Arch2008

Astronautical, the health risk level is unfortunately another unknown. Here is one link: http://ohioline.osu.edu/cd-fact/0185.html The problem is that astronauts would be living inside the magnetic "bubble" 24/7. No data exists for this level of exposure.

That’s why they call it rocket science. After hours of diligent searching I stumbled onto this by sheer luck: http://ksnn.larc.nasa.gov/21Century/pdf/p11_educator.pdf It may be too simple for what you need, but may give you some ideas. Using a flashlight to simulate the radiation source is pretty easy.

This is what we’re talking about: http://en.wikipedia.org/wiki/Health_threat_from_cosmic_rays It might be more prudent to have some sort of non-radioactive interactive device that demonstrated the effect of cosmic rays on tissue. Something like a cue ball hitting a rack of balls. I read in Astronomy magazine that even iron ions can be CRs and they rip through your brain cells like a wild bull in a china shop. This is a link to a company working on what you originally asked, a spacecraft shield. The problem with a magnetic shield is that this also creates a health risk to the crew. http://engineering.dartmouth.edu/~Simon_G_Shepherd/research/Shielding/index.html Here’s something else to think about: http://thayer.dartmouth.edu/~Simon_G_Shepherd/research/Shielding/docs/Parker_05.pdf The real problem with answering your question is that NASA has not answered it.

Astronautical, by ionizing radiation in space, did you perhaps means cosmic rays, which aren't rays at all. These particles can be stopped by the magnetosphere: http://en.wikipedia.org/wiki/Cosmic_rays It's a common mistake. This is what the astronauts saw as flashes in their eyes while they slept. The manned mission to Mars hopes to shield the crew by storing their water supply around the crew compartment. High speed ions of hydrogen and helium aren't the sort of stuff for science fairs though.

You're the expert, but some would disagree: http://www.valleywater.org/Water/Water_Quality/Protecting_your_water/_Perchlorate_Information/_pdf/EPA_Perchlorate_Update_2002-03_New.pdf

In addition to water, apparently there is some nasty stuff too. http://news.yahoo.com/s/ap/20080805/ap_on_sc/phoenix_mars http://www.sciam.com/blog/60-second-science/post.cfm?id=perchlorate-found-on-mars-makes-soi-2008-08-04&sc=rss

P.S. I just read in Astronomy magazine that two astronomers named Leahy and Ouled think that 2006gy may have created a super dense remnant they called a quark star. http://www.astronomy.com/asy/default.aspx?c=a&id=7037

I'll give it a look! The effect you mention, that a huge star’s own light prevents it from growing to even more enormous size, is the Eddington Limit. http://en.wikipedia.org/wiki/Eddington_limit I was able to find this link that somewhat explains how stars below this limit grow so large. http://www.livescience.com/space/scienceastronomy/080227-massive-stars.html As well as how large they may become. http://www.3towers.com/sGrasslands/Essays/HeavyStar/HeavyStar01.asp Essentially, at some point, the explosive force of the core counteracts the star’s own force of gravity, so that its outer surface attains zero gravity (that felt by astronauts in space) and the surface mass starts floating away. In James Kaler’s book “Extreme Stars” he addresses what he labels Hypergiants. Normally large stars, like Red Supergiants (RSG) or Large Blue Variables (LBV) fuse hydrogen into heavier so called metallic elements like helium, carbon, nitrogen and oxygen. This fusion releases energy according to Einstein’s equation. This energy counteracts the enormous gravity of these giants to keep the star from collapsing totally. However, once iron is created at the core, this process stops. It takes energy to fuse lighter elements into iron. At this point, the outer layers of the star collapse inward and bounce off the iron core, creating a shock wave ending in some form of nova. Depending on the force of the inward collapse, several outcomes can occur. If the iron core is squeezed to the point that the atom’s electrons are as tightly packed as is possible (called electron degeneracy), then a white dwarf star is the result. If the protons and electrons are crushed together into neutrons, then the star pretty much becomes an atomic nucleus the size of a city, called a neutron star. Finally, the core can become a singularity in a black hole. Hypergiant stars don’t follow this path. The core of a hypergiant is so compact that in addition to normal fusion, particle pairs are also created in abundance. At some critical point, particle-antiparticle pairs are annihilating at such a rate that the resulting gamma rays superheat the star’s core and it erupts (pair instability). The energy of this eruption tears the star apart from the core outwards. No core mass remains to implode into anything else. As you mention, they allude to the possibility that the star was low on certain elements and this could have caused the hydrogen envelope to remain in tact. The hydrogen added to the astounding luminosity of the SN.

WR stars start as blue supergiants that inflate to red supergiants. If they have a mass of 30-35 Suns, as SN 2008D did, then they go to the WR phase. After a million years or so the WR's explode/implode. Theoretically, one could simply implode to a blackhole without causing any explosion. The process is not well understood, because no WR has been observed before imploding. The emission spectroscopy lines of ejecta from supernovae match that of old WR stars, so “if it quacks like a duck”… There are only about a handful of the WO stars in all of the Milky Way, that is why I believe that a very rare SN may have originated from a very rare star. We’ll see.

