measurement idea for spacetime curvature as dark energy force

Could just look at the half moon from earth, and use an interferometer to look for a frequency shift of light from the sunlit and the side facing away from the sun too.

cheers, Jamie

I'm not sure exactly what a "flow of spacetime" means, but the way you seem to be using it would appear to be the same as any other movement. How would you measure this Doppler? The Doppler shift has to do not with the point on earth where the light originates, but the direction it is headed. Any device that measures the frequency of the light would be "feeling" the same relative "flow" and so would no see such a shift.

To see this shift you would need to send the light from point in space on one side of the sun and receive the light on the other side of the sun where the flow is in the opposite direction. Even then I'm not sure of the effect on the light as it passes through a gradient of space time flow.

In other words... what?

Hi,

It is an apparent movement, but with no actual movement necessarily, ie looking towards earth from the Sun, if there is a spacetime expansion centered on the sun, but the earth holds its orbit due to gravity, then it should appear (via doppler shift) like the earth is very slightly moving directly towards the sun in my idea anyway.

cheers, Jamie

How do you measure that difference? Would you look for a Doppler shift in the spectral lines of helium? Any idea how much change there would be? That's kinda important. So what fraction of the speed of light would this apparent motion have?

Hi,

I think the effect would be so small it would require long term averaging of a very precise measurement to possibly see any apparent movement in the signal.

Maybe something in this list:

or maybe something like this one with a modulation signal on the stark/zeeman tuning to get an aggregated more precise measurement of the input frequency spectral line etc:

I don't know the amount of apparent movement there would be but it would be somewhat proportional to the ratio of gravity to dark energy in the system being observed I guess. It must be super tiny if it exists since it wasn't detected before (probably it doesn't exist!)

cheers, Jamie

Jamie's proposal is just so much hand waving random word salad. It would be invariant under the application of the Shannoniser which is the first and most basic test of a no hoper crank theory. Another is that it should be written ALL IN CAPITALS.

However, the Shapiro time delay effect for em waves travelling through a moderately strong gravity field like Jupiter's is real and has been measured. In fact observations of the first binary pulsar allowed a tiny error in the VSPO82 fortran code for the solution of the positions of the planets in the solution of the planetary motions to be found. (a few continuation cards were missing the mark in the right column)

Real physics relating to this sort of thing relies on having a very accurate precision clock at great distance and a bit of luck that it is in the right place - near to the ecliptic so that Jupiter or the sun will be close enough from time to time for the GR corrections to be measurable. VLBI with H-maser clocks lends itself to this sort of thing.

A recent paper on this sort of measurement technique:

And on properties of binary pulsars (which themselves are very sensitive tests of GR). They make very fine clocks too once their characteristics have been quantified. Unfortunately from time to time they also have star quakes and suddenly change their spin rates (slightly but by a measureable amount - large cf GR corrections).

FWIW dark energy only becomes significant on cosmological scales.

Ultra distant type Ia supernovae (which are our best standard candles) appear brighter than expected and the HST observations of very distant galaxies. See for instance:

TBH "Dark Energy" being non-zero is after my time and I would far rather believe that there is something funny about type Ia supernovae in the early universe but I understand that has been ruled out.

You know that, I know that, how do you get Jamie to understand it? He is already picking out interferometers like a bride picking out china.

Makes you wonder about weapon systems and nuclear power plants...

I may have mentioned that I believe we are due for another Einstein-like update to physics. I may not be around for it, but it won't be too long before someone figures out a new perspective.

Hi,

What is the shannonizer? Also if there is a dark energy expansion force in the universe, then I guess it is a force that directly acts on matter or else it acts on spacetime. If it is acting on spacetime, then the result of the force may be an expansion of spacetime. If spacetime is expanding but two bodies remain at a stationary distance (ie two stars orbiting each other) then there can be an apparent motion measured between the two stationary masses, as they are effectively traveling through space time towards each other to keep a fixed distance in an expanding reference frame.

Its not rocket science its common sense, and I proposed a possible experiment to detect the apparent motion as a blue shift in the direction of apparent motion of the masses. An unlikely hypothesis but still valid!

cheers, Jamie

It seems to be a device for putting two more or less arbitrary two words together to create a vaguely plausible phrase - the choice of the first word constrains the second one, but not much.

It's not science of any sort, nor any kind of "common sense" - Jamie doesn't have any sense, in that sense of the word.

A proposed experiment isn't a hypothesis, it's a device for testing a hypothesis, and the aim is to find out if the hypothesis is valid.

