, the only language we should worry about when trying to decide names for planets we could land on is English, Russian, Mandarin, Japanese, or Hindi.
    Lord Omlette
    ICQ# 77863057
  • Who is English? Not me! I just live in England. I admit, that choice may make me stupider than actually being English... but none the less, I am not English.
  • That could get REALLY messy...
  • That 8 minute delay only means that the link would not be useful
    for real-time or on-line applications.
    Still, e-mail could be used together with a messaging system (perhaps XML) to perform tasks such as
    system monitoring and alert dispatching.
    i have done this myself with machines that can't
    talk to each other except through e- mail due to firewall restrictions and it works just fine.
    In fact, using something like SMS anyone could
    have an alert delivered to his/her cellphone if something goes wrong up there.
  • Electricity is 'faster than light' in that, when you turn on a generator, electrons can flow throughout the circuit instantaneously, without 'filling up' the wires with charge.

    That still doesn't make it faster than light, though. You put an electron into atom "A", which bumps over to atom "B", kicking its electron off to atom "C", et cetera. But the propagation only occurs at the 'speed of light'. Hence...


  • .. I can't really think of a practical purpose for it, except for perhaps e-mail...

    Yes, in the light of more than a few seconds turnaround (basically anything in space further away than the Moon), nothing but email would survive as a communication form. It is however, very suited for much larger delays too, I have some unanswered email in my inbox dating back a few years... (I mean to reply soon...).

    OTOH, nothing prevents us to come up with something email like, but utilizing video technology.. Sending a new message is trivial, just press record, and at the end, stop it, the interesting bit comes when replying. I hope MS dies when we need this tech, or you'll see "Original message follows" at the end of your partner's video, and you can see your own again :)

    Seriously, imagine a better way, you see your girlfriends face as she hears your message, she pauses, and tells the stories, and then unpauses to go on..

    Of course, the personal communications are not the single form you need from Mars (and obviously, in the first years, we won't have any), but most of it can be reduced to a form of offline, spooled data transfer. UUCP anyone? It (or some flashback of it) is very easily suited for bulk, offline data transfer. You could just program the local machinery to transfer data to be sent to a central spool machine, which then sends it away to Earth (or Pluto, for that matter). It's not internet, really, but IP need not be thrown away; and locally (ie. on Mars), TCP/IP is just as efficient, and well-working as here for us.

    For the real bulk transfer, something else would be needed than TCP, imagine that any missed packet can get reported only many minutes later, and you don't want to restart the connection then.. Add a bit forward error correction, and large buffering to cope with minutes (millions) of un-acked packets, and here we go.

    Shall I work on this, or let your billions of tax dollars work on this for a few years to get this built? :)

  • Okay, maybe this is totally out to lunch. But I've heard stuff like this before. Any idea if this is legit or not?

    If you split a beam of polarized light, and then do something to one (i.e. rotate the polarization), supposedly you can detect it on the other one, and it's instantaneous (i.e. faster than light). So what if you split a powerful laser somewhere equidistant from Mars and the Earth (try finding a place like that!), and had stations on both ends...could you communicate faster than light in that fashion?

    Or have I been mislead?
  • Even sadder is 2001:Odyssey.
    Both are technically and economically possible,
    but we lack the societal will.
  • by peter303 (12292)
    Nasa saved the Galileo Probe after its main
    attenna failed using compression. The emergency
    back up attenna has like one percent of the capacity of the main attenna or about the speed of Morse code.
    Every couple months Galileo passes by one of
    main moons and stores a dozen or two pictures
    on the tape recorder. Then it transmits them
    in compressed form over a day per image.
    The Galileo computers were reprogrammed from
    Earth to implement compression after attenna
    Galileo acheived 70% of its objectives in the
    main mission, and was extended several years.
    The bottleneck to extension is not the resources
    on Galileo but time on the Deep Space Network.
    This is less of a problem due to the Mars probe

  • When re-reading Ray Bradbury's seminal work
    recently, I niced most of the dates were
    between 1999 - 2006.
  • Why not? The ad campaign for Windows 95 claimed that it would "make a grown man cry." Microsoft already is the PAIN in Uranus.

