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Irish Whiskey
Caldari Warped Mining
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Posted - 2008.11.25 23:03:00 -
[31]
page 2!
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Akita T
Caldari Navy Volunteer Task Force
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Posted - 2008.11.26 00:17:00 -
[32]
"Is the Moon moving away from the Earth? When was this discovered?
The Moon's orbit (its circular path around the Earth) is indeed getting larger, at a rate of about 3.8 centimeters per year. (The Moon's orbit has a radius of 384,000 km.) I wouldn't say that the Moon is getting closer to the Sun, specifically, though--it is getting farther from the Earth, so, when it's in the part of its orbit closest to the Sun, it's closer, but when it's in the part of its orbit farthest from the Sun, it's farther away.
The reason for the increase is that the Moon raises tides on the Earth. Because the side of the Earth that faces the Moon is closer, it feels a stronger pull of gravity than the center of the Earth. Similarly, the part of the Earth facing away from the Moon feels less gravity than the center of the Earth. This effect stretches the Earth a bit, making it a little bit oblong. We call the parts that stick out "tidal bulges." The actual solid body of the Earth is distorted a few centimeters, but the most noticable effect is the tides raised on the ocean.
Now, all mass exerts a gravitational force, and the tidal bulges on the Earth exert a gravitational pull on the Moon. Because the Earth rotates faster (once every 24 hours) than the Moon orbits (once every 27.3 days) the bulge tries to "speed up" the Moon, and pull it ahead in its orbit. The Moon is also pulling back on the tidal bulge of the Earth, slowing the Earth's rotation. Tidal friction, caused by the movement of the tidal bulge around the Earth, takes energy out of the Earth and puts it into the Moon's orbit, making the Moon's orbit bigger (but, a bit pardoxically, the Moon actually moves slower!).
The Earth's rotation is slowing down because of this. One hundred years from now, the day will be 2 milliseconds longer than it is now.
This same process took place billions of years ago--but the Moon was slowed down by the tides raised on it by the Earth. That's why the Moon always keeps the same face pointed toward the Earth. Because the Earth is so much larger than the Moon, this process, called tidal locking, took place very quickly, in a few tens of millions of years.
[...]"
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Irish Whiskey
Caldari Warped Mining
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Posted - 2008.11.26 00:37:00 -
[33]
One thing I'd like to know is if someday we decide to test some weapons and attempt to obliterate a gas giant, say neptune, how quickly would the imbalance of gravities in the solar system cause us to orbit closer to the sun and melt?
(remember, we dont know how gravity works quite yet)
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Akita T
Caldari Navy Volunteer Task Force
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Posted - 2008.11.26 00:51:00 -
[34]
Originally by: Irish Whiskey One thing I'd like to know is if someday we decide to test some weapons and attempt to obliterate a gas giant, say neptune, how quickly would the imbalance of gravities in the solar system cause us to orbit closer to the sun and melt?
(remember, we dont know how gravity works quite yet)
Define "obliterate" Also, no, the sudden vanishing of ALL planets past Mars would do basically nothing to Earth's orbit.
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ReaperOfSly
Gallente Zetsubou Corp
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Posted - 2008.11.26 10:14:00 -
[35]
Originally by: Akita T
Originally by: Irish Whiskey One thing I'd like to know is if someday we decide to test some weapons and attempt to obliterate a gas giant, say neptune, how quickly would the imbalance of gravities in the solar system cause us to orbit closer to the sun and melt?
(remember, we dont know how gravity works quite yet)
Define "obliterate" Also, no, the sudden vanishing of ALL planets past Mars would do basically nothing to Earth's orbit.
In fact, it would make the Earth's orbit MORE stable because there would be fewer perturbations. ____________________
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Reven Cordelle
Caldari School of Applied Knowledge
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Posted - 2008.11.26 12:12:00 -
[36]
Originally by: ReaperOfSly
In fact, it would make the Earth's orbit MORE stable because there would be fewer perturbations.
Mmmm, Perturbations.
Sorry lads, this thread's IQ was about to breach critical.
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ouroboros trading
Gallente Medics On Fire
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Posted - 2008.11.26 12:20:00 -
[37]
yeah, my 4th question would be what the hell is gravity? it's the most obvious force in my life but what the **** is it.
hopefully the clever people figure it out in my lifetime.
126558? That's Numberwang! |
ReaperOfSly
Gallente Zetsubou Corp
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Posted - 2008.11.26 12:33:00 -
[38]
Originally by: ouroboros trading yeah, my 4th question would be what the hell is gravity? it's the most obvious force in my life but what the **** is it.
hopefully the clever people figure it out in my lifetime.
