Reasons for terraforming Mars?
i'm in debate and the resolution is terraforming mars should be nasa's top priority. i cant find any sources! i don't even know what i'm doing but i'm pro and needs reasons of why it would be good to terrform mars! please help i'm desperate!!
Could it one day be possible to modify the gravity of Mars?
I realize that at present moment, this type of operation may not be speculated as being feasible. There is a great deal of hypothesizing going on that is concerned with the complete recreation of Mars' environment (Terraforming) into an earth-like environmeny, which seems possible. However, the gravity which is currently present on Mars is about 1/3 of the gravity which exists on earth. People who would one day migrate to this terraforming Mars would find themselves in an environment similar to ours, but the gravity would be radically different and they may experience bone/muscle loss. So... any ideas on how to bolster or otherwise modify a planet's gravity field, to make it stronger until it is level with Earth's?
Why don't they generate artificial gravity in ISS by rotating the ship on its axis, to generate centrifugal force equivalent to gravity?
The rotating ship is simply Hollywood's answer to "Why aren't the actors floating around if they they are in space?"There are several reasons why the ISS does not.First, if you have gravity in a space ship, you are going to need floors that can support the weight of the crew walking around. You would also need carts to push stuff around in. Not only that, but now you only have walls and a ceiling to put all the other equipment. Without gravity, you can attach anything to any surface. and nothing needs to support the weight.Second, centrifugal force is not gravity so there are totally different rules in a spinning ship. Anything that is spinning needs an axis. And the closer you are to the axis, the less "gravity" and more dizzy you will feel. Gravity has fields, centrifugal force does not. So anything not moving along with the rest of the ship will appear to be flying down the hallway. Anyone who has been on "The Gravitron" at the county fair when someone threw up knows what I'm talking about.Basically a spaceship would have to be a perfectly balanced doughnut with one hallway down the outermost point. It would have to be a doughnut because the space in the middle would be pretty useless anyway. It would have a lot of wasted space and extra weight. If everyone gathered together in one place, it would disrupt the balance and change the simulated "weight of different things in other areas of the ship unless it was so massive, that the ship itself made up of 95% of the total weight.It's a fun idea, but a spinning ship is just too dangerous and not practical. It would have to be more on the scale of a space city.Another fun thought that also helps demonstrate the basic science behind the concept.... If the doughnut ship was fairly "small" (I don't know the exact math to figure out the ideal size) and well balanced you would be able to run down the hall in the opposite direction the ship was spinning and then just "fly" the rest of the way to the mess hall. Because once you are running at the same surface speed as the rotation of the floor beneath you, then you are not really moving anymore, and the ship is just spinning around you. You can just hover there, and try to grab the right doorknob as it goes by.
If we are able to send a few people to Mars, could they survive on the planet (barring a storm) with the same quality of life as the characters in The Martian, using the technology we currently have?
Aside from the storm at the beginning - and some nonsense about the final rendezvous with the rescue ship in orbit - the book and movie are really quite accurate.There are a couple of unknowns - one is whether humans can survive healthily with so little gravity for so long. It would take at least six months - maybe 8 of zero g just to get to Mars. Once you’re there - you can’t start back for about 2 years because of the orbital periods of Earth and Mars - and then you have another 6 to 8 months of zero g. Nobody has ever spend more than a little over a year in less-than-earth gravity…and we really don’t know what that might do to our astronauts.So if Mars gravity isn’t enough to be completely healthy - there is a serious concern about whether they’d survive long enough for the return trip.Another concern is equipment reliability.The people on this mission would be absolutely at the mercy of equipment failures. If something goes wrong with (say) the oxygen recycler on the ISS, you can survive for many days before you have to climb into the Soyuz emergency crew return vehicle - and sending spares up to help you keep the backup recycler working shouldn’t be too difficult.But if on Mars, you find that the perchlorates that people tramp into the habitat on their boots corrodes some gasket or other - then you’re dead.With an enforced 2 year stay on the planet…there are a hell of a lot of things that can go wrong.
Why does an alternator become harder to turn as load increases?
It's true that the rotor does not scratch the stator. The problem here relates to electromagnetic phenomena. Assume that the coil is the rotor. When the rotor turns, it cuts through the magnetic field generated by the stator, producing a current running through the rotor and the electrical device. The current in turn causes the rotor to produce a magnetic field that contrasts that of the stator, inhibiting rotation. The more intensive the current, the larger the inhibition. When the load increases, the current also increases, making it harder to turn the alternator. This phenomenon is consistent with the law of energy conservation: you have to work more to produce more electricity.