# Gamma-ray Blast from Billions of Lt-Yrs Away: Timing q.? **URL:** \ **Category:** Factual Questions\ **Created:** [February 20, 2009, 9:04pm UTC](https://boards.straightdope.com/t/gamma-ray-blast-from-billions-of-lt-yrs-away-timing-q/486770 "2009-02-20T21:04:13Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![choie](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/choie/32/7829_2.png) [@choie](https://boards.straightdope.com/u/choie)\ **Post date:** [February 20, 2009, 9:04pm UTC](https://boards.straightdope.com/t/gamma-ray-blast-from-billions-of-lt-yrs-away-timing-q/486770/1 "2009-02-20T21:04:13Z")
Okay, I’m sorry for being ignorant, science-wise. But I just read [this article about a massive gamma-ray blast in a constellation 12 billion light-years away](http://news.yahoo.com/s/afp/20090219/sc_afp/sciencespaceastronomy), and I’m confused. I’ve bolded the stuff I find odd: > [@](#): > > The US space agency’s Fermi telescope has detected a massive explosion in space which scientists say is the biggest gamma-ray burst ever detected, a report published Thursday in Science Express said. > > **The spectacular blast, which occurred in September in the Carina constellation,** produced energies ranging from 3,000 to more than five billion times that of visible light, astrophysicists said. > > “Visible light has an energy range of between two and three electron volts and these were in the millions to billions of electron volts,” astrophysicist Frank Reddy of US space agency NASA told AFP. > > “If you think about it in terms of energy, X-rays are more energetic because they penetrate matter. These things don’t stop for anything – they just bore through and that’s why we can see them from enormous distances,” Reddy said. > > A team led by Jochen Greiner of Germany’s Max Planck Institute for Extraterrestrial Physics determined that **the huge gamma-ray burst occurred 12.2 billion light years away.** First of all: this is very very cool. That out of the way, I don’t get it: if the burst occured in September in a location that’s 12.2 billion light years away, how the heck could we have observed it already? Unless this explosion goes faster-than-light, this seems impossible. Or are they trying to say that they _observed_ it in September, and this blast actually occured 12.2 billion years ago? Is this just a poorly worded article, or is my understanding flawed? (Rest assured, I know the latter is the likelier of the two possibilities!) ---
**Author:** ![Fish](https://avatars.discourse-cdn.com/v4/letter/f/bc8723/32.png) [@Fish](https://boards.straightdope.com/u/Fish)\ **Post date:** [February 20, 2009, 9:09pm UTC](https://boards.straightdope.com/t/gamma-ray-blast-from-billions-of-lt-yrs-away-timing-q/486770/2 "2009-02-20T21:09:16Z")
Sounds like they mean they observed the event in September. It can hardly mean anything else; gamma rays do not travel at supralight speeds. Unless, of course, the gamma rays were from the explosion of Praxis half a galaxy away, and then you just say “put it on screen!” and your Star Trek staff obliges. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [February 20, 2009, 9:11pm UTC](https://boards.straightdope.com/t/gamma-ray-blast-from-billions-of-lt-yrs-away-timing-q/486770/3 "2009-02-20T21:11:19Z")
> [@choie](#): > > Is this just a poorly worded article Yes. The explosion was _observed_ to occur last September, but actually happened about 12.2 billion years ago. It’s a common error in astronomy writeups. Journalists don’t seem to like what adding that particular bit of accuracy does to the impact of their sentences. ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [February 20, 2009, 9:14pm UTC](https://boards.straightdope.com/t/gamma-ray-blast-from-billions-of-lt-yrs-away-timing-q/486770/4 "2009-02-20T21:14:28Z")
That would explain the recent increase in incidents of “hulkism” reported since September. ---
