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A Very Long Wait

[ Posted Thursday, February 23rd, 2017 – 19:53 UTC ]

I thought I'd take a little break from politics today to address some scientific news. Astronomers recently announced (with much fanfare) that they had identified a planetary system with seven possible Earthlike planets orbiting it. This, inevitably, gave rise to claims such as "[it] could be the best place in the galaxy to search for life beyond Earth." That's a pretty superlative statement, but we'll ignore it for now (hey, even scientists like to create media buzz, right?). Because in all the stories I read about the discovery, there was a significant lack of some necessary context. Namely, the sheer distances involved.

The planetary system is being called TRAPPIST-1, for the telescope they used to discover it. Now, they really had to stretch the whole "making an acronym" rules here, since the telescope is named (with the odd capitalization you'd need) the "TRAnsiting Planets and PlanetesImals Small Telescope." It gets even more amusing, since the Belgian researchers are planning to look for similar planets in a project they've called SPECULOOS (also the name of a Belgian cookie): the "Search for habitable Planets EClipsing ULtracOOl Stars." As one article noted wryly, pointing out the fact that Belgians also love Trappist beer, the researchers' "next effort will have to be called WAFFLES."

Nomenclature aside, the discovery is an interesting one not so much for how close these planets are to Earth, but how incredibly different the star system is from our own Solar System. The star is much smaller, the planets orbit much closer, and their "year" is unbelievable short. The closest planet to the star takes only a day and a half to orbit its star, and the most-distant of the seven has a "year" of only 20 days. They should have called it the "Whirling Dervish System" instead, with the planets whipping around the star so incredibly fast. The fastest planet to orbit our sun is Mercury, which takes 88 days, by comparison.

What interests the scientists the most is that all seven planets seem to resemble Earth in size and mass, and all seven are in what astronomers call the "Goldilocks zone" -- neither too hot nor too cold for liquid water to exist. A planet with liquid water is considered the best chance for life to emerge, although this is a theory that hasn't really ever been tested (life might emerge on worlds with, say, liquid methane, who knows?). Additionally, three of the seven planets receive roughly the same energy from their star as Venus, Earth and Mars receive from Sol. This all might be planetary parochialism -- the assumption that since life emerged on Earth, the best chance for it to emerge elsewhere is on a planet as close to Earth conditions as possible. Again, these theories are untested, as of now.

Finding life on another planet may not be as cool as you'd imagine, either. Single-celled beings are "life," after all. Finding some bacteria or protozoa on Mars would be the discovery of a lifetime, but it wouldn't mean we'd start sharing technology with them or swapping ambassadors (to put it in context).

But suppose the real dream were achieved on one or more of these seven planets (named TRAPPIST-1a through TRAPPIST-1h). Suppose it was like all the science-fiction movies and there were actual intelligent and technological beings on one of these worlds. Imagine Trappist cities and Trappist television and all the rest. That's what most people assume when the subject of "life on other words" arises, after all. Even if this were true, the distances involved would be so daunting that it'd take incredibly long to really learn anything about them. The Trappist system is in the constellation Aquarius, and is 39 light-years away from the Solar System.

So even assuming for the sake of excitement that there were Trappistians (or whatever else you'd prefer to call them) that were technologically advanced enough to communicate with us. Suppose we trained our radio telescopes on the system and started picking up radio waves, or other electromagnetic communications. I can't believe nobody's yet done this yet, but perhaps nobody's been listening to all their television programs and CB radio broadcasts for all these years.

I say "CB radio" for a reason. Because even positing that intelligent Trappistians exist, and even assuming they had their own giant radio telescopes, they would right now be busily examining what was being beamed from Earth -- 39 years ago. They'd marvel at the miniseries Roots, and enjoy the first appearance of the Blues Brothers on Saturday Night Live. They'd be amazed at the new shows, watching the first seasons of Fantasy Island, Dallas, and Taxi. It's hard to imagine what they'd make of two other debut shows, when you think about it: Mork & Mindy and Battlestar Galactica. They might draw erroneous conclusions about our relative scientific achievements, to put it mildly, if they hadn't yet discerned the difference between fiction and non-fiction. Or they might consider us superbeings, since The Six Million Dollar Man, The Bionic Woman, Wonder Woman and The Incredible Hulk were all on the air as well. They might also wonder if we really should be classified as "intelligent life," since The Gong Show and Three's Company were also being broadcast (check out Wikipedia's "1978 television" page for a full list of what the Trappistians would be watching right now).

