I doubt we'll see anything resembling colonization in our lifetimes
Some of us may given current life expectancies. It took approximately one century from Columbus rediscovering the new world to the first permanent settlements: St. John's 1583, Jamestown 1607. While the conditions on Mars are a lot harsher our technology is considerably more advanced so I'd say the situation is roughly equivalent.
The only point of sending men to Mars is to prove the point that we can send men to Mars.
If we were only going to send men then you'd be correct. However the real, long term goal is to send women as well as men and establish a permanent colony. The reason for this is to hugely increase the survivability of our species and probably other species as well. Once we have a self-sustaining colony on Mars it becomes a lot harder for nature to wipe us out. Obviously you cannot just land a self-sustaining colony there all at once - or at least we cannot yet - so this is just the first of hopefully several steps along the path.
Not at all - it would know because of the pressure difference across the cell would always be changing direction.
The other guy who responded added this point, but I think he was right that it'd have a negligible effect for embryos, which are tiny.
Ah - but here is the crux of the matter. You are arguing on one hand that the pressure difference across the cell is a "negligible" but the only difference between zero-g and being on the surface of the earth is this pressure difference. So either you are correct and it is negligible - in which case the results are wrong - or it is not negligible and therefore you cannot neglect the effect of varying it and so the results are potentially wrong.
Come on X0563511. We are talking about the physics of the situation here, and your post is the one that makes no sense. The point I am making is that there is a difference between averaging to zero (the running around the track case or rotating the sample) and actually having the vector remain zero (the staying put case or true zero-g).
No it is significant because the fact that you are accelerating means that you are not experiencing the usual normal force which when a system is not accelerating, acts in an equal and opposite direction to gravity. This is a very common misconception. The thing that we "feel" as our weight is actually the reaction force to our weight. This is what actually causes the compression, tension etc. throughout our bodies, not gravity, since the force has to be transmitted from the point of contact throughout the body.
Orbit is just freefall around an object due to gravity. Yes, gravity acts on everything in the spacecraft, but not _relative_ to the spacecraft. Maybe English is not your primary language?
Sorry to disappoint but actually being English I can understand what you have written perfectly well and actually being a physicist I can also understand that you don't have a good grasp of the physics involved. Gravity is a force and forces are not relative like velocities. The fact that there is no acceleration relative to the spacecraft is because the spacecraft is an accelerating reference frame where Newton's first law does not apply. It does not mean that gravity has magically gone away. Hence it is wrong to say that gravity has no effect on the objects in the spacecraft (a point you have conceded) and it is also wrong to say that gravity does not act relative to the space craft. It does. It does not produce an acceleration relative to the spacecraft.
Yes because in observational mode you have to also accurately model the starting conditions which are vastly more complex than those in a lab and usually where all the errors creep in. For example you would need to be able to know that there is no other cause of brain damage in the army e.g. boxing is known to cause progressive brain damage so perhaps basic army training does too? Perhaps army recruits are more likely to have brain damage than the general population etc. etc.
You can do it but it is far, far harder than direct measurement in a controlled environment and far more prone to error. The only reason that astronomers use observation rather than direct experiment is because they have no choice.
Imagine you're at the center of a giant plastic ball full of water. You have to tell whether or not you're in zero-G.
Simple: first there is your inner ear balance and second there is the pooling of blood in your head when you are upside down. Both of these are affected differently by freefall and neutral buoyancy on the Earth because the two are very different physical environments.
If the direction of gravity is changing fast enough from gentle rotation it'd be hard for the cell to "know" whether it was in zero-G or not.
Not at all - it would know because of the pressure difference across the cell would always be changing direction. This is the same way that the macroscope organism can tell. I am not a biologist so I cannot tell whether this has an effect or not. However, since the purpose of the experiment seems to be to determine whether gravity has an effect I highly suspect that biologists themselves don't know either, otherwise why do the experiment?
As soon as you are in free fall, you're not affected by gravity (at least not in a significant way).
Then could you please explain why you are accelerating downwards? Hint: it is due to a force called GRAVITY. Freefall is when the ONLY force that acts on you is gravity. Under normal circumstances there are two forces which act on you: gravity and a reaction force between you and whatever you are sitting, standing, lying etc. on. In freefall you remove this normal force NOT gravity.
Right. Consider some indentical twins. Suppose one twin runs 30km in a loop and end up back where he started while the other twin just sat there waiting for him. In both cases each twin's net displacement, velocity and acceleration are all zero so clearly, biologically, they should both be in the same state right and the twin that ran the 30km should be as well rested as the one that just sat there?
