( – promoted by buhdydharma )
I apologize for not including a post last week, but I suffered from a large amount of lack of motivation. You see, this was the first wedding anniversary in 33 years on which the former Mrs. Translator and I were not wedded. I poured out my heart the previous Friday night here, and was drained.
Saturday I went to the mailbox and found a parcel from her. She had sent me one of the most authoritative and scholarly works about the American Civil War (I still have problems with the name of the war, because it was not, by definition, a civil war, but I am coming to understand that my previous preferred title, The War between the States, is quite inaccurate as well). In addition to the wonderful book she sent a card that touched me, in a good way, so much that I guess that I was dumbstruck. I will never mention anything about the contents of that card except to say that it was likely the most touching thing that I have known in many years, and the telephone conversation that followed made it even more so.
OK, now that I am done with my excuse for not writing, we shall tackle the topic of very fast space travel tonight. We are not talking about the hypothetical warp speed, wherein a vessel travels faster than light, but rather relativistic speeds, wherein a vessel travels close to the speed of light. Last night was Space Night on The Science Channel, and the amount of disinformation and omission of important points was ridiculous.
Please do not get me wrong, I like Professor Hawking very much, but he lent his name to a program that was rife with omission. I also used to like Michio Kaku until he became a regular contributor for the Fox “News” channel. However, those programs left out serious considerations about near light speed travel.
The first omission in both programs was mass increase. The “Hawking” one was particularly deficient, because with the example of the little girl running towards the front of a train at 99.999% of the speed of light just said that there was “some internal mechanism” implied in relativity that would prevent her running for a total speed greater than that of light. That missed the point completely, and made it sound like magick. Actually, and this has been proven over and over and over and over with high speed particle accelerators, the mass of an object increases without bound as the velocity of that object approaches the speed of light, henceforth referred to as c.
Thus, the little girl would have to expend an almost infinite amount of energy to run faster than the relativistic train was moving. Remember, from Newtonian mechanics, F = ma, or that force equals mass times acceleration. What they left out is that mass increases asymptotically towards infinity as c is approached, so the force to accelerate that mass also increases towards infinity. The glycogen in the little girl’s muscles would have to approach infinity as well to power her run. That was a very weak part of the program, and Hawking is better than that. I suspect that the producers are just using his name and a few cameos for their show, and I shall not watch it again.
They did get the time dilation part right, and as arbitrarily as close to c that a body can come, the passage of time can, relative to another observer, approach, but never attain, zero. That was the point of the show.
Another extremely important factor that was never mentioned is the phenomenon of dimensional contraction. It turns out that as an object approaches c, it gets flattened on the axis of travel. The bottom line is that the volume of an object becomes vanishingly small on the x-axis, assuming that it travels in that direction as its velocity approaches c. That produces the situation that the object approaches zero volume. Thus, for an object with no volume attains infinite mass, obviously a paradox. Let us review, now.
As the velocity of an inertial object (i.e., something made of normal matter) approaches c, the mass of the object approaches infinity and the volume of the object approaches zero. Thus, the paradox of something with no physical (x,y,z) dimensions attaining a mass greater than the sum total of the universe. That is why c is called the cosmic speed limit.
No reputable experimental evidence has ever refuted these prediction. By the way, both the Global Positioning System and all high energy particle accelerators have to compensate for relativistic effects (the show got that one right last night). Particle accelerator experiments prove both the increase in mass (the sweep frequencies of the field generators have to be adjusted for it) and the time dilation (unstable particles with know half lives at rest follow the time dilation predictions exactly, their half lives increasing as c is approached).
In the case of GPS, it is not not the speed of the satellites that cause the time difference as compared with that on earth, but rather the fact that time moves more slowly the nearer and object is to a massive object. Since the satellites are further away from the massive earth, time passes slightly more quickly at that altitude than it does at the surface, and since the position of a GPS receiver is determined by the differences in time required for the signals from several satellites (in space) to reach the receiver (on the surface), relativistic corrections are essential for accurate location determination.
