Starship Asterisk*

NASA's Fermi gamma-ray space telescope. has observed high-energy photons arriving up to 20 minutes behind smaller low-energy ones from a source 12 billion light years away. Why the Lag?

Mark

mark swain wrote:NASA's Fermi gamma-ray space telescope. has observed high-energy photons arriving up to 20 minutes behind smaller low-energy ones from a source 12 billion light years away.

Source?

http://asterisk.apod.com/vie ... =8&t=17555

Many times source events just take that long or longer. A gamma-ray burst (GRB), which I believe is the source here, can keep emitting gamma rays for over an hour after the initial photons get emitted.

Source Bystander?

Eye Eye Sir

http://www.newscientist.com/article/mg2 ... ?full=true

Mark

Thanks for the link. That clears things up a bit. I believe the galaxy Markarian 501 gamma-ray measurement occurred in 2005. There is later data that, I believe, better confines quantum gravity-related dispersion with GRBs. Please see:
http://arstechnica.com/science/news/200 ... -burst.ars

Quantum gravity theories wiped out by a gamma ray burst, Oh dear.

Hey, maybe Quantum Gravity, decided 'It' was going to fool us.

Thanks for the interesting link RJN.

Mark