Airbrush

Engine oil does not clump from gravity. The early universe was much denser than now, and gravity clumped gasses early. Those clumps were the seeds to galaxy clusters, which stopped expanding. Expansion has only been between proto-superclusters. So the answer to your question is gravity.

Keep in mind that the early universe had many more very massive stars that went supernova after only millions of years. Big stars blow up early.

I don't believe they would use telescopes from far away. I think they would, instead, mimick Earth-craft, such as airplanes and helicopters, or tiny drones that resemble birds or insects, coming and going from their bases underground, on the sea floor, or inside of abandoned buildings, or houses. Or maybe they fly around in flying saucers that use cloaking devices with impunity. Maybe some UFOs are actually slealthy and they are occasionally spotted by people before they activate their cloaking device. That would explain why they are so hard to track.

Yes, all they need to do is be careful to pick up their beer cans and trash before they leave, whatever the year.

If any of the UFOs are actually ETI controlled, then probably they would have some ability to time travel, because how else can they travel so far from their planet, which is probably over 100 or 1,000 light years away? The distances are too vast for conventional space travel. Or they travel so close to light speed, that time dialation for them is significant, and maybe they travel with their bodies in a state of suspended animation.

Justin: "Am I the only one on this forum that looks at this as a blight on personal freedom and liberty? Why not tax the air we breathe and give the money to combat co2 emmisions? Lets start taxing people's flatulance like they do livestock in Ireland. Is there some line that could be considered uncrossable when it comes to regulating and taxing for the greater good of society? If so what is it, and why is that the line? People say that the world is getting fatter, but has anyone considered that the ratio of people starving or going hungry might have dropped at a rate that corrolates with this gain in weight? Has anyone considered that most of the people that are unhealthily overweight have more reasons than just what they eat? Hey here's an idea that we can add to the food tax... Let's add a tax to people who DON'T excersize. THEY are obviously exponentially more unhealthy than people who do excersize, at least at probably close to the same ratio as fat:skinny. Why not go that route? Where do you want to draw the line on the control that a government can have on what people do with themselves? If everyone is so pissed off to have to pay into a system because of people's behavioral eticate then, by god, change the damn system. Don't keep choking people's wallets to prevent bad choices. It's beginning to look like people think of the government as a hypothetical parent." You are exactly correct and I agree with you totally. And yet......the future of human survival on this little spaceship Earth is government will be VERY involved in the life styles of the Billions of citizens. Taxes will be much larger to accomplish more towards social engineering, or we all die in chaos. But efficiency comes with economy of scale. If you have teenagers trained by experts to produce huge vats of healthy food, earning minimum wage, that saves Billions of individuals going thru Billions of hours of toil to cook a little bit of food.

People have been brain-washed by the food industry that food is something to worship as much and often as possible, and that eating should be an orgiastic experience 3 times a day (if not more). Fancy food makes people eat too much. Plain simple unprocessed foods are very delicious IF you restrict yourself until you are very hungry. Restaurant food is bad medicine, simply because it is too much fun. I'm 57 and I love to munch on raw cauliflower, celery hearts, etc, before my evening meal, because I don't eat anything solid all day. In the morning just coffee then I make my 2 daily protein smoothies (banana, frozen peaches, fruit juice, soy milk, protein powder, milled flaxseed, yogourt, and a tablespoon of liquid minerals), along with my vitamins. I pour them into two 20 fl.oz. bottles, one of which I drink slowly on my way driving to work. At mid day I have hot water with vege broth, later during my lunch hour I retreat to my car for my second smoothy with vitamins and I totally relax, space out listening to the radio, or meditate, and I don't feel hungry at all. When I get home from work I relax for a while to recover from my stressful job as a bookkeeper. Then I jog around my neighborhood for about a mile a few times a week. Then I might do some pushups and situps while watching TV and yoga stretching. By 8:00pm I am very hungry so I have my raw vege snack, all I want. And my dog loves cauliflower too! We eat it together. My religion is WAHWE (we are HOW we eat). I also have junk food occasionally, but if it costed much more, I would cut back more. I rarely get sick, not even a cold in many years. In 20 years I may have called in to work sick about a half dozen times, and most of those were so I could go surfing instead. I like the comment above about how different people should avoid different kinds of foods. Some are alergic to certain foods which are good for others. But some things like excess sugar, salt, and unhealthy fats, (and an excess of just about anything) are probably not very helpful for most people. In the future, when there are so many people and resources are being stretched to the limits, it might be necessary for government to get more involved in the life habits of people, that can be good and healthy which will result in a person who is not a charge upon society, and does not need much tax assistance for their never-ending supply of expensive drugs and other escalating health care costs.

Have public mess halls that anyone can eat at for free, but the food is all very nutritious, healthy food, prepared by expert chefs to make the food delicious. Maybe you are required to do exercise before eating before you are allowed this public benefit. These are financed by a progressive tax on foods generally accepted to be less healthy. Develop a food index. The higher the index, the higher the tax.

Fantastic answer SH! Thanks for your reply and insight. I need more time to study your presentation. I'm wondering if it is possible to summarize the chain of reasoning to arrive at a certainty that our Sun will last a few Billion more years. You are correct about the "reason is blah, blah, blah..." but it must be possible to put it into simpler, more understandable terms, so the non-expert can get a good idea about how they know this, in a FEW words, before you lose their attention.

They would use stealth, out of grave necessity. They would have "all the time in the world" to go back and remove evidence of their time travel. If ETs can travel great distances, they may also be able to time travel.

