The Dark Side
"Two groups" studying the same phenomenon of Type Ia supernovae, and both using the National Optical Astronomy Observatory (NOAO) telescopes in Cerro Tololo, Chile simultaneously announced dark energy in 1998. This was hailed by SCIENCE magazine as "Breakthrough of the year."
The largest group in Berkeley, the Supernova Cosmology Project, next planned a Supernova Acceleration Probe (SNAP). This would be a 2-meter infrared telescope located at L2, on the other side of the Moon. SNAP would find thousands of supernovae to further refine the "dark energy equation of state." This project would cost hundreds of millions of dollars.
At a conference in Tucson, Arizona in March 2004; another group led by NOAO's Tod Lauer announced a rival proposal. Their Dark Energy Space Telescope (DESTINY) was touted as a lower-cost alternative. Just last week NASA chose this concept for further funding. Below are concepts for SNAP (left) and DESTINY (right).
They look the same, don't they? The SNAP team should have taken out a patent. The main difference is that SNAP would have a 2-meter mirror and DESTINY a 1.65-m mirror.
The smaller mirror leads to a spacecraft with about half the mass, with corresponding economies of fuel and launch vehicle.
Without substantial changes, it is difficult to see how the SNAP proposal can fly when a lower-cost alternative is available.
Neither project may fly anytime soon, for the space astronomy budget is dominated by the James Webb Space Telescope. JWST will look at similiar infrared wavelenghts to SNAP and DESTINY, and can also be used to seek high-redshift supernovae.
Assuming that either of these missions get off the ground, they will not capture a single wave or particle of 'dark energy' to prove it exists. All they will do is refine the magnitude-redshift curve in an attempt to distinguish between the myriad models for DE. Even if "dark energy" exists, it has no conceivable practical value. It would be so diffuse in Space that it could not power your car or even your cellphone. Speculation about repulsive "dark energy" has not led to understanding, but to a divergence of possible solutions.
Those of you who hold real jobs and pay real taxes, do you wish to spend hundreds of millions to fund "dark energy" experiments? Perhaps you see why physics has lost respect among the wider public.
If one wishes to investigate whether c has changed, all one needs is an inexpensive experiment for independently measuring c. Soon you will hear about experiments which do exactly that.