If you are outside the atmosphere, and not accelerating then you're basically in free fall.
Err no. If you are in freefall then you ARE accelerating be the very definition of what freefall means. If you let go of a ball it will accelerate downwards and it is in freefall. Freefall means that you are free to fall i.e. that only force acting on you is gravity and so the force of gravity will cause you to accelerate.
Sure, gravity is pulling you somewhere, but it doesn't really have an effect on anything inside the spacecraft (your reference frame is moving with you).
Hang on a minute. How can you possibly say that gravity is pulling you somewhere and at the same time claim that it is not affecting anything inside the spacecraft? What do you think is causing things inside the spacecraft to accelerate then? By definition your reference frame is ALWAYS moving with you even if when your surroundings are not. What gravity does is make this an accelerating reference frame instead of an inertial reference frame and the two are most definitely NOT the same.The equivalence between gravity and acceleration is one of the core concepts of GR.
From a biological perspective there is no discernible effect due to gravity.
Yes there is. The reason that your organism is accelerating towards the centre of the planet is an easily measurable effect. In both the case of freefall and sitting on the surface of the planet there are discernable effects due to gravity. In the first case you are accelerating and in the second case you are not accelerating because there is a reaction force between you and the surface of the planet equal and opposite to your weight. In the latter case your internal structure must transmit this normal force throughout your body to cancel your weight in order to prevent all parts of you from accelerating but in both cases the force of gravity acts on all parts of you to the same degree (assuming the same field strength).
This is the same as taking a lift. When the lift accelerates down it does not mean that gravity has suddenly become less it just means that your body has a reduced normal force to distribute because you have a small, downwards acceleration.
All you need for zero gravitation field (in the Newtonian view) is for the fields to cancel. For example exactly half way between the line joining the centres of two perfact, massive spheres the gravitational field will be zero. Speaking as a physicist I do not see why is this particularly interesting.
It is good to see some serious thought and discussion about it.
It would be nice to see some serious data first. The article is based on rotating the cells on the Earth using the stupid assertion that this is somehow the same as no gravity. This is exactly the same as saying that shaking something vigorously is the same as leaving it alone: in both cases the net acceleration is zero. If you try that with a mixture of oil and water the outcome will hardly be the same will it? So why should we expect it to be the same for dividing cells?
Regardless of where the website is located the post was written in English using English spelling. My apologies if I caused any offence but it is hard to know when an American is spelling something wrong accidentally or on purpose.
I'm no military tactician, but it would seem to me that aircraft carriers are a very successful example of how maneuverability(sic) can be abandoned even at sea for weaponry.
Hardly - aircraft are a heck of a lot more maneouverable than ships. If they were not then the carrier would be nowhere near as useful.
You're not going to claim that if astronomers really wanted to be scientific, they would start their research by gathering up a bunch of hydrogen and piling it together in empty space and then watching what happens, are you?
Actually yes. While they do not actually do that (it would take too long and besides, the universe is already doing it for them) they use scientific results from laboratory experiments (e.g. plasma physics, particle physics, atomic physics etc.) to predict what they will observe and then go out and look for it or, if they see something unexpected e.g. helium, they turn to laboratory measurements and calculations to determine what causes it. This is what makes astronomy a science and is why it is so interesting to other scientists.
Without laboratory based experiments, either based on their observations or preceding them, all astronomers would be do is staring up at the universe and making pretty pictures. The best current example of astronomical observations leading experimental searches is Dark Matter. Astronomers have done an amazing job extracting information about the properties of Dark Matter just from observations but until we can actually make some in a lab we will not know what it is made of.
Batman has huge appeal, cost a fortune to make. If you just put it on shelves, only a few people will walk by and pick it up.
The problem is that, like most things, you need a good balance. If you spend huge amounts of marketing and very little on development then the chances are that someone will walk by, pick up the game, hate it and tell all their friends not to buy it thus undoing some of your marketing and harming your reputation. Then for your next game you spend even more money on marketing telling people that no, this time the game really is good and so the circle repeats until you spiral into bankruptcy.
If you are spending more to market a game than to produce it in this age of rapid, personal communication then I cannot help but think you are doing it wrong. If you make a good game, provide a reasonable level of marketing to get people aware of it then you can afford to let word of mouth/facebook/rblogs/... help do some of the rest. You will also grow a reputation and may be able to get away with less marketing in the future.
Something Lockheed makes makes India's planes' maneuverability(sic) irrelevant? How so?
I very much doubt that maneouverability will become irrelevant. The last time someone put all their trust in weaponry at the expense of maneouverability it did not go so well for them.
