Unexplained.

[Snape]

I believe you: and the answer to the mystery might be closer to home, but just as strange...
There's a UFO researcher called Jenny Randles who points out that, where UFOs have been tracked by radar, - and that does happen from time to time, - they often "vanish" just beyond the earth's atmosphere. Supposing, just supposing that in the distant future, mankind can master time travel, as least for probes...
This would explain why there are so many UFO sightings: otherwise, why would little green men bother to keep covering the immense distances just to watch people fish (!).
But for earth historians - what would we give for a glimpse of Walker at Redmire (to maintain the angling example)?
Now, what does the edge of space have to do with all this?
Randles points out that, for a time jump, it's no use doing it on the ground, because you might end up in the middle of a tree or a building, at the end of the time journey etc. But in relatively open space...? That makes sense; - far less risky.
Ah, but time travel is impossible? Well we travel forwards all the time, of course; and at the speed of light, we would travel forwards pretty rapidly, compared to earth time, and - after a high speed trip of just five years in a space craft, we would find that hundreds of years had passed by on earth. This is a fact, according to the theory of relativity.
Apart from the problem of the paradox, which is overcome if we accept that our travelling back in time would split some time lines, creating different versions of the future, most scientists today (Snape?) seem to accept that travelling back in time is not impossible, so far as we know.

The laws of physics do not prohibit travel in either direction but to travel back you need a device to link to two times and so it is impossible to travel back to a time before the time machine was built. There is speculation about the use of wormholes as time machines though. Of course you could travel back in time if you travelled faster than light which is also not prohibited but you just can't there there as you would have to cross the unobtainable speed of light barrier to get there. Particles could come into existence above the speed of light (tachyons) and travel backwards in time and so could be used to pass information into the past but tachyons are only hypothetical as they are not prohibited by relativity.
I think a better view of space-time is to see it like a field you want to cross when out on your morning walk. The conventional view of time would be that there is a clear path crossing the field which represents past going to the future. In this model if you were to travel forward or back you travel along the path. This gives rise to the grandfather paradox when you go back and kill your grandfather and so are never born to go back in time. However, my preferred model is that when we stand on the edge of the field there are an infinite number of paths (routes) across the field and none are the same. The routes which are close together are very similar and those further apart are very different. When I am halfway across the field I can move forwards and backwards but I end up at different places in the field (space-time) and so if I go back I do not return to my exact past and from that point there are an infinite paths forwards again. This allows movement within space-time and no paradoxes as if I go back and kill my grandfather I am not on the path where I started and whichever path I now move forward on it does not connect to where I started and therefore from that perspective I am never born. This means if you leave the path you are on to travel forwards or backwards there is no coming back to the exact point where you started. However the whether it is practically possible to move around like this is a completely different matter.
What this brings rise to is the mind-gurgling realisation that all possible pasts exist and all possible futures exist but we are only conscious of the moment we call 'now' and our consciousness is weaving a path from the past to the future and we retain memories of the points along the way we call 'past'. We exist in all pasts from after our birth and all futures. Yesterday and all other days which have gone do still exist getting to them from here, however is another matter.
This leads to a realisation that 'time' per se has no actual existence. Just infinite 'nows'.

See Prof Julian Barbour

[Bluedun]

It's true that one can, in theory, travel forward in time by charging off in a spacecraft, although there is no technology that would allow us to do that. However, going backwards is not possible other than in the sense of specific solutions to relativistic equations - wormholes and all that stuff. This is all theory and there is no reason to believe there is any practicable application. I certainly wouldn't take much notice of a "UFO researcher".

[Gary Bills]

It's true that one can, in theory, travel forward in time by charging off in a spacecraft, although there is no technology that would allow us to do that. However, going backwards is not possible other than in the sense of specific solutions to relativistic equations - wormholes and all that stuff. This is all theory and there is no reason to believe there is any practicable application. I certainly wouldn't take much notice of a "UFO researcher".

Will Hawkings do...?

On paper, time travel should also be in the cards because of Albert Einstein's general theory of relativity, which allows for the potential to warp space-time so much that a traveler could leave Earth in a rocket and return home before he or she ever departed, Hawking said. Of course, that means you have to be able to warp space-time, which is pretty tricky.

"I showed it would require matter with negative energy density, which may not be available," Hawking said.

In the same way that some Victorian scientists thought the speed of train travel would kill people, or that flight would always be impossible, we may be missing something. We may not easily be able to travel into the future, Bluedun - but we certainly cannot predict future advances with any sort of certainty.
I mentioned Randles because I thought it would interest and engage some members, nothing more.

[Snape]

We may not easily be able to travel into the future,

Personally I find this very easy and I have a time machine at home. I lie down in it and close my eyes, when I open them again I have time travelled 8 hours. I do this every night....

[Bluedun]

Hi FB

I'm not criticising, just that I don't place much store on the Ufologists out there. I know what Hawking said, though as he says it's just theory. Personally I doubt it will ever be practicable - all very SciFi. If it is feasible, where are all the advanced civilisations popping in? (I discount the alien abductions, etc.)

