swansont Posted October 30, 2009 Share Posted October 30, 2009 Please refer to the links in Moontanman's post; the context here is the quantum-mechanical vacuum/zero-point energy. Link to comment Share on other sites More sharing options...
Mr Skeptic Posted October 31, 2009 Share Posted October 31, 2009 What if you grab virtual particles and throw them? Or would that be less efficient than just throwing photons? What if you use the Casimir effect? I'm thinking small, wedge shaped cavities, pointing towards the front. Link to comment Share on other sites More sharing options...
Severian Posted November 1, 2009 Share Posted November 1, 2009 What if you grab virtual particles and throw them? You can't grab them because if you did, they wouldn't be virtual. In fact, they are completely unobservable.... which is, I suspect, at the heart of Bob's objection. Link to comment Share on other sites More sharing options...
Bob_for_short Posted November 1, 2009 Share Posted November 1, 2009 Look, the virtual photon is mostly the Coulomb potential of an electron (a propagator that reduces to 1/r in the non-relativistic case). It is well observable but it is not a photon in any sense and it cannot be detached and thrown away. That is why I say that there is no virtual particles in the classical vacuum (i.e., in an empty space). Link to comment Share on other sites More sharing options...
swansont Posted November 1, 2009 Share Posted November 1, 2009 Look, the virtual photon is mostly the Coulomb potential of an electron (a propagator that reduces to 1/r in the non-relativistic case). It is well observable but it is not a photon in any sense and it cannot be detached and thrown away. That is why I say that there is no virtual particles in the classical vacuum (i.e., in an empty space). Are we talking about the classical vacuum here? Link to comment Share on other sites More sharing options...
Sorcerer Posted November 1, 2009 Author Share Posted November 1, 2009 Yes. Sort of. What you need is a pressure difference. A vacuum is a good start, because almost certainly you will have a place somewhere else in space with a higher gas pressure. And then automatically the gas will flow from the high pressure area to the low pressure area. And you can move along with this flow of gas. This principle was already used by people thousands of years ago. In modern English, the craft that moves because of this principle is called a "sail boat". More recently, a new invention was made that created its own high pressure behind the craft. This is called the "rocket engine". Essentially, it creates a very high pressure gas (much higher than our own atmosphere). This gas wants to expand, and will therefore blend with the atmosphere. The action causes a reaction, moving the craft forward. You can also create a vacuum on the front of the craft, and sort of "suck" yourself forward. So far, scientists and engineers found that conventional rocket engines are more efficient, or at least are more cost-efficient. so, essentially it's the pressure difference that gives you power. The keyword here is "driving force", which is always a difference between somewhere and somewhere else. Potential, voltage, height, temperature, pressure, concentration - all these can have differences between two places - and can therefore create a driving force. A vacuum on itself it quite useless. But a vacuum and a high pressure gas next to each other will certainly cause some action. Did that answer the question? very good, but I wasn't really looking for the obvious answer. It was in reference to sci-fi/future propulsion. So, do you think there is a potential for a "driving force" within a vacuum, for instance, not all areas of a vacuum are equal, or if the vacuum has some structure and it could be altered, to provide a gradient. Eg, seperating out virtual particles and recombining them (I know... sorry Bob ) See Severians post for a more scientific/explained possibility. I understand my post is complete non-sense if u consider the vacuum of space to be a classical vacuum, ie. nothing. Link to comment Share on other sites More sharing options...
cameron marical Posted November 2, 2009 Share Posted November 2, 2009 Do you mean something like "warp-drive"? {The idea was actually from a mexican physicist, not star-trek} Link to comment Share on other sites More sharing options...
toastywombel Posted November 2, 2009 Share Posted November 2, 2009 That is why I say that there is no virtual particles in the classical vacuum (i.e., in an empty space). As far as we know your definition of a classical vacuum does not exist in the universe. There are virtual particles. Link to comment Share on other sites More sharing options...
Sorcerer Posted November 7, 2009 Author Share Posted November 7, 2009 As far as we know your definition of a classical vacuum does not exist in the universe. There are virtual particles. How could it "exist", by definition it can not. Merged post follows: Consecutive posts mergedDo you mean something like "warp-drive"? {The idea was actually from a mexican physicist, not star-trek} I'm not sure, I was just putting out a little story to hook the question. Link to comment Share on other sites More sharing options...
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