That is one possible disease. If you look at the life expectancy you will find that a national health care system is actually better: Canada 81.23, UK 79.01, US 78.11. I really don't care which way the US goes on this (neither being a US citizen or living there) but don't start spreading misleading statistics and, in some cases, outright lies about OUR national healthcare systems.
I would severely doubt the numbers given on that page. The UK tax rate is considerably higher than Canada's. Currently living in Canada with a considerably higher income (in absolute terms) than I had in the UK a smaller fraction of my salary is withheld than it was in the UK and I get money back for overpayment at the end of the year. In addition the GST rate is 5% in Canada vs. 17.5% in the UK (temporarily 15%). Road tax for vehicles is a lot more, petrol is considerably more expensive due to taxes in fact I cannot think of anything that is cheaper in the UK except for a few goods which are produced there and exported to Canada.
I am guessing that each number, since it is produced by a different institute, uses different criteria for what they include or exclude. I can therefore only guess that the reason the UK number is so low is because they exclude most of the taxes.
It's certainly not illegal to buy sheet music of one's favorite rock artists, and sing and practice said music in the privacy of one's home
Only if your group or family has less than 6 (or $LOCAL_LEGAL_MAX) people in it. Most countries have a legal limit for audience size above which the performance is defined as public. This limit is usually below the size of an above average family. While I'm not sure that a jury would find you guilty of a public performance and even the recording industry would not likely press charges due to public backlash technically you are breaking the letter of the law.
I criticize him for being inconsistent too. He manages to compete with the BBC when it comes to broadcast television where the BBC is "free" so why should it be different on the web? The BBC site is funded by advertising outside the UK, not the license fee, so they are competing on an equal footing. If the BBC can make money off their site - or at least keep it revenue neutral - then why can't Murdoch?
The only reason real bankers aren't stealing billions is because they don't want to go to pound-you-in-the-ass federal prison.
Correct - as long as they stick to only stealing millions they get to go to pat-you-on-the-back federal reserve and get a nice big bailout so they can do the same again.
It means that the real problem is nothing to do with Agile ScrumMasters(TM) leading their teams over developing waterfalls and all to do with that fact that their management's leadership abilities are clearly only exceeded by their communication skills.
Slashdot Mirror
I doubt we'll see anything resembling colonization in our lifetimes
Some of us may given current life expectancies. It took approximately one century from Columbus rediscovering the new world to the first permanent settlements: St. John's 1583, Jamestown 1607. While the conditions on Mars are a lot harsher our technology is considerably more advanced so I'd say the situation is roughly equivalent.
The only point of sending men to Mars is to prove the point that we can send men to Mars.
If we were only going to send men then you'd be correct. However the real, long term goal is to send women as well as men and establish a permanent colony. The reason for this is to hugely increase the survivability of our species and probably other species as well. Once we have a self-sustaining colony on Mars it becomes a lot harder for nature to wipe us out. Obviously you cannot just land a self-sustaining colony there all at once - or at least we cannot yet - so this is just the first of hopefully several steps along the path.
Not at all - it would know because of the pressure difference across the cell would always be changing direction.
The other guy who responded added this point, but I think he was right that it'd have a negligible effect for embryos, which are tiny.
Ah - but here is the crux of the matter. You are arguing on one hand that the pressure difference across the cell is a "negligible" but the only difference between zero-g and being on the surface of the earth is this pressure difference. So either you are correct and it is negligible - in which case the results are wrong - or it is not negligible and therefore you cannot neglect the effect of varying it and so the results are potentially wrong.
Come on X0563511. We are talking about the physics of the situation here, and your post is the one that makes no sense. The point I am making is that there is a difference between averaging to zero (the running around the track case or rotating the sample) and actually having the vector remain zero (the staying put case or true zero-g).
That's insignificant, biologically speaking...
No it is significant because the fact that you are accelerating means that you are not experiencing the usual normal force which when a system is not accelerating, acts in an equal and opposite direction to gravity. This is a very common misconception. The thing that we "feel" as our weight is actually the reaction force to our weight. This is what actually causes the compression, tension etc. throughout our bodies, not gravity, since the force has to be transmitted from the point of contact throughout the body.
Orbit is just freefall around an object due to gravity. Yes, gravity acts on everything in the spacecraft, but not _relative_ to the spacecraft. Maybe English is not your primary language?
