mistermack

The gravity on the Moon is so low, that a space elevator would be taking a sledgehammer to crack a nut. The amount of rocket power needed to lift off from the Moon is tiny. You only have to compare what the astronauts lifted off in on their return journey, to the gigantic rockets needed to lift men off from the Earth. It was tiny, and most of it was living space. The rockets were negligible. It's actually possible to build a gun, that would shoot materials off the surface of the Moon into orbit, just using normal shell propellant. The lack of atmosphere makes the job easier. Or you could build electrically driven railguns, that don't need propellant at all, just electrical power. Mars would be a totally different problem though. Lifting off from Mars would need big rockets, with lots of fuel, due to it's much higher gravity than the Moon.

Typical one-sided documentary, totally lacking in balance. Once the fire had been mentioned, it was subsequently always described as "raging", with no evidence to support that whatsoever, when bunker fires were common on steamships at the time, and due to the lack of oxygen, were more likely to smoulder than rage. But even the documentary didn't try to claim that the hull would have overheated or been weakened. They were talking about one of the internal watertight bulkheads, that they were trying to say gave way due to weakening by the fire, causing more flooding. However, the sonar studies done show substantial rips to the hull, opening up five of the watertight compartments. She could only cope with four, and it was realised very quickly that she was going to sink. The most that could be claimed is that she sank a bit quicker because of the fire, but that is highly debatable.

Just in case anyone's interested, there's a documentary on 4seven in the UK in ten minutes time, on this very subject, so I'm going to record it and watch it. Could be very convincing, or a load of hooey. It seems to be about the fire theory. Eight O'clock, Tuesday, 4th of April. Don't know about repeats.

I don't think power is going to be a problem on the Moon, in the long run. There is so much solar energy available in space, that can be diverted down with a simple orbiting mirror, I think that energy will be the last of the long-term problems. A space-mirror can be incredibly thin and light, and yet cover a vast area so it's payback per gram of weight is enormous. In the very early stages, power might be a temporary headache, but not long-term. I would imagine that there will be a number of space stations, in orbit around the Moon, which are big enough, and rotate fast enough, to give 1 g of artificial gravity, so that Moon workers can do shifts on the Moon, without harming their health with the low gravity effects. Cosmic radiation, safe atmosphere, and low gravity are the main problems I think. Energy will be abundant.

More proof ? ? ? I wasn't aware of any existing proof. No, what it adds is more proof that the past is retrodetermined.

It's certainly a way of providing constant power. It would depend on the desirability of the North Pole as a base though. You could mount reflectors on the peaks with the best light conditions, and direct the light to anywhere with a clear line of sight.

Doesn't happen when I pee, or shower. Funny thing is, it's not something that I've noticed all my life. It's lately it seems to have started. Not a problem, or anything, but it's odd.

Yes, I know that's what it says. But you're not being consistent. Earlier, you said that acceleration has everything to do with which clock reads slower when compared side-by-side. Now you're saying the cause is purely the motion, in line with the article. If you forget clocks, and imagine two new-born babies in relative motion, as in the twin paradox, with the third twin on the return leg. If the difference in speed is so great, that the time difference is ten to one, on the outward leg, the "static" twin ages ten years, and the "travelling" twin ages one. At that point, the travelling party meets the return ship. They send a photo of the one-year-old to the return ship. At the same instant, a baby is born on the return ship. It makes the return trip at the same speed as the outward one, so the time ratio is again ten to one. Then when it passes the point of origin, it sends the photo of the original twin, at one year of age, plus the photo of the return twin, again aged one to the static twin. He is now aged twenty, and he can see that in his 20 years, these two babies have only aged one year each. None of the babies have undergone acceleration, but the ageing for the moving babies was somehow slower than for the "static" one. The question that bothers me is, what decides which is static, and which is moving?

I don't have a problem with the case where acceleration is involved. It's the case where acceleration is removed by the third twin that I struggle with. And the bit of the wiki page that I quoted in blue, above : "Rather, the time differential between two reunited clocks is produced purely by uniform inertial motion, " Which seems to contradict what you said. Two reunited clocks, and side-by-side clocks, are the same thing.

That's what I would have thought, but apparently not : Again from wikipedia : "As mentioned above, an "out and back" twin paradox adventure may incorporate the transfer of clock reading from an "outgoing" astronaut to an "incoming" astronaut, thus entirely eliminating the effect of acceleration. Also, according to the so-called "clock postulate", physical acceleration of clocks doesn't contribute to the kinematical effects of special relativity. Rather, the time differential between two reunited clocks is produced purely by uniform inertial motion, as discussed in Einstein's original 1905 relativity paper,[15] as well as in all subsequent kinematical derivations of the Lorentz transformations. " So they are saying that acceleration is nothing to do with it, it's just the uniform inertial motion that makes one twin younger than the other.

I would like to know why my nose runs when I poo. Seriously, every single time I go, I have to blow my nose. I won't go into details, but it's the same whether it's a quick easy episode, or a strain. Maybe it's self protection, against your own stinkiness?

But in the case of actual twins, one ages more than the other.

