Airbrush

If it was possible for you to travel back in time, it would only be possible by entering a parallel universe (like in the series "Fringe"). In that universe there would now be 2 of you, and none of you in the first universe. If you (heaven forbid) murdered your younger self, your older self would not cease to exist, since there would be 2 of you, one from each universe, and only your older duplicate survived.

AT: "...Now back to your question. These protoplanets are now spinning because the original gas/dust cloud was spinning, even if ever so slightly. Due to the law of conservation of angular momentum, these bodies spin faster and faster as they contract. And before you know it, you have spinning planets and such...." Your answer was almost perfect, except the question is about planets in orbit, not spinning on their axes. When a proto-planetary disk collapses, the random motion becomes uniform in one direction around the central star. That motion becomes the orbit of the planets and most of the asteroids.

No, Jupiter is too far away for that. It is 5 times as far as the Sun. So the heat from a Sol-like star, at the distance of Jupiter (5AU) only 1/25 as much heat as our Sun will reach us.

Interesting how close your title is to my idea for "enhancing" gravity for humans on the Moon, Mars, and perhaps on the asteroids. I've never heard it mentioned before, except artificial gravity by centrifugal force in zero gravity of outer space. On the Moon or Mars there is some gravity but long-term human habitation would suffer physically from gravity deprivation. It is possible to increase gravity if the crew quarters are located in a slow spinning structure that "adds" gravity by boosting the G force. Where they live would be a giant centrifuge, but the floor is tilted towards center. This is comparable to a Merry-Go-Round. The effect of these living quarters is to add gravity to the Mars or Moon gravity to bring it to a comfortable Earth-like one G.

The only way the mass of Jupiter could "shine as bright as our sun" is if it became a black hole and the accretion disk happened to be small enough to generate the energy equivalent to our Sun. In the movie 2010 Jupiter became a tiny brown dwarf star and that would not shine as bright as our Sun.

Stephen Hawking would not say "ouch!" but would be glad, as we all should be, that we may not be in danger of being overwhelmed by ETIs who like our planet, and could easily take it from us. This is an excellent video clip of Geoff Marcy of the Kepler Mission. Skip forward to about minute 45 in his lecture where he gets into the probabilities of technological ETs. This is cutting edge thinking on this subject.

Although tool use is seen in other animals, including birds and octopi, let's use chimpanzees as an example, since they are closest to humans. "Chimpanzees split from the human branch of the family about 4 to 6 million years ago. The two chimpanzee species are the closest living relatives to humans, all being members of the Hominini tribe (along with extinct species of Hominina subtribe)." If chimpanzees have been using stone tools for at least 4,300 years, they have not made much progress. They use sticks to dig into termite mounds and a small twig to "fish" out termites. Why do they not carry a spear or club around with them at all times? They live in a dangerous area and yet a simple club or spear is not something they ever thought about carrying around for defense, even though the Senegal chimp knows how to hunt Bushbabies with a spear they sharpen with their teeth. "One of the most significant discoveries was in October 1960 when Jane Goodall observed the use of tools among chimpanzees. Recent research indicates that chimpanzee stone tool use dates to at least 4,300 years ago.[16] Chimpanzee tool usage includes digging into termite mounds with a large stick tool, and then using a small stick that has been altered to "fish" the termites out.[17] A recent study revealed the use of such advanced tools as spears, with which Common Chimpanzees in Senegal sharpen with their teeth and use to spear Senegal Bushbabies out of small holes in trees.[18][19] Before the discovery of tool use in chimps, it was believed that humans were the only species to make and use tools, but several other tool-using species are now known." How much longer will it take for the chimpanzee to make more sophisticated tools? Probably never. There is no pressure for them to make better tools. Their crude tools are good enough for them indefinitely. We are alone as a technological intelligence on this planet. http://en.wikipedia.org/wiki/Chimpanzee#Tool_use

You seem to be very knowledgeable. Please share with us your credentials. Are you a published scientist or professor? What does this mean: "Respect, I was as knowledgeable as morgs..."? What does it mean to "conduct things to a better intellect."? I guess knowledgeable people are hard to follow.

