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What no one has seen before: gravitational waveforms from warp drive collapse

arxiv.org

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Re: What no one has seen before: gravitational waveforms from warp drive collapse

#61

Post by addaon »

bluGill wrote: post #9
largbae wrote: post #6

This is excellent. Like the Dyson sphere, predicting signals for technologies that we can imagine but not yet construct seems like a great way to guide our search for other life. Now we need a team of smart folks to identify tearing or other processing anomalies in universe-scale simulations.

Advanced life. There is no particular reason to think there is life out there (if there is or not - both are extraordinary). If there is, there is no particular reason it is advanced - vs just some plants and animals living a life but not doing anything different from the first members of the species. (that is not advancing to where they might get a house)

> There is no particular reason to think there is life out there (if there is or not - both are extraordinary)

Well, no. One of those is ordinary (“commonplace or standard”). We just don’t know which.

Re: What no one has seen before: gravitational waveforms from warp drive collapse

#62

Post by danyala »

> The signal comes as a burst, initially having no gravitational wave content, followed by an oscillatory period with a characteristic frequency of order 1/[R]

Interesting...

> As discussed above, for a 1km-sized ship, the frequency of the signal is much higher than the range probed by existing detectors, and so current observations cannot constrain the occurrence of such events

And yet, you still chose the word ;)

So, how big are the ships, as a kindness for readers such as myself for whom the exercise should not be left?

https://www.ligo.org/science/GW-Burst.php

Re: What no one has seen before: gravitational waveforms from warp drive collapse

#64

Post by chownie »

StableAlkyne wrote: post #51
chownie wrote: post #37

Earlier quoted context omitted.

A better form of moderation exists in the form of whatever they were doing before, when you could ask a question and get an answer. At one point SE was my most used resource. As of now I haven't used SE at all for I think four years. Why would you, when so much of the site's content is outdated and the moderators enforce that situation?

"Marked as a duplicate of an outdated post" has been a common complaint since the 2000s, the only "before" was when the site was brand new. I even checked to make sure I wasn't misremembering things - here's someone complaining about the same thing in 2011: https://old.reddit.com/r/programming/comments/cm02a/you_cant...

That doesn't really show that it was a common complaint given it accrued zero Reddit agreement points.

The situation now is also much worse than it was, because answers could be two years out of date then and beyond a decade out of date now.

I quit when I realised I would be scrolling by walls of jQuery answers for the foreseeable future if I kept using the site, not worth the waste of my time.

Re: What no one has seen before: gravitational waveforms from warp drive collapse

#65

Post by [deleted] »

colanderman wrote: post #48
rachofsunshine wrote: post #39

Earlier quoted context omitted.

I worked this out once! Gravitational waves obey the inverse-square law much like most radiation does (and subject to some constraints about weird spatial geometry, but most of their propagation is going on in open flat-ish space, so we can ignore that). GW150914, the first gravitational wave observed, had an amplitude of about 4 times 10^-22 [1], i.e., differences changed by a factor of about that. Typical sound dis…

4 times 10^-17 doesn't sound right... 2.5 times 10^14 I think?

[deleted]

Re: What no one has seen before: gravitational waveforms from warp drive collapse

#66

Post by mappu »

hatthew wrote: post #57
ben_w wrote: post #28

Earlier quoted context omitted.

One of the reasons I no longer ask questions on Physics stack exchange: 1. I asked "how powerful" such waves would have to be to be audible. 2. I directly linked to another question whose accepted answer said "these waves can wiggle your ear drum" 3. Got my question closed as a duplicate but the link was to different question that only asked "is it possible" (and accepted the answer "yes") without there being any ans…

It was closed as a duplicate because you asked 3 separate questions in your post, and the most prominent one (the title) was a clear duplicate of the original. I doubt it would have been closed if you had asked only "how powerful would the waves have to be?"

It's the same cognitive disconnect that comes up with Wikipedia and Debian too.

People often add more facts to Wikipedia and complain when they get deleted. The misconception is that wikipedia is where facts go, whereas, Wikipedia is specifically trying to be a tertiary source, where all the facts can be traced back to primary sources and all the analysis can be traced back to secondary sources.