  • So if we will have a 1mbps line to Mars will we still need PAWS to be so flexible? Will I finally be able to send mp3's to the University of Mars? Personally I was hoping for sftp or scp - but all I've ever heard about is ftp to the UM.

    [if you don't get it read linux/net/ipv4/tcp_timer.c]
  • What kind of crack are you smoking?

    Yes it's a simple laboratory process to turn CO^2 to Oxygen, but there are several problems.

    First the average atmospheric pressure on mars is about 5 milibars. That means the atmosphere is 1/200th as thick as earths. Even if *ALL* the CO2 were converted to O2, it would still be about 1/200th as thick. This of course ignores the fact that a pure oxygen atmosphere is a bad thing fire-safety wise.....

    Second, it's cold as hell there. Average temperatures on Mars make Antarctica look like the Bahamas.

    Third, mars is a PLANET it's going to take a hell of a lot of effort to make it habitable. It's not going to be done in 20 years, it likely won't be done within any one person's lifetime. The most optimistic estimates I've seen are 100-400 years assuming technologies not yet developed. Many estimates are in the greater than 1000 years range.

    If you want to know some real facts instead of just spouting crap, try reading Robert Zubrin's "The Case For Mars []".

    It includes a whole chapter on terraforming mars. Plus chapters on the technologies needed before we can send anyone to Mars.
  • He just mentioned that they were going to translate it to an IP stack :)

    Personally I vote for ICP/IP

    (Interplanetary Control Protocol over IP)

    or maybe TCP/IP/ICP :)
  • yes... but he had people landing there.
  • True.

    I remember for the last few years feeling a sense of dread as 2001 aproached. Not "end of the millenium" blues, just "unrealized potential".

    It makes me sad that as a society we seem to have no desire to push pioneer anything anymore. Granted the frontiers have gotten tougher to reach (sail across the void vs. sail across the ocean), and the challenges are more technologically demanding (single stage to orbit vs. what longitude/lattitude am I at), and that only a small percentage of people actually took the challenge to explore...

    Ah heck. This is getting me too depressed, I'm just going to keep thinking about the Pan-Am logo on the side of the 2001 orbiter and smile.
  • From net/ipv4/tcp_timer.c:
    /* Increase the timeout each time we retransmit. Note that we do not increase the rtt estimate. rto is initialized from rtt, but increases here. Jacobson (SIGCOMM 88) suggests that doubling rto each time is the least we can get away with. In KA9Q, Karn uses this for the first few times, and then goes to quadratic. netBSD doubles, but only goes up to 64, and clamps at 1 to 64 sec afterwards. Note that 120 sec is defined in the protocol as the maximum possible RTT. I guess we'll have to use something other than TCP to talk to the University of Mars. PAWS allows us longer timeouts and large windows, so once implemented ftp to mars will work nicely. We will have to fix * the 120 second clamps though!*/

  • When you're stuck on a space station on mars for a year, porn is good no matter how long it takes to download. ;)

  • Everyone knows Mars can be made habitable by finding the secret alien oxygen-release compound that is buried deep underground. All you have to do is place your hand in the little hand mold and voila! Hasn't anyone seen Total Recall???
  • Weel, that is pretty much the definition of 'internet'.
  • Interesting how they plan to translate all this to a standard IP stack, described in the article a bit vaguely as thus:

    "We're working on developing a layered architecture that would allow us to move data from point to point without worrying about the fine details. That way, as new technologies come along, we'll be able to make changes to the underlying physical infrastructures without disturbing the protocols that are already in place. So we'll have a layering of how we flow information across some infrastructure that lets us evolve it in time and accommodate technology infusion without having to scrap our investment."

    This technology could be of great use to those in rural and/or remote areas here on Earth, especially where habitat and conditions are most demanding (Lord knows, broadband is currently beyond their reach in most cases..).

