Who thinks Faster Than Light travel is possible?

[Swank]

A philosophical concern rather than a physical one. Why this particular relationship between Force, mass and acceleration? Why not F = m a^2, F = ln (m a) or F^2 = 1 / (m cosh (a) ) or any of the infinite number of different mathematical relationships I could posit?

It seems like this is part of living in a relativistic universe. With no set base velocity, how could you say how far into an acceleration curve you were in? You'd end up with situations where you could manufacture energy from the differential in the force required to put two objects in identical orbits via different acceleration. It would be an unbalanced mess.

Sure this is Newton' s first law. Nice. And F = ma is Newton's 2nd law, and we have Newton's third: for every action there is an opposite and equal reaction. Yet some of the concepts used in all three are fundamentally axioms that I can still ask: why do we observe the universe seemingly applying these axioms? Are there deeper reasons?

While these make more sense stated as three laws, they really are the same law from different points of view. Take the linguistics out of it and it is one symmetrical law.

Imagine a universe where two identical objects orbiting a planet a millimeter apart would need to change orbit if they touched and therefore doubled in mass. It doesn't seem like there are a lot of other options besides F=MA.



Broon, you are a physicist, correct? I was hoping someone could answer this:
Given that you can get to places in the universe with a high degree of local time dilation without needing to expend the force normally associated with high acceleration reference frames, how would you know you weren't in a place with a greater degree of dilation?

I'm thinking of the Interstellar thing, where traveling to and from a world orbiting closely around a black hole can be accomplished without the kind of acceleration needed to get to a large percentage of lightspeed. Given that the dilation changes the way you observe the outside universe, would that change in observation hide the fact that the center of the galaxy's black hole is much, much bigger than we think, and the Milky way exists in a relatively high degree of dilation - affecting our observations about the rest of the universe's red shift?

 

[LordOfWizards]

The Newton was defined, as far as I can tell, by the equation F = ma, so it's kinda a circular argument!

Yes. I always imagine scenarios/examples. To me theory can't be well understood without examples (or possibly thought experiments).

So, a mass is at rest in space where there is no gravity. Something pushes it. What? acceleration? There is no acceleration without force. And no force without acceleration. very circular.
F = ma doesn't mention what object is doing the pushing, but if nothing was pushing it would stay at rest. It doesn't need to mention where the force comes from. It is only modeling what happens as the result of the push.

Mathematics is useful because through experiment we can observe what occurs in this universe. I'm kind of glad Newton found the relationship to be this simple. Newton didn't invent the underlying laws. They were already here. Newton found a model for interactions between masses, and experiments proved him correct over time.

I doubt Newtons 'Theories' of Force and Gravity were immediately accepted.

I like Max Planck's statement on scientific theories: “A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it.”

 

[Ensign Shah]

Having looked at the science, examined the theories, agonised over the formulas, I can only conclude that my answer should be, erm, maybe

 

[paranoid marvin]

I suppose it depends on what we mean by travelling faster than light. Can I - somehow - get from point A to point B faster than the light from (for example) a particle of light can? Yes I believe this is definitely possible. The answer doesn't lie in a straight line 'drag race', but in finding ways to circumvent this method of physical travel. 'Folding' space, teleportation, and natural or induced wormholes are just some of the possibilities, but I'm sure that there are plenty more.

As I have mentioned earlier in this thread, considering our position in the backwaters of the western spiral arm of the galaxy in the outer reaches of the universe, it seems incredible to me that we can say with any certainty how the universe works. I'm sure it was Douglas Adams who said (something along the lines of) our understanding of the universe is about the same as an ant's understanding of the workings of the Tokyo subway system. I wish I could find the exact quotation, but I don't think he's too far off the mark with this suggestion.

 

[Wayne Mack]

F = ma doesn't mention what object is doing the pushing, but if nothing was pushing it would stay at rest.

I feel that this may be confusing acceleration and velocity. Without force, an object in motion would stay in motion. I tend to find the concept of an object of being at rest to be a little bit confusing. When comparing two objects, we usually define one as being at rest because its frame of reference allows for the simpler description of the major forces acting on the two bodies.

Without any force acting on it, an object retains is speed and direction.