Correct me if I am wrong, but I believe the way to calculate the average speed the observable universe has been expanding, just take the current distance to the furthest observable object, the cosmic microwave background radiation, currently about 46 Billion light years away, and divide that by the age of the universe, 13.7 Billion years, and you get about 3.3 times the speed of light. That only applies to the average speed the CMB has been moving away from us since the Big Bang. Objects closer to us have been moving away at a slower average speed.

This is debatable. Would chimps necessarily develop increasing dexterity? Since we split off from chimps about 5 Million years ago, is there any evidence that chimp tool making and usage is any more advanced than it was 5 Million years ago? Chimps haven't even learned to walk upright yet. Our human ancestors were fully bipedal several Million years ago. Chimps can briefly walk upright, but are more naturally quadrupedal knuckle-walkers. Chimps do not make weapons, but merely manipulate an object, such as a branch. They do not carry weapon branches with them into battle with other Chimps. Maybe speech and other abilities are also necessary for a species to get very sophisticated technologically. Technology may need digital dexterity, speech, bipedalism, and maybe other intelligence that chimps may never develop. What other animals have demonstrated an increasing level of intelligence? That would be hard to prove. Animals seem to level off at a degree of intelligence which does not increase much over time. The only thing that will increase is adaptation through a new, useful, selective advantage, of which intelligence is only one of thousands. It could be for most other animals that intelligence could actually interfere with their survival. A certain level of intelligence in Chimps could possibly interfere with their reproduction, for example, or their social structure. Humans thrive on intelligence for now, but our intelligence could conceivably destroy us by nuclear or bio weapons.

The ability to finely manipulate objects is only a human ability. Birds and chimps may use a twig or branch, but there is no evidence for any other primates to develop human digital dexterity and real tool making. If we split off from a common ancestor with the chimpanzee about 5 Million years ago, why haven't any other chimp groups become more human-like and digitally skilled within the last 5 Million years? The answer is life evolves to be only as intelligent as it needs to be. A jelly fish doesn't even have a brain. Marcy believes that technological ETs may be more rare than we think, and he seems consistent with the Rare Earth Hypothesis, but there are probably a number of them in our galaxy. Maybe a thousand light years between them.

Geoff Marcy of the Kepler Mission made an interesting point about intelligent life on Earth. Of all the millions of species that have come and gone on Earth, humans are the only intelligent (technological) species. Dinosaurs did not grow in intelligence, and they survived just fine. Cockroaches, sharks, jelly fish, and millions of other species have other survival abilities than intelligence. Intelligence is only one of thousands of survival mechanisms, and may well be a very rare one.

Well said Captain, at such high temperatures, Celsius and Kelvin are approx the same. Fahrenheit is approx 1.8 times Kelvin, a significant difference. Kelvin is certainly standard, and I appreciate that, but I will convert it to F in my mind because I am a nonscientist.

"In traditional big bang cosmology, the Electroweak epoch begins 10^–36 seconds after the Big Bang, when the temperature of the universe is low enough (10^28 K) to separate the strong force from the electroweak force (the name for the unified forces of electromagnetism and the weak interaction). In inflationary cosmology, the electroweak epoch begins when the inflationary epoch ends, at roughly 10^–32 seconds." Questionposter provided the link to the highest temperature I've ever seen, thank you very much, 10 to the 28th power Kelvin. That is approx 10 Octillion Kelvin, which is a Trillion times a Trillion times 10,000 Kelvin. That would be approx 18 Octillion Fahrenheit. http://en.wikipedia.org/wiki/Timeline_of_the_Big_Bang#Very_early_universe

