Airbrush

I think you mean galaxies outside our Local Group are red shifted, not stars we see in the night sky. Stars we see in the night sky are all in our galaxy and thus not moving away from us. Right?

That sounds good Mr Skeptic. Maybe just before impact the Slapper splits into 3 rockets that spread the net and rocket past the object at very high closing speed, maybe 20 or 30 miles per second. Even a modest mass at such high velocity will deliver a high kinetic push (KE = 1/2mv^2). The cables may need some elasticity to soften the impact. After contact, ion rockets can continue pushing the object away. The angle of contact would be somewhere between 100 to 180 degrees.

Is everyone else in agreement with Sisyphus? I distinctly remember an episode of The Universe about parallel universes, the Type I parallel universe, or something like that, meant there could be an infinite number of distinct universes inside some kind of hyperspace. What makes you so sure that beyond our visual horizon there is not a lot more? Just like when we used to think our galaxy was the entire universe. If universes bud off of prior universes, or Big Bangs are caused by colliding higher dimensions, then that means a location in space, or hyperspace.

Maybe what we call the universe is only a regional peculiarity. There could be larger scale structures, universes that exist within a "multiverse". There could be individual big bangs separated by unimaginably long distances, such as Trillions or Quadrillions of light years between them. I also don't believe there would be an "outside" to such a multiverse. We don't have ANY evidence for any "nothing". Something seems to permeate all visible space. There are about one hydrogen atom per cubic meter of "empty space" even in the middle of the great voids between superclusters. NOWHERE is there nothing. There are also virtual particles popping in and out of existance everywhere.

You cannot watch electrons running along a wire, but we can witness the effects, electricity. Lot of things we cannot see that exist. We can see dark matter indirectly thru gravitational lensing.

I heard this idea on The Universe, History.com discussions, questions for the universe. Send large numbers of asteroids to impact on Mars to create more mass and heat it up and thus create atmosphere. I think the amount of matter it would take to significantly increase the mass of Mars (by about 50%) would be enough to melt the surface into pools of magma. That would be beyond our technical ability for hundreds or thousands of years. What do you think?

Yes, for lack of a better term, something is causing the outer edges of spiral galaxies to rotate as fast as the central region. That something appears to be several times as massive as all known "normal" (baryonic) matter. And we cannot see it except for gravitational lensing.

Our galaxy contains hundreds of Billions of stars plus unimaginable large mass of gas and dust, and above all dark matter. The galaxy is not held together by a black hole at the center. The mutual gravity of all the stars, dust, gas, and dark matter hold the galaxy together. The black hole at the center of any galaxy is a tiny mass compared to the galaxy. The Milky Way's supermassive black hole is a few million solar masses which is miniscule compared to the much greater mass of the entire galaxy of Billions of stars, gas, dust, and dark matter.

The poster to that physics forum doesn't sound like he knows what he is talking about. Be careful where you get your ideas. The experts are in agreement that the universe is expanding and accelerating in expansion.

What is the world going to do with it's nuclear arsenal? You are right, convert them into defense against short notice impactors (SNI). I have never heard the term "SNI". It distinguishes among NEOs and comets. It means an object that is big enough to cause significant damage on Earth that has been determined IT WILL IMPACT EARTH within perhaps a few years. Then the best you can do is convert as many nuclear missiles as possible to rocket into outer space towards the object and detonate close enough to cause outgasing from the object that can push it like millions of tiny rockets the other way. If enough of the nukes explode properly, it might be enough to save the Earth from a deadly impact.

Nice to know that. Anyone looking for someone to sweep up around the telescopes or cleaning around the computers? I have a BS degree in accounting and could help out with number crunching. If I had a job working on finding NEOs or helping the NEO search folks in other ways, like a gofer, there would be wings on my feet and I would sail to work each day with enthusiasm rather than the tedium of crunching numbers for a restaurant Anyone hiring? Merged post follows: Consecutive posts mergedHere is my idea for a kinetic slapper for short-notice impactors (SNI). For SNI only a direct method stands any chance for success. The kinetic slapper would be a rocket that just before impact splits up into a giant net to soften the impact and thus not break apart the bolide. The kinetic slapper would be built in multitudes and all assigned the same mission: hundreds of them speed towards the SNI at highest closing speeds possible, maybe 10 to 20 miles per second, and just before impact they split apart into a number of sections extending a giant net. The combined effect of hundreds of these kamakazi rockets could be just enough to cause it to skip off the atmosphere and go away.

Thanks for your thoughts and links Arch! This subject fascinates me. I wish I could help work on these, but I am only a bookkeeper for a restaurant.

