And to think I work for (not much of) a living.
Well, he told me after I asked him after we’d been camping together for a week. (Well, not together-in-the-same-tent, but together in the same circle of tents.) We’d built up something of a rapport by that time, although I wouldn’t call him my bff. But a week spent talking to someone and you do sorta get a read on him, you know? He’s not into conspiracy theories (other than this one) or bigfoot or even ghosts or “energy” or “magick”. He was at a counterculture festival because his daughter was doing a workshop there and he found out he could enjoy looking at bare tits if he came along. He was definitely the Muggle at Hogwarts.
Now, the one thing I did think of was that there may be some selection bias here: a kid fascinated with the possibility of aliens and starships and the rest might just pursue a career path taking him to NASA. Someone more skeptical to start with might not choose to work on space rockets, right? If he was lying about working for NASA, then his whole family was complicit, as I learned it from each of them independently before talking to him about it.
We have several Dopers who claim “the same security clearance as the President”, by the way, and say it isn’t really all that high. So I didn’t really think it was out of the realm of possibility.
Anyhow, it’s not like he totally convinced me. But he did bring me from, “No way, no how,” to “hmmmmmm…”
Really, the whole premise of aliens and UFOs is just so silly. It makes much more sense to ascribe the phenomenon to a collective neurosis-caused by the Cold war and fear of a nuclear holocaust. Now, that is over, nobody thinks about a “Mutual Assred Destruction” scenario. So, I expect the UFOs will die-what will replace it?
Which is why it sounds fishy. Why would anyone make a point of it? Basically there is Top Secret with some sort of polygraph stuff. The DoD denies there is anything higher (I’ve had the training, though it’s been years; I never got anything higher than Secret, though), like a Super Duper Top Secret. Once you get to Top Secret it’s pretty much controlled by need-to-know, and even the President gets limited as to what he needs to know.
Top Secret data is like sex. The ones that are really getting it don’t talk about it. 
:smack: Okay, okay, I’ll tell the rest of the story! I was trying to avoid this, as I know you’ll be shocked - shocked!
WhyNot (aka: dumb girl who knows nothing about security): So, do you have to have a high security clearance for your job?
NASA Dude: Well, sort of. I have the same security clearance as the President.
WhyNot: So, I shouldn’t pass you this joint, then, right?
NASA Dude: 
Probably not.
:o
Working for NASA is not an extraordinary claim. Working for NASA and having a humongous security clearance is. Drop the first A and then maybe, but I know what cover those guys have, and it isn’t NASA.
Telling someone about it without a background check would be very dangerous. With that clearance, I’d assume someone would know lots of interesting stuff, and the fewer people who know he knows, the safer he’d be.
He reminds me of the loser in True Lies. 
The problem I’ve always had with UFO’s (other than when they hover over my house), is that something designed for intra or inter galactic travel would probably have different characteristics than something designed for travel within our specific atmosphere.
Maybe they’re really bright, or maybe they bought the equivalent of an amphibious car, or maybe that’s why they crashed in Roswell.
The problem is, that the “lightspeed barrier” is not a barrier in the sense of the sound barrier, it is a fundamental property of the universe. No matter how technologically advanced it cannot be exceeded.
True, there are a few hypothetical methods to get around it, i.e wormholes or drives that compress the spacetime ahead of the vehicle and stretch it behind. These all rely on exotic matter with negative mass to make them work. No one has ever found such matter, and it’s existence is purely hypothetical.
Even if it did exist it’s not available locally (as far as we know) so you’d need some form of interstellar drive to get to it. It is possible that future generations could artificially create some, but you’d need a particle physicist to tell you how possible that is.
Which means that, for the foreseeable future, all space travel will be* c* limited.
Imagine if that view prevailed 100+ years ago. Ah, but of course now it’s different. Now we know how things really work. What a joy to be living in such an enlightened age.
all I can say is that every since I was abducted from Kansas and dumped in the state of Texas shortly after I have had a hard time dealing with the rejection.
Ok, on a more serious note… it’s plausable, but I am doubtful. just my opinion - it seems like more and more claims are being debunked with growing technology/research.
I didn’t mean to appear too negative. I really hope we can conquer the technical difficulties. I’m sure that people will work on it even if I don’t think it can be done and quite rightly so. One of the points of research is to push the boundaries of our knowledge.
However, as we currently have no knowledge of negative mass materials outside of pure theory, we should also put our efforts into c limited travel.
Personally I think it is much more likely that any interstellar travel will be done at sub-light speeds say ~0.9c. While difficult it is likely to be possible in the future. Quite how far in the future, I have no idea.
