Fortunately. NASA is involved in some new propulsion techniques. For example, DS1 used ion propulsion. It's engine push was very weak, about as mush as a paper pushes your palm as you hold it. But the experiment was successful.
DS1 was an experimental probe. At the end of the mission NASA landed it on Eros (one of the largest near Earth asteroid). DS1 was also capable of navigating on its own with its build-in software. The reference point for navigation was the second brightest star, Canopus.
A plasma engine is also in the development process. According to calculations, with this engine you can get to Mars in half the time compared to a traditional rocket.
In the long term this kind of propulsion is useless in space. What I mean is that it is quite primitive to shoot out hot gas or ions or hot plasma in a direction just to achive a relativly gentle acceleration in the other direction. Not to mention it is highly unefficient. You can fine tuning this technologie as mush as you want, but you cannot expect wonders from it. It is the same with car engines. They have been fine tuned during a whole century but the physics is the same.
Of course you are right according to the equation, but I stated that speed on its own does nothing to do with this time difference. Acceleration is the cause. And it does not matter if you reach half the speed of light in one day or in one year. You accelerated, so your time will be different to the time on Earth. If somehow, like a photon, you can reach half the speed of light instantly (which is impossible) you would measure the same time as on Earth.
No. When you accelerate from 5 mph to 50 mph and a predestrian measures that it took 30 seconds, you will measure eg. 29.999999999999 second. But at such a low speed the difference is negligable. The general rule is that you can use the Newtonian physics for speeds less than 60% of c. Above that you have to use Einstein's equations.
>Anyway, I hope you are right about Einstein not >being right. I really need to try to understand >relativity sometimes - to me if you go at the speed >of light for 4.2 years to Alpha Centauri, then 4.2 >years should have passed - both for you and at home.
This is a common misconception. If you travel at the speed of light 1 second for you is the same as 1 second on Earth. So, the time on the space ship and the time on Earth is the same. This is because from your frame of reference the Earth is moving away from you at the speed of light and from the Earth's frame of reference you are moving away at the speed of light. So, what is the difference?
The difference is that you have to accelerate to reach the speed of light while the Earth moves linear. Acceleration is not linear. This causes the slowing down of time in your frame of reference. Photons always travel at the speed of light, so for them 1 sec is the same as on Earth.
You are quite right. The problem is that even the speed of light is snail-pace compared to the vast distances in the universe, let alone the speed of Voyager.
This problem really annoys me, because it seems nobody gives a thought about how we will communicate or travel in space. It takes from 3 to 20 minutes for radio waves to cover the distance between the Earth and Mars depending their position around the Sun. Which means you can never phone to Mars from Earth, because you get an answer for your question in about 6-40 minutes. In our rushing world thats a lot of time.
As for travelling in space the twin paradox poses another problem. If we can reach almost the speed of light by some method we have to face this relativity problem. If you step in your space ship and after 1 hour you step out on Alpha Centauri you will have to face with the fact in the "real" world 4 years passed. Communication with Earth is quite futile also, because they get your message in 4 years.
In short, if Einstein is right we are in a dead end. So, I want to beleive there is worm hole or hyperspace or whatever which makes space travel possible otherwise humanity will stuck to this planet forever.
Or, as I hope, Einstein is not right. I hope a genius in the future will invalidate Einstein theory as Einstein invalidated Newton theory. It is interesting that nobody dares to say, but Newton theory about gravity and his equations were completely shattered by Einstein on the theoretical level. On the practical level we use them, because they are not so complex as Einstein's and provide us with the neccessary precision, but this does not do anything with the fact that Newton's theory is wrong.
It may be offtopic and you may call it rant, but...
IMHO, piracy is good. It is the only weapon against the big corporations. The RIAA and the MPAA are whining about how much profit they loose. The truth is the they are very profitable. The "piracy" commited by home users just levels the playing field. It makes the system a little bit more balanced. What I mean is that these corporations are very rich. Without "piracy", they will be mega-rich. You may even call it civil disobidience.
This "artist" conception makes me sick, too. Slashdot readers always refer to the "poor" artists as the slaves of the RIAA. And that the RIAA really wants control over distribution. The truth is that they are not artists, they are employees. An artist is such a person who makes himself distinguished by his own. Which means he does not do what he does for money but for self-expression. And if people like the artist's self-expression he will get money for it. So, IMHO today's "artists" are employees. I think the RIAA call this "work for hire" which is quite true. An artist has to be something more. I'm quite sure Picasso did not paint anything for money. He just painted something and people liked it and gave a lof of $$$ for it. So, there was no "work for hire" which, from my point of view, qualifies Picasso as an artist.
