[Herra Tohtori]

Scientists are also far from never wrong, one only has to think the words 'Cold Fusion'.

It's been done.

It didn't break even AFAIK, but it was done and it can be reproduced. IIRC it used a crystal to focus an electromagnetic field.

 

Source, source!

Actually, alas, cold fusion has been claimed to have been done, but it has never been reproduced aside from the few initial experiments where it is claimed to have happened - at least according to my best knowledge of this matter.

If you really have some information about successful and reproductable cold fusion experiments, could you throw a link or two? You'd think some newspapers would have told about it by now...

[aldo_14]

Well, it would be cooler than anything if it worked, but... Current knowledge of physics doesn't apply proposed kind of manipulation to space-time continuumwithout use of insane amounts of energy.

Douglas Adams has already pointed out that you can cross vast interstellar distances with nothing more than a strong cup of tea as a power source.

Pff.  what you want is a proper Bistro, none of that dangerous mucking about with improbability factors.

[Martinus]

Pff. what you want is a proper Bistro, none of that dangerous mucking about with improbability factors.

True, I didn't pass my A-level in advanced bistromatics though so I'm not going to risk it.

I am awfully careful when making tea now though, one slip of the spoon and I could be gasping for air around Neptune.

[aldo_14]

Pff. what you want is a proper Bistro, none of that dangerous mucking about with improbability factors.

True, I didn't pass my A-level in advanced bistromatics though so I'm not going to risk it.

I am awfully careful when making tea now though, one slip of the spoon and I could be gasping for air around Neptune.

you think that's bad?  All I did was discombubulate the milk matrix and ended up floating in an upside down purple-toned Skegness run by a half-fish, half-goat, half-Welsh mayor called Malcolm.

[Spicious]

Source, source!

Actually, alas, cold fusion has been claimed to have been done, but it has never been reproduced aside from the few initial experiments where it is claimed to have happened - at least according to my best knowledge of this matter.

If you really have some information about successful and reproductable cold fusion experiments, could you throw a link or two? You'd think some newspapers would have told about it by now...

Wikipedia has it under Pyroelectric Fusion.

[Herra Tohtori]

Thanks!

I should have been more exacti with my word... Would have saved a little time.

What I meant was that no cold fusion with capacity to produce net energy output greater than input has been implemented, at least not in a reproductable manner.

Yes, fusion happens in this phenomenon, but it demands more energy than it produces, thus being *not* useful power plant basis. There are other means of generating fusion in apparently low temperatures than than pyroelectric fusion, ie. myon catalyzed fusion, but they are all similar in this respect: they don't produce energy but instead consume it.

[Ghost]

Well, they had to put off Ragnarok till Tuesday, cos of rain

Snow, actually. Heehee.

[aldo_14]

I didn't know the end of the world was in Inverness.

Although, thinking about it, it does make sense........

[Flaser]

On the issue of faster than light and the problems of acceleration:

1) With all the energy in the universe you DON'T go faster than light as long as you have mass
2) The problem with acceleration has nothing to do with the acceleration itself - it's the force that creates the acceleration that's problematic.

All our prolusion methods produce surface type forces. In simple terms, the force will be countinously transmitted through surfaces. So when the rocket accelerates and I'm standing the floor will push against my legs. My lower bones will puch against my pelvic bone, against my spine...and so on up to my head.

The problem is that the very same force will exist between all the particles of my body along a given axis.
Changing position - sitting, kneeling, lying down can alleviate the problem since the human body has different tolerances in different positions. Note, that this tolerance also has a timelimit - on how long one can suffer this acceleration without injury.
A proposed theory - proposed by forefather of rocket sciences Tsiolkovsky - is to submerge the body in a solvent with similar density to the human body. The trick is that while the force of acceleration will act on the human body, the liquid will counteract with the Archimedean force - hence a body that floats in liquid would witstand a lot bigger accelerations and for longer periods of time.
This was tested and the human tolerance for acceleration was almost doubled. (A further step would be using liquid breathing medium, but this hasn't been tested yet.)

The nice thing about gravity and fields (electromagnetic) in general is on the scale of the human body they can be treated as volumetric forces. This means that the each and every single particle in the body will be pulled by the same force, instead being pushed by the neighbouring particle.
With a gravity field we could accelerate mass a lot more, since the differences in the field would produce surface forces only on very high accelerations.

[Herra Tohtori]

On the issue of faster than light and the problems of acceleration:

1) With all the energy in the universe you DON'T go faster than light as long as you have mass
2) The problem with acceleration has nothing to do with the acceleration itself - it's the force that creates the acceleration that's problematic.

