inertia

[person]

y does inertia exist (in other words, what causes it)?

[Andy]

what do u mean what causes it? there is nothing that really causes inertia. simply, why would an object move if no one touches it or why would an object stop moving if u leave it alone?

i guess its really because you cant get something for nothing... something must be inputed if u got something out of it

[Cervantes]

I think the better question would be, "Why doesn't inertia not exist?"

I wouldn't say "inertia exists", however. It doesn't exist in the same sense that the sun exists. It is an observable property of matter, but it differs from many things in that this inertia is more a lack of somethings existance.

It's sort of like the centrifugal force, which is ficticious, but it still has an impact. Perhaps that isn't the best example, since the centrifugal force is directly related to inertia.

[Martin]

Inertia exists because it has to exist. No inertia, no universe.

[shorthair]

Read A Book On Quantum Mechanics , that will clear everything up


You would probably set yourself on fire and jump out a window if you tried to understand it , especially becuae youdont have a firm grasp of classical physics yet.

sorry guys, just finishd a paper on it for Physics today, the prof had me in awe on the subjet

[codemage]

There can be no reaction without an action.

Therefore, anything with inertia will continue until some sort of action occurs on it.

[md]

It's the embodyment of one of newton's laws: an object in motion will stay in motion unless an action is performed upon it. If you throw a ball then (in a frictionless, gravity free eviroment) there would be nothing to stop it from moving unless it hit something. The inertia of the ball is a measure of the potential energy it has. I forget the forumula's to figure it out though, been a long time since physics.

[shorthair]

an object will not continue accelerating like classical physics says.
as you approach c , time will slow down and hte time it takes to accelerate will increase and you will end up never making it to c.
where c is hte speed of light.


So really inertia is much more complex.

[md]

shorthair wrote:

an object will not continue accelerating like classical physics says.
as you approach c , time will slow down and hte time it takes to accelerate will increase and you will end up never making it to c.
where c is hte speed of light.


So really inertia is much more complex.

Classical physics says nothing about an object continuing to accelerate... aceleration requires force. The equation e=mc^2 expresses the relationship between mass, energy, and the speed of light. It actually doesn't say anything about time either (though it has been theorized). Basically all it says is that as the energy of the object increases (like really big, and through acceleration), the mass must also increase as the speed of light is (theoretically, not in practice) constant.

[shorthair]

classical physics does say that it will continue to accelerate. Galileo himself said it.


the old hypothesis was that if you were flying at 3/4 light speed and fired a bullet out of a cannon on hte ship at 3/4 light speed.
hte bullet would be moving at 1.5 lightspeed.
because classical physics says to add vectors.

this is also reflected in newton . he says that an object will continue to accelerate until acted upon.

[codemage]

That's not "acceleration" though.

By the old theory, the bullet/cannonball would be going at 1.5 * c by adding the vectors.

It's not speeding up though, you've just added the relative velocities together.

Acceleration implies some sort of force that is making the object go faster over time, like gravity pulling an object down a hill; starting slow and gaining speed.

[shorthair]

i know that is not acceleration , im showing that classical physics believed in a >c world.

and that Galileo believed you could accelerate past c ( he didnt know about c, but he believed you could always goes faster, thus implying past c),my previous post was just an example he used to show how speeds add. he had other examples that used acceleration i added in c , to show how it wsa wrong at speeds close to lightspeed.

All in all , everyone here all knows the same things.
coolest inertia fact " while trying to get to lightspeed ,it would require more than all the energy in the universe to push you to c"

[md]

Although it's not really relavent here there have been many cases where the speed of light has been shown to be faster or slower then c. Unfortunately I don't have links to nay articles so I can't really back up my claim... but it is true! Slowing and speeding up light is a very useful ability for making light signaling devices ie. switches for wide area fiber networks.

On topic: even if people did believe that an object would continue to accelerate if no force was applied; that dones't mean that it will. An object which has no forces applied to it will not change speed or direction.

[shorthair]

Light cant be slowed down, not even through water , its actually an effect of our vison , that makes an illusion that it slows down.

id really like to see these articles where they speedup and slow down light to harnss it for data transfer.

light is a radiation which does not accelerate, ittravels at a constant velocity, so for it to slow down must either mean that hte radiation constant is changed (that aint happening) or it accelates to close to C. but becuase its a radiaton it cant accelerate.

im 99.9% sure i know what im talking aboutthanks to university and reading, but i have not hunted down these articles you speak of.

[Hikaru79]

shorthair wrote:

Light cant be slowed down, not even through water , its actually an effect of our vison , that makes an illusion that it slows down.

Are you sure about that? I'm certainly not a science major, but every written thing I've ever seen dealing with refraction has said it is caused by the change in speed as light changes mediums.

I could be very, very wrong