Physics question...

[D_Hailsham]

my ruler was made in China and the clock is certified to be accurate to +/- 1 terrapin. So there.

Actually, to be grammatically pedantic, your ruler (Queen Elizabeth II) was made in the UK, but your rule may be chinese

Not according the the Concise Oxford Dictionary.

One of its definitions of "ruler" is:

a straight-edged strip of rigid material, marked at regular intervals and used to draw straight lines or measure distances

And one of its six definition of the noun "rule" is:

a straight strip of rigid material used for measuring; a ruler.

 

[EddieM]

BUT....the time it is stationary is so small, and unmeasurable, it cannot be determined.

We seem to have determined it to be either zero (it time is continuous) or 1 planck (if time is discrete, but also continuous )

Unfortunately being stationary for zero time (which incidentally would be my real world answer) throws up the paradox of infinite acceleration.

 

[wreckedit]

First of all I am not going to be responsible for this answer.

1. It is not possible to throw anything up in the air and it will go in a straight line, the azimuth. Even bullets and rockets cannot achieve this.

2. The moon/air will also have an effect. As it does on every atom of water and air on earth so it will on an object flying in the air.

3. The object thrown will have a biased rotation due to its surface resistance which means it cannot possible stay on a straight path.

4. Other reasons why it willn't go straight are etc., etc.,

Conclusion. The object will never ever stop but continue on a course determned by the forces acting on it.

 

[JMLanders]

BUT....the time it is stationary is so small, and unmeasurable, it cannot be determined.

We seem to have determined it to be either zero (it time is continuous) or 1 planck (if time is discrete, but also continuous )

Unfortunately being stationary for zero time (which incidentally would be my real world answer) throws up the paradox of infinite acceleration.

Not so much a paradox as an ill-defined amount. (zero divided by zero)

 

[JMLanders]

First of all I am not going to be responsible for this answer.

1. It is not possible to throw anything up in the air and it will go in a straight line, the azimuth. Even bullets and rockets cannot achieve this.

2. The moon/air will also have an effect. As it does on every atom of water and air on earth so it will on an object flying in the air.

3. The object thrown will have a biased rotation due to its surface resistance which means it cannot possible stay on a straight path.

4. Other reasons why it willn't go straight are etc., etc.,

Conclusion. The object will never ever stop but continue on a course determned by the forces acting on it.

Which could be a straight line

 

[wreckedit]

JML What I have implied is that there are an incredibale amount of variables, and in nature which this function is about, I do beleive there are no straight lines.

Could,should, may, probably and possible it will happen one day.


Once again I claim no responsibiliy for this answer because I am to thick to know the right one.

 

[Lincsbodger]

JML What I have implied is that there are an incredibale amount of variables, and in nature which this function is about, I do beleive there are no straight lines.

Could,should, may, probably and possible it will happen one day.


Once again I claim no responsibiliy for this answer because I am to thick to know the right one.

um ignoring all that above, theres no straight lines because theres no such thing as flat euclidean space. All space is curved by gravity, and nothing in the universe is stationary, and if it was you couldn't tell anyway because you have no external absolute reference frame to measure it by. This was all figured out by Einstein in 1908..........

 

[lifesagasman]

That sums it up, then. During the interval between moving in one direction and the reversal to move in the opposite direction, no movement takes place, therefore 'stationary' applies. for a very short time. Even if this took place in a vacuum where no external forces other than gravity acted on the ball, there has to be a period where there is no movement up or down, as the two states cannot co-exist.
Where did you get this stupid question from, OP??

 

[lifesagasman]

my ruler was made in China and the clock is certified to be accurate to +/- 1 terrapin. So there.

do they calibrate grandfather clocks by the number of turtles?

It depends on where they hang out.

 

[Lincsbodger]

That sums it up, then. During the interval between moving in one direction and the reversal to move in the opposite direction, no movement takes place, therefore 'stationary' applies. for a very short time. Even if this took place in a vacuum where no external forces other than gravity acted on the ball, there has to be a period where there is no movement up or down, as the two states cannot co-exist.
Where did you get this stupid question from, OP??

as as I explained, this stationary period cant be any longer than the Planck time.

 

[lifesagasman]

I'll go with that answer, Lincs, and I note that no-one has yet disproved my earlier solution.

 

[joe-90]

Well I don't know the answer. I'm as thick as two short Plancks when it comes to QM.

 

[Lincsbodger]

Well I don't know the answer. I'm as thick as two short Plancks when it comes to QM.

All Plancks are the same length, that makes us as thick as you

 

[mikhailfaradayski]

i've got two coats on and my taxi is booked, so here goes-

Assuming that it is possible to get the ball to travel straight up and down, ignoring the practical problems of the moon, air resistance etc. then the ball is being subject to a constant force causing an acceleration of about -9.81m/s^2.
As velocity is a vector quantity that is always changing to try to calculate 'time spent at velocity=0' is impossible to equate.
Actually, i suppose at a finite level, it is impossible to equate 'vel=anything' at any instant in time. This could only really be evaluated during 'delta t' however you choose to define this quantity.

At best, it is only possible to approximate the standstill time in relation to human perception, i.e. <1 of those planck thingies.
Again, due to human perception and the finest possible resolution we can theorise over, as the smallest amount of time prior to the elusive Vel=0 and the smallest amount of time following vel=0, we could say that to adopt some kind of tangible answer, the apparent standstill time would be between 2 to 3 planck thingies.

In reality it never stops

i suppose its the same as trying to calculate the pressure experienced by a surface when a given load is present via a point contact.

Does that depend on how sharp the point is, or how small you can define a unit of length? What would happen if you could actually manufacture a true point?

off to the pub now

 

[Space cat]

What would happen if you could actually manufacture a true point?

The nearest we can get to a perfect point is a probe that ends in a single atom. It's been done. It's the key component in the scanning tunnelling microscope.