stupid questions about gravity and lasers

Okay so with LIGO we now know the wave form of gravity and that it is in facft a wave



okay some of these deep space objects have huge gravity fields(lightin my analogy) so seeing as gravity is a wave could we make a interference pattern for gravity. i imagine if you could there would be areas of no gravity and high gravity like when they do the double slit experiment with a laser.


would a gravity 'laser' be antigravity?

Well, you can indeed cancel out waveforms I do believe.

I think acoustic levitation does just that, but I could be wrong. In fact, it’s likely lol

Dooooouuuuuble post!

originally posted by: penroc3
Okay so with LIGO we now know the wave form of gravity and that it is in facft a wave



okay some of these deep space objects have huge gravity fields(lightin my analogy) so seeing as gravity is a wave could we make a interference pattern for gravity. i imagine if you could there would be areas of no gravity and high gravity like when they do the double slit experiment with a laser.


would a gravity 'laser' be antigravity?

Hang on, I’m still trying to get my head around properly what you meant

If you could affects/disturb the wave, which is gravity, the you’re effectively canceling gravity

And you want to make a laser which affects and conceals the wave?

Interesting. A GAZER -gravity amplification. Would come in handy for towing dead freighters in space. or as propulsion, lifting any weight like a super crane, etc. Lots of commercial uses. Probably exists somewhere in the universe.

A device giving powerful attraction at a distance? At it's focal point wherever aimed? Would be a nifty gadget.

a reply to: penroc3

Okay so with LIGO we now know the wave form of gravity and that it is in facft a wave

No. Gravity is not a wave (sorry senor Lazar).

LIGO has show us that, as predicted by general relativity, gravitational waves exist. Gravitational waves are a distortion which propagates through space-time, like a tsunami propagates through the ocean. Gravitational waves are not a "form of gravity."

Like a tsunami, it takes some sort of disturbance of a gravitational field to produce gravitational waves. Something like a black hole eating a neutron star.

Since gravitational waves are not a form of radiation, they cannot be amplified by stimulated emission.
www.aps.org...

a reply to: NoCorruptionAllowed

A GAZER -gravity amplification.

You mean GASER?
Gamma Amplification by Stimulated Emission of Radiation?

That is a really scary concept.

The field distortions do not have a negative value, only positive. So you cannot negate any gravitational effects by producing gravitiational waves with negative values.

a reply to: ManFromEurope

The field distortions do not have a negative value, only positive.

That's a really interesting point but I'm not sure it's accurate.

What is positive space-time?

a reply to: Phage

Lets ignore "positive" or "negative" space-time, the mathematics behind this are far too complex, for me at least.

Here is a picture of the "strain", the measured differences in length at LIGO, and we can see that there is indeed a waveform CONTRACTING and EXPANDING the measured length.

This means to me as a physics layman with basic university knowledge in relativity theory, that the space itself "wobbled" (I do not understand if time "wobbled", too and how much this might have been), and that means to me that there was indeed some force pulling *and* pushing, which could be interpreted as anti-gravity, in my opinion.

What do you think?

a reply to: ManFromEurope

I think that Einstein's model is holding up very well. That gravity is a distortion of space-time and that a gravitational wave is a distortion which propagates through space-time.

The space in which each leg is contained was distorted as the wave passed through it. Yes, time changed as well, though I don't think the detectors are capable of discerning that. Likewise, the "direction" of gravity did not change but the scalar values of it did. There was no "push", but the "pull" changed, a bit.

a reply to: Phage

Absolutely, Einstein's model is working perfectly.

But to me, I thought that LIGO measures the length between a sender and a receiver and when a massive ripple comes running through Earth, this lenght is stretched in one way and then bounces back and forth in smaller amplitudes some times and finally goes back to basis length.

I did not expect to see that the "strain" goes negative-positive-negative and so on. I do not know and right now I do not have the time to read in depth material from LIGO's website on how this strain is measured and what the scientists are making off the positive values in length. To me, it still seems to be anti-gravity, as it does expand the length by expanding the space-time between sender and receiver in LIGO. Which, to my interpretation, could be "felt" as a push, if the ribble would be far more intensive.. Far, far more. So incredibly far more, I would not like to experience it ;-)

a reply to: ManFromEurope

I did not expect to see that the "strain" goes negative.

Strain is longitudinal pressure on the rod.

When the rod gets longer due to the distortion of space the strain goes negative, the ends are farther apart. When it gets shorter the strain goes positive. It is not a gravitational effect, it is a mechanical effect caused by the change in the shape of space.

I would not like to experience it

No worries. Albert doubted it would be detectable at all.

originally posted by: Phage
a reply to: ManFromEurope

I did not expect to see that the "strain" goes negative.

Strain is longitudinal pressure on the rod.

When the rod gets longer due to the distortion of space the strain goes negative, the ends are farther apart. When it gets shorter the strain goes positive. It is not a gravitational effect, it is a mechanical effect caused by the change in the shape of space.

When gravity in relativity theory is shown as the effects of distortions in space-time, to me it is a gravitational effect.

