506 réponses à ce sujet

[metatheurgist]

I still want my damn jetpack!

The Martin Jetpack

[Kaiser Arian XVII]

It's a trap!

 

[The Devlish Redhead]

Hey forget the jetpack where are the flying cars?

 

So much stuff was predicted in the 50s, and 60s of what we would be doing now only like a 1/4 of what they claimed has come true if that..

[DeathScepter]

It's a trap!

 

 

 

Kelly Chambers will still hit that. James Kirk might join her.

[The Devlish Redhead]

Kelly Chambers will still hit that. James Kirk might join her.

Haha will Kelly Chambers tap anything?

[Dermain]

Haha will Kelly Chambers tap anything?

 

That was the implication.

[LPPrince]

Haha will Kelly Chambers tap anything?

 

Nah. She was pansexual I think, so it was depicted in game that she didn't care what species someone was or what their gender was, she had the potential to love and care for them.

 

Keyword is "potential". But people thought that meant she lays down for everyone and everything, [sarcasm] because gamers sure know how to pick up on context. [/sarcasm]

[MASSEFFECTfanforlife101]

It's about damn time

[Jehuty]

It's a trap!

 

10/10 would bang. 

[Gravisanimi]

10/10 would bang. 

Somebody doesn't know what a trap is.

[bEVEsthda]

I think you missed my point entirely. The fact that the pressure formula uses base dimensions does not make them the same as those dimensions. It is a mistake to consider the conceptual equality of work to displacement as much as it would be pressure to mass, length, or time. The point is that the distinction between the Newton's second law and the pressure formula differs only by area (height/volume). What is in effect is still the same, pressure = (mass x acceleration)/area. Both pressure and force ultimately create the effect of movement, but pressure is more applicable in certain situations like the lumen of an artery because its effect is more disperse than a single vector.

 

Of course, that doesn't make them totally non-distinct concepts. Work and the different types of energies (kinetic, gravitational potential, elastic potential, chemical) are also distinct, but how you want to make that distinction is only important to what you're trying to discover, explain, or apply.

 

I still miss your point entirely.

No Pressure formula here has used base quantities. (If you should want that, it's: Mass / (Time^2 * Displacement) )

Pressure doesn't create any movement by itself.

Pressures may certainly be involved in a dynamic process, where pressure differentials affects flow, which creates forces through accelerations of mass, etc. But that's physics in work, not the physical quantity of Pressure.

An aircraft sitting on a concrete pad, has more air pressure surrounding its wings than it ever has when flying. Yet it doesn't move.

 

Pressure is not "more applicable in certain situations" than Force. Force and Pressure are never applicable for any same situation. Because they are two different physical quantities.

You can perhaps attack some physical problem or question from an initial perspective of either Pressure or Force, and derive the same answer. Yes. But when you do so, that perspective differs depending upon if you start with Pressure or Force. There's nothing only about "only". It's not the same.

 

There's no case similarity in your analogy.

Kinetic Energy, Potential Energy, Heat Energy, whatever form of energy, is always Energy, the one and same physical quantity.

 

 

P.S. To illuminate this difference between Force and Pressure some more, let me go back to the initial example, pressure deep underwater. This pressure is caused by the weight of the water. This means we can easily calculate the pressure. A diver at 30m depth has 30m of water above him. If we're using SI units, the unit of pressure is Pa (pascale) which is derived as N/m^2. Which relate to our case as in how big force would gravity exert on a 1m X 1m column of water, 30m high? The mass of that column is 30 tonne, or 30,000 Kg. Gravity pulls on that with a force of 30,000Kg * g = 294,300N. So the pressure at 30m is 294.3 KPa,.. plus the atmospheric pressure, which is about 101.3 KPa, so = 395.6 KPa.

 

Neither diver nor fish feels much from this pressure. Yet, it supposedly corresponds to a "crushing force of 57.4 pounds per square inch" (or 39.56 N per cm^2), as a journalist might put it.

Baloney! There is no force in play. Both the fish and the diver are weightlessly suspended in the water, gently moving about, utterly oblivious of any force or weight that would supposedly crush them to pulp and bonemeal.

For a force to emerge, there would have to be a pressure difference. And there is none. The pressure in the water and inside the bodies of the fish and the diver is 395.6 KPa. The pressure is everywhere. It's a scalar quantity.

The pressure is not felt. Only force can be felt, and there is none.

 

But this does not mean that the pressure doesn't exist or is irrelevant. Not at all. As I said in a previous post, pressure affects - just like temperature - chemical processes. Including our bodies' own biochemical processes. If the diver, at a depth of 30m, now would suddenly breathe pure Oxygen, he would instantly die.

[Jehuty]

Somebody doesn't know what a trap is.

I am the trap. 

[bEVEsthda]

Hey forget the jetpack where are the flying cars?

 

So much stuff was predicted in the 50s, and 60s of what we would be doing now only like a 1/4 of what they claimed has come true if that..

 

...On the other hand, we have some things with functionality they only dared to predict for complete Science Fiction, millennia into the future. Like the common smartphone, for instance.

 

It's like some technologies and industries have a short period during which a lot happens. And then it grinds almost to a complete halt.
The 50s and 60s were the peak of the breakthrough of the car and the car industry, changing society. It was also a period during which nuclear power looked like the next big thing. So it probably made sense to speculate about flying cars and atom powered cars.

