There is probably something I am fundamentally misunderstanding here. I live in the UK. In winter I am familiar with the timezone being called GMT. 6:00am is definitely in the morning (and I am usually asleep).
If pretty pictures are what drive your boat, then I agree, high energy astronomy will not be exciting to you.
If you care about science breakthroughs, then high energy experiments are the place to look. This is a branch of astronomy that is decades old, rather then centuries old for optical astronomy. The relative improvement of each high energy instrument over its predecessors is huge and the science leap is correspondingly large.
Seeing the Universe for the first time in a new energy range is at least as exciting as seeing something we already know more sharply, but the images won't be as cool. I care about dark matter, physics in the presence of strong magnetic fields, gamma-ray bursts and the origin of the highest energy particles in the Universe. These won't make amazing images, but to me they are very exciting.
Excitement in science might be in the eye of the beholder.
Changing the length of the second would certainly help. In principle a leap second can be a leap forwards or backwards. So far all leap seconds have been positive. If the second had been defined to be a little longer the number of leap seconds would be a lot less (significantly alleviating the problem for people who have to deal with them) and we would have occasional negative leapseconds.
There is not really a contradiction between the results demonstrating that supernova remnants (SNR) in our Galaxy are the source of cosmic-rays and this result (suggesting that active galaxies (AGN) are the source). Both are likely correct: that SNR are the source of the lower energy cosmic-rays and that AGN are the source of the ultra-high energy cosmic-rays.
It had always been expected that the lower and higher energy cosmic-rays would have different origins. At lower energies, the magnetic fields in SNR are strong enough that the charged particles are magnetically trapped and rattle around inside the SNR continuing to be accelerated to higher and higher energies in the process. Once they attain a high enough energy, they are no longer contained in the SNR and escape (and thus do not gain more energy). The very high-energy cosmic-rays seen by Auger are much more energetic than anything in our Galaxy can produce. Active galaxies, which are known to accelerate particles very efficiently fueled by the accretion of matter onto a supermassive black hole had always been a leading candidate for the sources of the ultra high energy cosmic-rays. It is an outstanding result.
Terrestrial Gamma-ray Flashes were discovered in 1994 by BATSE - a space based experiment that operated in the 90's. They are quite common (several per day). It is amazing that there are such efficient accelerators in the Earths atmosphere.
GLAST , is a new gamma-ray mission which will launch early next year and will have the capability to measure TGFs up to much higher energies -- so we will get to really understand the acceleration mechanism. Both instruments on GLAST are designed to observe the celestial sky, but they have such large fields of view that they can also simultaneously make observations of the Earth for at least some of the time.
I think that you are making a bit of a generalisation, Ras Al Khaimah doesn't have much oil. The UAE (particularly Dubai) has a fairly diverse economy, so I suspect that it will not necessarily collapse in a heap when the oil boom ends.
I doubt that all the cosmic-ray light flashes in the eye are destroying rods or cones. Cosmic-rays (which are relativistic charged particles) produce a flash of blue light when they move faster than the spped of light in a medium. This is known as Cherenkov light. This would produce an observable flash of light which would not be damaging to the eye. On the other hand, sometimes the cosmic-ray might interact directly in cells in the eye which may cause damage.
I have heard that in the early days, some particle/nuclear physicists used the light flashes in their eyes to align their particle beams.
I am not knocking anyones right to free speech..
The French were perfectly entitled to express their opposition to the US approach to the war, and anyone can say what they like about the French
.
The war was not justified as a mission to free people (which I agree is a good thing), it was justified by saying that there was proof of WMD and that action needed to be taken to protect us from that.
It is much easier to prove that something exists than not exist. I fail to see why the US cannot produce something conclusive to shut people like me up. After all, they claimed to already have the information.
If the satellite monitoring is so good, how did they
manage to be so wrong abount WMD in Iraq. I can't help wondering if there was ever any real evidence...
I have a bunch of containers on my balcony. I really love them.
Tomatoes and herbs are nice to have, but don't ignore flowers: petunias, marigolds and geraniums
are good and are in flower for ages.
Outside is good as nature will help with the watering.
Make sure that your pots are big enough. Ones way bigger than you think you need will often turn out to be the right size.
It is not quite true that there is an upper limit for gamma-ray energies. For a gamma-ray to produce an electron-positron pair there has to be a second photon in the interaction (to conserve momentum). Thus in space where the photon density is low gamma-rays of very high energies can be produced
and transmitted accross large (astrophysical) distances without difficulty.
I find it amazingf that more people have not commented on the data in the plot being faked. Perhaps the story was published in an astrobiology magazine so that astrophysicists would not find it.
