# Uncategorized **URL:** https://ask.igwn.org/c/uncategorized/1.md [Latest](https://ask.igwn.org/latest.md) · [Categories](https://ask.igwn.org/categories.md) · [Tags](https://ask.igwn.org/tags.md) --- ## [Welcome to the gravitational wave message board!](https://ask.igwn.org/t/welcome-to-the-gravitational-wave-message-board/7)
**Author:** [@system](https://ask.igwn.org/u/system)\ **Replies:** 0\ **Last updated:** [February 3, 2022, 11:00pm UTC](https://ask.igwn.org/t/welcome-to-the-gravitational-wave-message-board/7 "2022-02-03T23:00:38Z")
This forum is for questions related to gravitational-wave research with LIGO, Virgo, and KAGRA. This is a great place to get support related to gravitational-wave data, gravitational wave software, GW Open Data Workshop… --- ## [Precision of GPS time in GWOSC catalog](https://ask.igwn.org/t/precision-of-gps-time-in-gwosc-catalog/1551)
**Author:** [@Devesh](https://ask.igwn.org/u/Devesh)\ **Replies:** 4\ **Last updated:** [July 28, 2026, 8:26pm UTC](https://ask.igwn.org/t/precision-of-gps-time-in-gwosc-catalog/1551 "2026-07-28T20:26:39Z")
This is regarding the CSV file available at GWTC on the GWOSC events portal. We are doing an analysis which requires the geocentric GPS time to a higher decimal place. However, the CSV file seems to store the values only… --- ## [Laser and Gravitational\_waves](https://ask.igwn.org/t/laser-and-gravitational-waves/1535)
**Author:** [@TaoTang-xw](https://ask.igwn.org/u/TaoTang-xw)\ **Replies:** 0\ **Last updated:** [June 18, 2026, 4:34pm UTC](https://ask.igwn.org/t/laser-and-gravitational-waves/1535 "2026-06-18T16:34:08Z")
1. Introduction When the stones hit the water, they generate concentric waves that move away from the source, as shown in Fig.1. \[Upload failed\] Fig.1.This an image of water waves. Gravitational\_waves are heard by LI… --- ## [A Pianist Used Your GW150914 Data to Send a Signal Back](https://ask.igwn.org/t/a-pianist-used-your-gw150914-data-to-send-a-signal-back/1449)
**Author:** [@nicholas\_clarke](https://ask.igwn.org/u/nicholas_clarke)\ **Replies:** 0\ **Last updated:** [April 8, 2026, 10:03pm UTC](https://ask.igwn.org/t/a-pianist-used-your-gw150914-data-to-send-a-signal-back/1449 "2026-04-08T22:03:35Z")
On March 25 2026, I sat down at a piano in Charlottetown, Prince Edward Island and improvised a live piece over the GW150914 gravitational wave signal. The bed track is the raw LIGO data, processed from gwosc.org under … --- ## [Request for fully reproducible calibration chain for GWOSC strain data](https://ask.igwn.org/t/request-for-fully-reproducible-calibration-chain-for-gwosc-strain-data/1397)
**Author:** [@Lino](https://ask.igwn.org/u/Lino)\ **Replies:** 5\ **Last updated:** [December 8, 2025, 4:30pm UTC](https://ask.igwn.org/t/request-for-fully-reproducible-calibration-chain-for-gwosc-strain-data/1397 "2025-12-08T16:30:46Z")
Dear GWOSC team, I am an external researcher working with GWOSC data and recently asked @LIGO on Mastodon about the calibration of the public strain h(t). They kindly referred me to this contact form. I have read the O… --- ## [Suggested updates to the GWTC](https://ask.igwn.org/t/suggested-updates-to-the-gwtc/859)
**Author:** [@AlexWinegardner](https://ask.igwn.org/u/AlexWinegardner)\ **Replies:** 4\ **Last updated:** [November 21, 2025, 5:50pm UTC](https://ask.igwn.org/t/suggested-updates-to-the-gwtc/859 "2025-11-21T17:50:04Z")
I recently downloaded the csv file for the Gravitational-wave Transient Catalog (GWTC), and after performing a bit of data cleaning I found a couple of issues that caught my attention and I thought would be worth sharing… --- ## [Projects listed on GWOSC](https://ask.igwn.org/t/projects-listed-on-gwosc/1393)
**Author:** [@Shan909](https://ask.igwn.org/u/Shan909)\ **Replies:** 4\ **Last updated:** [November 7, 2025, 12:48am UTC](https://ask.igwn.org/t/projects-listed-on-gwosc/1393 "2025-11-07T00:48:46Z")
Hi, I had a question about the GWOSC website. There is a section for projects and papers and that’s where a list of projects are enlisted for their successful use of GWOSC. I wanted to share a project I have made using … --- ## [Can light propagate backwards in time?](https://ask.igwn.org/t/can-light-propagate-backwards-in-time/1343)