I am working for Ericsson and IMHO, Ericsson is not a bad company. And I think it does not have a market dominance which it had a few years ago. Its shares are standing quite low at the moment and from the inside its future is not so bright.
IMO, Ericsson troubles can be traced back to one problem which name is AXE. AXE is a telephone exchange and the most successful product of Ericsson. All over the world you can find AXEs in exchanges. The problem is that everyone already bought an AXE, so there is almost no market to sell more. Another reason is that AXE is quite old. It was developed in the '70s and it starts showing its age. There were projects to create a new type of AXE, but they failed.
This is the reason why Ericsson partnered with Juniper. The future is IP telephony and Ericsson needs a partner to develop its next flagship product.
As for the article, it claims that MEN are holding back wireless technology. I think this is not true. From the inside it seems the carriers do not have the money to buy the state-of-the-art 3G and UMTS equipment because they threw away their money at the UMTS tenders. Ericsson hopes in 2003 the carriers will overcome their predicament and start buying. Otherwise, lay offs will continue...
Everything I wrote in this comment is my personal opinion only and NOT an official statement from Ericsson.
The long running question of whether Pluto is a planet or not was solved a few years ago. Pluto is just a big asteroid from the Kuiper-belt or the Oort cloud. As for its status, it is still a planet for tradition's sake. At least this was the decision of astronomers at their annual meeting in 1999.
"And what kind of idiot wouldn't know that any moon rocks for sale must be stolen property?"
This is not true. You can find Moon rocks (even Mars rocks) on Earth since meteorites can tear material from the Moon (or Mars) at impact which may land on Earth afterwards.
I am working at a really large corporation and we are using clearcase. All I can tell CC is really sucks. CC always needs some maintenance. We have a dedicated CC expert and IT for maintaining CC. And CC is painfully slow if you compile something from the repository (at least on Solaris). So, we use the snapshot-view feature which is more like CVS. In short, we use CC as it were CVS.
Of course, corporate policy forbids us to use CVS.
Fermi's Paradox can be easily defeated. The problem is that the paradox does not take into account the desire, expectations, etc. of sentient and mortal beings.
If there is no FTL then why on Earth would you travel decades in hibernation to reach a distant planet to colonize? Then multiply like rabbits and send a new colonization ship to the nearest habitable planet? And do this for thousands of years? And as the saying goes: what can go wrong, goes wrong. So, there will be lost colonization ships, the colony can be wiped out by a unknown virus and if the tecnology is destroyed by some catastrophic event the colonists will be no more than a cave man. There is even a theory which says the human kind is the descendants of ancient astonauts who tried to colonize Earth.
The whole Fermi Paradox is built on the multiply-and-colonize concept which is not the prime directive of sentient beings, IMHO. So, even if FLT travel is possible this galaxy-scale colonization won't occur.
Graviton is a hypotetical particle which may not exist. As far as I know it makes some calculations easier. However, according to Eistein, gravity is just the curvature of space-time. There is no graviton or any particle which causes gravity.
If Eistein is right then an Anti-Gravity device cannot be made, because there is no particle to shield. However, as far as I know it is an ongoing debate in the science community whether a particle or the curvature of space-time causes gravity.
I was visited by a mighty computer-magician who knew many secrets.
During our conversation I told him about that I had installed a new
Windows version. I showed him the install CD which was perfectly
round and glittered magnificently.
My friend face became dark when he saw the disk. To my astonishment
and distress the wizard threw it into the microwave oven and turned
it on at the maximum. I gave a cry and tried to turn it off , but
the magician held me back. Holding my breath I watched as the CD was
revolving in the oven. Then the magician got the CD from the oven and
dropped into my hands.
- It's quite cool. Take it!
The CD was unscratched and cold and it seemed to have become thicker
and heavier in my hands.
- Hold it up! - said the magician. - And look closely.
As I did so, I now saw fine lines, finer than the finest pen-strokes,
running along close to the center of the CD. They shone piercingly bright,
and yet remote, as if out of a great depth.
- I cannot read the fiery letters - said I in a quavering voice.