Slashdot Mirror
There is probably something I am fundamentally misunderstanding here. I live in the UK. In winter I am familiar with the timezone being called GMT. 6:00am is definitely in the morning (and I am usually asleep).
Hmmm, Julian day starts at noon. Greenwich mean time starts at midnight, just like any other timezone. http://en.wikipedia.org/wiki/Western_European_Time
16:05 GMT = 16:05 UTC (12:05 pm EDT)
If you care about science breakthroughs, then high energy experiments are the place to look. This is a branch of astronomy that is decades old, rather then centuries old for optical astronomy. The relative improvement of each high energy instrument over its predecessors is huge and the science leap is correspondingly large.
Seeing the Universe for the first time in a new energy range is at least as exciting as seeing something we already know more sharply, but the images won't be as cool. I care about dark matter, physics in the presence of strong magnetic fields, gamma-ray bursts and the origin of the highest energy particles in the Universe. These won't make amazing images, but to me they are very exciting.
Excitement in science might be in the eye of the beholder.
Changing the length of the second would certainly help. In principle a leap second can be a leap forwards or backwards. So far all leap seconds have been positive. If the second had been defined to be a little longer the number of leap seconds would be a lot less (significantly alleviating the problem for people who have to deal with them) and we would have occasional negative leapseconds.
This is described in a physics today article from a year or so ago.
There is not really a contradiction between the results demonstrating that supernova remnants (SNR) in our Galaxy are the source of cosmic-rays and this result (suggesting that active galaxies (AGN) are the source). Both are likely correct: that SNR are the source of the lower energy cosmic-rays and that AGN are the source of the ultra-high energy cosmic-rays.
It had always been expected that the lower and higher energy cosmic-rays would have different origins. At lower energies, the magnetic fields in SNR are strong enough that the charged particles are magnetically trapped and rattle around inside the SNR continuing to be accelerated to higher and higher energies in the process. Once they attain a high enough energy, they are no longer contained in the SNR and escape (and thus do not gain more energy). The very high-energy cosmic-rays seen by Auger are much more energetic than anything in our Galaxy can produce. Active galaxies, which are known to accelerate particles very efficiently fueled by the accretion of matter onto a supermassive black hole had always been a leading candidate for the sources of the ultra high energy cosmic-rays. It is an outstanding result.
GLAST , is a new gamma-ray mission which will launch early next year and will have the capability to measure TGFs up to much higher energies -- so we will get to really understand the acceleration mechanism. Both instruments on GLAST are designed to observe the celestial sky, but they have such large fields of view that they can also simultaneously make observations of the Earth for at least some of the time.
I think that you are making a bit of a generalisation, Ras Al Khaimah doesn't have much oil. The UAE (particularly Dubai) has a fairly diverse economy, so I suspect that it will not necessarily collapse in a heap when the oil boom ends.
I doubt that all the cosmic-ray light flashes in the eye are destroying rods or cones. Cosmic-rays (which are relativistic charged particles) produce a flash of blue light when they move faster than the spped of light in a medium. This is known as Cherenkov light. This would produce an observable flash of light which would not be damaging to the eye. On the other hand, sometimes the cosmic-ray might interact directly in cells in the eye which may cause damage. I have heard that in the early days, some particle/nuclear physicists used the light flashes in their eyes to align their particle beams.
I am not knocking anyones right to free speech.. The French were perfectly entitled to express their opposition to the US approach to the war, and anyone can say what they like about the French . The war was not justified as a mission to free people (which I agree is a good thing), it was justified by saying that there was proof of WMD and that action needed to be taken to protect us from that. It is much easier to prove that something exists than not exist. I fail to see why the US cannot produce something conclusive to shut people like me up. After all, they claimed to already have the information.
If the satellite monitoring is so good, how did they manage to be so wrong abount WMD in Iraq. I can't help wondering if there was ever any real evidence...
I have a bunch of containers on my balcony. I really love them. Tomatoes and herbs are nice to have, but don't ignore flowers: petunias, marigolds and geraniums are good and are in flower for ages. Outside is good as nature will help with the watering. Make sure that your pots are big enough. Ones way bigger than you think you need will often turn out to be the right size.
It is not quite true that there is an upper limit for gamma-ray energies. For a gamma-ray to produce an electron-positron pair there has to be a second photon in the interaction (to conserve momentum). Thus in space where the photon density is low gamma-rays of very high energies can be produced and transmitted accross large (astrophysical) distances without difficulty.
I find it amazingf that more people have not commented on the data in the plot being faked. Perhaps the story was published in an astrobiology magazine so that astrophysicists would not find it.
EGRET stands for the Energetic Gamma Ray experiment.