They didn't say it was illegal, their assets were frozen. Until it was decided what they did wasn't illegal, hence the assets where melted so to speak.
"My understanding was that it was plasma temperature and density that mattered, which depends only on the energy deposited and how symmetrical you can get the pellet implosion...."
You are correct as far as I know, but as Stephen correctly pointed out I was talking about fission. In the US a project which might be called something like the national combustion lab, and uses 192 similar (but less powerful) high powered lasers, to initiate fusion.
I like your explanation it's concise, but I'm going to make one point. You said that a relativistic particle is one that is nearly travelling at the speed of light. This isn't incorrect, but it isn't the whole picture. Relativistic effects can become really noticeable at as little as 30% of the speed of light. At these speeds gamma values of 1/sqrt(1.3) which is approximately 0.9 are calculated. This means basic special relativistic effects such as length contraction and time dilation could be observed. Of course in the situation where the particles are accelerated they are much closer to the speed of light as this allows them to be given far more energy for doing interesting things when they collide with other particles...
We have one next to our physis lab that pulses for femtoseconds, that is 10^-15 seconds. At an energy of around 3milliwatts, which using the formula Power = Energy * Time gives a power of about 3TW. This kind of power laser gives focussed energies greater than 10^20 W/cm^2. This actually means that you can use a single laser of this power to initiate fission, because the energy of bound nuclei is less than this!
size does matter, if we don't develop bigger hard drives because we make them reliable to hundreds of decimal places, ten years down the line we will need hundreds of hdd, instead of one.
As you might have guessed by my.sig i'm a mac user, but you make a very good first point. On behalf of mac users everywhere, sorry.
I went down to my girlfriends art department the other day, and besides showing her the wonders of the network, which it seems art students were not previously aware. (read into this taking files between networked computers on an external hard disc). I had the chance to play around with their copy of DVD studio pro, which was a very nice bit of software to use. It has a nice clean interface and was simple to use for the basic interface that I created in a few minutes. Would be interested to know what people think of it for creating more complex structures. The only downside of this is that now i need enough money to replace my long served original iBook.
not explicitly, the parent said that we can't see further than the age of the universe multiplied by light year. I went a step further and said that any further than this doesn't actually exist to us, as we cannot in anyway be affected by anything beyond this horizon. I.e. no gravitational effects, etc.
This is all of course assuming that general relativity is obeyed and we are not in a model of the universe, where space-time is bent back on itself. (Three dimensional analogy, the universe is like a football (proper football, not football of the american variety).
It's only a minor point but I hope you understood my potentially subtle point.
Well they're still a few hundred million light years from seeing the Resuarant at the end of the universe yet, so when they do, that will be the end of the universe.... .....or will it?
I like the Hubble, but I've feeling an orbit boosting won't do much good. I don't know exactly how many working gyroscopes are left on board, but I think only one or two more can break before Hubble is useless unless they are replaced. They are at the end of their expected lifetime, but lets hope that they can last out for a lot longer.
"2. the shuttle is the weak link here. two have exploded so far. you need to service the telescope once in a while. currently nobody wants to hear the word shuttle, so why should we then service it?"
your right, the shuttle is the weak point it has far outlived it's operational expectation, and there needs to be a more cost effective replacement for it.
" the argument from NASA that it is too expensive to service it is BS. it's just that they are having a hard time to sell their budget in general and so they need to focus on more popular topics."
I find this a little harder to believe. NASA's over-riding argument seems to be the safety point of view, which goes back to the fact of the shuttle. The shuttle cannot reach the ISS orbit from the Hubble orbit, therefore if a chunk of insulating tiles are damaged by space debris, then the occupants would have to try there chances in a damaged shuttle, rather than going for the safer option of returning to terra-firma in the soyuz capsule (which is often rather unfairly referred to as the "life-raft". Since Hubble has I believe three new major pieces of equipment already paid for and essentially sitting on the launchpad, i would find it hard to believe that they could claim that making one or two launches is too expensive, since they were already paid for. The change in policy came after a review of safety at NASA in the wake of the Shuttle accident.
The crux of the situation is that they are taking less risk by visiting the ISS. When visiting the Hubble it would be energetically impossible to change orbit in order to dock with the ISS. Hence if a chunk of space debris were to damage the shuttle to the point where it is deemed dangerous to re-enter the atmosphere, the crew would not be able to use the soyuz capsule on the ISS to return safely to the earth.
"So if there is an edge, it's so far away light hasn't had the chance to get here from there. However, we can't even see that far."
As far as I understand, relativity seems to suggest that infact the edge of the universe is essentially the same as the age of the universe multiplied by light-years (for an open or static model). Since light from further out cannot reach us, neither can information hence essentially this part of the universe does not exist from our point of view. Although this is really quite a philosophical argument.