In a previous discussion "Stellar cores - how hot really?" it was mentioned that during the one second in which a Type II supernova creates half the elements heavier then iron, the temperature reaches about FIVE Billion Kelvin. Then a poster said something about a neutron star (at its' core I suppose) the temperature may reach about ONE Trillion Kelvin. Baric: "Temperature is a measure of the average speed of the particles contained within the sample being measured. At some early point after the Big Bang you are no longer dealing with particles so the notion of temperature doesn't apply, at least in a traditional sense. "Also, neutron stars start out at about one trillion Kelvin before cooling down, which is 10 times the temperature you listed." At 1/100 of a second after the Big Bang the temperature was about 100 Billion Kelvin. Before that there may not have even been particles in the traditional sense, so temperature may be meaningless. Does anyone know if temperatures higher than ONE Trillion Kelvin are possible, even after only a Billionth or Trillionth of a second after the Big Bang?

Very interesting. Thank you. Can you give me a link to this incredible info? A neutron star starts out hotter than a Type II supernova during the one second it creates half the elements heavier than iron? Wow. I am going to do some wiki search to see if I can verify this info. Here it is, you are correct Sir. Ask.com: "According to the Wikipedia, a newly formed neutron star would have a temperature of 10^11 - 10^12 Kelvin, but after a year, it will cool down to 10^6 (a million) Kelvin, due to the large number of neutrinos it emits.) Read more: http://wiki.answers.com/Q/How_hot_is_a_neutron_star#ixzz1c0akxuU4 Then is it correct to say that the hottest anything can get in the universe, including at the earliest moments of its' birth, is about a Trillion Kelvin?

You are correct. And yet, in the spirit of wanting science to be better understood, I prefer to use terms that are most recognizable to myself and my audience, the average non-scientist. Scientists are smart people who can easily convert units in their head. I and others may lack that ability. Go ahead and use the Kelvin scale, and the average non-scientist will wonder if that is a lot hotter or colder than Fahrenheit. But they won't say it because they are embarassed that they don't know what the Kelvin scale means (because they only spent a little time discussing it in high school) and spent the rest of their lives hearing temperatures in Fahrenheit on a daily basis. In discussing temperatures of Billions of degrees, the difference between Fahrenheit and Kelvin is significant. Fahrenheit is approx 1.8 times Kelvin, almost DOUBLE. My question still stands for an expert here. If the Big Bang was 100 Billion degrees Kelvin at 1/100 of a second after the Big Bang, how hot was it at one trillionth of a second after the Big Bang? Just how hot can hot get?

The question how hot it can get at the center of the most massive stars led me to the Wiki article I posted above that said at the moment of a Type II supernova the temperature reaches and incredible 9 Billion degrees Farenheit. That made me wonder how hot the Big Bang started out at. I finally found this by using ask.com. This article says at 1/100 of a second after the Big Bang the temperature was about 100 Billion degrees Kelvin. So I immediately convert it to Farenheit, because I like a scale I am familiar with, and I get 180 Billion degrees F. Anyone know how hot the Big Bang was after a Millionth, Billionth, or Trillionth of a second? http://csep10.phys.utk.edu/astr162/lect/cosmology/hotbb.html