    Additionally, if they can really pull this off, it could be the next NASA "killer app" like Velcro/Teflon/Tang/etc., improving their profile in the public eye dramatically by developing new "space-age" technology with everyday usefulness. Nice!

  • Don't you think that before we actually decide to terraform this place, we should investigate it thoroughly first? Sure, we could try to head the place up by dumping a few nuclear reactors there, changing the atmosphere, but it would also mean that we could never investigate it in it's original form. And, with NASA saying they found life on Mars, that might just be worth doing no?
  • And what're his pings going to look like from almost 49 million miles away?

    Probably a lot like any AOL user.

  • It sounds nice, but I can't really think of a practical purpose for it, except for perhaps e-mail...

    Or IRC. 8 minutes lag is nothing compared to what you can get on IRC.


  • Err, I believe that the sliding window on TCP is not tuneable per session. I think it's fixed in the OS. This may vary from OS to OS, but I'm not very farmiliar with network stack implementation.

    I suspect NASA will end up inventing a new protocol for this. IP really wasn't designed for the kind of latencies and packet lossyness that you get on deep space links.

  • Mars is going to get broadband before I do.

  • Umm... doesn't multiple interconnected internet's just equal 1 internet?
  • AFAIK the method you suggested is still an area of research. It's all got to do with quantum entanglement. When a property of a quantum system is measured it is forced to take a fixed eigenstate of the measurement operator. If this quantum system has recently interacted with a different quantum system (effectivly making them one quantum system) when one of the particles is measured and forced to take a fixed value so is the other system. Experiments have been done (I think) to show that the fixing of states happens instantly, although generally it is thought this method can't be used to transmit information as to find out what information was transmitted you would need to know what reading the person making the first measurement got. Don't take my word on this though as I'm only starting to get the hang of the quantum world.
  • I knew it wouldn't be long before a cable modem comment was mentioned.
  • kinda makes you wonder that with such a long mission, would NASA allow its astronauts to bring along porn? (seriously)
  • It's easy for me to understand that particles themselves (in this case electromagnetic energy) cannot travel faster than the speed of light. Thus, the large amount of "lag" between Earth and Mars.

    However, would it be possible to do something similar to the following poor example? If not, please explain.

    1) String a rope between two points, one near Mars, one near Earth (yes, I realize the problems this would cause due to orbits and whatnot).

    2) Rather than sending electromagnetic energy between the two points, simply "tug" on the rope. Rope only has to move a few millimeters rather than billions of miles.

    Please note that I have never taken a physics class... and it shows.
  • Are there any other crazy concepts for transmitting data faster than the speed of light? Perhaps something along the lines of the "Rope Trick" [] I suggested a few threads back?
  • ...that more bandwidth-ignorant people aren't already wondering why Mars doesn't at least have a 2.0 Gbit/sec link since they themselves are able to get 4.5 Gbit/sec from their local cable company in Omaha, Nebraska.
  • Hang on, did I hear that right?

    We can't think of a practical purpose for the ability to communicate arbitrary information between two different PLANETS with an 8-minute delay?

    There are still lots of practical uses of first-class mail, which takes about a day to deliver non-arbitrary information 50 miles!

    It's certainly a situation which terrestrial communications haven't had to face up to very much; even current satellite relays only give a delay of a few seconds. The increased latency means you have to use better FEC techniques rather than relying on an ARQ retransmission system, but the basic principles are still due to Shannon (RIP).

    Most of the trouble faced by communications software and hardware stems from operating in a regime of limited bandwidth or continuously changing router loading, rather than high delays. But as the article points out, scientists have adressed these problems on previous space missions, and the techniques are firming up to make the whole thing more interoperable.

    Now we just need to work out how to colonise the planet, before we completely destroy our own one :-\
  • For our deep-space links, we're dealing with many issues that can cause the IP stack to break down, like a lot of latency, intermittent links and high bit-error rates because of very low signal strength. We can encounter latency approaching more than 30 minutes on the link from the orbiter back to Earth, for example. We borrow a lot of the concepts of Earth's Internet but come up with protocols that will work in this deep-space application.