A combination of Bisto and a particular beverage imported to England from the east (gravy tea).
More seriously, it's simply an attractive force between massive objects. If you start from the idea that light always travels in a straight line, you can think of it as a curvature of spacetime (and that light bending is simply a straight line along a geodesic of that curve). The question is really more involved than can be answered in this forum.
(Yes, I'm chickening out because I don't really know the answer either) ____________________
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ouroboros trading
Gallente Medics On Fire
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Posted - 2008.11.26 12:45:00 -
[39]
how dare you put gravy in my tea, i hate gravy! it's a culinary mudslide in an art gallery.
but aye have read about gravity for years, tbh I think it's not something transmitted between particles as such, more like a thing particles transmit to something else which we don't know what it is yet, or how, which then affects everything else. I don't think mass is innate to a particle but rather it is 'given' to it by something else if you get my meaning. that particles somehow constantly emit mass 'particles' makes no sense to me so i think they must be given it.
tbh i can imagine being newton under the apple tree and wondering wtf made that happen. such a simple question in a simple place, but the answer....perhaps profound beyond words.
also they say the universe is accelerating but that makes no sense as eventually won't objects accelerate to and past the speed of light or something?
786642? That's Numberwang! |
Rosolo Refili
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Posted - 2008.11.26 12:50:00 -
[40]
Originally by: ouroboros trading heh i'd never even heard of centripetal force, thanks :)
Don't think the accepted american scientist accept centrafugal force? He puts it down to something else can remember what!
this is V interesting
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Andrue
Amarr
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Posted - 2008.11.26 12:50:00 -
[41]
Edited by: Andrue on 26/11/2008 12:53:25
Originally by: ouroboros trading Edited by: ouroboros trading on 24/11/2008 22:48:01 could tidal power destabilise the moons orbit and make it crash into the earth?
No. The Moon would break up due to tidal forces before it hit the surface..unless it came in very fast which is highly unlikely.
Quote: if you rotate a tangent about a point, could you make it so that the one end moves faster than light?
No. Nothing can go faster than the speed of light within this universe.
Quote: and lastly, if you had a rod a few million miles long and moved the one end, would the other end move as well, thus making infomation travel faster than light?
No. Information cannot travel faster than the speed of light within this universe. -- (Sarcastic mission running veteran, 4+ years)
[Brackley, UK]
My budgie can say "ploppy bottom". You have been warned. |
Rosolo Refili
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Posted - 2008.11.26 13:07:00 -
[42]
Edited by: Rosolo Refili on 26/11/2008 13:08:44
Originally by: ouroboros trading yeah, my 4th question would be what the hell is gravity? it's the most obvious force in my life but what the **** is it.
hopefully the clever people figure it out in my lifetime.
from my 16 YR old physics might be a bit wrong as that was a few years ago (or more) :P
It is the attraction of any two objects with mass, and is evident even in every atom we just see the effects on large objects like the moon and the earth. It is a force so it is basically a physical law. The gravitational pull is proportional to the mass as is the proximity to each other although that is disproportional (Gravity has less effect on you if your in an aeroplane for example but not half as much if you went twice as far up! it works out at about 1/4(very approx/memory), although I might add that even just the drag the tips of the wings produce make it 80% more effiecient for a plane to fly several feet off the floor rather than high in the sky A very interesting russian discovery)
But it is a law of time and space and we can't change these yet :)
The perpetual motion of an object in orbit isn't possible because as stated in another post even the moon (at a slow rate) is spinning out of orbit every year. Human made satelites (intentional or not) will rotate out of orbit or burn up when it hits us. Other wise you could put a magnet on a satelite and turn the earth into a big (but very weak) generator and although that would be tiny amount of energy if a perfect orbit was possible then we would be getting energy out of nowhere (can't create energy from nothing) A bigger example is the moon tidal energy one day the waves will stop waving as the moon gets further away.
I am boring myself now
Sorry dodgy English
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Doomed Predator
The Graduates Morsus Mihi
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Posted - 2008.11.26 13:30:00 -
[43]
Originally by: Brilf
Originally by: Atama Cardel While we're on the topic of weird physics questions, I have one that's been irking me for a little while. Keep in mind that I don't have a huge background in physics please.
If it can be said that if you were to accelerate up to the speed of light you would have infinite mass, then does that mean that if you were to somehow able to completely stop all motion, and you had a velocity of zero (if there was a way to be able to measure that of course), then would that mean you would have no mass?
I don't think anyone really knows the answer to that question.
e=mc^2 So if you assume absolute zero implies zero energy then there must be zero mass as well right?