Sorry to disappoint but actually being English I can understand what you have written perfectly well and actually being a physicist I can also understand that you don't have a good grasp of the physics involved. Gravity is a force and forces are not relative like velocities. The fact that there is no acceleration relative to the spacecraft is because the spacecraft is an accelerating reference frame where Newton's first law does not apply. It does not mean that gravity has magically gone away. Hence it is wrong to say that gravity has no effect on the objects in the spacecraft (a point you have conceded) and it is also wrong to say that gravity does not act relative to the space craft. It does. It does not produce an acceleration relative to the spacecraft.
Yes because in observational mode you have to also accurately model the starting conditions which are vastly more complex than those in a lab and usually where all the errors creep in. For example you would need to be able to know that there is no other cause of brain damage in the army e.g. boxing is known to cause progressive brain damage so perhaps basic army training does too? Perhaps army recruits are more likely to have brain damage than the general population etc. etc.
You can do it but it is far, far harder than direct measurement in a controlled environment and far more prone to error. The only reason that astronomers use observation rather than direct experiment is because they have no choice.
Imagine you're at the center of a giant plastic ball full of water. You have to tell whether or not you're in zero-G.
Simple: first there is your inner ear balance and second there is the pooling of blood in your head when you are upside down. Both of these are affected differently by freefall and neutral buoyancy on the Earth because the two are very different physical environments.
If the direction of gravity is changing fast enough from gentle rotation it'd be hard for the cell to "know" whether it was in zero-G or not.
Not at all - it would know because of the pressure difference across the cell would always be changing direction. This is the same way that the macroscope organism can tell. I am not a biologist so I cannot tell whether this has an effect or not. However, since the purpose of the experiment seems to be to determine whether gravity has an effect I highly suspect that biologists themselves don't know either, otherwise why do the experiment?
As soon as you are in free fall, you're not affected by gravity (at least not in a significant way).
Then could you please explain why you are accelerating downwards? Hint: it is due to a force called GRAVITY. Freefall is when the ONLY force that acts on you is gravity. Under normal circumstances there are two forces which act on you: gravity and a reaction force between you and whatever you are sitting, standing, lying etc. on. In freefall you remove this normal force NOT gravity.
Right. Consider some indentical twins. Suppose one twin runs 30km in a loop and end up back where he started while the other twin just sat there waiting for him. In both cases each twin's net displacement, velocity and acceleration are all zero so clearly, biologically, they should both be in the same state right and the twin that ran the 30km should be as well rested as the one that just sat there?
If you are outside the atmosphere, and not accelerating then you're basically in free fall.
Err no. If you are in freefall then you ARE accelerating be the very definition of what freefall means. If you let go of a ball it will accelerate downwards and it is in freefall. Freefall means that you are free to fall i.e. that only force acting on you is gravity and so the force of gravity will cause you to accelerate.
Sure, gravity is pulling you somewhere, but it doesn't really have an effect on anything inside the spacecraft (your reference frame is moving with you).
Hang on a minute. How can you possibly say that gravity is pulling you somewhere and at the same time claim that it is not affecting anything inside the spacecraft? What do you think is causing things inside the spacecraft to accelerate then? By definition your reference frame is ALWAYS moving with you even if when your surroundings are not. What gravity does is make this an accelerating reference frame instead of an inertial reference frame and the two are most definitely NOT the same.The equivalence between gravity and acceleration is one of the core concepts of GR.
From a biological perspective there is no discernible effect due to gravity.
Yes there is. The reason that your organism is accelerating towards the centre of the planet is an easily measurable effect. In both the case of freefall and sitting on the surface of the planet there are discernable effects due to gravity. In the first case you are accelerating and in the second case you are not accelerating because there is a reaction force between you and the surface of the planet equal and opposite to your weight. In the latter case your internal structure must transmit this normal force throughout your body to cancel your weight in order to prevent all parts of you from accelerating but in both cases the force of gravity acts on all parts of you to the same degree (assuming the same field strength).
This is the same as taking a lift. When the lift accelerates down it does not mean that gravity has suddenly become less it just means that your body has a reduced normal force to distribute because you have a small, downwards acceleration.
All you need for zero gravitation field (in the Newtonian view) is for the fields to cancel. For example exactly half way between the line joining the centres of two perfact, massive spheres the gravitational field will be zero. Speaking as a physicist I do not see why is this particularly interesting.
It is good to see some serious thought and discussion about it.
It would be nice to see some serious data first. The article is based on rotating the cells on the Earth using the stupid assertion that this is somehow the same as no gravity. This is exactly the same as saying that shaking something vigorously is the same as leaving it alone: in both cases the net acceleration is zero. If you try that with a mixture of oil and water the outcome will hardly be the same will it? So why should we expect it to be the same for dividing cells?