1. Yes, that's why the only way to seemingly exceed the speed of light would be to

a. Shorten the path between A and B, as in Star Trek's warp speed, or
b. Create some space-time that connects A and B being shorter than the original path (or in other words, create a wormhole between the places)
c. Move onto another space-time continuum, where our space-time-continuum's places seem to be a lot closer to another, move from A to B in there, then jump back to normal-space (FS2 / B5 sub/hyperspace method)

If the path to B from A shortens, the time to travel the distance does reduce even if the ship doesn't (and can't) exceed the speed of light. This does not even breack the laws of causality.

2. Yeah, well... you could say that, I suppose, but since force is always tied to acceleration in relation F=ma, different sized people can stand forces of different magnitude, but generally the ability to withstand accelration remains the same.

Example. Here we have a skinny little kid (45 kg) and a Sumo wrestler (150 kg). Now, if the same force is applied to both person's feet by spaceship's floor (let that force be F = 4413 N), they have different acceleration. Skinny kid would accelerate at ~10 g and would probably faint if he was forced to stand rather than lay down. The sumo wrestler would only accelerate at 3 g and would probably withstand it quite long even when standing.

Yes, when it comes to causing injury the force is the primary culprit, but you must remember that the supporting force is defined by ship's acceleration and the injured ones mass. On the other hand, in a spaceship that accelerates steadily at 10 g, the sumo wrestlers spine and joints and whole body would be in a lot bigger risk of sustaining injury, because of his greater mass and thus much greater supporting forces.

[Flaser]

On the issue of faster than light and the problems of acceleration:

1) With all the energy in the universe you DON'T go faster than light as long as you have mass
2) The problem with acceleration has nothing to do with the acceleration itself - it's the force that creates the acceleration that's problematic.

1. Yes, that's why the only way to seemingly exceed the speed of light would be to

a. Shorten the path between A and B, as in Star Trek's warp speed, or
b. Create some space-time that connects A and B being shorter than the original path (or in other words, create a wormhole between the places)
c. Move onto another space-time continuum, where our space-time-continuum's places seem to be a lot closer to another, move from A to B in there, then jump back to normal-space (FS2 / B5 sub/hyperspace method)

If the path to B from A shortens, the time to travel the distance does reduce even if the ship doesn't (and can't) exceed the speed of light. This does not even breack the laws of causality.

2. Yeah, well... you could say that, I suppose, but since force is always tied to acceleration in relation F=ma, different sized people can stand forces of different magnitude, but generally the ability to withstand accelration remains the same.

Example. Here we have a skinny little kid (45 kg) and a Sumo wrestler (150 kg). Now, if the same force is applied to both person's feet by spaceship's floor (let that force be F = 4413 N), they have different acceleration. Skinny kid would accelerate at ~10 g and would probably faint if he was forced to stand rather than lay down. The sumo wrestler would only accelerate at 3 g and would probably withstand it quite long even when standing.

Yes, when it comes to causing injury the force is the primary culprit, but you must remember that the supporting force is defined by ship's acceleration and the injured ones mass. On the other hand, in a spaceship that accelerates steadily at 10 g, the sumo wrestlers spine and joints and whole body would be in a lot bigger risk of sustaining injury, because of his greater mass and thus much greater supporting forces.

Oh, boy, you've got it all mixed up. The ship is accelerating - all occupants will bear the same acceleration regardless their mass.
The point where you're wrong is that they would both witstand the same force. It won't be the same force.
Why? Becuse it's a counter force. Actually the thrust of the ship will do Z Newtons. This will force the ship to accelerate by Z/M=A where M is the mass of the ship.

All occupants will also accelerate with A. However their feet will have to produce different ammount of force to counter this. The heavier the person is the more his legs will have to work....you see you actually got it all backwards.

If I draw a coordinate system where the human inside the ship is stationary I can better demonstrate what happens.
I'm in freefall, I don't have to exert any whatsoever force.
The rocket kicks in.
In this coordinate system the floor starts pushing against my feet. The molecules in my feet in turn push against the molecules in my leg. This goes on from foot to head.
The reason why my feet have to handle the biggest force is beacuse Newton 3rd law, and the fact that I can add the counter force from all the molecules above.

Inside a forcefied - gravity, an electromagnetic field - there each and every particle in my body can be accelerated at the same time. Therefore, my body won't have to transfer the force from one particle to another.

[Herra Tohtori]

I don't actually have anything mixed. If you read my message again, you'll see that what I wrote was exactly the same thing you wrote in your last message, but in a slightly altered form.

If skinny kid and sumo wrestler are standing on a floor of a rocket that yelds standard power to give itself standard acceleration, the force exerted to sumo wrestler by the floor (and through the legs up to head, all the way becoming smaller as the amount of supported mass reduces) is bigger than the force exerted to skinny boy. That's really basic physics and I know that very well... 

