Comments on On Starships and Stephen Hawking

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You're right, Gome...

It is an interesting article, not only for what the author says, but also for what he does not say. As is the case for so many writers, this writer has difficulty seeing beyond the very real problem he has presented. In fact, his concern falls squarely into the category I discuss in my book, The Chicken Little Agenda.

Here, as Paul Harvey would say, is the rest of the story. Deep space radiation – consisting primarily of cosmic rays – is only a problem if it penetrates your cells. The reason it doesn't penetrate you right now while you are reading this article, is because of the Earth's magnetic field, which deflects the cosmic rays around our planet, for the most part. (Actually, you are experiencing some primary and secondary radiation right now, but it is minimal.)

We can protect future starship passengers either by shielding them directly as our atmosphere shields us, but using some form of heavy metal, or we can deflect the radiation around the ship using an appropriate magnetic field. I suspect we will use the second more than the first, especially if we end up using magnetic "wings" as I described earlier. In fact, the wings and magnetic shielding probably will be elements of the overall ship propulsion system, so that the problem raised in the article becomes moot.

posted by arGee on December 2, 2006 at 4:18 PM | link to this | reply

arGee - I found this article on the subject very interesting

HERE . . . I think it is a NASA site.

The possibilities you outline in your last comment are interesting but also illustrate just how much we will have to alter out thinking once we do venture further into space. In my comment I mentioned the frailty of our human bodies. I have to agree that it does stand to reason that once we have mastered near light speeds; we will also have developed the requisite acceleration/deceleration methods and formulas. But we still do not know how the human body will react to cosmic radiation once outside, of the earth's magnetic field or the varying gravitational forces of any planets we may choose to visit.

When we consider some of the space heroes of our lifetime such as John Glenn, Neil Armstrong or Buzz Aldrin, just to name a few; as we begin to examine the possibilities of deep space travel and the possible risks, it illuminates just how brave these guys were in their respective eras.

posted by gomedome on December 2, 2006 at 2:50 PM | link to this | reply

For what it's worth, Gome...

How fast a body travels is not particularly pertinent, at least in terms of velocity induced stress on the body. Acceleration stress can be a problem, but in the kind of drives I discussed (matter/antimatter or the extended magnetic "wings"), acceleration, while constant, would be set to 1 g, or the gravitational pull on the Earth's surface, with no apparent effect, therefore, on the traveling passenger.

On the other hand, for any but the shortest of trips, another factor becomes VERY significant. For example, such a craft could travel to the star Sirius in about 12 or 13 human years, measured at the starting or end point. That consists of about a year accelerating to near light speed, about 11 years at near light speed, and about a year decelerating back to planetary speed. For the folks on the spacecraft, however, the subjective time would be only the acceleration and deceleration time – about 2 years. Thus, on the outward bound trip they would "leapfrog" 10 years or so into the "future." Since nothing else can arrive at Sirius any earlier, at their destination they would be in the "present" for all practical purposes. But following the return trip to Earth, they would arrive about 4 years older themselves, but about 25 years into the Earth's future, relative to when they left. And this is for a star quite close to us.

If they were to make such a trip across our galaxy, which is about 100,000 light years across (as opposed to the 11 to Sirius), they would arrive back at the Earth following a round trip approximately 200,000 years into the Earth's future, while themselves only aging several years. While this extreme example illustrates the kind of "leap-frogging" into the future that such space travelers could experience, in a more practical sense, for a human civilization contained in a sphere of say 100 light years or so, we would necessarily create a group of humans who would appear from time to time in the locations they physically visit, apparently little aged from their last visit, but decades to generations happening between each visit.

To planet-bound folks, these star travelers would appear immortal, although in fact, their actual life spans would be similar to those of planet-bound humans. Since even these apparently immortal folk will fall in love, have babies, etc., the concept of "dating" will become quite complex, unless the couple travel together. If they make separate trips, they will have to do complex computations for specific journeys that will end up with their being at the same place, at the same time, at the same physical age. And remember, they will not be able to communicate these calculations to one another in order to assist each other in making them, because the communications cannot travel between them any faster than they themselves could travel.

Interesting food for thought, don't you think? This would cause havoc with many religious ideas about second comings, etc.

posted by arGee on December 1, 2006 at 10:38 PM | link to this | reply

arGee -I think the biggest question will not be how we propel craft through

space but instead how we will overcome the frailty of our human bodies.