At absolute zero there is still movement, matter will be in a solid state but the atoms will still be oscillating,thus movement even if it's almost negligable. The 'Fendahlian Collective' strikes again |
ReaperOfSly
Gallente Zetsubou Corp
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Posted - 2008.11.26 14:21:00 -
[44]
Originally by: Doomed Predator
Originally by: Brilf
Originally by: Atama Cardel While we're on the topic of weird physics questions, I have one that's been irking me for a little while. Keep in mind that I don't have a huge background in physics please.
If it can be said that if you were to accelerate up to the speed of light you would have infinite mass, then does that mean that if you were to somehow able to completely stop all motion, and you had a velocity of zero (if there was a way to be able to measure that of course), then would that mean you would have no mass?
I don't think anyone really knows the answer to that question.
e=mc^2 So if you assume absolute zero implies zero energy then there must be zero mass as well right?
At absolute zero there is still movement, matter will be in a solid state but the atoms will still be oscillating,thus movement even if it's almost negligable.
Except that absolute zero is DEFINED as being that state where atoms do not oscillate. You fail, please try again.
As for the original question, no. Objects have a rest mass, and this mass increases asymptotically as velocity approaches the speed of light. Not moving means mass = rest mass. ____________________
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Dr Slaughter
Minmatar Rabies Inc.
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Posted - 2008.11.26 16:46:00 -
[45]
Originally by: Andrue
- No. Nothing can go faster than the speed of light within this universe.
- No. Information cannot travel faster than the speed of light within this universe.
Care to explain what superluminal means in context of superluminal evenecent waves then?
You're welcome to say 'no'
~~~~ There is no parody in this thread. Honest. |
Nyphur
Pillowsoft
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Posted - 2008.11.26 17:55:00 -
[46]
Originally by: ouroboros trading yeah, my 4th question would be what the hell is gravity? it's the most obvious force in my life but what the **** is it.
hopefully the clever people figure it out in my lifetime.
General relativity states that gravity is a geometric curve in spacetime that is somehow caused by mass. The classic visual aid used to explain it is placing a cloth over a pillow or something and then putting a heavy object on top of it. The cloth represents spacetime and the cloth dipping down toward the object represents the curve in spacetime caused by the object's mass. Just due to the geometric shape, the shortest route for something travelling in a straight line through this dip is to go into it, from our perspective pulling it toward the object. This theory explains how light (which has no mass) can be affected by very strong gravity (like a black hole). It's not actually being affected by the gravity, it's just travelling in a straight line through the dip in the fabric of spacetime.
The particle physics approach is trying to define exactly what gravity is made of. Compared to the electromagnetic force, gravity is an order of magnitude weaker and if it's just another force being transmitted between particles by a force carrier, that doesn't really make sense. The Large Hadron Collider is planning to investigate the existance of the higgs boson, which if it exists would explain how particles are given mass, though I'm not sure of the specifics. I'm not much of a particle physics buff so I'm sure someone else would be better explaining all this.
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Dr Slaughter
Minmatar Rabies Inc.
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Posted - 2008.11.27 01:05:00 -
[47]
Originally by: Nyphur .. . over a pillow or . ..
Is that soft marketing?
~~~~ There is no parody in this thread. Honest. |
F'nog
Amarr Celestial Horizon Corp. Celestial Industrial Alliance
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Posted - 2008.11.27 01:20:00 -
[48]
Originally by: Nyphur
Originally by: ouroboros trading yeah, my 4th question would be what the hell is gravity? it's the most obvious force in my life but what the **** is it.
hopefully the clever people figure it out in my lifetime.
General relativity states that gravity is a geometric curve in spacetime that is somehow caused by mass. The classic visual aid used to explain it is placing a cloth over a pillow or something and then putting a heavy object on top of it. The cloth represents spacetime and the cloth dipping down toward the object represents the curve in spacetime caused by the object's mass. Just due to the geometric shape, the shortest route for something travelling in a straight line through this dip is to go into it, from our perspective pulling it toward the object. This theory explains how light (which has no mass) can be affected by very strong gravity (like a black hole). It's not actually being affected by the gravity, it's just travelling in a straight line through the dip in the fabric of spacetime.
The particle physics approach is trying to define exactly what gravity is made of. Compared to the electromagnetic force, gravity is an order of magnitude weaker and if it's just another force being transmitted between particles by a force carrier, that doesn't really make sense. The Large Hadron Collider is planning to investigate the existance of the higgs boson, which if it exists would explain how particles are given mass, though I'm not sure of the specifics. I'm not much of a particle physics buff so I'm sure someone else would be better explaining all this.
The current hot theory explains the lack of force in gravity by the fact that it travels out of our universe into others. Thus most of its effect is lost to us.
