When you start bringing in the effects of gravity as anything other than a
force acting on an object (its bending of space/time) you are going into the
terriotiry of General Realitivy and I never took that course as I failed
some of the advanced calculus needed.
I think the effects are cumualtive but not linear. So if you are in a strong
gravity field and moving at a high velocity the observer would see an effect
of both but it would not be as simple as addint the two together so if you
are going very fast the relativistic effects of anything except a very
strong gravity field would be negligible. (this could be wrong I am a layman
in this area , special realtivity I used to undersntand well , General
realtivity I have never had a clue about)
Its worth noting that for most purposes realtivistic effects are negligible
until you get very high veolcities , at 0.1C you get an effect on the order
of 1% and 0.1 C is really fast . Likewise you need really strong gravity
with a sharp gradient for major effects (Neutron starts/black holes)
On 21 July 2010 23:42, <> wrote:
>
>
> Interesting. So the effects of relativity are based on speed (relative to a
> frame of reference), not gravitational force?
>
> Well, that brings up another question: if gravity distorts time
> measurements, are you under the effects of both that and the speed you're
> moving at (relative to your observer? Or, is that what einstine said were
> actually the same?
>
>
>
> Sent on the TELUS Mobility network with BlackBerry
> ------------------------------
> *From: *Andrew Moreton <>
> *Sender:
> *Date: *Wed, 21 Jul 2010 23:18:48 +0100
> *To: *<>
> *ReplyTo:
> *Subject: *Re: [Traveller_TNE] speed/acceleration/mass/energy/etc
>
>
>
> In short No.
>
> Once you have accelerated your ship to 0.99c relative to your twin on the
> planet, when you stop accelerating your velocity relative to the twin will
> remain .99c until another force acts on your ship to change its velocity.
> The time dilation effect is relative to the observer to the captain on the
> ship see's that his twin his aging incredibly quickly compared to him, while
> the twin on the planet see;s the captain aging very slowly. If the ship
> slows down and then returns to the point it left at and is stationary
> relative to that point again then both of them will find their clock now
> move at the same speed , however the clock which was on the ship which moved
> is now behind the clock which was stationary.
>
> Another observer moving at a different velocity may perceive things
> differently
>
>
> http://www.scribd.com/doc/7221399/Feynman-Lectures-V1-Ch15-Special-Theory-of-Relativity
> is probably a good source as Feynmans lectures have a good reputation fro
> being accessible to none physicists and they where always the stuff I
> understood while I failed my physics degree
>
> On 21 July 2010 23:11, <> wrote:
>
>>
>>
>> Yeah, it's relativity I'm trying to wrap my head around. I thought it
>> would be fun to see what kind of an effect it would have in a Traveller
>> setting.
>>
>> Let me reword the question slightly. If a ship accelerated to near-light
>> speeds, using the galaxy it is in as the frame of reference, and then
>> stopped accelerating and just coasted, would the effects of relativity
>> (using our frame of reference) cease to distort time and mass?
>>
>> Or, in ortherwords, is relativity dependant on the force created by the
>> acceleration of the object, on on the given speed of that object regardless
>> of force?
>>
>> In even different words, while it may not be possible to accelerate *up
>> to* the speed of light without the inconvenience of relativity, is it
>> possible to *exist at* the speed of light while aging at the same rate as
>> our paradoxical twin who lives at planet-bound speeds?
>>
>> Does that help clarify what I'm trying to figure out, or muddy the waters
>> further?
>>
>> Sent on the TELUS Mobility network with BlackBerry
>> ------------------------------
>> *From: *Evyn MacDude <>
>> *Sender:
>> *Date: *Wed, 21 Jul 2010 12:31:33 -0700
>> *To: *<>
>> *ReplyTo:
>> *Subject: *Re: [Traveller_TNE] speed/acceleration/mass/energy/etc
>>
>>
>>
>>
>>
>> On Wed, Jul 21, 2010 at 11:36, <> wrote:
>>
>>> Does anyone on this list know how speed/acceleration work in relation to
>>> required energy/mass?
>>
>>
>> Yes i am reasonable conversant in basic physics.
>>
>>
>>> Theres something Im not understanding. Heres a
>>> sample situation:
>>>
>>> A 100 tonne starship comes into existence in deep space (how it got there
>>> is irrelevant). It has unlimited fuel and can accelerate at whatever Gs
>>> its captain wants without harm to the captain (who is the only person on
>>> board). The captain accelerates the ship at 1 G in a particular
>>> direction
>>> (which direction is not important).
>>>
>>> Now, the energy needed for the ship to remain motionless is nothing at
>>> all, right?
>>>
>>> The energy needed for the ship to accelerate, measured in tones of
>>> thrust,
>>> is 10 tonnes of thrust per 1 G of acceleration per tonne of ship = 1,000
>>> tonnes of thrust, right?
>>>
>>
>> Ok, your kinda mixing units here. A ton of thrust is a ton of thrust, so
>> it generates a impulse of 1 ton at one g. i.e. a 100 ton ship requires 100
>> tons of thrust to accelerate at 1 g. Which addresses the force question.
>>
>>
>>>
>>> Okay, lets say the ship accelerates up to a certain speed; say 1,000 km
>>> per hour (it doesnt really matter). How much energy is required to
>>> remain at that speed? I would assume none as the ship would simply be
>>> drifting.
>>
>>
>>
>> You are correct zero
>>
>>
>>> Now, if the captain wanted to start accelerating again at 1 G, how much
>>> thrust will he need? It will be 1,000 tonnes of thrust again, right?
>>
>>
>> Yes it will be the 100 tons of thrust again.
>>
>>
>>
>>>
>>> Now for something slightly different. Einstein said that the force of
>>> gravity was the same force as that which you notice when you accelerate.
>>> So, if thats true, the ship will never actually *not* be near a source
>>> of
>>> gravity as long as it is accelerating, because if it is accelerating it
>>> *is* a source of gravity. This gravity, however, would only be present
>>> when accelerating, and not when drifting, would it not?
>>>
>>
>> Simulated Gravity at thrust.
>>
>>
>>>
>>>
>>> So the ship is getting speedier and measurements are starting to change.
>>> Apparently this is because energy equals mass (with the numbers depending
>>> on how you measure it). The faster you go, the more mass you have. No
>>> no
>>> no, that cant be right. Going a certain speed does not require any
>>> energy at all. Only accelerating up to that speed requires energy.
>>> Right?
>>>
>>
>> It depends on your frame of reference. its all relative.
>>
>>
>>> This should mean that if the ship accelerated to near-light speeds, and
>>> then stopped accelerating and coasted at that speed for a while, while it
>>> is just coasting time is behaving normally (due to there not being any
>>> gravity well when coasting) and the ships mass is 100 tonnes because
>>> its
>>> not using any energy to accelerate.
>>>
>>> So, if this ship was coasting at such a speed that, if it started to
>>> accelerate its mass would double, is this change in mass instant?
>>>
>>
>> There is no change in mass from the ship's point of view. Nothing has
>> changed.
>>
>>
>>> I think one of my assumptions may be wrong, but I dont know what one.
>>> Can anyone help?
>>>
>>
>> I would take a run at relativity if I where you.
>>
>> --
>> Evyn
>>
>>
>
>
> --
> "Any Sufficiently analysed magic is indistinguishable from Science"
> Agatha, Girl Genius
> http://www.girlgeniusonline.com/comic.php?date=20081205
>
>
>
--
"Any Sufficiently analysed magic is indistinguishable from Science"
Agatha, Girl Genius
http://www.girlgeniusonline.com/comic.php?date=20081205