**Author:** ![choie](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/choie/32/7829_2.png) [@choie](https://boards.straightdope.com/u/choie)\ **Post date:** [February 20, 2009, 9:23pm UTC](https://boards.straightdope.com/t/gamma-ray-blast-from-billions-of-lt-yrs-away-timing-q/486770/5 "2009-02-20T21:23:42Z")
Heh. Well played, **msmith537**. Thanks, guys. I’m a little relieved to know I’m at least able to comprehend a mistake like this when I see it. Thank you, Carl Sagan! It seems odd that they wouldn’t add “observed,” since I think it makes this even _more_ awesome – the fact that we’re just seeing something _now_ that occured 12.2 billion years ago ! I mean, astronomy’s almost a sort of time machine, isn’t it? (Or a VCR, anyway.) ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [February 20, 2009, 9:29pm UTC](https://boards.straightdope.com/t/gamma-ray-blast-from-billions-of-lt-yrs-away-timing-q/486770/6 "2009-02-20T21:29:21Z")
Except that everything we see occurred in the past. The light we see from the sun was emitted eight minutes in our past. The light you see in the photons on your screen reading this left the screen nanoseconds in the past. Nothing is ever happening in the actual _now_. Astronomy just amps these numbers up so that they seem more impressive, but its same phenomena we encounter every single second of our lives. ---
**Author:** ![Manduck](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/manduck/32/256_2.png) [@Manduck](https://boards.straightdope.com/u/Manduck)\ **Post date:** [February 20, 2009, 9:30pm UTC](https://boards.straightdope.com/t/gamma-ray-blast-from-billions-of-lt-yrs-away-timing-q/486770/7 "2009-02-20T21:30:13Z")
> [@msmith537](#): > > That would explain the recent increase in incidents of “hulkism” reported since September. I find those reports incredible. ---
**Author:** ![choie](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/choie/32/7829_2.png) [@choie](https://boards.straightdope.com/u/choie)\ **Post date:** [February 20, 2009, 9:58pm UTC](https://boards.straightdope.com/t/gamma-ray-blast-from-billions-of-lt-yrs-away-timing-q/486770/8 "2009-02-20T21:58:35Z")
> [@Exapno\_Mapcase](#): > > Astronomy just amps these numbers up so that they seem more impressive, but its same phenomena we encounter every single second of our lives. Way to harsh my buzz, dude. 🙂 Seriously, I know that, but eight minutes, even eight years, don’t hit the point home as much as 12.2 billion years do. At least not for me. ---
**Author:** ![aldiboronti](https://avatars.discourse-cdn.com/v4/letter/a/9fc348/32.png) [@aldiboronti](https://boards.straightdope.com/u/aldiboronti)\ **Post date:** [February 20, 2009, 10:10pm UTC](https://boards.straightdope.com/t/gamma-ray-blast-from-billions-of-lt-yrs-away-timing-q/486770/9 "2009-02-20T22:10:16Z")
> [@choie](#): > > Way to harsh my buzz, dude. A gem! New to me, that phrase goes straight into my riposte repository. 🙂 ---
**Author:** ![Telperion](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telperion/32/509_2.png) [@Telperion](https://boards.straightdope.com/u/Telperion)\ **Post date:** [February 20, 2009, 10:16pm UTC](https://boards.straightdope.com/t/gamma-ray-blast-from-billions-of-lt-yrs-away-timing-q/486770/10 "2009-02-20T22:16:25Z")
> [@choie](#): > > Way to harsh my buzz, dude. 🙂 Seriously, I know that, but eight minutes, even eight years, don’t hit the point home as much as 12.2 billion years do. At least not for me. I’m with you. I find it a lot more impressive to be able to watch something that happened long before there even was a planet Earth than to see something that occured just before the last commercial break on TV. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [February 21, 2009, 1:16am UTC](https://boards.straightdope.com/t/gamma-ray-blast-from-billions-of-lt-yrs-away-timing-q/486770/11 "2009-02-21T01:16:15Z")
> [@aldiboronti](#): > > A gem! New to me, that phrase goes straight into my riposte repository. 🙂 New? That phrase (or the similar “harsh my mellow”) is about 12.2 billion years old. 😃