"Your statement is totally falsified by the continued existence of the nations of Germany and Japan."
The nations of Germany and Japan still exist yes. However they are certainly not run by those who perpetrated attrocities during world war 2 to which I assume you are referencing. There is now a new generation of citizens which was not involved in the conflict and hence will find it much harder to remember. It's a shame that we will have to keep a boot on the throat of the Muslim world for the foreseeable future, but it was their choice. So be it."
I don't know where your privileged position to rule the world has come from, maybe it is the arrogance that allows Western governments to gloss over the attrocities that they ever so often perpetrate themselves in conflicts.
Maybe Violence settles the argument in the short term. But to settle all your arguements your gonna have to kill 6 billion people because for each person you kill your gonna piss 10 more off.
As far as I understood there wasn't a massive problem with the power of lasers. The one in the lab opposite my lecture theatre can produce powers in the terawatt range. The main problem with lasers is as far as I can see is making ones that work at higher frequencies, hence higher bandwith for optical fibres etc. Of course it's much more fun just to get lots of terawatt lasers and see if you can get stuff to take part in fusion:D
The refractive properties of diamond as far as I understood were fixed. The crystals used in the paper need to be able to have their refractive index changed easily. Normally you can't grow on a large industrial scale crystals with non uniform structures. Silicon chips for example are grown uniformly then processes such as lithography are used to add features such as transistors.
Diamonds aren't destruction proof. Diamonds are hard, that is to say if you try and scratch them they don't. But they are also brittle, that is to say if you hit them with a hammer they break. I'll leave it as an exercise to the student to test that one. Remember, don't use your mum's wedding ring....
It would be pretty damn cool, but i have a feeling it's not gonna happen at the moment. With NASA cancelling missions due to the lack of fail-safe points. Sounds like we still have a few years to design a replacement space-shuttle.
Jon
Originally NASA had planned to have a mission to fit thrusters to hubble to bring it down in a controlled fashion. As it stands they seem to be planning on doing a controlled landing like they did with spacelab... i.e. "spacelab splashed down safely into the pacific" reading more into this it crashed into Australia. I think I read somewhere that there was a one in seven chance of Hubble hitting civilisation.
Slashdot Mirror
They didn't say it was illegal, their assets were frozen. Until it was decided what they did wasn't illegal, hence the assets where melted so to speak.
Smacks of 9/11!
You are correct as far as I know, but as Stephen correctly pointed out I was talking about fission. In the US a project which might be called something like the national combustion lab, and uses 192 similar (but less powerful) high powered lasers, to initiate fusion.
I like your explanation it's concise, but I'm going to make one point. You said that a relativistic particle is one that is nearly travelling at the speed of light. This isn't incorrect, but it isn't the whole picture. Relativistic effects can become really noticeable at as little as 30% of the speed of light. At these speeds gamma values of 1/sqrt(1.3) which is approximately 0.9 are calculated. This means basic special relativistic effects such as length contraction and time dilation could be observed. Of course in the situation where the particles are accelerated they are much closer to the speed of light as this allows them to be given far more energy for doing interesting things when they collide with other particles...
We have one next to our physis lab that pulses for femtoseconds, that is 10^-15 seconds. At an energy of around 3milliwatts, which using the formula Power = Energy * Time gives a power of about 3TW. This kind of power laser gives focussed energies greater than 10^20 W/cm^2. This actually means that you can use a single laser of this power to initiate fission, because the energy of bound nuclei is less than this!
size does matter, if we don't develop bigger hard drives because we make them reliable to hundreds of decimal places, ten years down the line we will need hundreds of hdd, instead of one.
As you might have guessed by my .sig i'm a mac user, but you make a very good first point. On behalf of mac users everywhere, sorry.
I went down to my girlfriends art department the other day, and besides showing her the wonders of the network, which it seems art students were not previously aware. (read into this taking files between networked computers on an external hard disc). I had the chance to play around with their copy of DVD studio pro, which was a very nice bit of software to use. It has a nice clean interface and was simple to use for the basic interface that I created in a few minutes. Would be interested to know what people think of it for creating more complex structures. The only downside of this is that now i need enough money to replace my long served original iBook.
Ok, I wasn't aware of this. Would be interested if you could point me in the direction of the documentation, if it is available online. Thanks.
not explicitly, the parent said that we can't see further than the age of the universe multiplied by light year. I went a step further and said that any further than this doesn't actually exist to us, as we cannot in anyway be affected by anything beyond this horizon. I.e. no gravitational effects, etc.
This is all of course assuming that general relativity is obeyed and we are not in a model of the universe, where space-time is bent back on itself. (Three dimensional analogy, the universe is like a football (proper football, not football of the american variety).