If we trained our radio telescopes on them, and they were broadcasting their own inane entertainment, it would also be 39 years out of date. That's what a "light-year" means, after all: the distance light (or radio waves, or any electromagnetic signal) can travel in a year's time. Heck, the Trappist star could even have gone supernova 38 years ago, killing all life on all its planets -- and we wouldn't even realize it until next year. That's the way the lag time works.

Say we did pull in some radio waves from the Trappist system. Say we learned how to decode their signals and learned their language, too (this might take years, if not decades, in real life -- especially if, as on Earth, they spoke a multitude of languages -- but let's ignore that for the moment). Even with a common language and knowledge of their existence, though, communication with them would be so slow as to test the patience of... well, a Trappist monk, I suppose.

Suppose all of Earth's scientists put together a message of greeting (in Trappistian, of course), and we build a satellite with a gigantic transmitter to beam the message to them (on Trappistian broadcast wavelengths, of course). Assume also that the Trappistians have noticed our radio transmissions and are listening in at the right moment. Even if all this were true -- a perfect set of circumstances to establish communication -- the conversation would go something like the following.

In 2017, we send a message of greeting, together with all the info we think they'd be interested in hearing about human beings and life on Earth -- similar to what we put on the Voyager spacecraft, in other words. We beam it out to them.

They would hear this message in the Earth-year 2056. If they immediately responded with their own summary of life on their planet and beamed it back to us, we would get their answer in 2095. Our answer to their first broadcast would get to them in 2134 AD.

That's a long wait. So long, in fact, that the technological advances that would have happened in the meantime are unimaginable at the moment.

So maybe instead of just talking to them on the radio, we Earthlings decided to go pay our neighbors the Trappistians a visit. Communication would be a lot easier in person, after all. But this would be even more laughably slow in reality. Barring discovery of a warp drive (faster-than-light space travel), it would take centuries to make such a trip. Light waves can traverse the distance in 39 years, but a spacecraft could not. Not even close, really.

Consider that a trip to Mars using the best technology available (chemical-reaction rocket propulsion) would take months, currently. That's just to get to the nearest planet in our own Solar System, mind you. Using the same method, it would take years to get to Jupiter or Saturn. The Voyager space probes are the farthest man-made object from Earth. They were launched 40 years ago -- meaning the Trappistians would just have seen the launches covered on the Earth news a year ago. After over three decades of travel, Voyager-1 entered interstellar space in 2012. It took all that time just to get out of our own Solar System.

Even looking forward a few decades wouldn't help the equation all that much. Suppose Earth scientists began a crash program to develop technology to make an interstellar voyage. Suppose a nuclear-powered engine design was created (it'd almost have to be nuclear, because otherwise you'd have to carry too much fuel) that could provide thrust continuously for the entire voyage (instead of, like not only Voyager but like all our space missions to date, they only received an initial boost from a rocket, and then just coasted to their destination). Even assuming all that -- and that is decades of technological improvements we're talking about -- a spacecraft could probably only achieve a small fraction of the speed of light, even at the fastest point of the voyage (halfway through, because the other half would be spent decelerating).

This would mean a trip of centuries. We'd either have to send just a robotic probe or we'd have to build what science-fiction writes call a "generational ship" which would be the size of a small asteroid, and carry hundreds of humans -- who would breed their own replacements during the voyage. The descendents of the early travelers would be the ones to make first contact -- many generations later.

So even assuming perfect conditions all around -- intelligent life on the other end, a crash project to build a monstrously-large spacecraft, and no disasters -- humans couldn't reach Trappist planets before (at the very earliest) perhaps 2300 AD. More like 2500, in reality, even given a few additional decades of spaceflight technological advances.

