Hawkin'sDawkins

I think it is brilliant that NASA is outsourcing it's taxi work. The whole industry can now be energised by market forces - it's amazing how fast progress goes when there's money to be made. However, I think it is nothing short of tragic that the moon/mars plans have been dropped. It could be done robotically, but what would be the point? Who actually benefits from sending robots to other planets. It still costs billions and all you get is a little bit of data that the most intelligent academics in the world consider to be quite interesting. Thats not good value. IMAO, the only reason to invest in spaceflight is to get the human race off this planet. As long as we're all stuck here, we're doomed. A super-volcano, a comet impact, a plague, or just constant wars over how to distribute our diminishing resources between our ballooning population. So yes, outsource the LEO taxi runs, let spacex or somebody supply the ISS, and free up NASA (and ESA and JAXA etc) to colonise the solar system.

Well that one got shot down pretty quick. Ah well, thanks anyway. and Mr Boyd lied to me

Hi all, I've been thinking about this for a while and can't get it to add up in my head. I know that according to Mr Einstein, a jolly clever chap by all accounts, nothing can move faster than light. This includes information, as described by light cone diagrams. However, thinking way way back to school, I remember my physics teacher telling me that electricity actually travels instantaneously. The analogy he used was that an electric current in a wire is like a smarties tube full of marbles: If you push another marble in one end, a marble comes out at the other end. i.e. if you push electrons at a power station, the electrons in my kettle move instantly because every electron in the system sort of budges one atom along. So my question is this. If a superconducting electric cable could be made in the order of light-years long,that stretched to to another star system, could signals be sent along it faster than light? Obviously this is a BIG hypothetical as there would be countless engineering problems to overcome, not to mention an existing human presence in another star system, but is the idea plausible?

I think politicians have completely lost sight of the purpose of space travel. We can invest hundreds of millions of $/€ to put a device into orbit that will tell us very interesting information about dark matter, or extra-solar planets, or the makeup of the sun or a hundred other things that only our top scientists will understand anyway. This is good science, but shockingly bad value for money. As long as this is what our space programs amount to, I say scrap the lot and buy food for sub-saharran africa instead. The only way the extreme cost of space exploration can be justified IMAO is if it allows mankind to colonise the universe. Almost all the problems on planet earth stem from lack of resources - there are just too many of us for one planet. We need to go! An unmanned space program is like alcohol-free beer.

You are of course correct there, my mistake.

I think I can see what you're getting at Mr Skeptic - that god is not an event and so does not require a cause. However, by that same logic it could be said that the universe is also not an event and so it did not require a cause. Common sense however denies that the universe had no initial cause because we see events all around us. Each event was caused by something that was caused by something ..... and on and on and on, leading to the search for the ultimate cause. The solution that theists would posit is that the ultimate cause of the events that make up the universe was the act of creation by God. Now you are right, God's existence in itself is not an event, any more than the existence of the universe is an event, but the second he creates, then there is an event - creation. An event does need a cause and so we must ask what caused that act of creation. Now, if we accept the god hypothesis we must start examining the mechanics of God. When he created, what exactly was happenning, as in, what events? What events caused those events and what events caused those events. So he may exist without cause as long as he has no effect. As soon as he has an effect on the universe then we must rightly ask for a cause.

Hi all, I'm Hawkin'sDawkins (name obviously taken from two of the greatest thinkers of our age) Made a few posts already and am loving the forum. Bit of intelligent discussion - it's what seperates us from animals. I'm an IT geek by trade but have a love of theoretical physics religion and philosophy. Look forward to locking intellectual horns with you all.