  • i wonder what will happen as the human race expands into the outer reaches of the solar system. do you think any company will really want to be known as "the dot in .uranus?"
  • I'm sorry, but having 4 or 5 probes on an extremely high-latency link, probably not directly connected to the Internet, does not qualify to be part of the Internet.

    It wasn't that long ago that people were using UUCP [] and bang paths [] to push mail around. The jargon file entry for Internet address [] mentions that the term is used loosely for anything reachable from the Internet, including bang paths.

  • Before we had a decent Net connection, few Americans thought the idea of a manned Mars mission made a lot of sense. Who would want to be away from their pr0n for that long?

    But the idea of trolling from Mars should sound intriguing enough to the average American that people might actually get interested in it again.

    red sand beach party 2010 []

  •> traceroute
    traceroute to, 60 hops max, 40 byte packets
    1 ( 2 ms 1 ms 1 ms
    2 ( 2 ms 1 ms 1 ms
    3 ( 12 ms 11 ms 11 ms
    4 ( 22 ms 21 ms 21 ms
    5 ( 342 ms 341 ms 341 ms
    6 ( 400 ms 321 ms 511 ms
    7 ( 291 ms 160 ms 320 ms
    8 ( 4261 ms 4280 ms 4291 ms
    9 ( 4210 ms 4200 ms 4241 ms
    10 ( 8222 ms 8221 ms 8221 ms
    11 ( 8222 ms 8221 ms 8221 ms
    12 ( 8222 ms 8221 ms 8221 ms
    13 ( 8226 ms 8224 ms 8224 ms
    14 ( 8227 ms 8325 ms 8318 ms
    15 ( 8341 ms 8347 ms *
    16 ( 8329 ms * 8348 ms
    17 ( 8351 ms 8343 ms 8340 ms
    18 ( 8340 ms * 8361 ms
    19 ( 8386 ms 8384 ms 8379 ms
    20 ( 8386 ms 8385 ms *
    21 ( 8387 ms * *
    22 ( 8391 ms 8390 ms *
    23 ( 8391 ms 8390 ms *
    24 ( 8391 ms 9040 ms *

    Trace complete
  • Mars is alive

    Well, I guess that answers THAT question.

    The REAL jabber has the /. user id: 13196

  • Mars is 4 light minutes away from the earth. Even if we had things working at light speed, there would be an eight minute delay between a request and a response... It sounds nice, but I can't really think of a practical purpose for it, except for perhaps e-mail...
  • This sounds like something being pushed by the DSL providers -- who only seem capable of providing broadband where it isn't needed.

    Seriously though, the data rate of 1Mbps is pretty pathetic. I have a cable modem that is faster than that. I am writing communications firmware for a satellite that will be relaying data back to Earth at over 20 times that speed via X-band. If we want broadband, let's really get it rather than settling for something that will be saturated shortly after deployment.

  • Quick, someone trademark Mars Online, MOL, and
  • The International Astronomical Union name for the planet is "Mars".

    The web site you point to mentions that English is the international language for professional astronomy.

    And .ma already is used for Morocco
  • by Alik (81811) on Wednesday February 28, 2001 @01:31AM (#396394)
    d00d! w3 0wn j00! @ll y0r r0v3r R b3l0ng 2 us!1! PH34R 0UR M4D SK1LLZ!!!!
  • by fgodfrey (116175) <> on Wednesday February 28, 2001 @07:56AM (#396395) Homepage
    If you fill a 747 with DAT tapes and fly it from LA to New York and then call someone in LA to say that it arrived, you're going to get a lot more than 1MB/sec. In fact, I'll wager that you'd get almost a terabyte a second (how many terabytes of DAT tapes fit on a cargo 747?? :) Granted, it'll take 6 or 7 hours, but you'll deliver a *LOT* of data.