While it is nice to see science in the news, the reality of interstellar distances is rarely mentioned, because it's such a wet blanket for dreaming about life elsewhere. Even if intelligent life existed in the Trappist system, and even if it used electromagnetic waves to communicate, the earliest we'd be able to say "Hello" to them would be 39 years from now. And then we'd have to wait another 39 years to hear their initial response. Even if we spent the entire planet's resources on building an interstellar ship, first contact would still be many centuries off. So while it is fun to see "artist's conceptions" of what the newly-discovered planets might look like, for the time being we're all going to have to be content with sheer speculation, because that's all we're going to have for a very long time.

Even assuming the best possible perfect conditions -- that the Trappistians had noticed us first, and started beaming their answers back long ago -- if we tuned in our radio telescopes to their message, it might sound something like: "Breaker breaker one-nine, there here's Trappist Monkey, hopin' someone's got their ears on over there on Earth. Catch you on the flip side, good buddy...." They would have broadcast this in 1978, remember. In other words, even a CB-radio-style conversation with such beings would take a very long time.

[Note for science-fiction fans: The "generation ship" is a favorite theme in sci-fi literature, since (barring faster-than-light travel) it'd be the only real way to get to other star systems. Even going to the closest stars (Alpha Centauri or Proxima Centauri) would take decades to accomplish in this fashion, at a minimum. My favorite generation-ship stories would have to be Orphans Of The Sky by Robert A. Heinlein and Captive Universe by Harry Harrison, both of which I highly recommend. Interestingly enough, in both of them, so much time has passed that the occupants of the ship have lost all practical memory of why they were launched in the first place -- which could certainly be a problem on a voyage of centuries.]

-- Chris Weigant


Follow Chris on Twitter: @ChrisWeigant


10 Comments on “A Very Long Wait”

  1. [1] 
    TheStig wrote:

    I'd like to propose naming those 7 dwarf star planrts Happy, Dopey, Sleepy etc.

  2. [2] 
    neilm wrote:

    There was an Asimov short story along the lines of the conversation problem. It turned out that old women have already solved this problem. Both sides talk all the time :)

  3. [3] 
    neilm wrote:,_the_Physicist

    I loved Asimov as a kid. I think I read everything he wrote.

  4. [4] 
    Powderhound522 wrote:

    Another problem with interstellar travel is inherent in the speed - it's really hard to turn when you're going that fast.

    And you'll need to turn to avoid things. Space is pretty empty, but not entirely empty. If you hit a *one gram* asteroid at 1% of the speed of light, it's the same as a 21-kiloton bomb going off. For those of you keeping score at home, that's the same amount of energy as the "Fat Man" bomb dropped on Nagasaki. Even if you hit a piece of dust that weighs one-tenth of a milligram, you're colliding with the same force as a 2000-pound bomb.

    Once you get into science-fictional drives, where you're going at a decent clip - say, 90% of the speed of light - things get even worse. When you're going that fast, not only can you not see any incoming obstacles because you're pretty much going as fast as the waves from your radar or what-have-you, but the energies involved in a collision increase exponentially. That same 1 gram asteroid at 90% of the speed of light hits with 96 kilotons. At 99% of the speed of light it's 150 kilotons. At 99.9% of the speed of light, 480 kilotons.

    tl;dr - Probably no going to other stars, especially for these fragile meatsacks. Sad!

  5. [5] 
    nypoet22 wrote:


    so basically we're stuck where we are.

    anyone ever seen 'vlad the astrophysicist' by peter mulvey?

    mind blowing stuff.


  6. [6] 
    John M wrote:

    Things aren't necessarily as bleak as they might seem. The real keys are how much time, effort and money we want to put into developing the technology to undertake an interstellar voyage.

    There are several proposals and possibilities:

    Project Daedalus was a study conducted between 1973 and 1978 by the British Interplanetary Society to design a plausible unmanned interstellar spacecraft. Alan Bond led a team of scientists and engineers who proposed using a fusion rocket to reach Barnard's Star 5.9 light years away. The second closest star system to Earth after Alpha Centauri. Travelling at 12 percent of the speed of light, it would take 47 years to reach the star.

    The key of course being developing working nuclear fusion.