- No - said the magician, - but I can. The letters are hexadecimal,
of an ancient mode, but the language is that of Microsoft, which
I will not utter here. But this in the Common Tongue is what is
said, close enough:
One OS to rule them all, One OS to find them,
One OS to bring them all and in the darkness bind them
It is only two lines of a verse long known in SysAdmins-lore:
Three OSs for the Corporations under the sky,
Seven for the Software-lords in their halls of Silicon Valley
Nine for Mortal.coms doomed to die,
One for the Dark Gates on his dark throne
In the Land of Redmond where the Shadows lie.
One OS to rule them all, One OS to find them,
One OS to bring them all and in the darkness bind them
In the Land of Redmond where the Shadows lie.
He paused, and then said slowly in a deep voice.
- This is the Master CD, containing the original source code of
Windows. This is the CD that he lost many ages ago, to the great
weakening of his monopolistic power. He greatly desires it - but
he must not get it.
I sat silent and motionless. Fear seemed to stretch out a vast hand,
like a dark cloud rising in the East and looming up to engulf me.
- This CD, - I stammered, - How, how on earth did it come to me?
You can crate lockpicks, but you do not know if they work for that house you want to break in.
However, Dimitri knows that his lockpick works so, this means he tried it by breaking into the house. Otherwise he couldn't hold the presentation.
What DMCA does is to punish those who break into houses (programs) which are protected with "virtual" locks (protection). When you buy a program you just buy the right to use it and not the ownership of the program. This means if you crack the protection of the program you virtually enter into a private territory. I think you would expect a burglar to be punished if he breaks into your house. I think this analogue is exactly the same if you crack a protection.
And since breaking into a house by circumveting its security system is not an academic research neither is craking a protection system. And it also doesn't do anything with free speech. I think you wouldn't be happy if somebody told the whole world how to enter into your house which has a burglar alarm system.
Slashdot Mirror
You can find more info about advanced propulsion techniques (like the Orion-project) and other interesting space-science stuff at Warp Drive When?.
Fortunately. NASA is involved in some new propulsion techniques. For example, DS1 used ion propulsion. It's engine push was very weak, about as mush as a paper pushes your palm as you hold it. But the experiment was successful.
DS1 was an experimental probe. At the end of the mission NASA landed it on Eros (one of the largest near Earth asteroid). DS1 was also capable of navigating on its own with its build-in software. The reference point for navigation was the second brightest star, Canopus.
A plasma engine is also in the development process. According to calculations, with this engine you can get to Mars in half the time compared to a traditional rocket.
In the long term this kind of propulsion is useless in space. What I mean is that it is quite primitive to shoot out hot gas or ions or hot plasma in a direction just to achive a relativly gentle acceleration in the other direction. Not to mention it is highly unefficient. You can fine tuning this technologie as mush as you want, but you cannot expect wonders from it. It is the same with car engines. They have been fine tuned during a whole century but the physics is the same.
Of course you are right according to the equation, but I stated that speed on its own does nothing to do with this time difference. Acceleration is the cause. And it does not matter if you reach half the speed of light in one day or in one year. You accelerated, so your time will be different to the time on Earth. If somehow, like a photon, you can reach half the speed of light instantly (which is impossible) you would measure the same time as on Earth.
No. When you accelerate from 5 mph to 50 mph and a predestrian measures that it took 30 seconds, you will measure eg. 29.999999999999 second. But at such a low speed the difference is negligable. The general rule is that you can use the Newtonian physics for speeds less than 60% of c. Above that you have to use Einstein's equations.
Try goole with words "usenet physics faq".
>Anyway, I hope you are right about Einstein not
>being right. I really need to try to understand
>relativity sometimes - to me if you go at the speed
>of light for 4.2 years to Alpha Centauri, then 4.2
>years should have passed - both for you and at home.
This is a common misconception. If you travel at the speed of light 1 second for you is the same as 1 second on Earth. So, the time on the space ship and the time on Earth is the same. This is because from your frame of reference the Earth is moving away from you at the speed of light and from the Earth's frame of reference you are moving away at the speed of light. So, what is the difference?
The difference is that you have to accelerate to reach the speed of light while the Earth moves linear. Acceleration is not linear. This causes the slowing down of time in your frame of reference. Photons always travel at the speed of light, so for them 1 sec is the same as on Earth.
You are quite right. The problem is that even the speed of light is snail-pace compared to the vast distances in the universe, let alone the speed of Voyager.
