We talk about theory a lot, both in and out of the ATM forum, and some of the discussions are very interesting. I do feel, however, that many (or most) of the major breakthroughs in the next ten years will come from the experimental side. Does anyone want to propose a good experiment or survey or discuss one that is already planned or under way? You wouldn't even necessarily need any access to equipment - there is a vast amount of publicly available data.

I have suggested a few things in my postings.
Lately I have been wondering if physicists have
tried monitoring a hard dark vacuum with
light detectors in the search for fundamental
things. Also I have thought that a Quincunx
using sand or salt might be a quick and easy
way of showing the gravitational field of a
large mass to the side if it distorts a normal
repeatable curve produced by same. Tried
putting this on a Science Fair suggestion
board in the hope somebody might try. Could
have been a way of getting somebody to do
the work

I have suggested a few things in my posts.
Lately I have wondered if folks have tried
monitoring a hard dark vacuum with light
detectors in the search for fundamental things.
Also suggested a Quincunx using sand or salt
for detecting the gravitational field of a
large mass to the side. Thought a Science
Fair suggestion board would be a way of
getting someone to do the work

Shucks! I thought the first post was lost.

In any case, mind restating exactly what you mean by this statement; as it is, it is quite unintelligible.

Gsquare

I would like to put a casimir device in orbit around the Earth, with the plates first oriented so that the gap points at the Earth and get readings for a few orbits, and then repeat with the gap perpendicular to that radial direction, to see if the quantum vacuum can be polarized by the presence of matter (Earth, Moon, Sun).

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The ether of general relativity therefore differs from that of classical mechanics or the special theory of relativity respectively, in so far as it is not 'absolute', but is determined in its locally variable properties by ponderable matter.

Albert Einstein, "On the Ether", 1924

There are a bunch which might test, or at least put some constraints on, LQG (Loop Quantum Gravity).

In a nutshell, very distant point sources will be 'smeared out' by space (which is a 'spinfoam' in LQG), so determining the angular size (as we detect it) of very distant point sources should also test (or set limits on) some properties of space.

What might these very distant point sources be? Supernovae and GRB afterglows are the two which spring to mind, but there might be others. How to determine angular size? With the ACS on the Hubble, for one; maybe VLBI observations as well, and perhaps one or more of ground-based optical interferometers. With the right amount of good luck, a night-side lunar occultation might also be possible.

The role of amateurs? Little chance for using their own telescopes I suspect, but all the Hubble raw and processed images are public domain, so maybe a re-examination of archival supernovae images, with the right kind of image analysis software?

Somebody on this forum recently proposed an experiment to see whether electrostatic charges moving in cars would generate magnetic fields. And whether someone riding in a car would measure a magnetic field while driving past an electrostatic charge.

This inspired me to wonder whether a nonmagnetic metal (such as silver) could be used to make a dynamo powered by the centrifugal force. The idea would be to have a rotating sphere or disk with one sliding contact on the equator and another sliding contact near the axis of rotation. If the crank were turned, an electromotive force should be generated, though perhaps a very tiny one.

Perhaps the idea of cars could be amended by using charged bullets, which could reach much higher speeds than cars and which would have better insulation during their flight than something sitting in a car. Especially if they could be fired through a vacuum. The charge might even be used to accelerate the bullet in the first place; i.e. it could be fired from an charged metal gun.

So, here are two ideas for experiments, though perhaps they need refinement to become feasible.

Well I try to be concise I presume you know
what a Quincunx is, particles falling through
an array of pins into columns at the base. Lets
have 40+ columns for a smooth normal distribution
which repeats every operation. Then any mass to
the side could bias the particles slightly one
way causing a noticable change in the curve. I
envisage a device that can be reset quickly by
rotating backwards so that the particles fall
out of the columns and back into the hopper at
the top ready to fall through the pins again.
Hope this is clearer!

Similarly, measuring the arrival time of 100TeV photons versus MeV photons from the short GRBs could tell us something about LQG. This might be harder to measure, since we don't yet have very directional detectors for the higher energy range photons.

