Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: thedoc on 05/10/2012 00:30:01

Title: How does gravity distort time?
Post by: thedoc on 05/10/2012 00:30:01
David Michaels  asked the Naked Scientists:
   
Hi Naked Scientists

I have listened to pretty much all your podcasts (http://www.thenakedscientists.com/HTML/podcasts/), and have built up a lot of dumb questions, and knowing the only dumb question is the one not asked, I have loaded up.  (I apologize if any of these have been covered, or if I should have figured them out .)

They say gravity distorts space-time, why do all shows only show the space distortion ? Could you explain the time distortion part ? ( I bet you can explain it on the radio better.)

Great show (http://www.thenakedscientists.com/HTML/podcasts/), I wouldn't change a thing (except for having really naked scientists).

Regards,
Dave

What do you think?
Title: Re: How does gravity distort time?
Post by: butchmurray on 05/10/2012 06:34:39
And when the “dumb” or “stupid” question is asked others invariably think or even say, “I’m glad someone asked that question”.

That was the second thing I would tell my students. The first thing was my name.
Title: Re: How does gravity distort time?
Post by: yor_on on 05/10/2012 07:04:18
Well, time is a property with a direction, and a 'magnitude' if you like, but it share that definition with three other properties, or 'degrees of freedom' for something to 'move' in SpaceTime. Any event you define in SpaceTime must have all of those properties to get a position. It's not enough with time. Treating it this way it can't be a distortion as I think although your definition of clock and ruler will make other frames of reference 'suspect' both when it comes to time and arrow, as well as when it comes to the distance defined existing at that other frame.
Title: Re: How does gravity distort time?
Post by: old guy on 09/10/2012 21:40:42
David Michaels  asked the Naked Scientists:
   
Hi Naked Scientists

I have listened to pretty much all your podcasts (http://www.thenakedscientists.com/HTML/podcasts/), and have built up a lot of dumb questions, and knowing the only dumb question is the one not asked, I have loaded up.  (I apologize if any of these have been covered, or if I should have figured them out .)

They say gravity distorts space-time, why do all shows only show the space distortion ? Could you explain the time distortion part ? ( I bet you can explain it on the radio better.)

Great show (http://www.thenakedscientists.com/HTML/podcasts/), I wouldn't change a thing (except for having really naked scientists).

Regards,
Dave

What do you think?
I think that the problem lies in the lack of examining what time is in the first place.
The same could be said for space, as one is always left wondering what exactly is distorted if space is just the 3-D volume in which things and forces exist and move around.
But the question "What is it?" in both cases (all three if you count "spacetime") is an ontological question, and physics does not like to get into the "What is it?" question. Physicists call it philosophy and avoid the question.
("Time is that which clocks measure... space/distance is that which measuring rods measure... both tautologies which avoid addressing what "it is.")

If time remains just the concept of "that which elapses as things move," it is not an entity which can be distorted. We do know that clocks slow down in rate of "ticking" the deeper they are in a 'gravity well.' But that is an observable, empirical observation. We do not observe "distortions in time" because time is not something that can be observed.
Good question.
Title: Re: How does gravity distort time?
Post by: syhprum on 09/10/2012 22:28:58
There seem to be basically two kinds of clock in common use those that depend on gravity pendulums which of course are much affected by variations in gravity and those that depend on the electromagnetic force such as springs, crystals and Cesium atomic clocks that are much less affected by the much weaker gravitational force.
There could well be an even less affected kind depending on the weak or strong nuclear force but I do not think any have been developed as yet.
Title: Re: How does gravity distort time?
Post by: edward9 on 09/10/2012 23:08:13
in my mind we have 2 engines to consider 1. Newtons and 2nd Einsteins - both may be relevant - if you can think that we exist in a universe comprised of 4 spatial dimensions but the primary 1 thought of as a dynamic.

for example Newton's notion was that Space was static once some Space had been created.  Later Michelson tried to demonstrate that actually this Space - aether was like a invisible space wind.  Einstein on the other hand thought that Space had no meaning and only a hypothetical importance as all Space and  time was  distorted by mass existing in it.

But!.. if you can think that we live in the 4D but with one actually moving - after all the universe is expanding therefore NEW SPACE must be created second for second - not just at the periphery like a balloon at the periphery but also between our ears. For example in the 'space' - 'time' of a few hours the Space which has been created in a few hours has grown very significantly to some trillions of 'NEW MILES' distance.  Think of it that we exist in an expanding orthogonal expanding egg and not a traditional static balloon.  If you go think on this all new kinds of understanding are possible.

