Originally posted by ark13Because it is theoretical, Ark. Making the earth wobble is not an easy feat. So, you going to make us Google your sources, Xanthos, or are you going to make it easy?
Cool. But if it's 1.06 c, then why don't people send messages with gravity?
Originally posted by ark13The experimental value is 1.06c but it has a huge uncertainty. It could be anything from 0.848c to 1.272c.
Cool. But if it's 1.06 c, then why don't people send messages with gravity?
If General Relativity holds then future experimental readings (all this is based on astrnomical data so it is hard to be accurate) will show it to be c.
Originally posted by XanthosNZActually you are totally wrong. NOTHING happens simultaneously
The sun is 8 light [b]minutes from earth.
When you fall off a roof you are not affected by the Sun's Gravity but by the Earth's.
However from my vague understanding of space-time and gravity I believe the effect would be instantaneous despite the complete crap you just posted.[/b]
except maybe superposition of particles. Gravity can be in the
form of waves, LIGO and other experiments are searching for them as
we speak but it is pretty sure they are going the speed of light.
If you were able to somehow say, transport a star through a star gate,
the sudden lack of mass would cause a leading edge of a powerful
gravity wave to eminate from the place where the sun used to be.
That would be space springing back into relative flatness from
the bending the mass caused it to have in the first place.
We live in bent space because of the mass of the sun.
You can imagine it kind of like if you had two sheets close together
and there was a sticky marble holding them together and you all of a
sudden removed the marble, the previously bent sheets, bent in where
the marbles were, will spring back to the flat shape of the sheets
outside the influence of the sticky marble. That wave would be
similar to a gravity wave started by the sudden removal of mass.
Of course nobody knows how to do just that but it could be simulated
in a computer easily enough.
Originally posted by ark13Didn't you see the 20 % uncertainty part? That means they are
Cool. But if it's 1.06 c, then why don't people send messages with gravity?
giving a definite maybe to the whole proposition.
The problem is gravity's weakness compared to electric or magnetic
fields, any of the other standard forces. The fact that they could
measure it at all is a testimonial to the cleverness of the experiment.
Gravity is something like 390 DB lower "pound for pound" as
electromagnetic forces. Try making an antenna with THAT much gain!
Makes a Yagi look sick! Thats what the LIGO is in fact doing, well
trying to do anyway, they are almost ready to gather real data,
Its a B Itch to get rid of all the seismic activity, electromagnetic
interferance, planes passing by overhead, etc., and leave only
a signal responding to gravity waves. Weber tried 30 years ago
with a huge aluminum cylinder on its side dangling in mid-air and
covered with sensors. Wasn't sensitive enough by about ten orders
of magnitude but it was a good first shot. It may not even be
possible on earth at all which is why the space born detectors are
being readied now. Three spacecraft separated by a couple million
kilometers with laser beams attempting to keep the distance known
to within one micron (40 millionths of an inch)
Then reflections of the laser beam will hopefully reveal gravity waves
impinged on the beams by distant events such as colliding black holes
or neutron star collisions or supernovae. When this all happens
the amount of new data will transform our understanding of the
fundamental underpinnings of our universe with just a great an
impact as relativity which set off this search for gravity waves in the
first place.
One problem with these differant kinds of detectors,
gravity waves come in differant wavelengths depending on the
kind of event causing them. Two orbiting neutron stars spiraling in
towards each other causes one kind of wave, a slowly increasing
frequency that makes a big splatter effect when the two actually
collide. These kind of events have been simulated and shows what
wavelengths to look for. The ligo and it brothers are looking for
frequencies of a few Kilohertz but the one in space may be only
sensitive to longer waves. Remember, one hertz in radio talk is
186,000 miles give or take. So one thousand hertz is a wavelength
of 186 miles. 10,000 hertz, 18.6 miles, etc. Each kind of event
leads to a differant wavelength and each type of sensor, assuming
they can get them to actually detect gravity waves, will be sensitive
to its own designed frequency so they target this sensitivity band
to their best guess as to which event will give the strongest signal in
simulations.