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Forming opinions as we speak

Another one that I've suggested several times here is this:

Extended GAIA

First four ideas this assumes:
- The GAIA project is going to produce some very useful results.
- One of the ideas for manned missions to Mars (and beyond) involves spacecraft going much faster than escape velocity from the Sun, and then slowing down as they approach their target.
- We will develop some useful power source for deep space probes (RTGs are kind of expensive these days, since we seem to be out of the right isotope of Plutonium).
- We will build and test a highly directional communications system (such as laser) that will allow high-speed data communication over very long distances.

The basic idea is to build more probes like GAIA (improved as is possible by the technology advances in the time between now and then), and release them from the manned probes when they have their maximum anti solar velocity. Send at least one toward Jupiter so it can have it's direction changed to far outside the plane of the ecliptic as possible.

The parallax measurements from these missions should allow us to get direct distance measurements to bright stars in nearby galaxies, plus all the bright stars in the milky way.

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Here's another one I've mentioned here before:

Inner Asteroid Search

This is another mission involving a fleet of space craft. This fleet is designed to look for asteroids further from the sun than they are, and get launched into circular solar orbits the same distance from the Sun as Venus.

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Here's another one I've proposed here before:

Galactic Orbit Parallax

The idea is that now that we have the large Earth-based interferometry telescopes coming on-line soon that we should specifically photograph nearby galaxies and background distant galaxies now (espeically in the directions near Cassiopeia), and again every decade, to measure the parallax distance to the closer galaxies to a high degree of accuracy. This might even get distances to the nearer quasars.

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Forming opinions as we speak

My proposed experiments:

--A Kamiokande-type proton decay sensor that can use seawater instead of ultrapure water. The idea is that maybe they could put one of these things on the seafloor, and thus have an unlimited supply of water to sift through. Don't know enough about particle physics to know if it's workable, though.

--A cheap solar sail. 'Nuff said.

--An amateur space telescope. There was serious talk about putting one of these at the ISS before the Columbia disaster, and making it free for people to use. Those plans seem dead in the water, but I still think it's a great idea, and would go far in promoting public interest in space.

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"Call me old-fashioned, but I think fire is magic. And it scares me a lot."

--The State

One last one collecting my previous suggestions:

Neutrino Velocity Experiment

We detected a burst of neutrinos from SN1987a in the LMC. This is, so far, our only detection of supernova-based neutrinos. This event happened 180KPc away. If we can detect similar bursts from 10MPc away, we would be able to observe supernovae every few years, from varying distances away, enabling us to see how the peak get smeared out and/or delayed with distance. This would tell us information about the mass of the neutrino among other things.

I am not sure whether Ice-Cube will be detecting the right types of neutrinos to tell us this, but I hope so. Ice-Cube is not working with ultra pure water.

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I believe that GLAST will try to measure the difference in speed between higher- and lower-frequency gamma rays from really distant GRBs.

"radiation from distant cosmic explosions called gamma-ray bursts might provide a way to test whether the theory of loop quantum gravity is correct.... The discrete nature of space causes higher-energy gamma rays to travel slightly faster than lower-
energy ones.... The GLAST satellite, which is scheduled to be launched in 2005 (sic), will have the required sensitivity for this experiment."

GLAST will be able to measure gammas up to about 10GeV, which puts it in the 'maybe' range for detecting the effect. Maybe it will observe it, maybe it will be borderline, and not conclusive.

None the less, I am very interested in the GLAST results, since they are going to come well before any experiment such as the one I suggested above could ever be built.

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Good one, Turbo; but why would you need to put it in orbit? Why not just do it on the earth's surface (in a man-made vacuum)?
I believe it is possible there is a variation in energy density with direction. It is my opinion that it may be possible to show gravity itself to be a 'polarization' of the vacuum. However, the measurement of the variation in Casimir force must have very high sensitivity since the change in energy density is likely very tiny. If discovered it would be quite significant.

Gsquare

We know that the trajectory of light is bent when it leaves a vaccuum or optical medium of one optical density enters a curved optical medium with a different density. This is attributed a change in the constant speed of light in the new medium and it is claimed that while the medium would have to be exerting and an effect on the light for this to occur the individual photons expereience no net loss of energy. This is not notwithstanding those that are adsorbed and remitted. Similarly the gravitational field around a massive object in a vaccuum bends light without affecting its speed. I wonder how movement to each of