Relativistic travel also has the advantage that time travels slower the faster you travel so for the crew of the ship the journey time is much reduced. Of course for those of us not travelling at 0.9c it takes a long time.
For a scientifically accurate, but fictional account of this, I recommend the Revelation Space series by Alastair Reynolds, who was also a part time astrophysicist at ESA. He also provides an excellent solution to the Fermi Paradox in the form of the Inhibitors, a species who exterminate other space faring species.
It is my opinion that even if some form of FTL were possible, not every species could achieve it due to the technical difficulties involved and therefore the likelihood is that the majority of any space faring species would be c limited.
That is, until they met a species with FTL technology, which they would [del]steal[/del] reverse engineer. A species without the initiative to steal interesting technology deserves to putter along in the slow lane. The funny thing about technology is that something can seem impossible until somebody else does it–see Koxinga’s link.
I don’t think those quotes, although by respected scientists, really reflect the general consensus at the time. As we discussed in a recent thread, no one can even locate that Lord Kelvin quote, and I’m beginning to doubt that he ever actually said it in those words – and I’d be interested in exactly what he did say. By that time, as I pointed out in Teemings, there had already been flights by heavier-than-air models , decades earlier. There was a respectable body of theory and engineering by Cayley and others on heavier-than-air flight, also several decades old. There was even work on spaceflight, both respectable speculation by scientists and lots of speculative fiction by the likes of Tsiolkovsky, Verne, Moore, and others. None of this required special breakthroughs of the sort we got from quantum theory , or chaos theory or catastrophe theory or any 20th century developments. Or even elpectromagnetic theory, for that matter. Heavier than air flight and space flight was derivable from traditional mechanics and fluid theory and imagination.
Fast and easy interstellar travel, even with more recent developments, isn’t. That’s the point. I’m not saying it’s impossible. Just hard. Harder than the wishful fantasies of Doc Smith and Raymond Z. Gallun fredric Brown and the recent “The Farmer Astronaut” would have it. Which is a pity, because I’d like it if you could buold even a short-range interplanetary craft i your backyard, dammit.
I can’t believe you used those two sentences in succession.
But anyway, it allows me to clarify my original point. I have a basic knowledge of Relativity and understand that the light barrier is not comparable to the sound barrier; to accelerate a solid object to c would require infinite energy. Travelling faster than c would mean travelling backwards in time etc.
But it is my suspicion that there will be some way around the problem. It obviously won’t mean strapping on a Super Hyper Rocket; I suspect it won’t involve “propulsion”, at all.
I have a book “The Science of Science Fiction”, from the 70s, where the authors describe all kinds of things as impossible that we’re now contemplating. e.g. they say invisibility is impossible because for a human to have the same refractive index of air we’d have to be as light as air (even as a child I thought that they were being short-sighted in assuming that this was the only way to achieve invisibility).
All I’m saying is, with how long the Universe has been around, a hypothetical extraterrestrial civilisation may be many orders of magnitude more advanced than ours. Much more advanced than we could hope to imagine. So I would not rule out extraterrestrial visitation on purely that basis: that AFAWK there’s no way to transport a widget from point A to point B a light year away, in, or less than in, 1 year.
Look, I don’t believe we’ve been visited by aliens. I also think that the film “what the bleep do we know?” is horseshit.
I don’t believe Relativity will be “overturned” in any sense. But science isn’t about declaring things impossible, and “FtL seems impossible to us now, so…” is a pointless sentence.
Just the point I was trying, inelegantly I admit, to make. I’d love it if it were possible.
I was flipping through channels and caught a couple of minutes of Larry King showing some footage from a military missile test, in which you could see pretty clearly the missile, and another bright object moving around in the sky eventually coming to circle around the missile, and then, I kid you not, a laser (or something!) firing from the bright object to the missile, causing the missile to explode.
It was weird.
I have no further info on this–it was a channel surfing event, like I said–but I was wondering if anyone here knows what it was I saw, the source of the footage, the debunking of it, and so on.
-FrL-
And who exactly knows what other hypothetical methods will be envisioned 20, 50, 200 years down the road?
Besides, classical mechanics worked quite well until recently, and still does, “except when” (except for very high speed, except at the quantum level, etc…) . Are you sure that there’s a 0% chance that c being an absolute limit doesn’t have some “except when” yet to be discovered?
I didn’t see it, but perhaps it was lightning? Short NASA blurb on lightning and rockets
I would tell you what I feel about it but Diogenes would then harangue me until I agreed with him. 
Agreed. What we know about relativity is mostly from observation, and the science we have is basically describing in a formal way those observations. Until we know why exactly the speed of light is limited, and why it’s limited to that particular speed, it’s not really fair to say that we know that it’s a fundamental obstacle.