Until the experiment has been done - and produced the result hypothesised - the hypothesis can't be described as valid.

first word constrains the second one, but not much.

Hi,

Physicists say spacetime is expanding, assuming it is an even expansion rate over the whole space, then if there are two masses that are stationary with respect to each other, will there be a blue shift in the light observed from one to the other?

cheers, Jamie

Since Hubble's constant was determined by measuring red shift as a function of distance, you are going to have trouble separating your imagined blue shift from the well-known and omnipresent shift.

A word frequency and adjacent word analysis technique that generates syntactically valid gibberish after parsing a document. Unfortunately no publicly accessible implementations remain online that I know of.

Bayesians meet Markov chains.

This is a perfect example of hand waving Shannonesque word salad.

Small scale stuff like the solar system, our galaxy and the local group don't feel enough from dark energy to have any chance of detecting.

It is only at the most extreme distances now becoming available to direct observation that dark energy shows its influence.

Only if they are moving towards each other. The Andromeda galaxy M32 and its satellites are blue shifted moving towards us and collision will be in about 4bn years. Don't hold your breath...

Hi,

From the page:

"Because of the high rate of expansion, it is also possible for a distance between two objects to be greater than the value calculated by multiplying the speed of light by the age of the Universe. These details are a frequent source of confusion among amateurs and even professional physicists."

I think that seems to imply that there is some spacetime expansion that can't be explained directly by movement of masses without a reference frame. If that is so then there might be a blueshift/redshift as well from the rate of spacetime shrinking or expansion etc.

cheers, Jamie

Hi,

Might seem that way, but it is my way of describing a possible experiment to do, to look for miniscule blue shifts of emitted light.

Dark energy isn't necessarily being observed at extreme distances but more like extreme scales, it is still possible that at smaller scales it is having an influence. If dark energy can be the dominant force in some extreme scale situations, then why can't it possibly be measured as a tiny force at smaller scales?

cheers, Jamie

Also from that page:

"At smaller scales matter has become bound together under the influence of gravitational attraction and such things do not expand at the metric expansion rate as the Universe ages."

If there is an overall metric expansion of space, even at small scales ie. two masses at fixed (ie orbiting) distances. There should be a way to possibly measure the metric expansion of space in that situation, ie by the blue shifted light idea I had, as an apparent movement of the two objects towards each other, resisting the metric expansion of space.

cheers, Jamie

I know that my idea is totally unsupported by evidence, ie it is a backwards idea in context of the Hubble expansion causing redshift.

If stars are moving outwards and viewed as a redshift, then in my idea spacetime would currently be contracting while matter is not "shrinking" as fast, this would be a hard to explain situation so I admit my idea is probably totally wrong and also the idea of movement of spacetime being the same as motion of matter seems unsupported.

cheers, Jamie

Bingo! We are observing the expansion of the universe by measuring the rate at which the objects in the universe move away from one another. If you assume there is an effect that changes "spacetime" without affecting the distance between object, then by definition it would not be part of the data we have observed or at least would be counter to the trends we have detected.

Your blue shift would be subtracted from the red shift and the expansion of the universe is even faster than we are seeing.

I think that too (although calling it "Einstein-like" is maybe an overstatement, since I don't expect it to have the kind of direct effect on us that relativity and Einstein's other work has had). I can't help feeling that dark energy, and to a lesser extent dark matter, is just a fudge-factor added to cosmological theories to make force observations to fit with relativity.

But since we already know there is something missing from relativity at the small scale (where it fails to mesh nicely with quantum mechanics, or black hole physics), we should not be surprised if it is also shown to be inaccurate at cosmological scales.

My own pet theory (for which I no justification in theory or observation

- it's merely an idea) is that rather than there being a "dark energy" causing repulsion on intergalactic scales, gravity simply gets weaker

such a distance. If gravitational force is mediated by graviton particles (comparable to photons for the EM force), then over long enough distances the gravitational interaction between distance objects will be affected by the quantum nature of gravitons. Once the force predicted by relativity is too small for a single quantum of gravity, it simply cannot be mediated at all.

(Feel free to explain how that theory could be wrong - this is way outside my area of expertise.)

Dark matter has a bit more substance as a hypothesis, but I still suspect that "dark matter" will be found in a modification of relativity or ordinary non-luminous matter, rather than a new type of particle.

However, all options are open - and maybe the LHC will turn out something new as it searches at higher energies.