[Gary Bills]

We may not easily be able to travel into the future,

Personally I find this very easy and I have a time machine at home. I lie down in it and close my eyes, when I open them again I have time travelled 8 hours. I do this every night....

Of course, dreams can be one form of time travel, and very vivid they are too, at times.

Returing to my last post, - if there are two things that dismay me about modern science: one is the determination of the majority to follow the received, current "party line" on most topics, coupled with an almost complete lack of genuine curiosity. The "what if" factor - it seems to me - is almost invariably missing, as science turns into a secular religion, with list of things you must and must not countenance. It is, increasingly, no longer a useful methodology to explore existence and discover new things. It seems, now, that most things have been discovered, to listen to many science buffs.
Anyone can seem wise, and clever, by saying yes in a crowd of others saying exactly the same thing, at the same time, in much the same way that anyone can seem holy by merely singing along to the hymns in a church service.

[Snape]

Hi FB

I'm not criticising, just that I don't place much store on the Ufologists out there. I know what Hawking said, though as he says it's just theory. Personally I doubt it will ever be practicable - all very SciFi. If it is feasible, where are all the advanced civilisations popping in? (I discount the alien abductions, etc.)

Where are all the time travellers is a good question. There are several answers in decreasing order of likelihood.
a. Time travel is possible in theory only and we will never achieve it so there are no time travellers.
b. It is possible but the exit point either does yet exist (ie you can't go back to a time before the time machine existed) or it is far away (it being a wormhole elsewhere in the galaxy)
c. There are strict controls over who can time travel in the future and on very few come back and they ensure the blend in.
d. There are loads of them here but they don't give themselves away and who would believe them anyway.

[Gary Bills]

Hi FB

I'm not criticising, just that I don't place much store on the Ufologists out there. I know what Hawking said, though as he says it's just theory. Personally I doubt it will ever be practicable - all very SciFi. If it is feasible, where are all the advanced civilisations popping in? (I discount the alien abductions, etc.)

Where are all the time travellers is a good question. There are several answers in decreasing order of likelihood.
a. Time travel is possible in theory only and we will never achieve it so there are no time travellers.
b. It is possible but the exit point either does yet exist (ie you can't go back to a time before the time machine existed) or it is far away (it being a wormhole elsewhere in the galaxy)
c. There are strict controls over who can time travel in the future and on very few come back and they ensure the blend in.
d. There are loads of them here but they don't give themselves away and who would believe them anyway.

Yes, I think that covers the bases nicely, Snape; and to return to Muskieman's original post, I believe him, and you, like a true scientist, are curious. I think we must accept that Muskieman has presented a true account of something very strange; something that happened to him. Of course, he may have see a "black project" - something like the British technology demonstrator, "Taranis"; or he may have seen a probe of some sort, and it could be a probe from the future - who knows? I certainly don't. The Randles idea is logical, on many levels - and it might be safer to send a probe through time than a human being...Notice, I don't say I think this has happened, but I'm open to the possibility.

[Kevanf1]

I'm not going to delve into the realms of UFO's being from another planet. I used to be heavily into this sort of stuff starting from when I was 9 years old and first read Erik von Danikens books, Chariots of The Gods etc. What I will say is that it is quite possible to see into the past and we have all done it. Stand outside and look at the stars. What you are seeing is the past, sometimes thousands of years into the past. Some of those stars are no longer there having collapsed or expanded and exploded hundreds maybe thousands of years ago. We are seeing the depiction of them as shown by the reflected light that has taken many light years to reach us.

Time travel by human beings in a physical sense? Hmm, maybe.... I'm happy to leave it to the sci fi writers and let my imagination run wild that way

Oh, one last thing. If you are interested in possible species from other worlds in a serious and scientific manner then take a look at a book called 'Evolving the Alien: The Science of Extraterrestrial Life' by Jack Cohen and Ian Stewart http://www.amazon.co.uk/Evolving-Alien- ... 113&sr=1-1 I bought this years ago and couldn't put it down. It goes deep even into the possibility of magnetic life forms that could evolve and live inside stars.

[Bluedun]

Returing to my last post, - if there are two things that dismay me about modern science: one is the determination of the majority to follow the received, current "party line" on most topics, coupled with an almost complete lack of genuine curiosity. The "what if" factor - it seems to me - is almost invariably missing, as science turns into a secular religion, with list of things you must and must not countenance. It is, increasingly, no longer a useful methodology to explore existence and discover new things. It seems, now, that most things have been discovered, to listen to many science buffs.
Anyone can seem wise, and clever, by saying yes in a crowd of others saying exactly the same thing, at the same time, in much the same way that anyone can seem holy by merely singing along to the hymns in a church service.

Probably not the place to discuss science and scientists. But anyway, I don't think all scientists are following a party line, if you like to call it that, although certain ideas do become part of the furniture of course, generally for good reason. The problem for science these days is lack of funding, and the demand to produce - hence the name of the game is to churn out papers; never mind the quality, count the pile. Much of this is to do with govt policy in recent years, which of course is down ultimately to the electorate. So don't blame the scientists so much as everyone else. Hard to be original when someone's cracking a whip over you.