 

Ships went from something made from wood with masts and sails, used for a thousand years, to the modern engine driven steel ship in just a couple of decades. And then we have used that for a hundred years or so.

 

Same with firearms. The modern (even the automatics) cartridge loaded guns, emerged from black powder muzzle loaders in just a few decades. Before, those muzzle loaders had been in service for several hundreds of years with small changes. Since, the cartridge guns have been in service for a hundred years with only small changes.

 

Aircraft rushed things for about the first 40 years or so. But nothing much has happened in the last 60 years. Major civilian operators often operate 20-30y old aircraft. Even 60 year old aircraft are in use with small operators (like DC3, C-46, DC6), and military (like the B-52).

 

 

We're probably in the middle of what will be known as the IT period. And no one saw it coming.

[The Devlish Redhead]

...On the other hand, we have some things with functionality they only dared to predict for complete Science Fiction, millennia into the future. Like the common smartphone, for instance.

 

It's like some technologies and industries have a short period during which a lot happens. And then it grinds almost to a complete halt.
The 50s and 60s were the peak of the breakthrough of the car and the car industry, changing society. It was also a period during which nuclear power looked like the next big thing. So it probably made sense to speculate about flying cars and atom powered cars.

 

Ships went from something made from wood with masts and sails, used for a thousand years, to the modern engine driven steel ship in just a couple of decades. And then we have used that for a hundred years or so.

 

Same with firearms. The modern (even the automatics) cartridge loaded guns, emerged from black powder muzzle loaders in just a few decades. Before, those muzzle loaders had been in service for several hundreds of years with small changes. Since, the cartridge guns have been in service for a hundred years with only small changes.

 

Aircraft rushed things for about the first 40 years or so. But nothing much has happened in the last 60 years. Major civilian operators often operate 20-30y old aircraft. Even 60 year old aircraft are in use with small operators (like DC3, C-46, DC6), and military (like the B-52).

 

 

We're probably in the middle of what will be known as the IT period. And no one saw it coming.

 

 

 

And now we may have bullets that can lock onto targets and steer themselves

 

http://www.smithsoni...0955139/?no-ist

 

 

I remember this being fiction and the subject of a movie back in 1984 with the movie Runaway

[Fast Jimmy]

...On the other hand, we have some things with functionality they only dared to predict for complete Science Fiction, millennia into the future. Like the common smartphone, for instance.
 
It's like some technologies and industries have a short period during which a lot happens. And then it grinds almost to a complete halt.
The 50s and 60s were the peak of the breakthrough of the car and the car industry, changing society. It was also a period during which nuclear power looked like the next big thing. So it probably made sense to speculate about flying cars and atom powered cars.
 
Ships went from something made from wood with masts and sails, used for a thousand years, to the modern engine driven steel ship in just a couple of decades. And then we have used that for a hundred years or so.
 
Same with firearms. The modern (even the automatics) cartridge loaded guns, emerged from black powder muzzle loaders in just a few decades. Before, those muzzle loaders had been in service for several hundreds of years with small changes. Since, the cartridge guns have been in service for a hundred years with only small changes.
 
Aircraft rushed things for about the first 40 years or so. But nothing much has happened in the last 60 years. Major civilian operators often operate 20-30y old aircraft. Even 60 year old aircraft are in use with small operators (like DC3, C-46, DC6), and military (like the B-52).
 
 
We're probably in the middle of what will be known as the IT period. And no one saw it coming.

Agreed. Discovery, invention and scientific application is far from a linear path. It is sporadic, unpredictable and often neglected in favor of other areas of research once it reaches a plateau of functional status quo, until the next breakthrough comes in and explodes into a new round of chaotic advancement.



To quote one of the greatest philosophers of the last century... "Scientific progress goes BOINK."

[DeathScepter]

a part of me wants to discuss Kelly Chamber and Jim Kirk's xenophile natures in relations to BSN. 

[Fast Jimmy]

a part of me wants to discuss Kelly Chamber and Jim Kirk's xenophile natures in relations to BSN.

Art imitating reality? Or reality imitating art?

[DeathScepter]

Art imitating reality? Or reality imitating art?

both.

[The Devlish Redhead]

Forget warp ships we need working cryosleep

[LPPrince]

Forget warp ships we need working cryosleep

 

Hah, sure.

[The Devlish Redhead]

Hah, sure.

Well what's the point of a warp ship if we can't hibernate for a long journey?

[Sully13]

But can they make my overboard work on water?

[bEVEsthda]

Well what's the point of a warp ship if we can't hibernate for a long journey?

 

What's the point of highly unhealthy hibernation, if we can go there quickly in warp ships?

 

Warp = quick journey.  Non-warp = decades, centuries, millenia,..

 

 

There are two separate things discussed in this thread. EM-drive. Makes space ships much more practical because they don't need a colossal load of reaction mass. They still require energy though. It's not clear that it will work in interstellar space, and the journey will still be slow.

 

Warp field. Makes the very unlikely suggestion that FTL travel might be possible.

[Kantr]

Until the Em-Drive has been peer reviewed in a Journal it's snake-oil.

 

Like the faster than light neutrinos. If bouncing microwaves created a "warp field" then microwaves would have started moving long ago.