Okay, my interpretation now goes as follows:
Timestamp (t0): grav-wave (negative amplitude) reaches emitter of laserlight and runs "along" the laser impulses, the reflected impuls runs back through streched (strained) space-time, experiencing red-shifting and a slightly longer distance than the impuls going 90° to it in the other leg of LIGO.
Timestamp (t0+0.3ms): grav-wave reaches end of 1000m long leg of LIGO, laser impulses are still showing "longer leg".
Timestamp (t0+x ms): wait. If the grav-wave (negative amplitude) has left LIGOs leg, the offset should be reset to zero, "leg-length" should be back to normal, right? Where does the positive ampitude come from?

What happens when scientists are telling us "three solar masses were converted to gravitational energy/forces"?
I tried to picture the events happening in a billion lightyears from Earth, but could not come further than seeing two stellar objects rotating around each other, sometimes lining up with earth, and half a rotation later being at a right angle (with their axis to each other in relation to the axis to Earth), which would give a small difference in gravitational force, but that is happening in billions of places all over the universe every second.

The crash is measured, not the rotation of those stellar objects. Right?


BTW: I think there is no physical rod, but a laserimpuls reflected and interferentially measured to 10^-21 cm in length difference.

a reply to: ManFromEurope

experiencing red-shifting

No. Experiencing a change in distance. While a change in frequency may be an effect, it seems that distance (in space) is what is measured. The speed of light is not relative.

The crash is measured, not the rotation of those stellar objects. Right?

The math is beyond me. The concept I can grasp.

Where does the positive ampitude come from?

The trough (or peak) of the wave. I'm not sure which.

BTW: I think there is no physical rod, but a laserimpuls reflected and interferentially measured to 10^-21 cm in length difference.

Thus "strain" is a theoretical value based on the change in distance (space) between endpoints.

a reply to: ManFromEurope

It is not anti-gravity, but a rapid change in gravity caused by some huge masses undergoing extreme accelerations. As Phage said, there is no "pushing" involved. It is a changing "pulling" from those masses.

originally posted by: moebius
a reply to: ManFromEurope

It is not anti-gravity, but a rapid change in gravity caused by some huge masses undergoing extreme accelerations. As Phage said, there is no "pushing" involved. It is a changing "pulling" from those masses.

That is what I thought initially to this thread, too.

But then I looked at the LIGO's graphics of the Strain and there are definitive negative and positive absolute values on the amount of strain, and I think that they are measured in centimeters. I might be wrong about the scala, and that would explain a lot to me, but I cannot find better data right now.

If there is a shortening and a lengthing of the LIGO's leg, that would mean that the distance were at one time shorter and at another longer than the normal length. This would mean that spacetime shortened and lengthed itself. Which would in turn mean that some event stretched and shortened spacetime.

What does that mean?

In non-relativistic terms, if I get pulled towards a gravitational mass (Earth, for example), I experience a force pulling me, and that does not length me, but shortens me = that is a gravitational effect to me.

I understand that if I were in the close vicinity to a black hole, my body would be spaghettified (an official term, don't smirk), because of the huge gravitational gradient close to the black hole. That is another gravitational effect, lenghtening me. (Is "lenghtening" even a word?)

But if I experience both of these effects close to each other, this seems to be a sign for counteracting forces, one that is pulling and another that is pushing.

Because, as you can see in LIGO's own pictures, the offset (the normal) is zero, and the measured values are wobbling around zero, so there is a moment where the leg is longer than normal and a moment when the leg is shorter than normal.

Which I cannot really understand.

a reply to: Phage

A wave is a wave no?

and if we could bring it in and out of coherence it might do neat things, i wish i was smarter so i could explain my idea better

a reply to: penroc3

My smplified, uninformed thinking regarding gravitational waves might help some of us put the more scientific discussion in context...this is just what I've been able to formulate in terms of wrapping my mine around it. Here goes:

Imagine the "fabric of space-time" like an actual fabric. Think of this like a stretchy screen material, with all of the interconnected threads having elasticity between all points. Put a marble on the screen, and it will make an indentation, with the size of the screen holes stretching furthest in the area around the marble, and less so (but still stretched to a degree) in the area leading up to the marble.) That's the pull of gravity, and the stretching of space-time around a planet, a star, and to a much larger degree, a supermassive black hole.

Now imaging suddenly introducing a 3' diameter marble of Tungsten onto the screen - what happens? That space around it is pulled WAY down, like a well, and the fabric all around it has a sudden pull that ripples all the way to the edges (less so as the effect of the pull spreads out further.) That would be the gravity wave detected. A sudden drastic increase in gravity in a particular spot, echoing across the galaxy/universe/whatever.

a reply to: dogstar23

good analogy i love the stretchy blanket idea



my idea in comparing gravity to light was this:in a room when we turn the table lamp on we are surrounded by the light and with the proper tools (like a lens or a mirror) we can concentrate the light that is seemingly everywhere into a point.

gravity is all around us like that light is, if we had the right tools we might be able to control it without steller sized objects.


spacetime is just the medium that gravity travels across and not the actual force if you know what i mean. kind of like the room is just what the light is in.