So, in this scenario (and basically every else, too) there actually is a difference between how great an acceleration these people can take before collapsing to ground because their legs no more can transfer the induced supporting force to body and upwards. The skinny boy supposedly will be able to stand longer, as his bones, joints and muscles will have a fraction of strain that the sumo wrestlers bones, joints and muscles must withstand if the acceleration is the same.

Unfortunately, as long as the acceleration is the same and both can support their weight, still both of them will faint in this scenario, before their "structural integrity" collapses (aka legs no longer can support the great powers working on them). This is because the blood packs to their lower body, and this happens quite equally with both the skinny kid and sumo wrestler. There are some individual differences between people, but generally the blood packs to legs if they're standing upright in great accelerating movement, like on this example. Thus, both people faint and collapse to floor at ~4-5 g's, I'd wager. They might be able to support their weight even in greater acceleration, but it becamos impossible when they are no longer able to control themselves when their brains black out of loss of oxygen.

However, generally it can be said that the smaller the mass, the greater is the acceleration needed to inflict damage, because if the acceleration is the constant and the force needed to inflict damage (for example, break a bone) is constant (it probably is, if the skinny boy and sumo wrestler are both healthy people, their bones will be approximately of same strength), then when the Sumo wrestlers ankle bones start crakcing and being crushed, the skinny boys ankles are just fine, because of lesser force is applied to them.

Thus, lighter person can withstand greater acceleration than a heavier person, because of that difference in forces in effect if the acceleration is constant. So, actually there is no difference between our opinions, I just wanted to make clear that I don't have this thing mixed up at all, even if my last message might have been a bit ambiguous.

Of the force field moving the ship as a whole... I don't think it's even possible. Except that with space time manipulation there is no longer any need to accelerate, actually. Just make clear that there is nothing between A and B, then create a shorter path between those two, take a short ride at nice and pleasant acceleration, and after a few minutes, you're in B, after seemingly passing thousands of light years.

That is, if such space time manipulation ever will be possible...

[Flaser]

Boy, I'm getting tired of this but let me give some further info:

Although the force is bigger for the heavier person, weight alone doesn't tell which will collapse first.
Thing is, muscles are pretty complicated machines, and in this reagard we could simply say the stronger person will stand longer.
However from a structural integrity point of view what matters is tension not force - which is force divided by the surface of the crossection of the body through which force is transmitted.
Heavier people have bones with a bigger cross section, unless they spend their life in a wheelchair.

It's not that easy to tell.
However this whole discussion has nothign to do with FTL drives.

[Grug]

*peeks inside*

LoL.

Leave it to the scientists to debate boys and girls.

[Janos]

*peeks inside*

LoL.

Leave it to the scientists to debate boys and girls.

A worthwhile contribution indeed. What's wrong here?

[Charismatic]

 Well tho it may b a farshot i still think its good that they are interested in space travel and space related things.

Does anyone else notice this:

Shouldent we be working on better and bigger space craft and stations before we take the big leap into warp and subspace drives? Its like seriously. Going from caveman to our age now, skipping midevil. We should come up with several space stations, bigger ones, like Arcadias', and then a larger amount of space craft, and come up with FIGHTERS and faster ships; BEFORE we jump into warp surprassing several dimentions..

[aldo_14]

Well tho it may b a farshot i still think its good that they are interested in space travel and space related things.

Does anyone else notice this:

Shouldent we be working on better and bigger space craft and stations before we take the big leap into warp and subspace drives? Its like seriously. Going from caveman to our age now, skipping midevil. We should come up with several space stations, bigger ones, like Arcadias', and then a larger amount of space craft, and come up with FIGHTERS and faster ships; BEFORE we jump into warp surprassing several dimentions..

Did you ever consider that maybe the reason why we don't have giant ships and space stations is because current propulsion methods make it prohibitively expensive to travel into space anyways?  And that maybe, just maybe, being able to realistically and cheaply reach exploitable resources might just be a spur to expansion into space?

also, are you drunk?

[Carl]

Source, source!

Actually, alas, cold fusion has been claimed to have been done, but it has never been reproduced aside from the few initial experiments where it is claimed to have happened - at least according to my best knowledge of this matter.

If you really have some information about successful and reproductable cold fusion experiments, could you throw a link or two? You'd think some newspapers would have told about it by now...

Wikipedia has it under Pyroelectric Fusion.

Tabeltop fusion is NOT cold fusion.

[karajorma]

Yep. Cold fusion is bunk. It's never been repeated by any test and the claims originally made for it seem pretty unlikely anyway.

Tabletop fusion is very different. It involves completely different materials and a completely different branch of physics from cold fusion.

[Ashrak]

eeeeem heres a question that might be stupid

if you make a anti gravity generator cant you place a field arround say a ship which would mkae the ships weight (notice weight not mass) 0? in which case the relativity theory dosent apply since photons have no weight either you should be able to pop to C in notime?