As I wrote earlier, "both clocks can't run at 0.6 x the rate of the other." The problem is explaining what is special about the stationary clock, compared to the moving clock, when the moving clock can be regarded as stationary, and the stationary clock as moving. I'm not arguing that it's ACTUALLY contradictory. As I said earlier, I can't get my head around the problem. That doesn't mean I'm arguing for errors in SR.

No, the way the thought experiment works, is that the third twin is in non-accelerating inertial motion, coming to meet the second twin. As they pass each other, the clock reading of the second twin is transferred to the third twin, who then continues back to the first twin, where both his clock reading, and that of the second twin, are transferred to the first twin. So nothing physical is actually accelerated in the whole process. Wikipedia on the subject : Eventually, Lord Halsbury and others removed any acceleration by introducing the "three-brother" approach. The traveling twin transfers his clock reading to a third one, traveling in the opposite direction. Another way of avoiding acceleration effects is the use of the relativistic Doppler effect (see What it looks like: the relativistic Doppler shift below). Neither Einstein nor Langevin considered such results to be problematic: Einstein only called it "peculiar" while Langevin presented it as a consequence of absolute acceleration.[A 10] Both men argued that, from the time differential illustrated by the story of the twins, no self-contradiction could be constructed. In other words, neither Einstein nor Langevin saw the story of the twins as constituting a challenge to the self-consistency of relativistic physics.

The problem I have with that explanation, (not disputing it, but getting my head round it) is that the assumption seems to be made that I am stationary, and it's the other clock that is moving. But according to SR, it's equally valid to assume that the other clock is stationary, and I am moving. So from his viewpoint, my clock ticked 0.6 as fast as HIS clock. That is the twin paradox, both clocks can't run at 0.6 x the rate of the other. I have read the various explanations of the twin paradox, and struggle to make them work in my head. The role of acceleration required to make two twins separate and return to each other makes the most sense. But then you have the example of a third "twin" meeting the second one halfway, and taking the reading of the clock back to the first twin, eliminating acceleration from the event entirely. So that's where I struggle. For one clock to ACTUALLY run slower than another, in non-accelerated motion, there needs to be an actual difference between the two states of inertial motion. Not just a relative difference.

Have a series of parabolic solar reflectors orbiting the Moon in such a way that your base is always bathed in light, even at night. It wouldn't be particularly hi-tech to arrange. There is no atmosphere to dilute the reflected sunlight, it would be just a question of getting the materials into the optimum Moon orbit, and maintaining the correct angle as the reflector orbits. A bit like shining a torch from above. Easy.

And even if there was some kind of universal time, it would still be impossible to fall behind in it, as only the present would exist. You could age slower, and so could your clock. That's all. That wouldn't mean that you exist "in the past" just because you aged slower.

My own take on gravity is that the Earth is sucking in inertial frames, so that at the surface, we are accelerating through them at a rate of 32ft per sec squared. The force is provided by the chair I'm sitting on. If I fall off a cliff, I temporarily stay motionless in one of those inertial frames, till I and the frame hit the foot of the cliff. At which point, the inertial frame keeps going, whereas I stop dead. (literally).

There is no such thing as falling behind in time. I think you are using the wrong words to make your point. You can AGE slower than me. As in the twin paradox. Your clock can run slower than mine. But you can't fall behind in time. There is no universal time that you can fall behind in. At least, not one that it's possible to detect or interact with. That's "mainstream". As far as observing objects in their past, so what? You are watching a recording of what happened. Just like watching video of the last Olympics. Are you observing the athletes in their past? I suppose you could say that you are. But you can't interact with them in their past. It's just a recording, whether it's Olympic video, or light from Mars.

Store hot water, and use it to boil liquid CO2 and send it through a turbine. Like a steam turbine here on Earth. Or just use warm water and let the pressure off to produce steam. Might have trouble with the water freezing that way, though.

Like all of our systems, our brains started off at a very basic level. If worms were organising their lives through numbers, then I could see the point of the question. We have a brain that evolved from that of an aquatic worm. It was responding to chemical signals etc. At what point would numbers get involved, in such a way that our brains started operating like a computer? In reality, the worm brain just got bigger and more complicated. Eventually, it got past the point of our chimpanzee-like ancestor, to something that can handle numbers, to some extent. Nothing surprising in all of that. Computers on the other hand, started out with numbers, and just got bigger and more complicated, in the way that it uses them. Totally different.

Ultrasound and infrasound are still sound. The clue is in the name.

The way I look at it, because you are seeing events via light travelling from the event to you, what you are seeing is a RECORDING of the events, because of the finite speed of light. You aren't watching live. When you are moving fast, relative to me, the recording I see of you is running slow, and so is the recording that you see of me. So it's not that the two events are running slower than each other, it's the recordings that you each receive that run slower. So if we each clap our hands three times, one per second, I can clap three times, and only see you clap twice, and you will see me do exactly the same. It's because you can't experience things "live". We get an illusion that events are live, in everyday life, because we move slowly compared to the speed of light, so things appear to happen instantly, and time dilation is so tiny day to day, that we can't notice it, and it feels like time can't vary.

I believe that they are about twice the weight of a female, compared to about ten percent more in humans. Also, male chimps have hugely enlarged canines, which females don't have.

There are things on this Earth that we can't even begin to understand :