There are a number of techniques for FTL travel which are scientifically plausible but not yet technically possible. The Alcubierre 'warp' drive is well within the bounds of physics: To achieve this we would need awesome amounts of energy to warp space so that in front of a ship the space is compressed and behind the ship the space is expanded. Then moving locally at sub-relatavistic speeds, the ship would appear to an external observer to be moving faster than light. It may be possible to achieve this energy with a matter/anti-matter reaction and the large electron-positron collider at CERN has already produced small amounts of antimatter. Projects are currently underway to find mass-production methods. The wormhole idea as already mentioned is plausible. Most senarios that allow traversable wormholes insist that the wormhole will close if any matter comes into contact with it and so yes, exotic particles with negative energy are required to hold it open. Negative energy can be produced by moving 2 matal plates infinitessimally close together to the point where particle pairs can no longer appear between them. At this point the energy in the space between the plates becomes less than the vacuum energy hence negative. (I think that's how it works anyway, feel free to correct me on the details of that) So if a shell of this composite material could be placed around traversable wormhole then it becomes stable. The problem with wormholes is that they connect across space AND time. Since time is relative, hence passing at different rates in different places, it is unlikely that both ends of the wormhole would be experiencing the same passage of time and so a hypothetical colony on one end would be in a different time to the other end. You may find yourself arriving at your destination before you left. The other possibility is hyperspace. It's a word that's thrown around a lot in sci-fi without any real explanation of what it means. Essentially there are another (probably 6) dimentions in addition to our conventional 4 dimensional space-time. At the big bang, as our 4 dimensions expanded into the known universe, the other dimensions contracted and are now curled up at the plank length, which is something like a billionth the width of a proton. If we could access these other dimensions and travel through them emerging again at our intended destination, the actual distance travelled would be miniscule. This is all of course, highly theoretical at the moment. I recommend Michio Kaku's book, "Physics of the Impossible" It explains the possible science behind a lot of pure sci-fi ideas. In the mean time, I'm in favour of generation ships. Load 10,000 people onto a giant ship and their decendents will arrive to colonise another star system. I'd volunteer in a second!

There is actually one known floor in the famous "E=mc2" For Einstein or anyone else deriving and simplifying this equation there is a square root to be resolved. Any function involving a square root always has 2 solutions, one positive and one negative. e.g. the square root of 4 is 2, but it is also -2. So the famous equation should read E=±mc2 In this formula, the existence of negative matter and negative energy are allowed for.

It is truly amazing how little this country cares about space! Not too long ago, the UK was the only european power with the ability to launch a rocket, now we've just given up, like it's just not that important. I don't think there's anything more important! Our problems on Earth are all due to overpopulation and control of resources. Mankind needs to get going in space and the UK is going to get left behind.

Well this becomes a bit more tricky since we're discounting cosmic expansion. However, in the universe we're imagining here which is empty and initially static except for these two objects, we can't rule out the second law of thermodynamics: The level of entropy always increases. The Black Holes evaporate into hawking radiation. If there was enough initial mass in the 2 black holes to be drawn together (just how super-massive can you get?) then it all collapses into a big crunch. Otherwise (more likely given that there are only 2 bodies to begin with) the matter-energy from the black hole spreads out, spreading further and further apart until it approaches absolute zero and infinitesimally low density and you have a big freeze. The 2 possible ends of the universe. How long it would take would depend on the initial conditions of the universe. Of course, long before big crunch or big freeze, the black holes themselves will have evaporated so we need to ask the question, do the initial gravity waves from one BH reach the other before it has completely evaporated. This would depend entirely on how much mass is in each BH to begin with. They would have to be very very very big to last for a septillion years. I thought we were discounting cosmic expansion? Certainly if they had started off closer together they would indeed be interacting, but then if 2 supermasive black holes with their immense gravity fields were so close together, how could they ever have drifted so far apart? Otherwise we could assume a universe without a beginning - they have simply "always" been there. In this case, since they evaporate in a long but finite amount of time, they would have evaporated an infinately long time ago. I think a lot of the problem with this is that we're trying to talk classical physics, but classical physics struggles to describe interactions over such huge distances and timescales. Fun to think about though

Assuming no cosmic expansion we would have to assume that at the moment of creation these 2 planets simply came into being. In this case, they would not initially affect one another. The instant they appear, each one would send out gravity waves in all directions at the speed of light, so neither one would move at all for the first 100,000,000 years and would then start moving towards one another. The point about 2 objects a septillion light years apart is a bit shaky as it would take a septillion years for gravity waves from these objects to reach each other. This is almost certainly longer than the lifetime of our universe and so no, these hypothetical objects would not interact. Also, Hi, cool forum!