We have a small, under-funded program to search for NEOs. I only propose we scale it up so we can detect 99% of all NEOs that can cause more than local damage within the next decade. Instead of spending so much on other kinds of space exploration, devote more on planetary defense. If our enemies know we are working on systems to save THEM and their loved ones, that will take SOME of the steam out of their terrorist attacks. We need to develop two kinds of threat mitigation strategies, the direct method, and the indirect method. I have discussed these here before but basically the direct methods are much cheaper and intended for short-notice threats, such as nuclear explosions in close proximity or kinetic impactors. The indirect methods are more costly and take much longer to deploy because they must travel to the object and change course up to 180 degrees to match the speed and direction of the object. Then using techniques such as gravity tractors or laser cannons to slowly nudge it off course over a period of years. We still may do something to control malaria and world hunger, but those are not from NASA's budget. I would like to see fusion power in the near term, but it seems so difficult to accomplish, maintaining a core temperature of over 200 million degrees F. Over the next few decades I think we can do a lot more with wind, solar, nuclear, and perhaps tidal power, along with improved energy efficiency.

Thanks for the link Arch. That is an interesting site. No, defeating malaria and world hunger are not the top priority. Population control, global warming, and environmental degredation trumps them. So you give impoverished countries food. The local war lords just steal it, and whatever is left over just gives people the energy to rape each other to make more starving people. The threats from space are not known. We need to scan more local space. We will probably not be annihilated over the next few decades, but it will TAKE decades, at the snail pace space exploration is now going, before we have tested defense systems on line ready to go. You think it is more important to send a probe to Europa to look for bacteria under miles of water ice, than to secure this planet from dangerous, or even catastrophic impacts? BTW, fusion power is far off in the distant future. Wind and solar, along with improved batteries, are more promising for the near future.

How much of the NASA budget should go towards exploration of NEOs with robotic probes and testing methods of deflection? Manned space missions to the Moon or Mars are comparatively costly, and not an imperative. We would look like the good guys to the rest of the world, for a change, if we shifted the emphasis of our future space exploration budget, maybe up to 50%, towards protecting our planet. Even if the probability is very low that we will suffer a major impact in the next few decades, we should vastly expand detection stations and start testing defensive methods long before we ever detect the real thing. How about telescopes on the far side of the moon? They would always be facing away from Earth scanning our surrounding space? Then they relay messages to satelites orbiting the Moon to send back to Earth.

The concept that the universe is flat, or so nearly flat that any curvature is not detectable, means that it curves back on itself. Parallel lines may meet. Expansion of space, although may be a kind of curvature of space as you argue, is not the kind of curvature that the closed universe concept implies.

I believe the intense luminosity of quasars comes from the inner edge of the accretion disk, along with it spinning at high rps and something incredible going on near the poles. The jets are something else. If the jets were the brightest thing of a quasar it would not resemble the point source we see, but rather a band of luminosity. However, the cloud of gas and dust in the accretion disk conceals what is going on, and blocks the path, and only the polar regions allow light to escape. Do the radio waves penetrate the gas and dust, along with gamma and X-rays, anything else? Maybe quasars appear as point sources because the most intense energy release and luminosity that escapes from the black hole is very near both poles of the quasar. Since the distance between the two poles is extremely relatively short, we see what looks like a star at such great distance, hence the name quasi stellar radio source. I am still not clear on what generates so much power. According to wikipedia the reaction is about 20 times as energetic as nuclear fusion, but that seems low. What do you think?

"...if there is an unobservable part of the universe...." IF there is? Certainly there is, we know there are unobservable regions of the universe, simply beyond our visual horizon, the CMB. What is beyond that? Antimatter universes could exist if in a multiverse medium there are Big Bangs, here and there, now and then, on unimaginably vast scales of space and time. Among these budding universes are Big Bangs that had more antimatter than matter, so those became antimatter universes.

Interesting concept Mr. Alien. If this Big Bang area of expansion has a limit, and there are multiple Big Bangs separated by "hyperspace" (region of NO atoms or particles of any kind) then the next "bubble" universe could be an antimatter universe because it had a slight over abundance of antimatter?

Would this suggest that quasars brighted at meal time? Does that mean their accretion disks deliver fuel to the supermassive black hole at irregular intervals? BTW, do you have an opinion of what powers quasars? Is it simply gas and dust getting heated to Trillions of degrees or is matter-antimatter being created and annihilated?

"The Sun itself is about 40% richer in metal than other stars formed at the same time [~4.6 billion years ago] & location in the [Thin] Disk." Do you mean richer in metal than stars in our area? If so how can that be, for a supernova to enrich the Earth with more metals than our neighboring stars?

I thought a white dwarf is what is left AFTER a supernova. How can a white dwarf explode if it is so dense, about one ton per cc?

Space is expanding, but only between superclusters of galaxies. Space is not expanding within galaxies, nor within solar system, and certainly not within atoms. Gravity overcomes the expansion of space, and certainly the atomic forces prevent atoms from expanding.

Science never said what existed, or did not exist, before or at the moment of the Big Bang. There could have been matter from a pre-existing universe. The BB obliterated any trace of what pre-existed the BB. I don't believe a pure vacuum or absolutely nothing existed before the BB. Conditions existed which triggered the BB, and that ain't nothin'.

The term "mind control" sounds simple, yet it is very far reaching. If these super-advanced ETI can mind control their members, everyone must follow orders, like some giant ant hill.