It's only a minor point but I hope you understood my potentially subtle point.
Well they're still a few hundred million light years from seeing the Resuarant at the end of the universe yet, so when they do, that will be the end of the universe....
.....or will it?
I like the Hubble, but I've feeling an orbit boosting won't do much good. I don't know exactly how many working gyroscopes are left on board, but I think only one or two more can break before Hubble is useless unless they are replaced. They are at the end of their expected lifetime, but lets hope that they can last out for a lot longer.
"2. the shuttle is the weak link here. two have exploded so far. you need to service the telescope once in a while. currently nobody wants to hear the word shuttle, so why should we then service it?"
your right, the shuttle is the weak point it has far outlived it's operational expectation, and there needs to be a more cost effective replacement for it.
" the argument from NASA that it is too expensive to service it is BS. it's just that they are having a hard time to sell their budget in general and so they need to focus on more popular topics."
I find this a little harder to believe. NASA's over-riding argument seems to be the safety point of view, which goes back to the fact of the shuttle. The shuttle cannot reach the ISS orbit from the Hubble orbit, therefore if a chunk of insulating tiles are damaged by space debris, then the occupants would have to try there chances in a damaged shuttle, rather than going for the safer option of returning to terra-firma in the soyuz capsule (which is often rather unfairly referred to as the "life-raft". Since Hubble has I believe three new major pieces of equipment already paid for and essentially sitting on the launchpad, i would find it hard to believe that they could claim that making one or two launches is too expensive, since they were already paid for. The change in policy came after a review of safety at NASA in the wake of the Shuttle accident.
The crux of the situation is that they are taking less risk by visiting the ISS. When visiting the Hubble it would be energetically impossible to change orbit in order to dock with the ISS. Hence if a chunk of space debris were to damage the shuttle to the point where it is deemed dangerous to re-enter the atmosphere, the crew would not be able to use the soyuz capsule on the ISS to return safely to the earth.
"So if there is an edge, it's so far away light hasn't had the chance to get here from there. However, we can't even see that far."
As far as I understand, relativity seems to suggest that infact the edge of the universe is essentially the same as the age of the universe multiplied by light-years (for an open or static model). Since light from further out cannot reach us, neither can information hence essentially this part of the universe does not exist from our point of view. Although this is really quite a philosophical argument.
"Your statement is totally falsified by the continued existence of the nations of Germany and Japan."
The nations of Germany and Japan still exist yes. However they are certainly not run by those who perpetrated attrocities during world war 2 to which I assume you are referencing. There is now a new generation of citizens which was not involved in the conflict and hence will find it much harder to remember.
It's a shame that we will have to keep a boot on the throat of the Muslim world for the foreseeable future, but it was their choice. So be it."
I don't know where your privileged position to rule the world has come from, maybe it is the arrogance that allows Western governments to gloss over the attrocities that they ever so often perpetrate themselves in conflicts.
Maybe Violence settles the argument in the short term. But to settle all your arguements your gonna have to kill 6 billion people because for each person you kill your gonna piss 10 more off.
Time, distance, it's all space-time...
Everyone knows everything slows down in the cold. Why didn't people think of slowing down light in the fridge before?
As far as I understood there wasn't a massive problem with the power of lasers. The one in the lab opposite my lecture theatre can produce powers in the terawatt range. The main problem with lasers is as far as I can see is making ones that work at higher frequencies, hence higher bandwith for optical fibres etc. Of course it's much more fun just to get lots of terawatt lasers and see if you can get stuff to take part in fusion :D
The refractive properties of diamond as far as I understood were fixed. The crystals used in the paper need to be able to have their refractive index changed easily. Normally you can't grow on a large industrial scale crystals with non uniform structures. Silicon chips for example are grown uniformly then processes such as lithography are used to add features such as transistors. Diamonds aren't destruction proof. Diamonds are hard, that is to say if you try and scratch them they don't. But they are also brittle, that is to say if you hit them with a hammer they break. I'll leave it as an exercise to the student to test that one. Remember, don't use your mum's wedding ring....
considering he is now an undergraduate studying computer science i should imagine he probably wasn't a script kiddie
It would be pretty damn cool, but i have a feeling it's not gonna happen at the moment. With NASA cancelling missions due to the lack of fail-safe points. Sounds like we still have a few years to design a replacement space-shuttle. Jon
Originally NASA had planned to have a mission to fit thrusters to hubble to bring it down in a controlled fashion. As it stands they seem to be planning on doing a controlled landing like they did with spacelab... i.e. "spacelab splashed down safely into the pacific" reading more into this it crashed into Australia. I think I read somewhere that there was a one in seven chance of Hubble hitting civilisation.