    Basically, latency and bandwidth have nothing to do with each other. The reason we perceive latency to affect bandwidth on the internet is because the internet requires acknoledgements for every n packets. That means that if you have a high latency, it'll take awhile for the ACK to come back and thus you slow down the transmission. If you design a protocol that takes into account that an ACK takes 8 minutes to arrive, you can get full bandwidth at high latency. You could even use TCP, if you expand the sliding window to allow it to send, say, 16 minutes worth of packets without requiring an ACK. It would suck for telnet, but streaming data (which is what NASA wants to do) would be fine.

  • by Megane (129182) on Wednesday February 28, 2001 @07:06AM (#396396) Homepage
    It's a lot easier to talk to a geosynchronous satellite a couple of miles up than it is to talk to another planet that's not only millions of miles away, but isn't even always visible from whatever side of Earth happens to be pointing in its general direction. Even with a worldwide network of tracking stations, sometimes Sol or Luna gets in the way.

    Just imagine being on Mars and being unable to read /. for a whole week because Earth and Mars are on opposite sides of the sun. Will you be tough enough to survive it?

  • No what you do is get a very long noodle, you put a Rabbi on one end and touch the other end with a bit of pork or shrimp, I believe Tryef is in fact faster than light. So now you have a faster than light signaling system.

    How you streach a noodle from Earth to Mars is left as an exercize for the reader.
  • by Mozai (3547) on Wednesday February 28, 2001 @05:10AM (#396398) Homepage
    *shudder* I apologize for the word "Ameriocentric."

    When domain names were drawn up for nations, we used ISO 3166, which was agreed upon by people who don't only speak English. Germany isn't .ge, it's .de for Deutchland.

    Granted, we don't know the Latin spelling of what Martians call their home planet (nevermind their native tounge), but I find it hard to believe that "Mars" is the only name for that particular moving star in the sky.

    Italian, Spanish, Romanian: "Marte"
    Czech: "Smrtonos"
    Arabic (the language that many stars are named in) "Merrikh"
    Hebrew: "Ma'adim"
    Mandarin: "Huoxing"
    Japaneese: "Kasei"

    Most languages seem to agree on using an "M" sound to start the word. Perhaps we should use the .ma domain? or would that suggest that residents of Massachusetts, USA, are not of this Earth? .h tml for further reading.
  • by Jules Bean (27082) on Wednesday February 28, 2001 @01:28AM (#396399)
    So why don't you read the article, then?

    Of course, you're absolutely right about the latency. But latency doesn't adversely affect, for example, the transmission of pictures, geological data, or even streaming video.

  • by Jailbrekr (73837) <> on Wednesday February 28, 2001 @01:29AM (#396400) Homepage
    bash-2.04$ ping -i 100000 pathfinder.mars
    PING pathfinder.mars ( 56 data bytes
    request timed out
    request timed out
    request timed out
    64 bytes from icmp_seq=3 ttl=245 time=86603.712 ms
    request timed out
    request timed out

    Would be kinda cool to set up a quake2 server at mars, even thou the ping would suck.....

  • by darkwhite (139802) on Wednesday February 28, 2001 @01:28AM (#396401)
    Ultimately, we could see a spaceborne Internet that could revolutionize how people work in outer space, just as the Internet is changing our more prosaic Earth-bound life.

    I'm sorry, but having 4 or 5 probes on an extremely high-latency link, probably not directly connected to the Internet, does not qualify to be part of the Internet. It will be decades before anything beyond low earth orbit will attain enough connectivity to really become connected to the Internet.

    Don't get me wrong, I'm fascinated by NASA's Deep Space Network and everything, but we're not there yet. Hell, even the combined bandwidth of all low earth orbit satellites is miniscule compared to ground links.

  • by OpCode42 (253084) on Wednesday February 28, 2001 @01:53AM (#396402) Homepage
    * Increase the timeout each time we retransmit. Note that
    * we do not increase the rtt estimate. rto is initialized
    * from rtt, but increases here. Jacobson (SIGCOMM 88) suggests
    * that doubling rto each time is the least we can get away with.
    * In KA9Q, Karn uses this for the first few times, and then
    * goes to quadratic. netBSD doubles, but only goes up to *64,
    * and clamps at 1 to 64 sec afterwards. Note that 120 sec is
    * defined in the protocol as the maximum possible RTT. I guess
    * we'll have to use something other than TCP to talk to the
    * University of Mars.