Read about the Montauk Project and you will wonder if it is possible. H.G. Wells is probably the first true scifi writer. He wrote the original The Time Machine before 1895. http://en.wikipedia.org/wiki/The_Time_Machine

I love science programs, but my pet peeve is when they just state facts without giving a clue HOW they know it. For example, they will always say our Sun will last for a few more Billion years before swelling into a red giant and destroying the inner planets, probably including Earth. How do they know the sun will last so long? Maybe they are way off, and the Sun will become unstable in Millions or even thousands of years from now.

This seems like such a no brainer, why don't we hear about it? The problem is America is grossly overweight, and sickly, due for the most part in unhealthy living habits. Why not put a big tax on junk food, and use it to subsidize fruits, veges, and other quality nutritional food? Then poor people will better afford healthier food, and can't afford junk food. Also there should be a tax break for being very healthy, and not needing expensive health care.

Scientists will make a distinction. The observable universe is called exactly that. "Universe" generally means everything, even beyond the observable limit.

Scientists use precise, specialized terms. "Nothing" is useless as a term. More accurate would be "nothing as yet identifiable". Or can someone give a better term?

Is dark energy the result of a total vacuum beyond our visual horizon? A total vacuum would accelerate expansion and maybe explain dark flow. There is no total vacuum anywhere we can see. What do you think?

I don't understand the math above, but I thought the reason we see only matter, and no antimatter, is because shortly after the big bang there was a tiny bit more matter than antimatter. When all the antimatter annihilated an equal amount of matter, there was a tiny bit of matter left over, which is the universe.

Just today I was watching a program about the universe and someone said that ALL galaxies are moving away from us, and they are moving faster and faster away from us. That is only partly true. Not ALL galaxies are moving away from us faster and faster. The galaxies within the Virgo supercluster, our home, are bound together. They are not speeding away from us, but rather they are all orbiting the center of mass of the Virgo supercluster. The galaxies of our Local Group are also orbiting the center of mass of the Local Group.

That's a very good question Zapatos. I hope someone here can answer it. I don't believe DE is responsible for inflation. Inflation is something that happened very briefly shortly after the big bang. Your question seems to be about universal expansion.

Your title should be "Expansion of the Universe", since dark energy has nothing to do with the expansion, only the acceleration of expansion. The expansion of the universe takes place ONLY between superclusters of galaxies. Galaxies are bound together by gravity. Clusters of galaxies are bound together by gravity. And superclusters (clusters of clusters of galaxies) are bound by gravity. But all superclusters are moving away from all other superclusters. This is a very common misunderstanding of the expansion of the universe. Dark energy has nothing to do with it. Dark energy is the term they use to address the strange fact that superclusters are moving faster and faster way from other superclusters.

The reason why I think the Drake Equation will always be too vague for science, is because no matter how much you know about solar systems and planets in the habitable zone, we will never know if life became intelligent, unless it broadcasts something. We will someday be able to say how many planets have life on them by analyzing atmospheres for oxygen and other indicators, but our telescopes will never be able to see intelligence, unless they detect waste gases in their atmospheres that indicate industry. FROM WIKIPEDIA: "Values based on the above estimates: R* = 7/year, fp = 0.5, ne = 2,[citation needed] fl = 0.33,[citation needed] fi = 0.01,[citation needed] fc = 0.01,[citation needed] and L = 10000 years[citation needed] result in N = 7 × 0.5 × 2 × 0.33 × 0.01 × 0.01 × 10000 = 2.31 "Criticism of the Drake equation follows mostly from the observation that several terms in the equation are largely or entirely based on conjecture. Thus the equation cannot be used to draw firm conclusions of any kind. "...Another objection is that the very form of the Drake equation assumes that civilizations arise and then die out within their original solar systems. If interstellar colonization is possible, then this assumption is invalid, and the equations of population dynamics would apply instead. "...One reply to such criticisms is that even though the Drake equation currently involves speculation about unmeasured parameters, it was not meant to be science, but intended as a way to stimulate dialogue on these topics. Then the focus becomes how to proceed experimentally. Indeed, Drake originally formulated the equation merely as an agenda for discussion at the Green Bank conference."

The most absolute relative motion we can say is our motion relative to the center of mass of the Virgo supercluster. We move around the sun at S speed, the sun moves around the galaxy at G speed, the milky way moves around our Local Group at LG speed, and the Local Group moves around the center of mass of the Virgo supercluster at V speed. Depending on where each orbit is will add or subtract to the absolute relative motion of us, and our velacity is always changing.

How long would it take an advanced ET intelligence to come to the conclusion that they gain nothing by broadcasting their location to all listeners? I would think they go stealth not long after they reach our level of technical capacity.

Why confuse matters with centripetal and centrifugal forces? Just gravity and inertia are in relative equalibrium for the planets. However, over Billions of years, the planets and moons will be located differently, and the Sun will swell up as a red giant. I think you have a point, but I may be wrong since I am not expert. Electrons follow their orbits because of their energy level, and planets follow their orbits because of their energy level (inertia).

The Drake Equation is basically sound. The only things that will change are the values of each unknown. Drake and Carl Sagan were more optimistic that current scientific opinion. And Stephen Hawking pointed out we would be better off the numbers are lower. Encounters with superior intelligence will probably not be good for us. But then if we merely detect them very far away, hopefully they cannot find us and put us on their menu.