I read the link, which doesn’t offer a lot of info, however this is the general explanation of these massive star implosions. The largest stars were first discovered by two Frenchmen, Charles Wolf and George Rayet. http://en.wikipedia.org/wiki/Wolf-Rayet_star http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/980603a.html As more of these stars were found, a category named after the discoverers was created. Wolf-Rayet stars are further categorized by their elemental make-up. Giant stars fuse hydrogen into many other elements and almost all of the elements are created during the explosion of these stars. Three types of WR stars are known, those that contain mostly carbon, denoted as WC, those dominated by nitrogen (WN), and those rare WR with a large mix of carbon and oxygen (WO). http://cfa-www.harvard.edu/~pberlind/atlas/htmls/wrstars.html (The elements in a star can be determined from the star's light using emission spectroscopy.) http://en.wikipedia.org/wiki/Emission_spectroscopy This rather unique event mentioned in the article may have been a rare WO star going nova. The star was most certainly a WR star, since they shed a cloud of hydrogen before they explode. This is also indicated because it was a Type Ib supernova (with oxygen lines). http://en.wikipedia.org/wiki/Type_Ib_and_Ic_supernovae That would be my guess.

Here's a free DL program that simulates the solar system: http://www.download3k.com/Software-Development/Editors-Tools/Download-Solar-System-3D-Simulator.html

MOdified Newtonian Dynamics-MOND http://en.wikipedia.org/wiki/Modified_Newtonian_dynamics My pleasure, Klaynos. I had a link to one of the members of the WMAP team where he explained this. I'll see if I can find it.

The WMAP data indicate the existence of Dark Matter right from the beginning of the universe. This pretty much pulls the rug out from under VG or MOND. Neutrinos were also found to have a miniscule mass.

The Wilkinson Microwave Anisotropy Probe (WMAP) shed some light on dark matter. Apparently it was here right from the beginning of the universe. Some candidates for DM are MACHOS (MAssive Compact HalO objectS) and WIMPS (Weakly Interactive Massive ParticleS). MACHOS are described as brown dwarf stars or minor black holes in the halo of a galaxy, whereas WIMPS are simply nuclear particles that interact weakly with the electromagnetic force, so they can essentially float right through your molecules and do not reflect light, etc. Since there were no stars at the beginning of the universe, I think that WIMPS are the most likely candidate. The DM was unaffected by the energy of the early universe. Enormous clouds of DM started collapsing while the ordinary matter was still too energized to form atoms. At about 380,000 years after the Big Bang, the universe cooled and atoms of hydrogen, helium and a dash of lithium formed. The gravity of the DM clouds caused these atoms to collapse and form the first stars and galaxies. Thus the supermassive black holes formed because of the DM. http://map.gsfc.nasa.gov/news/

Would this help? http://www.space.edu/documents/McLaughlin2.pdf

If you meant to ask, “Why did the black hole stop feeding on the surrounding matter”, here is the answer: http://jilawww.colorado.edu/www/research/blackholes.html A large black hole creates a sort of shock wave that moves infalling matter back to a stable orbit.

About 6 billion years ago, dark energy started to accelerate the expansion of the universe. http://chandra.harvard.edu/photo/2004/darkenergy/ At the same time, galaxy mergers slowed and star formation with them. http://www.astronomy.com/asy/default.aspx?c=a&id=6491 Astronomers see more than a mere coincidence in this.

Over 6 billion years ago, the rate of acceleration in the expansion of the universe started increasing due to the effect of Dark Energy. This “stunted” star formation because intergalactic clouds of hydrogen were no longer massing together. So, the expanding universe had an impact on stunting star formation.

Sweet! I hope that this event is still a fond memory for you in 2037.

Does the theoretical response exist to deflect NEO’s? Yes. Does the hardware exist? No. Also, although a lot of NEO’s have been logged, a comet coming at us from the direction of the Sun would not provide much warning or response time. The more time we have, the greater our chances for survival. Be aware that a Gamma Ray Burst would come at us from the depths of space (up to 1000 light years away) at the speed of light, so there would be no response time. A supernova within 40 light years would also destroy life on Earth without much warning. Or a mini Black Hole singularity might rip through the Earth. Of course, none of these events are very likely.

Not every star becomes a supernova. The determining factor in this event is the star’s mass. We are able to calculate the Sun’s mass. We know the Earth’s mass from its force of gravity and we know how the Earth moves around the Sun. We use this to calculate the Sun’s mass (about 300000 times the Earth’s mass), which is not enough for the Sun to become a supernova. Once the Sun becomes a white dwarf, it may not “fade away” for 10^100 years.

There's no difference. The effect of traveling at c remains the same. Unless you see something that I don't.

This is a more accurate discussion of what will happen to the Sun. http://imagine.gsfc.nasa.gov/docs/science/know_l1/dwarfs.html As a white dwarf, the Sun will no longer fuse elements, however the heat that was in the Sun’s core when it collapsed will be trapped by the now super dense Sun. This heat will take something like a trillion trillion years to dissipate by convection. So an enterprising race will still have a source of heat and light, although a very small source, from the Sun for a very long time.

http://www.amnh.org/learn/pd/physical_science/week3/time_dilation.html t(rocket) = t(Earth) √[1 - (v/c)2] In this equation, time on the rocket moving near the speed of light c is equal to time for an observer (in this instance on Earth) times the square root of 1 minus the square of the ship’s velocity divided by c. Mmmmkay? If the ship’s velocity is c (like inside a black hole), then the value on the right becomes zero. Therefore, an infinite amount of time for an outside observer would pass before one second passed for the observer on the ship traveling at c. However, time still passes for the observer traveling at c. The universe would grow old and all the protons would evaporate and then time for this observer inside the black hole would continue.

Right, I have the differentiation of planets orbit a star and moons orbit a planet, although there are tiny moons that orbit some asteroids too. I think brown dwarf stars are like 20-80 Jupiter masses and they are stars because they sustained hydrogen fusion for a while. It should be possible to calculate a planet size (19 Jupiter masses?) that doesn’t permit fusion. This would be the upper limit for planets. This system would then mesh perfectly with the H-R diagram for stars. http://abyss.uoregon.edu/~js/ast122/lectures/lec11.html (The star’s temp and luminosity are related to the star’s mass)