    So maybe we're a while off, eh? ;-)


  • by Talkischeap (306364) on Wednesday February 28, 2001 @02:08AM (#396403) Homepage
    Somehow I don't see this as all so wonderful...

    Mars is going to get broadband before I do out here in the stix, damn!

    It's NOT fair I tell you...
  • by stevelinton (4044) <> on Wednesday February 28, 2001 @03:40AM (#396404) Homepage
    This is actually quite an insightful question.

    The problem is that when you tug on a rope what you actually do is send a "wave" of compression and stretching down the rope, and it takes time for the wave to reach the other end and be felt.
    The same happens if you push on a rod.

    The speed of this wave is determined by the stiffness and mass of the rope or rod. The stiffer and lighter, the faster it travels. So, you say, make your rod or rope stiff enough and light enough and it should travel faster than light!

    In fact you can't do that. The stiffness of a rope or rod is determined by the strength of the forces between the atoms that make it up, which are determined by electromagnetic effects (same as light). The fact that these effects only transmit information between the atoms at the speed of light puts an absolute limit of how stiff a rope or rod you can make, and ensures that the waves always travel slower than light.
  • by weave (48069) on Wednesday February 28, 2001 @01:29AM (#396405) Journal
    Chad Edwards, when asked about the possibility of online gaming to Mars, said that they were concerned about high ping times. Edwards did say that they are confident, however, that their ping times will be lower than those currently enjoyed by players on Blizzard's service.
  • by kievit (303920) on Wednesday February 28, 2001 @05:22AM (#396406) Journal
    You have probably read something somewhere about the EPR paradox and the Aspect experiments, which are key ingredients in discussions about the interpretation of quantum mechanics. This is a delicate subject, even many physicists will make errors when trying to explain it. I will also, I am sure, but I count someone will correct me (I actually hope somebody skilled in foundations of QM will comment on this, I am only an experimental nuclear physicist).

    EPR (Einstein, Podolsky and Rosen) considered a correlated pair of particles with spin. E.g. when a neutral pion (spin zero) decays into two photons, the spins of the two photons must be opposite (conservation of angular momentum). Spin is always measured along a polarization axis, with only two possible answers, say + and -.

    In the case where both spins are measured along the same axis you know what the measurement will read as soon as you know one of them, namely the opposite. If the two axes are under an angle, quantum mechanics gives a simple formula for the probability that the measurements will give opposite answers (cos^2 of half the angle between the axes, or so).

    If you would assume that the actual direction of the polarization was already determined in the middle (when the pion decayed), then you can show that this probability distribution must have a certain property (the illustrious 'Bell inequality'), which is *not* fulfilled by the quantum mechanical prediction. Then Aspect actually tried it out (and it is a very difficult experiment) and lo & behold, QM was right and hence the 'actual spins' (which is a vague concept) are *not* determined in the middle but at the moment of the measurement, and hence the information about the *other* measurement travels faster than light, instantaneous even.

    The sad point to note for your superluminal lasercommunication is that you cannot *influence* the information. It is Nature who decides the direction of the spins. So the answer to your question is 'No, in that fashion you cannot communicate faster than light'. Information can be superluminal, influence cannot. For communication you need to be able to influence the information.

    With your measurement you can predict what the other would measure if the polarization axis there would be chosen (anti)parallel to yours. You cannot tell from your (measurements) the direction of the other polarization axis, which is what you were suggesting. If, for instance, one (the sender) would keep its polaxis constant and the other (the receiver) would do a series of measurements with the (wrong) idea that due to the correlation you should see an angular dependence; well then, pity, you would measure in any angle + and - equally often (with some random deviations). The QM correlation only tells you whether the other one will measure the same or the opposite, if you would *already*know* the other axis.

Every nonzero finite dimensional inner product space has an orthonormal basis. It makes sense, when you don't think about it.