Google News top four Sci/Tech headlines for this morning, or… “One of these things is not like the others”:
Oppenheimer downgrades Apple to perform [from “outperform”, a stock rating]
Microsoft plans quick fix for IE [please be sure to download and install the patch to keep your passwords and other personal data safe]
Yahoo to scrub personal data after three months [glad to know that…]
and, oh yes…
Scientists say universe is expanding
Okay, let’s assume that we all guessed correctly that #4 is the one not like the others. The timescale of this item far outlasts the timescale of the other three. And let’s look more in depth at this breaking news.
Haven’t we in fact known that the universe is expanding for, well, years now, if not decades? But the big news here is that we now have added evidence that the expansion is accelerating. And you know what that means… Sometime in the future we will not be able to see any other galaxies but our own, even with the most powerful telescope because they will all be past the event horizon — farther away than the speed of light can carry their image to us. And we will be isolated in a lonely universe.
The implication of this discovery is that we (well, at least some of us) now believe that so-called empty space is not really empty at all; rather, it’s full of energy. And this energy also prevents the further “clumping” of stars into galaxies and galaxies into larger and larger galaxies, which our current mathematical modeling of the universe would predict but which we do not observe.
On a personal-interest sidenote, Einstein has also been vindicated. When he developed the General Theory of Relativity, people (including him) believed that the universe was static (not expanding). According to Einstein’s original theory, the measured effects of gravity should have been stronger than they actually were. And so Einstein introduced a kind of fudge factor into his equations known as the “cosmological constant”, set to -1. The purpose of the cosmological constant was to reconcile the mathematics of the general theory with observed phenomena. But with an expanding universe, the cosmological fudge factor–er, constant–was no longer needed. At one point, Einstein called the introduction of the cosmological constant his greatest error. But it turned out that the measured expansion of the universe did not sufficiently account for the discrepancy, and this set scientists looking for dark matter, and later for dark energy. And now, this measurement of distant galaxy-clusters reported in the news today may finally account for the discrepancy and explain the need for the cosmological constant by proving the existence of dark energy in otherwise empty space.
And where does all this leave string theory, the ten-dimensional universe, parallel universes, and other approaches not yet considered mainstream physics? They are not disproved. Quantum field theory predicts that the energy of a vacuum should be 120 orders of magnitude (yes, ten to the 120th power) higher than those observed. So we still have a way to go.