Starship Asterisk*

Anthony Barreiro wrote:MOND is not "self-published ... clearly insane crack-pottery."

To be clear, I did not make that assertion. I started out conceding that I haven't read the paper ... that's my way of pointing out that I have no specific opinion about the work involved.

-s

Another possible explanation for the so-called "missing mass problem" is modified Newtonian dynamics . "Rather than invoking some invisible form of dark matter, [MOND] hypothesizes a subtle change to the effective force law at extremely low accelerations (< 10-10 m/s/s)." ... An...

Heh, i almost said massive, but for us non-scientific folks, it's included in 'bigger'. So a proton and electron are physically the same size? Subatomic particles don't really have sizes in the classical sense. An electron is believed to have no internal structure, so it is considered to have no si...

I think it might be dangerous to look down the jet of an active galaxy . Ann For sure, and not just looking down the jet. It wouldn't be wise to fly across it ether! I wonder what the numbers are like... energy flux and particle flux? I recall vaguely from my high energy astro class (a couple decad...

Still, I have to wonder if it is better for life to be inside a much, much quieter galaxy. How about NGC 205 , one of the obvious satellite galaxies of the Andromeda Galaxy, here photographed by Adam Block? Would that galaxy offer living organisms more hospitable conditions than the Large Magellani...

How hospitable do you want it to be? I imagine that if our world were much more hospitable to life, we might have been wiped out by a superior species of arthropod. Those damned arthropods, they seem to get everywhere. Fortunately, we've recently been getting better at making really huge lasers .

I followed the Comet ISON link and there's a nice nutshell summary of what is known so far. There's a nice video about sungrazer comets. So, apparently, this is the first time this comet has passed through the system! Even more crazy, this comet is expected to escape the system completely. One pass ...

I finally managed to take that list of PHAs and convert it to xml format which I opened in Universe Sandbox and created a stereograph. :) http://www.geckzilla.com/astro/PHAs_3d_sm.jpg (Milky Way background is not oriented correctly to the solar system. It's just there for depth.) Slick looking visu...

I guess this is where "budget serious" really comes in to play. We need to develop some new capability. We'd have to spot these things while they're still in the outer solar system; And have spacecraft pre-positioned out there prepared to ride in to the inner solar system with them... Gra...

Yeah, we better start taking this threat seriously. Like, budget serious. It is being taken pretty seriously for something that actually has rather low risks associated with it. We are pretty rapidly identifying all the hazardous asteroids. At this point, we're getting close to having all of them b...

Then there is the Tunguska event. Assuming it was asteroid related, it would be devastating if it happened again to a populated area. While that happened in 1908, a long time from a human stand point, in astronomical time frames, that is a blink of an eye. Yeah, we better start taking this threat s...

Even if that were the case, I just don't see how it is true that "inclination is meaningless" in terms of considering the risk of collision. Because intersecting orbits can have any difference of inclination. Alright, I agree with that. Given two orbits that intersect, the angle of inclin...

Right, assume pure randomness... So given that, any interaction with the moon will almost always cause a deflection along an angle that misses the Earth. Because on the dartboard, the Earth is a tiny bullseye compared to the vast area that constitutes the miss zone. So there are two possible cases:...

Again, "vertical separation" is meaningless. Every body is orbiting on its own plane, with the Sun at the center, and crosses Earth's orbit perfectly in two spots. Edit: that's still not quite clear, I think. Not every pair of inclined eccentric orbits have to intersect at two points (or ...

This 2D map is dramatic. But when you consider vertical separation of those orbits, the threat ought to be less than the 2D diagram implies. Again, "vertical separation" is meaningless. Every body is orbiting on its own plane, with the Sun at the center, and crosses Earth's orbit perfectl...

Yeah, I'm wondering about that 3rd dimension... Do all of these Earth-crossing asteroids have inclinations that are dead-on in Earth's plane? It seems to me that it would be easy for an Earth-crossing asteroid to have an inclination that deviates out of Earth's plane by several Earth diameters in a...

Right, assume pure randomness... So given that, any interaction with the moon will almost always cause a deflection along an angle that misses the Earth. Because on the dartboard, the Earth is a tiny bullseye compared to the vast area that constitutes the miss zone. So there are two possible cases: ...

I've searched for but never found anything discussing what may happen if a PHA strikes the Moon. Depending on size, speed, angle, and location it seems like any effects could range from visually spectacular to deadly. Unless the asteroid is truly massive, it seems to me that ejecta from an impact o...

I've searched for but never found anything discussing what may happen if a PHA strikes the Moon. Depending on size, speed, angle, and location it seems like any effects could range from visually spectacular to deadly. One day we'll get to see a high res video of a large strike on the moon. That wou...

we found the enemy and they are everywhere ( in 2D anyways ) Yeah, I'm wondering about that 3rd dimension... Do all of these Earth-crossing asteroids have inclinations that are dead-on in Earth's plane? It seems to me that it would be easy for an Earth-crossing asteroid to have an inclination that ...

I'm sorry but you are wrong. The"evidence" does not support that, or there would be no question. It would be fact not debate. I posted one out of many possible (thousands really). Ok Babarino, let's see your "thousands". That would be at least two thousand credible scientific st...

Why are "planetary" nebulae still called planetary? That really bugs me. How about a nice complicated academic-sounding 4 syllable latin word or something? Ok, I got it, let's all start calling it a "Stella Mortis" nebula . Maybe it will catch on 8-) -s ps: My apologies, in adva...

Why are "planetary" nebulae still called planetary? That really bugs me. Me too! If "they" are going to go to so much trouble to alter terminology and thereby demote Pluto, they might as well stop using blatantly misleading ill-educated terms like this. How about a nice complica...

Anyway, my main question would be: if we on planet Earth, in the Milky Way, were part of this same cluster, how would we see the night sky with the naked eye? Would we be able to see these numerous galaxies with the unaided eye on a clear night sky, or still need binoculars or small telescope to vi...