This problem really annoys me, because it seems nobody gives a thought about how we will communicate or travel in space. It takes from 3 to 20 minutes for radio waves to cover the distance between the Earth and Mars depending their position around the Sun. Which means you can never phone to Mars from Earth, because you get an answer for your question in about 6-40 minutes. In our rushing world thats a lot of time.
As for travelling in space the twin paradox poses another problem. If we can reach almost the speed of light by some method we have to face this relativity problem. If you step in your space ship and after 1 hour you step out on Alpha Centauri you will have to face with the fact in the "real" world 4 years passed. Communication with Earth is quite futile also, because they get your message in 4 years.
In short, if Einstein is right we are in a dead end. So, I want to beleive there is worm hole or hyperspace or whatever which makes space travel possible otherwise humanity will stuck to this planet forever.
Or, as I hope, Einstein is not right. I hope a genius in the future will invalidate Einstein theory as Einstein invalidated Newton theory. It is interesting that nobody dares to say, but Newton theory about gravity and his equations were completely shattered by Einstein on the theoretical level. On the practical level we use them, because they are not so complex as Einstein's and provide us with the neccessary precision, but this does not do anything with the fact that Newton's theory is wrong.
It may be offtopic and you may call it rant, but...
IMHO, piracy is good. It is the only weapon against the big corporations. The RIAA and the MPAA are whining about how much profit they loose. The truth is the they are very profitable. The "piracy" commited by home users just levels the playing field. It makes the system a little bit more balanced. What I mean is that these corporations are very rich. Without "piracy", they will be mega-rich. You may even call it civil disobidience.
This "artist" conception makes me sick, too. Slashdot readers always refer to the "poor" artists as the slaves of the RIAA. And that the RIAA really wants control over distribution. The truth is that they are not artists, they are employees. An artist is such a person who makes himself distinguished by his own. Which means he does not do what he does for money but for self-expression. And if people like the artist's self-expression he will get money for it. So, IMHO today's "artists" are employees. I think the RIAA call this "work for hire" which is quite true. An artist has to be something more. I'm quite sure Picasso did not paint anything for money. He just painted something and people liked it and gave a lof of $$$ for it. So, there was no "work for hire" which, from my point of view, qualifies Picasso as an artist.
I am working for Ericsson and IMHO, Ericsson is not a bad company. And I think it does not have a market dominance which it had a few years ago. Its shares are standing quite low at the moment and from the inside its future is not so bright.
IMO, Ericsson troubles can be traced back to one problem which name is AXE. AXE is a telephone exchange and the most successful product of Ericsson. All over the world you can find AXEs in exchanges. The problem is that everyone already bought an AXE, so there is almost no market to sell more. Another reason is that AXE is quite old. It was developed in the '70s and it starts showing its age. There were projects to create a new type of AXE, but they failed.
This is the reason why Ericsson partnered with Juniper. The future is IP telephony and Ericsson needs a partner to develop its next flagship product.
As for the article, it claims that MEN are holding back wireless technology. I think this is not true. From the inside it seems the carriers do not have the money to buy the state-of-the-art 3G and UMTS equipment because they threw away their money at the UMTS tenders. Ericsson hopes in 2003 the carriers will overcome their predicament and start buying. Otherwise, lay offs will continue...
Everything I wrote in this comment is my personal opinion only and NOT an official statement from Ericsson.
The long running question of whether Pluto is a planet or not was solved a few years ago. Pluto is just a big asteroid from the Kuiper-belt or the Oort cloud. As for its status, it is still a planet for tradition's sake. At least this was the decision of astronomers at their annual meeting in 1999.
"And what kind of idiot wouldn't know that any moon rocks for sale must be stolen property?"
This is not true. You can find Moon rocks (even Mars rocks) on Earth since meteorites can tear material from the Moon (or Mars) at impact which may land on Earth afterwards.
I have some ideas about "anal designs". Where can I sign on?
I am working at a really large corporation and we are using clearcase. All I can tell CC is really sucks. CC always needs some maintenance. We have a dedicated CC expert and IT for maintaining CC. And CC is painfully slow if you compile something from the repository (at least on Solaris). So, we use the snapshot-view feature which is more like CVS. In short, we use CC as it were CVS.
Of course, corporate policy forbids us to use CVS.
Fermi's Paradox can be easily defeated. The problem is that the paradox does not take into account the desire, expectations, etc. of sentient and mortal beings.
