Dark Energy Doubted
We’ve been told recently that two thirds of the universe consists of a mysterious phenomenon called dark energy. Now, some scientists at ESA say it doesn’t exist.
Observations by the European Space Agency’s XMM-Newton X-ray Observatory of clusters of galaxies 10 billion light years distant show remarkable differences from nearby clusters in the amount of X-ray energy emitted. One interpretation is that dark energy is not needed to explain their structure, because they appear too dense, and emit more X-rays than expected by the “concordance model” that posits 70% dark energy. If confirmed, “we may have to rethink our understanding of the universe.”
Related stories: 07/07/2003, 05/30/2001.
Nevertheless (bad timing?), Science magazine Dec. 19 issue) and its editor Don Kennedy, convinced that “the data conclusively prove the existence of dark energy,” awarded the “discovery” of dark energy the journal’s “Breakthrough of the Year.” (This was probably voted on before the XMM-Newton telescope results were announced.)
Models are playthings for theorists. They may or may not correspond to reality. Beware of popularizers who speak of models as facts. Cosmological facts obey Dunlap’s Laws of Physics: (1) Fact is solidified opinion. (2) Facts may weaken under extreme heat and pressure. (3) Truth is elastic.