    Then there is the Star Shot Initiative announced to the public on announced April 12, 2016. Using tiny light sail spacecraft propelled by several ground-based lasers, a fleet of several small spacecraft would be capable of making the journey to Alpha Centauri, our closest stellar neighbor at 4.3 light years away, at 20% the speed of light and take about 20 years to get there.

    Finally, there is the British designed EM Drive. The EM Drive was developed by the British inventor Roger Shawyer nearly 15 years ago and has been undergoing a series of tests since then to prove that the concept actually works. The drive, which has been likened to Star Trek’s Impulse Drive, produces thrust by using solar power to generate multiple microwaves that move back and forth in an enclosed chamber. This means that until something fails or wears down, theoretically the engine could keep running forever without the need for rocket fuel.

    Such a working electromagnetic propulsion drive, would be capable of getting to the Moon in four hours, could get to Mars within 70 days and Pluto within 18 months. A trip to Alpha Centauri, could be reached in just 100 years.

  7. [7] 
    John M wrote:

    To put things in perspective, the Apollo astronauts took 3 days to get to the Moon, as opposed to 4 hours!

    One last thing, I also forgot to mention:

    Project Orion, whose idea was that your engine shoots a series of “nuclear pulse units”—atomic bombs of roughly Hiroshima/Nagasaki power—out the back. Each unit explodes and the shockwave delivers concussive force to an immense, steal pusher plate, which is connected to the most immense shock absorber system that you could imagine.

    The researchers calculated the ship to could reach five percent the speed of light, resulting in roughly a 90-year travel time to Alpha Centauri. The Nuclear Test Ban Treaty of 1963, which forbade nuclear explosions in the atmosphere, and the Outer Space Treaty of 1967, which forbade nuclear explosive devices in space, effectively ended Orion.

    In his epic TV series Cosmos, Carl Sagan noted such an engine would be an excellent way to dispose of humanity’s nuclear bombs, but that it would have to be activated far from Earth.

  8. [8] 
    altohone wrote:
  9. [9] 
    altohone wrote:

    Hey CW

    You should have titled this column "Wet Blanket".

    "So even assuming for the sake of excitement that there were Trappistians (or whatever else you'd prefer to call them) that were technologically advanced enough to communicate with us."

    I think we should prefer to call them what they call themselves.

    "Say we learned how to decode their signals and learned their language, too (this might take years, if not decades, in real life -- especially if, as on Earth, they spoke a multitude of languages"

    Come now.
    As we all know, aliens may have their own language, but they all speak English too.

    "or we'd have to build what science-fiction writes call a "generational ship" which would be the size of a small asteroid, and carry hundreds of humans -- who would breed their own replacements during the voyage"

    Typo alert.
    "writes" should be writers.

    I'm all for building one now... with a secret ballot to decide who gets voted off the planet.
    But seriously, there are already people signing up for the Mars colony... eager to go... and there are way too many of us on our planet already, so let's send some off as soon as possible.

    1978 was one year too early... Salvage-1 came out in 1979... but if NASA or Elon Musk can't get their act together, we just need an Andy Griffith type with a decent junkyard of supplies to send them on their way.
    It might not make the best first impression, but waiting around while all the naysayers create delays and a spiffy modern ship is built, or waiting for pleasantries to be exchanged just seems counter to the American can-do spirit.


  10. [10] 
    TheStig wrote:

    John M-7

    Although it was classified until fairly recently, Orion's "pulse units" were to be directed energy atomic devices, analogous to chemical explosive shaped charges, bulk of the blast directed away from the shield. Dr. Ted Taylor, the physicist who conceived Orion was a master of configuring nuclear warheads:

    "To some extent-and in all cases , to an important extent-you can select what to enhance and what to suppress. The relative amounts and directions can be controlled over very wide ranges."

    As he rather famously said:

    "If you want a bomb that spews out nothing but green paint,you can do that."

    As an undergrad, I once attended a small, day long seminar featuring Dr. Taylor. It was in the early 1970s, and he was into looking into small and large scale alternatives to fossil fuels, memorably to my mind, slush ponds, for air conditioning during summer months. Make slush up north in the winter, pump it south in the summer. All the numbers added up beautifully. I have never encountered such an agile engineering mind, before or since. He deserves to be much more well known than he is.

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