Timeline for Transfer of energy from gravity back to other "more familiar" forms of energy?
Current License: CC BY-SA 3.0
8 events
| when toggle format | what | by | license | comment | |
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| Jul 23, 2016 at 23:57 | comment | added | Emilio Pisanty | It might well be true that gravitational waves can only be detected by at least partially converting them into other forms of energy, but this is not at all self- evident and should be backed by appropriate evidence. (As an example, gravity waves (the ones in water and other fluids) can easily be detected without altering their energy content by simply looking at them. Gravitational waves may well be different but if so this difference needs to be suitably explained.) | |
| Jul 23, 2016 at 23:56 | comment | added | sammy gerbil | Yes, I read Rod Vance's answer and I don't understand it either.... In some cases you might want to minimise how much energy is extracted or exchanged during measurement, in order to preserve what you are measuring. However, in detecting weak signals like gravity waves you don't care about destroying them, you want to make use of every drop of energy they carry, in order to maximise the SNR and the chance of detection. So gravity wave detectors are designed to extract as much energy as possible. | |
| Jul 23, 2016 at 23:49 | comment | added | uhoh | I've only had one answer there. It says a zero energy measurement is possible but I can't understand the argument - based on theoretical frictionless billiard ball computers. I'm beginning to think this is a very good point! So I've asked this question. | |
| Jun 16, 2016 at 12:47 | comment | added | uhoh | So I've asked. This is interesting! | |
| Jun 16, 2016 at 12:33 | comment | added | uhoh | I'm thinking about it actually. This is not an ordinary measurement, it's space that is changing. There aren't a lot of previous experiments sensitive to the metric expansion of space, are there! I think there's something in neutron interferometry that allows you to measure something without necessarily exchanging energy with it, but that will take some digging, or a new SE question! | |
| Jun 16, 2016 at 12:23 | comment | added | sammy gerbil | @uhoh : Do you know of a counter-example? | |
| Jun 16, 2016 at 12:10 | comment | added | uhoh | Are you absolutely sure? One can only ever detect things that are converted to energy? | |
| Jun 16, 2016 at 11:36 | history | answered | sammy gerbil | CC BY-SA 3.0 |