Regardless of where the website is located the post was written in English using English spelling. My apologies if I caused any offence but it is hard to know when an American is spelling something wrong accidentally or on purpose.
I'm no military tactician, but it would seem to me that aircraft carriers are a very successful example of how maneuverability(sic) can be abandoned even at sea for weaponry.
Hardly - aircraft are a heck of a lot more maneouverable than ships. If they were not then the carrier would be nowhere near as useful.
You're not going to claim that if astronomers really wanted to be scientific, they would start their research by gathering up a bunch of hydrogen and piling it together in empty space and then watching what happens, are you?
Actually yes. While they do not actually do that (it would take too long and besides, the universe is already doing it for them) they use scientific results from laboratory experiments (e.g. plasma physics, particle physics, atomic physics etc.) to predict what they will observe and then go out and look for it or, if they see something unexpected e.g. helium, they turn to laboratory measurements and calculations to determine what causes it. This is what makes astronomy a science and is why it is so interesting to other scientists.
Without laboratory based experiments, either based on their observations or preceding them, all astronomers would be do is staring up at the universe and making pretty pictures. The best current example of astronomical observations leading experimental searches is Dark Matter. Astronomers have done an amazing job extracting information about the properties of Dark Matter just from observations but until we can actually make some in a lab we will not know what it is made of.
Batman has huge appeal, cost a fortune to make. If you just put it on shelves, only a few people will walk by and pick it up.
The problem is that, like most things, you need a good balance. If you spend huge amounts of marketing and very little on development then the chances are that someone will walk by, pick up the game, hate it and tell all their friends not to buy it thus undoing some of your marketing and harming your reputation. Then for your next game you spend even more money on marketing telling people that no, this time the game really is good and so the circle repeats until you spiral into bankruptcy.
If you are spending more to market a game than to produce it in this age of rapid, personal communication then I cannot help but think you are doing it wrong. If you make a good game, provide a reasonable level of marketing to get people aware of it then you can afford to let word of mouth/facebook/rblogs/... help do some of the rest. You will also grow a reputation and may be able to get away with less marketing in the future.
Something Lockheed makes makes India's planes' maneuverability(sic) irrelevant? How so?
I very much doubt that maneouverability will become irrelevant. The last time someone put all their trust in weaponry at the expense of maneouverability it did not go so well for them.
It certainly used to be true in the UK.
PROSTATE 5-YEAR CANCER SURVIVOR RATE...
That is one possible disease. If you look at the life expectancy you will find that a national health care system is actually better: Canada 81.23, UK 79.01, US 78.11. I really don't care which way the US goes on this (neither being a US citizen or living there) but don't start spreading misleading statistics and, in some cases, outright lies about OUR national healthcare systems.
I would severely doubt the numbers given on that page. The UK tax rate is considerably higher than Canada's. Currently living in Canada with a considerably higher income (in absolute terms) than I had in the UK a smaller fraction of my salary is withheld than it was in the UK and I get money back for overpayment at the end of the year. In addition the GST rate is 5% in Canada vs. 17.5% in the UK (temporarily 15%). Road tax for vehicles is a lot more, petrol is considerably more expensive due to taxes in fact I cannot think of anything that is cheaper in the UK except for a few goods which are produced there and exported to Canada.
I am guessing that each number, since it is produced by a different institute, uses different criteria for what they include or exclude. I can therefore only guess that the reason the UK number is so low is because they exclude most of the taxes.
It's certainly not illegal to buy sheet music of one's favorite rock artists, and sing and practice said music in the privacy of one's home
Only if your group or family has less than 6 (or $LOCAL_LEGAL_MAX) people in it. Most countries have a legal limit for audience size above which the performance is defined as public. This limit is usually below the size of an above average family. While I'm not sure that a jury would find you guilty of a public performance and even the recording industry would not likely press charges due to public backlash technically you are breaking the letter of the law.
I criticize him for being inconsistent too. He manages to compete with the BBC when it comes to broadcast television where the BBC is "free" so why should it be different on the web? The BBC site is funded by advertising outside the UK, not the license fee, so they are competing on an equal footing. If the BBC can make money off their site - or at least keep it revenue neutral - then why can't Murdoch?
The only reason real bankers aren't stealing billions is because they don't want to go to pound-you-in-the-ass federal prison.
Correct - as long as they stick to only stealing millions they get to go to pat-you-on-the-back federal reserve and get a nice big bailout so they can do the same again.
It means that the real problem is nothing to do with Agile ScrumMasters(TM) leading their teams over developing waterfalls and all to do with that fact that their management's leadership abilities are clearly only exceeded by their communication skills.