# Naked Science Forum

## Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: davissp14 on 25/08/2012 07:32:19

Title: What determines the maximum speed of an object in space?
Post by: davissp14 on 25/08/2012 07:32:19
With little to no resistance to applied to an object in space, what causes an object to hit its max speed?

Also is it our limitation of applied force that prevents us from reaching speeds beyond light?

Note: I have no background in physics, just something I am curious about.

Title: Re: Max Speed of an object in space.
Post by: Soul Surfer on 25/08/2012 07:40:50
There may be no resistance that causes an object to slow down but it always requires a force to accelerate an object  this is defined by the well known relationship  force = mass x acceleration.
Title: Re: Max Speed of an object in space.
Post by: Emc2 on 25/08/2012 08:14:05
and about the speed of light, that is a constant, and as of yet, there is not the physics or the reality that could allow us to travel faster then the speed of light........

it is around 300,000 kilometers per hour I believe......

aim a flashlight in a darkroom at a wall, turn on the flash light, that's a speed I doubt humans can achieve, ever....
unless things such as worm holes and the like are reality...
Title: Re: What determines the maximum speed of an object in space?
Post by: chris on 25/08/2012 08:21:34
Just to clarify, the speed of light is constant for any given medium; light actually travels at a slightly slower speed in a more dense medium - like glass - compared with a less dense medium, like air.
Title: Re: What determines the maximum speed of an object in space?
Post by: Emc2 on 25/08/2012 09:47:27
yes, the medium is critical in any case or occasion...
Title: Re: What determines the maximum speed of an object in space?
Post by: yor_on on 26/08/2012 23:39:25
The speed of light is defined as a constant (299792.458 km/s) in a vacuum. It depends on your definition whether you will find it to have a different speed in a denser medium, myself I think of it as the interactions, annihilating and 're-birthing'  that photon as becoming the limiter there. Space is not defined as a medium in main stream physics as it show no resistance/friction that we know of, not as long as we're discussing uniform motion at least. Although theories as the Higgs assume bosons acting in accelerations, in Einsteins terms giving us the equivalence of 'a gravity' (uniform accelerations), I know of no explanation to what way the Higgs could create the type of accelerations(as in gravity) a mass express, when uniformly moving through space, as a planet?

And there is yet to be seen a definition of how LorentzFitzGerald contractions fit the Higgs theory. We have other geometrical ideas in where you get 'volumes' that act as 'particles' relative other 'volumes' that then becomes a 'original space' but they also will have to explain, or deny, time dilations and its complementary  LorentzFitzGerald contraction. It's not enough to assume that 'time' is a illusion, not if you consider its opposite side, the contraction seen by the observer.
Title: Re: What determines the maximum speed of an object in space?
Post by: CliffordK on 27/08/2012 01:18:22
To have a fixed speed of light, one must have some kind of a structure, fabric of space/time (http://en.wikipedia.org/wiki/Spacetime), or aether (http://en.wikipedia.org/wiki/Luminiferous_aether).

Without some kind of a structure, one would be able to accelerate to 90% of the speed of light.  Then accelerate again to 90% of the speed of light...  and end up travelling faster than the speed of light.

Having some kind of background also accounts for planetary motion.  I.E.  the earth is spinning not with respect to the sun, or Milky Way, but with respect to some undetermined background matrix.

It is often assumed that this background structure aligns with the Cosmic Microwave Background Radiation (http://en.wikipedia.org/wiki/Cosmic_microwave_background_radiation), but this hasn't been proven yet.
Title: Re: What determines the maximum speed of an object in space?
Post by: Bored chemist on 27/08/2012 10:03:09
"To have a fixed speed of light, one must have some kind of a structure, fabric of space/time, or aether."
Really? I thought it was the reciprocal of the square root of the product of the permeability and the permittivity of a vacuum.
http://en.wikipedia.org/wiki/Maxwell's_equations#Relation_between_electricity.2C_magnetism.2C_and_the_speed_of_light

It's like saying the speed of sound in air is a function of the properties of air (density + bulk modulus I think)
The speed of light in vacuo is a function of the properties of the vacuum.
Those properties must be independent of the velocity of the vacuum because the velocity of a vacuum isn't meaningful.
Title: Re: What determines the maximum speed of an object in space?
Post by: yor_on on 28/08/2012 17:24:21
The permeability of a medium is defined from a vacuum, that being no resistance at all. We have gravitational 'friction' though, if you deviate from a ideal geodesic. I don't know if one can guarantee that all paths taken by heavenly objects are without that type of  'friction'? That's why I mostly refer to it as the paths of least resistance. The point with that gravitational friction to me is that it should be stored in SpaceTime, expressed in the relation(s) creating it. That as you can translate it into 'energy'. As for the rest of it I believe BC to be perfectly correct, especially considering a 'velocity' of a vacuum.
Title: Re: What determines the maximum speed of an object in space?
Post by: yor_on on 28/08/2012 17:32:29
The point there is that if you consider it as a four dimensional SpaceTime, can one assume that, considering all directions for uniformly moving objects inside some defined space, that they all are without gravitational 'friction'. If one can, then geodesics are properties belonging to directions, relative motions and mass. If you on the other hand think that what's defining a geodesic is just that gravitational 'friction'? Then they somehow become 'corridors' and? Einstein defined them as without resistance as I understands it?
Title: Re: What determines the maximum speed of an object in space?
Post by: waytogo on 22/09/2012 23:25:57
@ davissp14

If you trust the formula e=mc^2 , it's near the speed of light.

If you don't (like me) it can be more faster.