For instance.  Einstein is correct mass does distort space and a rotating planet does cause frame dragging etc.   But this - His perception of Space exists in only 3D.  Forget temporal time for the moment.  Temporal time only exists if you have a mass which actually exists at all.  Then you have the luxury of Euclidian 3 Dimensions i.e. width, length and height  + temporal time TIME.  Which is in my mind incorrectly stated as a dimension in its own right thanks to Minkowski - Einsteins university tutor following Einsteins STR ( special theory of relativity ). In my thinking a dimension is a dimension i.e. a box has 3 real sides - you cannot have a variable dimension as that would cause all kinds of chaos in the universe - it exists or it does not.  To have one side of the box constantly varying one would not know from one second to the next what the actual shape of the box is!!

However, I believe in STR and perfectly understand how temporal time is shortened with increasing velocity.  It only becomes difficult to understand if one knows it to be a dimension.  i.e. we do not wonder what causes the ebb and flow of the tides as we perfectly understand the moon dynamics even though we cannot see it's effect only the effects of  hysteresis on the oceans.

Temporal time is subject to variation and only measurable so long as matter exists in the universe. Where such mass may be a space ship moving at 3/4 speed of C.

Back to Newton - he thought that Space - the universe consisted of a background absolute where time was fixed!  Einstein discounted this as it did not fit with this notions of STR and GTR.  Space is mathematically meaningless he suggested - with no application ( unquote )!?

Newton's notions may be actually closer to the realism - meaning that if you can think of the universe as it expands is constantly creating 'New Space' around us - This providing us with the Primary spatial Dimension which is very busily expanding - but more than that actually a factory for NEW SPACE! It is creating space every second where space in the previous second actually did not exist !!! WOW!  that might be a difficult one to swollow?  But just think about it - we all know the universe is expanding but it is actually doing much  more than just expanding it is actually providing and extension to the primary dimension into which the other 3 spatial dimension can be located.

Newton thought that the background absolute time was fixed - once again I am compelled to agree with him.  Fixed in the sense that the universe has a construct of 'Time Unity' meaning that the time is uniform everywhere in the universe - meaning there is no time differential between its sides some 40 billion light years wide!  The time is exactly the same everywhere - hence this solves all manner of paradoxes - commencing with the horizon problem and  temporal time dilations where masses are caught up with velocities. ( nav satelites etc )

Also some other very exciting ideas are possible.  IF one can think that the universe is indeed a unity dimension which has an opening dynamic - WHICH just so happens to be creating new space at the rate of 300,000Kms. This would implicate the determination for the velocity of light.  Where in this case light is no more than an indicator for the local ( constantly ) expanding universe.  Light in this case can only move into available space - it cannot move into space which 'has not yet come into existence'!!  Hence the proton accelorator at LHC only manages to convert it energy into mass.  The proton is obliged to get heavier as it  simply cannot move any faster - as it has to wait for new space to be created - accidentally at the rate of 300,000 kms.

Should the universe be expanding at a slower or faster rate then the speed of light would adjusted accordingly.  The speed of light in my mind is a serious misunderstanding.  Of course it is constant but not because of its own dynamics!  It can only move as fast as the rate of new space being created.

We can only see to the fringe of the Hubble Zone - beyond that light is actually moving faster - so light is NOT constant.  It only moves as fast as the conveyor - new space is being created.  This is a perfect illustration why contemporary science is flawed and contradictory.  However for our every physics such contradiction works well for us as we inhabit such a tiny part of the universe where new space is being created constantly.

so - we have temporal time, not a dimension which can only occur where mass exists, and fixed universe time which is expanding constantly. In a book Absolute Relativity Theory of everything - some very interesting ideas by the author and repairs many Einstein paradoxes and others.
Title: Re: How does gravity distort time?
Post by: yor_on on 14/10/2012 17:21:05
Kind of nice flow to it, but maybe more fitting for 'New Theories' than our main stream thread Edward. And you said you cited him saying "Space is mathematically meaningless"?  It wouldn't be  'Exceeding the speed of light gives a mathematically meaningless ..' that you mean instead? I would dearly like to see a link to that statement if you can find it.
Title: None
Post by: Sam Chacon on 05/06/2013 13:03:49
To convert light to energy, Einstein’s formula E=mc2 is transposed to c = √(E⁄m).    
According to the formula c = √(E⁄m), in the beginning there was no mass, so m = 0.  The leaves E in the square root sign.  E is compacted and converted to photons, electrons, up quarks, down quarks, neutrinos and many other particles; each particle pushed space energy apart and formed a graviton.  A graviton is to gravity what a photon is to light.  The gravitons produced by up quarks and down quarks pulled them together to form protons and neutrons.  The gravitons produced by protons, neutrons and electrons, pulled them together to form a large variety of atoms.  The gravitons produced by atoms pulled different atoms together to create molecules and make different kinds of gases, liquids, and solids.
Einstein view about gravity is that it is a distortion in the shape of space-time.  To put this in practical terms, the distortion is the compacting of space energy by c =√(E⁄m), when m equals zero.  “Space-time” means that it takes a certain amount of time for something to happen in space, and it happens in three dimensions.