Wondering why there is no active radar unit at FAST. It´s probably not a question of budget, is it? How they can give up of such a chance to monitor NEOs and other interesting rocks while it is so big and complex observatory?... :o Sorry, probably stupid question, but can´t get it out of my head.
Vladimir Pecha I believe it's a question of weight and design. FAST has a very different, much lighter instrument platform than Arecibo. This means it can be moved laterally and vertically, so as the dish is deformed to change the focal point the whole instrument platform moves too - which gives it a much larger field of view than Arecibo. The disadvantage is that the platform is too light to hold many instruments at once - especially radar transmitters which are heavy, bulky things (because of the ~1 MW of power being transmitted they need large cooling systems). In fact rather than taking new instruments up to the platform, FAST's approach is to be able to lower the platform to the ground. Arecibo's heavier design has an advantage here : it has the receivers installed on a turntable which can be rotated to select whichever instrument is required for the observations at the push of a button. I forget the exact numbers, but Arecibo has around 10 available receivers at any one time whereas FAST will have something closer to 1.
«A benefit, profit, or value of something that must be given up to acquire or achieve something else. Since every resource (land, money, time, etc.) can be put to alternative uses, every action, choice, or decision has an associated opportunity cost.» businessdictionary.com/definition/opportunity-cost.html
«… an opportunity cost is the cost of a missed opportunity. It is the opposite of the benefit that would have been gained had an action, not taken, been taken—the missed opportunity.» inc.com/encyclopedia/opportunity-cost.html
«Opportunity cost refers to a benefit that a person could have received, but gave up, to take another course of action. Stated differently, an opportunity cost represents an alternative given up when a decision is made. This cost is, therefore, most relevant for two mutually exclusive events. In investing, it is the difference in return between a chosen investment and one that is necessarily passed up.» investopedia.com/terms/o/opportunitycost.asp
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Wondering why there is no active radar unit at FAST. It´s probably not a question of budget, is it? How they can give up of such a chance to monitor NEOs and other interesting rocks while it is so big and complex observatory?... :o Sorry, probably stupid question, but can´t get it out of my head.
ReplyDeleteVladimir Pecha I believe it's a question of weight and design. FAST has a very different, much lighter instrument platform than Arecibo. This means it can be moved laterally and vertically, so as the dish is deformed to change the focal point the whole instrument platform moves too - which gives it a much larger field of view than Arecibo. The disadvantage is that the platform is too light to hold many instruments at once - especially radar transmitters which are heavy, bulky things (because of the ~1 MW of power being transmitted they need large cooling systems).
ReplyDeleteIn fact rather than taking new instruments up to the platform, FAST's approach is to be able to lower the platform to the ground. Arecibo's heavier design has an advantage here : it has the receivers installed on a turntable which can be rotated to select whichever instrument is required for the observations at the push of a button. I forget the exact numbers, but Arecibo has around 10 available receivers at any one time whereas FAST will have something closer to 1.
«Opportunity cost: the loss of other alternatives when one alternative is chosen.»
ReplyDeletegoogle.com/search?q=Opportunity+cost
«A benefit, profit, or value of something that must be given up to acquire or achieve something else. Since every resource (land, money, time, etc.) can be put to alternative uses, every action, choice, or decision has an associated opportunity cost.»
businessdictionary.com/definition/opportunity-cost.html
«… an opportunity cost is the cost of a missed opportunity. It is the opposite of the benefit that would have been gained had an action, not taken, been taken—the missed opportunity.»
inc.com/encyclopedia/opportunity-cost.html
«Opportunity cost refers to a benefit that a person could have received, but gave up, to take another course of action. Stated differently, an opportunity cost represents an alternative given up when a decision is made. This cost is, therefore, most relevant for two mutually exclusive events. In investing, it is the difference in return between a chosen investment and one that is necessarily passed up.»
investopedia.com/terms/o/opportunitycost.asp
khanacademy.org/economics-finance-domain/microeconomics/choices-opp-cost-tutorial/production-possibilities/v/production-possibilities-frontier
youtube.com - Opportunity Cost
Rhys Taylor Thanks much!
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