We simply do not know if these bags of water and chemicals, that are our human bodies, will withstand the physical stress of light and hyper-light speeds. We also seem mired in premises of conventional travel, transporting items and persons from point A to point B. Overcoming the vast distances of space may not even involve a traditionallly configured craft travelling through space. Other hypothetical avenues of potential space travel are teleportation and the manipulation of space itself. At this stage of our collective knowledge/ignorance it is not without merit to suggest that we may travel in space by other means. Possibly by transmitting ourselves as opposed to propelling ourselves. Then there are the notions of folding space or cutting holes through it (wormholes). Where all of these things, including warp drive, have been illustrated for us by science fiction, all are based on at least a scientific possibility.

posted by gomedome on December 1, 2006 at 10:30 AM | link to this | reply

arGee

Thank you for explaining that to me. Hopefully the g/children will figure it out. I enjoyed reading..

posted by Offy on December 1, 2006 at 8:22 AM | link to this | reply

Good luck, Taps...

And don't forget the plastic bags!

posted by arGee on December 1, 2006 at 7:52 AM | link to this | reply

When it comes to matter/antimatter propulsion, Beats...

We're not even close to a solution. Whether or not we have any fuel right now is moot. We really haven't any idea how to do this. Hawking was discussing something different – what could be a source of sufficient energy that would simultaneously be sufficiently compact to carry with you on such a trip. The ONLY such source of energy that we know of right now is matter/antimatter conversion, and this knowledge is strictly hypothetical. We know how much energy we can get from a specific amount of antimatter, but that's it for now.

There is another way to do tis that Hawking did not mention. In principle, we could generate vast "magnetic wings" extending at right angles from the starship, perpendicular to our direction of travel. This "wings" would collect and funnel interstellar matter (mostly hydrogen gas) to the starship, where it would be used as reaction mass in a more conventional matter. We don't know how to do this either, since the "wings" would need to extend out several thousand miles at a minimum to collect sufficient reaction mass to make such a system work.

I suspect both systems will be researched and eventually built by our grandchildren or great grandchildren.

posted by arGee on December 1, 2006 at 7:51 AM | link to this | reply

For some reason, they don't work for me. If I ever choose to fly again, take another cruise, a bus or train tour, or go to Disney World with my grandkids, I definitely will try one of those patches behind my ear. But, I don't have much faith in them either. Even playing video games with Peter (grandson) makes me nauseous and many movies. I am able to ride in a car only if I am the driver. For some reason that seems to make me exempt. Hey, do you think they would let me drive the space ship? LOL

posted by TAPS. on November 30, 2006 at 11:36 AM | link to this | reply

aRge

But there isn't enough anti matter on the planet now to support such a sophisticated craft. The craft doesn't exist to support the anti matter. The US has only been in the business of anti matter for the last decade and I am of the understanding we still don't have enough to fuel anything. The process takes several years so any suggestions on how to fast track the formula? It's a very interesting concept in theory, alas reality is what we live in. Unless that is what area 51 is really working on!

posted by Offy on November 30, 2006 at 11:22 AM | link to this | reply

Don't give up on yourself, Taps...

Grab a motion sickness pill and go for it! We get only one shot at life – live it to the fullest. Check out my personal website to see how I have tried to do this.

posted by arGee on November 30, 2006 at 11:14 AM | link to this | reply

I must respectfully disagree, Passion...

The universe is inherently violent – violent in a way that humans cannot even begin to imagine. I will write an article on this in the near future, so keep an eye out for it.

Just remember that humans have managed to move from simplistic machinery to sophisticated spacecraft in a matter of less than 100 years. It was only 66 years between the first flight of the Wright Brothers to Neil Armstrong stepping on the Moon! Some of our most significant advances have come during time of our most violent activities – war.

So swallow hard and get a grip. We will survive BECAUSE we are violent.

posted by arGee on November 30, 2006 at 11:12 AM | link to this | reply

You're welcome, Ariala.

posted by arGee on November 30, 2006 at 11:04 AM | link to this | reply

arGee, Stephen Hawking is indeed an interesting person and an interesting writer. He does make one wish that they could be involved in space travel and time travel. I would have adored being a part of such when I was younger. Now, if I had such an opportunity, I would refuse the trip for fear of motion sickness which plagues me.

posted by TAPS. on November 30, 2006 at 11:02 AM | link to this | reply

I really enjoyed your post...

I had not read about the Hawking interview but I completely concur. I wrote something similar myself about 5 or 6 months ago. I'll see if I can dig it out.

I wish the future looked brighter for mankind but sadly, I do think we're facing extinction. Only I don't believe our race has any right to survive. We haven't proven our value/worth in the cosmos. Plus we're far too violent.