If we go back to the very useful sheet analogy: if the universe is a 2d sheet, then any object's mass causes gravity. This gravity spreads out from the object. Since the universe is a 2d sheet, only a small amount of the gravitational force is in that plane. The rest escapes into the 3d world beyond the sheet, i.e. other universes, the multiverse, etc.
It's quite interesting. Also it explains how many of my favorite comic books and sci-fi shows could be real.
Originally by: Kazuma Saruwatari
F'nog for Amarr Emperor. Nuff said
Originally by: Chribba Go F'nog! You're a hero! Not a Zero! /me bows
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Crumplecorn
Gallente Eve Cluster Explorations
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Posted - 2008.11.27 03:03:00 -
[49]
Originally by: Lance Fighter Isnt the idea of FTL communications that twinned particles will react exactly the same as the other twin? So if you use morse code or something on one, the other will do the same...? Or is this star trek im thinking of
Link -
DesuSigs |
Lance Fighter
Amarr
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Posted - 2008.11.27 05:27:00 -
[50]
Edited by: Lance Fighter on 27/11/2008 05:27:24
Originally by: Crumplecorn
Originally by: Lance Fighter Isnt the idea of FTL communications that twinned particles will react exactly the same as the other twin? So if you use morse code or something on one, the other will do the same...? Or is this star trek im thinking of
Link
i tried reading that, but all i got was this
Originally by: Akita T
Seriously ?
...wow... I'm such a forum ho' !
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Andrue
Amarr
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Posted - 2008.11.27 08:24:00 -
[51]
Originally by: Dr Slaughter
Originally by: Andrue
- No. Nothing can go faster than the speed of light within this universe.
- No. Information cannot travel faster than the speed of light within this universe.
Care to explain what superluminal means in context of superluminal evenecent waves then?
You're welcome to say 'no'
At a wild guess, if it involves waves "Unfortunately we frequently read in the newspapers about how someone has succeeded in transmitting a wave with a group velocity exceeding c, and we are asked to regard this as an astounding discovery, overturning the principles of relativity, etc. The problem with these stories is that the group velocity corresponds to the actual signal velocity only under conditions of normal dispersion, or, more generally, under conditions when the group velocity is less than the phase velocity. In other circumstances, the group velocity does not necessarily represent the actual propagation speed of any information or energy. For example, in a regime of anomalous dispersion, which means the refractive index decreases with increasing wave number, the preceding formula shows that what we called the group velocity exceeds what we called the phase velocity. In such circumstances the group velocity no longer represents the speed at which information or energy propagates." More accessible description. -- (Sarcastic mission running veteran, 4+ years)
[Brackley, UK]
My budgie can say "ploppy bottom". You have been warned. |
Dr Slaughter
Minmatar Rabies Inc.
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Posted - 2008.11.27 11:21:00 -
[52]
Originally by: Andrue -lots of math & reasoning-
I still think 'no' would have been a shorter answer
ps. So perhaps 'superluminal' is a poor choice of words for laymen as it's natural to infer that something physical (physical wave front) is travelling faster than light rather than something conceptual. I hadn't understood group velocities relationship with the actual propagation speed. Thanks for setting me on the right path.
~~~~ There is no parody in this thread. Honest. |
Nyphur
Pillowsoft
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Posted - 2008.11.27 17:21:00 -
[53]
Originally by: Lance Fighter Isnt the idea of FTL communications that twinned particles will react exactly the same as the other twin? So if you use morse code or something on one, the other will do the same...?
FTL communication via entangled particles is not possible. The information has to be carried between the particles by something and that something can't be travelling faster than the speed of light.
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Andrue
Amarr
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Posted - 2008.11.28 14:07:00 -
[54]
Edited by: Andrue on 28/11/2008 14:07:18
Originally by: Dr Slaughter
Originally by: Andrue -lots of math & reasoning-
I still think 'no' would have been a shorter answer
ps. So perhaps 'superluminal' is a poor choice of words for laymen as it's natural to infer that something physical (physical wave front) is travelling faster than light rather than something conceptual. I hadn't understood group velocities relationship with the actual propagation speed. Thanks for setting me on the right path.
Lol - well I only found the link. I am not a physicist
Personsally I hate the whole FTL limit thing. It seems so unfair. When I was a young lad (eeeh, when I were a nipper) it was just a theory and you could hope that it was wrong. Now there seems to be a lot of evidence (including things as mundane as GPS) that seem to be confirming it.
I take no pleasure in shooting down superluminal explanations. I do it in the hope that just one time a physicist would say "Well, actually...". But they never do.
Bastards.
-- (Sarcastic mission running veteran, 4+ years)
[Brackley, UK]
My budgie can say "ploppy bottom". You have been warned. |
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