Scary Stuff

[coquina]

I don't know much about this subject, so I usually stay out of this neighborhood, however, I have a question. This event happened in a galaxy 50,000 light years away, and affected our ionisphere on 12/27/04. Since nothing travels faster than the speed of light, what we witnessed in December acutally happened 50,000 years ago --- right?

 

When you talk about the event causing more damage if the burst came from a "nearby star" is that because some of the energy is dissipated as the burst travels through space?

 

As far as gamma ray bursts causing extinctions - many scientists have speculated that the Ordovician Extinction (where the trilobites disappeared) may have been caused by a gamma ray burst.

 

Here is a link to a paper hypothesizing that this is so...

It was written by several researchers from the astronomy department at Columbia University.

 

http://64.233.161.104/search?q=cache:kiaVO6zayx0J:www.astro.columbia.edu/~dave/papers/grb_extinction.pdf+gamma+ray+burst+extinction&hl=en

 

One of the problems of answering this question for certain is that scientists don't know what kind of indicator to look for in the geological record. It wasn't until it was learned that iridium mostly comes to earth via meteorite, and that there is a world-wide iridium layer at the K/T boundary, that scientists realized the dinosaurs must have been killed by an impact - then, they went looking for a "smoking crater" and found it at Chicxulub.

[star dust]

No. The dinosaurs were wiped out by a comet (or a comet shower).

 

has this actually been scientifically proven??? or is it just a theory?

[ed84c]

http://www.ucmp.berkeley.edu/diapsids/extinction.html

http://web.ukonline.co.uk/a.buckley/dino.htm

 

btw this is my 1000 post. wahey!

[herme3]

Why should anyone worry or be afraid of something they have absolutely no power to defend against? If you're scared of being mugged' date=' take a defense course. If you're scared of getting cancer, avoid carcinogens and see your doctor often. If you're scared of being wiped out by a cosmic event along with the rest of the planet, you are worrying needlessly.

 

There is nothing you could do to prevent it.[/quote']

 

I think there is a disagreement about what fear is. Phi for All and Sayonara³ seem to be thinking that fear means always being worried about it and thinking of ways to prevent it. I think when us.2u says fear, he means that you would probably be scared if you look up at the sky and see a giant fireball heading straight for Earth. There is nothing you can do about it, but I don't think you would be very relaxed knowing you are about to die.

[TimeTraveler]

I don't know much about this subject, so I usually stay out of this neighborhood, however, I have a question. This event happened in a galaxy 50,000 light years away, and affected our ionisphere on 12/27/04. Since nothing travels faster than the speed of light, what we witnessed in December acutally happened 50,000 years ago --- right?

 

Yes.

 

When you talk about the event causing more damage if the burst came from a "nearby star" is that because some of the energy is dissipated as the burst travels through space?

 

There is a long answer and a short answer, the short answer is basically yes. The long answer you would want to hear from someone more versed in physics than I am, I might screw it up.

[swansont]

When you talk about the event causing more damage if the burst came from a "nearby star" is that because some of the energy is dissipated as the burst travels through space?

 

Presumably the burst was spherically symmetric' date=' or nearly so. So you will get a 1/r[sup']2[/sup] reduction as the surface area increases, and you will lose photons to interactions along the way, depending on how much material there is along the path the photons travel.

 

I would surmise we are pretty well shielded against bursts opposite us in the galaxy. It would be stuff on this side of the galactic center we would need to worry about - closer and less intervening material.

[swansont]

has this actually been scientifically proven??? or is it just a theory?

 

As Coquina said, there is the iridium layer and the impact crater that date to 65 mya.

 

"just a theory" is really a bit of an oxymoron in science. If it's a theory it must, by definition, have evidence to support it.

[Sayonara]

I think there is a disagreement about what fear is. Phi for All and Sayonara³ seem to be thinking that fear means always being worried about it and thinking of ways to prevent it. I think when us.2u says fear, he means that you would probably be scared if you look up at the sky and see a giant fireball heading straight for Earth. There is nothing you can do about it, but I don't think you would be very relaxed knowing you are about to die.

I understand the meaning of "scariness" in us.2u's question. I think perhaps he simply chose the wrong word.

 

Certainly it concerns me that humanity could be wiped out by a catastrophic event, but I do not lose any sleep worrying about it, and it does not scare me. Being scared of something, concerned about something, and worrying about something are all different things.

[Ophiolite]

Being scared of something, concerned about something, and worrying about something are all different things.

If all three occur at the same time you are probably in real trouble.

 

This event happened in a galaxy 50,000 light years away.

A small correction here. The explosion occurred in this galaxy.

 

has this actually been scientifically proven(dinosaur extinction)???[/i'] or is it just a theory?

Coquina and Swansont have both commented on this.

It wasn't until it was learned that iridium mostly comes to earth via meteorite, and that there is a world-wide iridium layer at the K/T boundary, that scientists realized the dinosaurs must have been killed by an impact - then, they went looking for a "smoking crater" and found it at Chicxulub.

There is not universal agreement that this was the cause. Some researchers, led by McClean, believe that the massive eruption of basalt lavas in India disastrously effected climate. It is probable, in my view, that both events are implicated. [it may also be the case that the impact triggered the eruptions.]

 

Here is far more than you ever wanted to know, in McClean’s words, where he lambastes Alverez, the originator of the impact theory. If you ever thought the practice of science was dispassionate and objective read this and have your eyes opened.

 

http://filebox.vt.edu/artsci/geology/mclean/1Dinosaur_Volcano_Extinction/pages/scienpol.html

[us.2u]

Maybe I did choose an incorrect word? but being alarmed, concerned, worried or scared..."to me all brings about much the same feeling"- within, to me. Being terrified I would say is different but close to panic hence the title of my page "scary-stuff" but indeed not sleepless nights but I guess if I feel there is a geniune threat to mankind it doe's scare the hell out of me to think we may all be doomed? but not in a panic sense... hopefully scientists... maybe will prolong life indefinately now some may find that scary too...us.2u

[coquina]

If all three occur at the same time you are probably in real trouble.

 

A small correction here. The explosion occurred in this galaxy.

 

Coquina and Swansont have both commented on this.

There is not universal agreement that this was the cause. Some researchers' date=' led by McClean, believe that the massive eruption of basalt lavas in India disastrously effected climate. It is probable, in my view, that both events are implicated. [it may also be the case that the impact triggered the eruptions.']

 

Here is far more than you ever wanted to know, in McClean’s words, where he lambastes Alverez, the originator of the impact theory. If you ever thought the practice of science was dispassionate and objective read this and have your eyes opened.

 

http://filebox.vt.edu/artsci/geology/mclean/1Dinosaur_Volcano_Extinction/pages/scienpol.html

 

I had read about Dewey McLean's work before - he's at VA Tech - a couple of hundred miles west of me. I'd like to meet him one day. I knew he and Alvarez had opposing theories, but I didn't know how bitter it was.

 

I tend to agree with you - that both events played a part. I, too have read theories that the impact actually caused the eruption of the traps, due to the massive shock wave that was sent through the earth's interior. The last paper I read was online somewhere - don't know if I can find it again) stated that the eruptions began before the impact, so it is impossible that the prior caused the latter.

 

(There is a great deal of bitterness about the Chesapeake Impactor too. - One of the three principle investigators wrote a book that was published for public reading and did not give proper credit or royalties to the other two. I don't think they even knew what he was up to until the book hit the shelves. )