Now, let us get back to high speed space travel.
First, space is not empty. By far the most common inertial particles are hydrogen atoms, but there are also helium ones, and also ones of much heavier elements. Along for the ride too, are massive particles that are unstable. Some of those are traveling at relativistic speeds, so might be quite massive but long lived because of their velocities. Here is the problem. On earth, most cosmic rays are relativistic atomic nuclei, and if you are in a ship traveling at a relativistic velocity, it does not matter if those atoms are stationary, going towards you, or away. Running into a stationary hydrogen atom at relativistic velocities us just like you being stationary and one of them running into you at a relativistic velocity. Both instances are cosmic rays, and it does not matter which one is going faster. In either instance they are highly penetrating, ionizing particles and cause severe cellular damage. Even the solar flares can do this if intense enough, and manned space flight is severely limited because of that. On earth, our atmosphere and especially our magnetic field protects us from that. Fortunately, most of the solar particles are charged. This was not mentioned at all in the program. But it gets worse.
If your craft encounters heavier atoms, the damage is increased with the square of the velocity and linearly with the mass of the particle. This does not take into consideration at all the strong nuclear force, which certainly will cause those particles, as such high energies, to begin to transform the hull of the vessel into different elements, almost certain to be weaker that the original materials of construction. The faster your vessel goes, the more energetic the collisions are, and also the more that your encounter. Whilst I have not done any quantitative calculations, I suspect that lethal exposures would be antecedent to hull failure, but either would be, indeed, lethal.
On Star Trek, Enterprise has a dish that sweeps out those particles before they get a chance to hit the hull. The only problems are these. First, there is not any known way to affect the trajectory of a particle that is not charged. Ions and electrons can be moved by an electric or a magnetic field, but not neutral ones. The magnetic field of the earth is wonderful about deflecting the deleterious effects of the solar wind, but that consists of mostly charged particles. In addition, the magnetic field of the earth is enormous, and is generated by the magnetohydrodynamic properties of our planet’s molten core caused by the rotation of our planet. That requires no energy from fuel, and is an artifact from our planet’s molten iron core and rotational motion. Certainly, there is an energy drain that tends to retard that rotational motion, but since our planet is so massive, in comparison with a vessel, that the net effect is nil over the span of a human lifetime. Interestingly, Mars seems to have had such a core a long time ago, and a magnetic field. Now it seems that the core of Mars has solidified, so has no magnetohydrodynamic influence on the planet. Thus it is devoid of protection from the solar wind, and the solar flares. My speculation is that if we can not find a way to awaken the core of Mars and remelt it, colonization is very unlikely, even though the intensity of the solar wind is only around one-third to one-quarter of that which bombards Earth.
However, on a vessel of finite size, a large amount of energy must be supplied to make such a deflector. With superconducting magnets, it might be possible to construct one that would sweep out charged particles, but as velocity increases, the field strength requirements would increase exponentially. This also does not address what to do about uncharged atoms, and how to sweep them out of the way remains to be solved. The only only known force that works of them (at distances that would be useful) is gravity, and it is extremely weak. I see no way to prevent neutral atoms from becoming highly ionizing radiation when the velocity of the vessel becomes relativistic.
The energy requirements to run a gravitational deflector would be huge, even if we knew how to make one. Our science is still in its infancy on even detecting gravitons (the particles that should transfer the gravitational force), let alone make an emitter for them. There is yet another problem. As far as we know for sure, gravity is only an attractive force, so even if we could emit a graviton stream, it would only attract neutral inertial particles. However, cleverly pointed beams could in conjecture overcome this problem. If you can attract something, you can move it out of the way. But we have not even confirmed gravitons as of yet for sure, so this is very iffy.
Fuel is also a horrible problem. Remember, as c is approached, the mass of the object increases asymptotically to infinity. Thus, ever increasing amounts of fuel are necessary to continue the acceleration. Unless a way to find a source of fuel in free space is found (the particles that destroy are far too few, and too energetic to be caught for fuel), this makes relativistic travel impossible as well. Remember, as an object accelerates at relativistic velocities, it becomes more massive, and just to make an incremental increase in velocity requires a huge amount of useful energy.
