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Gamma-Ray Burst Mystery Solved

How do you navigate in deep space? You take readings from 2 or more beacons and use basic trigonometry.

We simple earthings, being incapable of intersteller travel, misinterpret these beacons as gamma ray bursts from supernovae....
 
beacons

only problem with space is there arnt any other points of refrence such as stars shame eh.
 
Re: beacons

Tin Finger said:
only problem with space is there arnt any other points of refrence such as stars shame eh.

Hmmm... bit like saying that you don't need road signs 'cos there are plenty of trees, buildings, etc.
 
As I recall there is a bit of a problem about bursters being the product of supernovae - where do they get the energy? IIRC (rynner where are you when we need you???) the energy equations of supernovae are pretty accurate and the energy in the gamma rays makes a nonsense of them
 
Well its either pulsars,stars or other natural phenomina or going to all the bother of having to colapse a star,if that is what is behind gamma ray bursts,isnt the beam of energy a bit narrow for galaxy wide navagation
If you are outside of the focused beam is it any use?
Unless you only plan only to travel in the same direction.
 
Hundreds, if not thousands, of pulsars have been detected so far - estimates as to the total number of pulsars vary from 100,000 to 100,000,000. And, on the universal scale, Earth is pretty much a fixed point.

To get a precise navigational fix, even in 3-D, you'd need maybe half-a-dozen.

I don't see a problem with that. :)
 
gamma ray bursts

What if these are an atempt to kill us off.
If enough of these hit the earth when life was first forming could it have been enough to stop early life starting,before an atmosphear formed?
They could have just miss calculated the time scale for an attack!
 
intaglio said:
rynner where are you when we need you???)
'Ere I be!

For the first time scientists have predicted the explosion of a star.
The star in question is designated Supernova 2003dh and was seen to brighten on 8 April.

The prediction was the consequence of detecting a pulse of energy in the form of gamma rays from the same direction ten days earlier.

Before this observation, and the prompt given to them by the gamma-ray burst, scientists could not predict the explosion of a supernova to an accuracy of better than a few million years.

Right place, right time

Scientists Arnon Dar and Alvaro de Rujula from the European Centre for Nuclear Research and the Technion Institute of Technology in Israel made the prediction about the explosion and watched it happen.

The pair developed a theory to account for the mysterious gamma-ray bursts that come from the depths of the Universe.

For over 30 years these bursts of high-energy radiation have mystified scientists, who cannot explain their enormous energies.

According to the Cern-Technion team, gamma-ray bursts are linked to supernovae, the cataclysmic explosions of massive stars at the end of their lives.

To test their theory, the researchers needed to wait for a gamma-ray burst that was relatively close, in cosmic terms at least.

On 29 March a particularly close and powerful gamma-ray burst, designated GRB 030329 was detected.

Looking at their calculations the CERN-Technion team immediately predicted that light from a supernova would first become clearly visible on Earth on 8 April.

And so it did. It has even been detected by advanced amateur astronomers.

This is the first time that scientists have predicted the exact day of observation of a supernova.

Astronomers will now be very interested in why the gamma-ray burst occurred first and the explosion of the star several days later.
BBC Link
 
This seems reasonable un like my last post.
Chucking stones at our sun is more likely
lol.
 
energy release

Dont atoms release an amount of energy whilst there electrons change to a lower orbit around them?
If the suns atoms did this all at once.
But the link to gamma rays?
A blip in time?
 
The sun is predominantly a mixture of hydrogen and helium, so in terms of electron transitions you would be limited to their electronic energy levels. Sadly (or happily, depending on your point of view ;) ) none of these transitions are in the correct energy range to allow the emission of a gamma-ray.
 
BLACK HOLES

IIRC wasnt it one of hawkings therories that matter would relese energy, when torn apart by a black hole.
What if we are seeing a planet hitting a black hole thats why they seem to come from nowhere as the scorce is well black!
 
Re: gamma ray bursts

Tin Finger said:
What if these are an atempt to kill us off.
If enough of these hit the earth when life was first forming could it have been enough to stop early life starting,before an atmosphear formed?
They could have just miss calculated the time scale for an attack!

A burst of fire from a weapon of some kind...? Scary.
 
Fortis said:
The sun is predominantly a mixture of hydrogen and helium, so in terms of electron transitions you would be limited to their electronic energy levels. Sadly (or happily, depending on your point of view ;) ) none of these transitions are in the correct energy range to allow the emission of a gamma-ray.
that's a half truth at best, the sun is releasing gamma all the time from its center. I think you are confusing ionization energies (the energies it takes for an electron to jump orbitals) with the nuclear fusion reaction that takes place in the center of the sun. The thermonucler reaction goes as such 4H + E => 2He + neutrino + gamma ray

But the fact that the sun is as big as it is, limits the number of gamma rays that reach our planet. The earth is always being bombarded with gamma, but the amounts that actually reach us aren't anything to worry about :D
 
I'm not really sure about all this-
it is probably due to the dumbing down effect of popular science reporting, but do they propose that all gamma-ray bursters are associated with supernovae?
Or that all supernovae are associated with gamma ray bursters?