People often complain that Debian testing gets almost no updates at all for six months every two years. The misconception is that it's a general rolling release distro, whereas, testing is specifically trying to become the next stable release and needs to have a freeze period.

People often complain that stack exchange deletes their questions. The misconception is that it's a site to ask a question and get an answer, whereas, stack exchange is specifically trying to produce a 1:1 mapping between specific questions and answers.

There's a saying in business that "you're not in the business you think you're in; you're in the business that your customers think you're in". If any of the above wanted to pivot, into what their less-informed users think they are, they'd do great at it, but their (sometimes inconvenient) organizational goals are what produces the high quality that made them all popular in the first place.

Re: What no one has seen before: gravitational waveforms from warp drive collapse

#67

Post by rachofsunshine »

colanderman wrote: post #48
rachofsunshine wrote: post #39

Earlier quoted context omitted.

I worked this out once! Gravitational waves obey the inverse-square law much like most radiation does (and subject to some constraints about weird spatial geometry, but most of their propagation is going on in open flat-ish space, so we can ignore that). GW150914, the first gravitational wave observed, had an amplitude of about 4 times 10^-22 [1], i.e., differences changed by a factor of about that. Typical sound dis…

4 times 10^-17 doesn't sound right... 2.5 times 10^14 I think?

EDIT: the CALCULATIONS are right, but they're based on an incorrect assumption. As a poster further down this thread corrects me, while the energy of a GW obeys inverse-square, the amplitude is just inverse. I can't edit my original post, but the corrected calc is here.

There is also a typo in my post where there's 10^-7 instead of 10^-5, but the calculations are done correctly.

That corrected assumption gives:

    d_audible / d_actual = 4 x 10^-17 x 410 Mpc = about 500,000 km
or about the distance to the Moon.

----

Re: What no one has seen before: gravitational waveforms from warp drive collapse

#68

Post by tomrod »

hatthew wrote: post #57
ben_w wrote: post #28

Earlier quoted context omitted.

One of the reasons I no longer ask questions on Physics stack exchange: 1. I asked "how powerful" such waves would have to be to be audible. 2. I directly linked to another question whose accepted answer said "these waves can wiggle your ear drum" 3. Got my question closed as a duplicate but the link was to different question that only asked "is it possible" (and accepted the answer "yes") without there being any ans…

It was closed as a duplicate because you asked 3 separate questions in your post, and the most prominent one (the title) was a clear duplicate of the original. I doubt it would have been closed if you had asked only "how powerful would the waves have to be?"

What a horrible policy to classify as dupe the more informative question. A better approach would be to close the original question instead, with the original answers merged, color coded, and inserted the original question as a quote block at the top.

Re: What no one has seen before: gravitational waveforms from warp drive collapse

#69

Post by ldunn »

rachofsunshine wrote: post #67
colanderman wrote: post #48

Earlier quoted context omitted.

4 times 10^-17 doesn't sound right... 2.5 times 10^14 I think?

EDIT: the CALCULATIONS are right, but they're based on an incorrect assumption. As a poster further down this thread corrects me, while the energy of a GW obeys inverse-square, the amplitude is just inverse. I can't edit my original post, but the corrected calc is here. There is also a typo in my post where there's 10^-7 instead of 10^-5, but the calculations are done correctly. That corrected assumption gives: d_aud…

Strain drops off as 1/r, not 1/r^2

Re: What no one has seen before: gravitational waveforms from warp drive collapse

#70

Post by Cyphase »

perrygeo wrote: post #59
bongodongobob wrote: post #47

Earlier quoted context omitted.

If you tell it to use wolframalpha it could probably do some ballpark spherical cow physics.

Amazing comment for two reasons: The idea of asking an LLM to generate code for a more rigorous but still high-level language is under-explored. This way you can experiment with AI - but at least have an intermediate code artifact that you can review and test before it gets published! Exposing the raw token stream is reckless. I had never heard of "spherical cow" science before but I love the imagery.

You really are one of today's lucky 10,000!

For anyone else: https://en.wikipedia.org/wiki/Spherical_cow

Meta reference: https://xkcd.com/1053/

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