On Star Trek they solved that problem by using antimatter as the energy source, but even using antimatter would not do if the mass of the object approaches infinity. There is not an energy source in the universe that could propel a vessel nearing c.
Mentioned largely was the scientific fact that if high relativistic flight were possible (and it is not), that the occupants of the vessel, and the vessel itself, would “travel” into the future. That is well known, but what is the point? Under this set of known facts, it would be impossible to return to one’s original temporal realm. So why go?
Let me use myself as an example, from 20100627. Somehow I overcome all of the technical and theoretical difficulties and captain a ship at 99.9999% of c for what is for Earth two centuries (I am being loose with the maths, but there do exist exact equations). Now I choose to return. I am a couple of years older, and so is my vessel.
My children would be long dead, and my vessel centuries obsolete. My children’s children’s children, assuming the same lifespan as now, would be in their dotage, and their children in late middle age. I would be obsolete, but younger than most of my offspring. Why would I choose to do that? This is a philosophical question, with an infinite number of answers.
There is also another fundamental problem with this. I think that we humans want to explore, do research, report back, and also make friends with other species. Being bound by relativity makes that impossible. In my vessel, I can only meet individuals that are yet to be, and can not report back to my human fellows about what I have found, because they are long dead by the time that I make first contact with others, traveling in this way. Being chained by Einstein is likely the most horrible punishment that I can consider. Now, I do not blame Albert personally, but his view is so limiting that I just can not accept it.
So, what about going BACK in time? The show had some good points, but again missed the idea. The show used the axiom that effect always follows cause, and I am not convinced of that. I believe in the phenomenon of coincidence as well, and that sometimes nothing is correlated with anything else.
Einstein was likely the most advanced thinker around 1915. However, he allowed his religious beliefs to influence his science. He was sure that a deity was in control, and never let go of that. His science was tremendous, but believing in magic lessened it. I have a whole story in the wings about The Doctor and Albert, but that is not germane to this discussion.
Now, warp speed would sort of take care of most, if not all, of those problems, but that thesis assumes much more technology that we have now, or are likely to have for many, many years. Going faster than light would decrease the relativity effects, and the faster the better. If that were possible, objects would travel extremely fast, but in a realm of spacetime that has nothing to do with relative time, so the vessel and the occupants would experience time at about the same rate of others in the galaxy. This is speculation, but everything above is well known science. I hope that we can master the warp universe, but there is no chance of the sublight speed one to get what we want and need.
Now, warp speed has its own problems, the first of which is to accelerate a vessel past c. We do not know how to do that yet, but getting away from that asymptote of c lessens the effects of time dilation, mass gain, and dimensional distortion. In a very real way, the vessel would have to avoid c at all costs because of the effects already enumerated. In other words, it would have to “jump” over the barrier without ever attaining it.
But if a vessel could overcome this cosmic speed limit, assuming that relativistic effects diminish as c is exceeded, wonderful things could happen. However, that is the subject of a very different post. What I have indicated in this one are backed up by the scientific facts as we now know them. Warp speed is completely speculative, as almost all of the astrophysicists will allow. Personally, I think that it is possible. Actually, I think that it is ESSENTIAL so that we can break our bond with earth, which will certainly be destroyed as our sun becomes a red giant in the distant future.
Well, you have done it again! You have wasted another perfectly set of many einsteins of photons reading this high speed drivel. And even Joe Barton, the insane Republican representative from the oil patch in Texas, apologizes for apologizing about apologizing about his stupid apology to BP when he reads me say this, I ALWAYS learn much more while writing this series than I could possibly ever hope to teach. Thus, please keep those comments, questions, corrections, and other thoughts coming here. Remember, nothing is off topic here if it has to do with science or technology. I will be here for some hours during Comment Time, and will return on Monday around 8:00 PM for Review Time.
Crossposted at Dailykos.com