Thanks for the link Barac. This is a very interesting question. True that the silicon burning reaches 3.5 Billion Kelvin, but Wiki also says the highest temperatures that can be reached at the center of the most massive of stars is up to 5 Billion Kelvin, which lasts for only seconds, just before a very dramatic moment, a Type II supernova occurs, which synthesizes half of all the elements heavier than iron. These elements are created in a second. I'm more familiar with heat measured in Farenheit, so 5 Billion Kelvin is about 9 Billion F, a very hot moment (F = 1.8(K-273) + 32). What was the highest temperature at the 1st moments of the Big Bang? Wiki says after several minutes the universe was about 1 Billion K. Wikipedia: "...The entire silicon-burning sequence lasts about one day and stops when nickel–56 has been produced. Nickel–56 (which has 28 protons) has a half-life of 6.02 days and decays via beta radiation (in this case, "beta-plus" decay, which is the emission of a positron) to cobalt–56 (27 protons), which in turn has a half-life of 77.3 days as it decays to iron-56 (26 protons). However, only minutes are available for the nickel–56 to decay within the core of a massive star. At the end of the day-long silicon-burning sequence, the star can no longer release energy via nuclear fusion because a nucleus with 56 nucleons has the lowest mass per nucleon (proton and neutron) of all the elements in the alpha process sequence. Although iron–58 and nickel–62 have slightly higher binding energies per nucleon than iron–56,[2] the next step up in the alpha process would be zinc–60, which has slightly more mass per nucleon and thus, would actually consume energy in its production rather than release any. The star has run out of nuclear fuel and within minutes begins to contract. The potential energy of gravitational contraction heats the interior to 5 GK/430 keV and this opposes and delays the contraction. However, since no additional heat energy can be generated via new fusion reactions, the contraction rapidly accelerates into a collapse lasting only a few seconds. The central portion of the star gets crushed into either a neutron star or, if the star is massive enough, a black hole. The outer layers of the star are blown off in an explosion known as a Type II supernova that lasts days to months. The supernova explosion releases a large burst of neutrons, which synthesizes in about one second roughly half the elements heavier than iron, via a neutron-capture mechanism known as the r-process (where the “r” stands for rapid neutron capture)." http://en.wikipedia.org/wiki/Silicon_burning_process

They see very few stars more massive than 150 solar masses. The most massive yet discovered at over 250 solar masses, may be a binary. The question is how hot is the core of these most massive of stars? How much heat does it take to fuse the element before iron into iron?

I stand corrected, overwhelmingly. Funny thing that Theories and Laws of Science are roughly equivalent.

Dark matter is believed to be mostly nonbaryonic matter, which excludes black holes, since black holes are believed to be baryonic (ordinary) matter. I don't know a link to this but try wikipedia on "dark matter". Wikipedia: "...dark matter constitutes [approx] 83% of the matter in the universe, whereas ordinary matter makes up only 17%." http://en.wikipedia.org/wiki/Dark_matter "Massive astrophysical compact halo object, or MACHO, is a general name for any kind of astronomical body that might explain the apparent presence of dark matter in galaxy halos. A MACHO is a body composed of normal baryonic matter, which emits little or no radiation and drifts through interstellar space unassociated with any solar system. Since MACHOs would not emit any light of their own, they would be very hard to detect. MACHOs may sometimes be black holes or neutron stars as well as brown dwarfs or unassociated planets. White dwarfs and very faint red dwarfs have also been proposed as candidate MACHOs. The term was chosen whimsically by contrast with WIMP, another proposed form of dark matter."

"...the Big Bang is said to have exploded from an infinite singularity. [if] it was infinite, the explosion would be infinite as well, and that would eliminate the possibility that the universe will collapse upon itself. Or am I wrong in thinking I read that the singularity was infinite?" I'd like to hear more about an "infinite singularity". I don't know what an infinite sized singularity has to do with whether the universe could collapse upon itself. It wouldn't matter if the universe was infinite. It would simply be such a rarified infinity that it could not recollapse, since expansion is observed to be accelerating. Or that would apply to only our local region of infinity, whereas other regions would be recollapsing. "Do you have a link for this infinite singularity? I think whether the universe is finite or infinite is still an open question in cosmology." I would also like to see a link to the infinite singularity. An "infinite singularity" is an interesting and novel concept. Maybe so. All they can say is the entire observable universe originated from a region smaller than a proton. But probably the universe is MUCH bigger than the observable universe and maybe infinite as well. (There is a huge difference between a HUGE universe and an infinite one. In fact the difference is infinite.) So with an infinite universe, the region of origin may also be infinite in size.

Myuncle: "No wind required, you start rotating them and they will never stop, energy problem solved, is it?" For a turbine to generate power in space, just from spinning and no solar power, will require the friction necessary to generate energy. Once you start this spinning, the friction will cause the "wind turbine" to grind to a stop after not very long.

Sure, here are examples, the Academy Awards, Emmys, American Music Awards, etc. Sorry, I'm not familiar with the Nobel Prizes.