If there is no FTL then why on Earth would you travel decades in hibernation to reach a distant planet to colonize? Then multiply like rabbits and send a new colonization ship to the nearest habitable planet? And do this for thousands of years? And as the saying goes: what can go wrong, goes wrong. So, there will be lost colonization ships, the colony can be wiped out by a unknown virus and if the tecnology is destroyed by some catastrophic event the colonists will be no more than a cave man. There is even a theory which says the human kind is the descendants of ancient astonauts who tried to colonize Earth.
The whole Fermi Paradox is built on the multiply-and-colonize concept which is not the prime directive of sentient beings, IMHO. So, even if FLT travel is possible this galaxy-scale colonization won't occur.
Tell this to the Vogons...
For $58 billion, I think it may be feasible to send the waste into the Sun. The Sun takes care of the rest...
Save the Planet, Kill Yourself!
Graviton is a hypotetical particle which may not exist. As far as I know it makes some calculations easier. However, according to Eistein, gravity is just the curvature of space-time. There is no graviton or any particle which causes gravity.
If Eistein is right then an Anti-Gravity device cannot be made, because there is no particle to shield. However, as far as I know it is an ongoing debate in the science community whether a particle or the curvature of space-time causes gravity.
The tale of a modern hobbit...
C 20 4F6E65204F5320746F
2 69 6E67207468656D20
0 62 696E64207468656D
.coms doomed to die,
I was visited by a mighty computer-magician who knew many secrets.
During our conversation I told him about that I had installed a new
Windows version. I showed him the install CD which was perfectly
round and glittered magnificently.
My friend face became dark when he saw the disk. To my astonishment
and distress the wizard threw it into the microwave oven and turned
it on at the maximum. I gave a cry and tried to turn it off , but
the magician held me back. Holding my breath I watched as the CD was
revolving in the oven. Then the magician got the CD from the oven and
dropped into my hands.
- It's quite cool. Take it!
The CD was unscratched and cold and it seemed to have become thicker
and heavier in my hands.
- Hold it up! - said the magician. - And look closely.
As I did so, I now saw fine lines, finer than the finest pen-strokes,
running along close to the center of the CD. They shone piercingly bright,
and yet remote, as if out of a great depth.
4F6E65204F5320746F2072756C65207468656D20616C6C2
2066696E64207468656D2CDA4F6E65204F5320746F20627
616C6C20616E6420696E20746865206461726B6E6573732
- I cannot read the fiery letters - said I in a quavering voice.
- No - said the magician, - but I can. The letters are hexadecimal,
of an ancient mode, but the language is that of Microsoft, which
I will not utter here. But this in the Common Tongue is what is
said, close enough:
One OS to rule them all, One OS to find them,
One OS to bring them all and in the darkness bind them
It is only two lines of a verse long known in SysAdmins-lore:
Three OSs for the Corporations under the sky,
Seven for the Software-lords in their halls of Silicon Valley
Nine for Mortal
One for the Dark Gates on his dark throne
In the Land of Redmond where the Shadows lie.
One OS to rule them all, One OS to find them,
One OS to bring them all and in the darkness bind them
In the Land of Redmond where the Shadows lie.
He paused, and then said slowly in a deep voice.
- This is the Master CD, containing the original source code of
Windows. This is the CD that he lost many ages ago, to the great
weakening of his monopolistic power. He greatly desires it - but
he must not get it.
I sat silent and motionless. Fear seemed to stretch out a vast hand,
like a dark cloud rising in the East and looming up to engulf me.
- This CD, - I stammered, - How, how on earth did it come to me?
Your reasoning is good, but the logic is flawed.
You can crate lockpicks, but you do not know if they work for that house you want to break in.
However, Dimitri knows that his lockpick works so, this means he tried it by breaking into the house. Otherwise he couldn't hold the presentation.
What DMCA does is to punish those who break into houses (programs) which are protected with "virtual" locks (protection). When you buy a program you just buy the right to use it and not the ownership of the program. This means if you crack the protection of the program you virtually enter into a private territory. I think you would expect a burglar to be punished if he breaks into your house. I think this analogue is exactly the same if you crack a protection.
And since breaking into a house by circumveting its security system is not an academic research neither is craking a protection system. And it also doesn't do anything with free speech. I think you wouldn't be happy if somebody told the whole world how to enter into your house which has a burglar alarm system.