There are 3 main classes of supernovae,
1/ the explosion of material that is deposited on a white dwarf star by a close companion-
(smaller versions of this are seen as ordinary novae)
2/the core collapse of a giant star, producing a neutron star (pulsar) as the end product-
3/ the collapse of a supergiant star , collapsing into a black hole.

I would tend to suspect that only the very rare class 3 supernovae would produce a gamma ray burster big enough to be detectable over 10 billion ly,
and then Martin Ree's polar ray hypothesis would probably have to be invoked to explain the energyflux.
Furthermore, there is another model , which involves colliding neutron stars- these are still considered as candidates, AFAIK.

This really seems to be 1/2 the story, I think.
 
Search said:
that's a half truth at best, the sun is releasing gamma all the time from its center. I think you are confusing ionization energies (the energies it takes for an electron to jump orbitals) with the nuclear fusion reaction that takes place in the center of the sun. The thermonucler reaction goes as such 4H + E => 2He + neutrino + gamma ray

Search, I was replying to Tin Finger's

Dont atoms release an amount of energy whilst there electrons change to a lower orbit around them?
If the suns atoms did this all at once.
But the link to gamma rays?
A blip in time?

and my reading of that was that he was referring purely to electronic energy levels, for which I think that my reply was correct. :)

Nucleosynthesis in the Sun, however goes in a multi-stage process (rather more like...

1) 1H1 + 1H1 -> 1H2 (i.e. a deuteron) + positron + electron-neutrino

(you need the latter in order to conserve lepton number)

2) 1H1 + 1H2 -> 2He3 + gamma

(making a helium 3 nucleus)

3) 2He3 + 2He3 -> 2He4 + 1H1 +1H1

Of course at higher temperature, and in the presence of carbon nuclei, we can end of with the carbon catalysed CNO cycle, but neither of these two routes involve electron capture by a proton.
:)
 
Eburacum45 says:
1/ the explosion of material that is deposited on a white dwarf star by a close companion- (smaller versions of this are seen as ordinary novae)

I'm afraid I must disagree. This type of novae is regular and is of a characteristic energy. This is the type of novae that was used to calculate the rate of expansion of the universe, due to knowing what the absolute luminosity of the event was. There are no big or small versions of this type of novae. There are big and small supernovae explosions that are cause by the end of stars however.

I agree that GRB could be caused by colliding neutron stars and that this is theoretically convincing, but until the gravity wave observatory is on-line the jury will probably stay out. It is much more likely that GRB and very intense supernovae explosions appear much brighter than they really are due to polar ray intensification.

As to GRBs being used to kill off life on Earth, I don't think so. You will get a lot more gamma rays from the sun than from GRBs in your life. There is also a theory that Supernovae are the cause of some of the mass extinction events observed in Earth’s history.Article
 
I'm afraid I must disagree. This type of novae is regular and is of a characteristic energy. This is the type of novae that was used to calculate the rate of expansion of the universe, due to knowing what the absolute luminosity of the event was. There are no big or small versions of this type of novae.

I apologise- I'm trying to teach myself astronomy on the net- not very satisfactory (my degree was in ecology).
still, from here is a type 1 supernova,
A Type 1 supernova is composed of two stars, one the ancient core of an old star like our own sun (a white dwarf, made of carbon and oxygen), the other is either a young (main sequence star like the sun) or a middle-aged (red-giant) star. The stars must orbit each other closely enough that gravity can pull material from the envelope of the younger star onto the surface of the white dwarf. Once enough matter builds up, the temperature and density of the white dwarf reach a point where a thermonuclear runaway begins.

"Then the entire star blows up. It's similar to a huge hydrogen bomb," Hoffman said. "Amazingly, research suggests the younger star may survive the explosion, although only its dense core would remain. In the process most of the white dwarf is transformed into radioactive nickel, which decays to iron."
and here is an ordinary nova
If the white dwarf and main sequence remnant of a close double are close enough, the white dwarf can raise tides in the main sequence star, and mass will flow the other way, from the main sequence star to the white dwarf. Theory and observation both show that the flowing matter first enters a disk around the white dwarf from which it falls onto the white dwarf's surface. Instabilities in the disk can make such a star "flicker" over periods of days and weeks, even producing sudden outbursts of light. The star that became the white dwarf had lost almost all of its hydrogen envelope during its own evolution. When enough fresh hydrogen from the main sequence star has fallen onto the white dwarf, it can, in the nuclear sense, ignite, fusing suddenly and explosively to helium. The surface of the white dwarf blasts into space, the star becoming temporarily vastly brighter. On Earth we see a "new" star or "nova" (meaning "new in Latin) erupt into the nighttime sky, not a new star at all but an old one undergoing eruption. Novae are common, 25 or so going off in the Galaxy every year, once a generation one close enough to reach first magnitude.
so you can see where I get confused.
 
Having said that, thanks for the
link- this theory can go someway towards explaining mass extinctions and the apparent lack of ancient alien civilisations in our galaxy.

although our little worldbuilding gang are having a little trouble choosing which mass extinction is a good candidate for this sort of event...
 
This thread is very well researched. I enjoyed reading it. :) x

Nice you ressurected this thread i never would have read it otherwise, as to the question posed at the start of the thread about navigating in space, that is easy, satnav, always works for me :hahazebs:
 
Sat Nav is brilliant especially when you have a famous person voice on it.:)
 
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