**Author:** [@Shan909](https://ask.igwn.org/u/Shan909)\ **Replies:** 2\ **Last updated:** [October 25, 2025, 1:40am UTC](https://ask.igwn.org/t/can-light-propagate-backwards-in-time/1343 "2025-10-25T01:40:17Z")
I was reading Kip Thorne’s book on the science behind interstellar and a phrase there stuck with me. “What happenes inside the event horizon? Time is so extremely warped there that if flows in a direction you would have… --- ## [Using nds2 on Google colab?](https://ask.igwn.org/t/using-nds2-on-google-colab/783)
**Author:** [@ecm](https://ask.igwn.org/u/ecm)\ **Replies:** 7\ **Last updated:** [October 12, 2025, 6:56pm UTC](https://ask.igwn.org/t/using-nds2-on-google-colab/783 "2025-10-12T18:56:19Z")
Hi! I am trying to make call with the nds2 client from Google colab. So far I failed because the nds2 module does not appear to be installed automatically by pip. The following lines: ! pip install -q ‘gwpy==3.0.4’ … --- ## [Pattern in the data](https://ask.igwn.org/t/pattern-in-the-data/1348)
**Author:** [@TAURIEL](https://ask.igwn.org/u/TAURIEL)\ **Replies:** 0\ **Last updated:** [June 29, 2025, 7:59am UTC](https://ask.igwn.org/t/pattern-in-the-data/1348 "2025-06-29T07:59:25Z")
Hello First i have to say I’m nobody, just a deep thinker. I have done my best to look through what little data i could actually find and i made a spreadsheet to look for the pattern i thought up, before mentioning to … --- ## [Docker setup for all GW libraries](https://ask.igwn.org/t/docker-setup-for-all-gw-libraries/1319)
**Author:** [@Shan909](https://ask.igwn.org/u/Shan909)\ **Replies:** 0\ **Last updated:** [June 1, 2025, 10:21am UTC](https://ask.igwn.org/t/docker-setup-for-all-gw-libraries/1319 "2025-06-01T10:21:04Z")
So I was wondering how there is no unified software for performing various GW analysis tasks and one idea that occurred to me was a Docker setup. I have been working on building a GUI interface for some of the tasks of … --- ## [Data Challenge Results](https://ask.igwn.org/t/data-challenge-results/1314)
**Author:** [@Shan909](https://ask.igwn.org/u/Shan909)\ **Replies:** 0\ **Last updated:** [May 24, 2025, 4:53pm UTC](https://ask.igwn.org/t/data-challenge-results/1314 "2025-05-24T16:53:17Z")
Hi everyone, I might have missed the part of the workshop where this was covered. Where and what format do we get the results of the Data Challenge? --- ## [GWOSC server down?](https://ask.igwn.org/t/gwosc-server-down/1216)
**Author:** [@Shan909](https://ask.igwn.org/u/Shan909)\ **Replies:** 1\ **Last updated:** [March 30, 2025, 1:06pm UTC](https://ask.igwn.org/t/gwosc-server-down/1216 "2025-03-30T13:06:55Z")
Not sure if this belongs here but I am facing an server time out error while fetching data from gwosc.datasets using event\_gps and timeseriesTimeSeries.fetch\_open\_data I am using the template script from GWOSC workshops… --- ## [GW found on 2.6](https://ask.igwn.org/t/gw-found-on-2-6/1178)
**Author:** [@wing](https://ask.igwn.org/u/wing)\ **Replies:** 3\ **Last updated:** [March 6, 2025, 6:18am UTC](https://ask.igwn.org/t/gw-found-on-2-6/1178 "2025-03-06T06:18:44Z")
Hello, I am a graduate student.I was wondering if LIGO had detected a gravitational wave event on February 6th of this year, and I heard about it from somewhere else, because it’s probably non-public data, so I’m very so… --- ## [Could use keener eyes on my math please](https://ask.igwn.org/t/could-use-keener-eyes-on-my-math-please/1149)
**Author:** [@Julian](https://ask.igwn.org/u/Julian)\ **Replies:** 1\ **Last updated:** [March 5, 2025, 7:13pm UTC](https://ask.igwn.org/t/could-use-keener-eyes-on-my-math-please/1149 "2025-03-05T19:13:15Z")
Revisiting the Foundations of General Relativity (GR) The journey began with a deep engagement with Einstein’s General Relativity (GR), which remains one of the most successful theories for describing gravity. GR provide… --- ## [A Potential Longitudinal Pressure Wave Component of Gravity](https://ask.igwn.org/t/a-potential-longitudinal-pressure-wave-component-of-gravity/1169)
**Author:** [@crkunferman](https://ask.igwn.org/u/crkunferman)\ **Replies:** 1\ **Last updated:** [January 25, 2025, 7:56am UTC](https://ask.igwn.org/t/a-potential-longitudinal-pressure-wave-component-of-gravity/1169 "2025-01-25T07:56:49Z")
Hello, This is my first post here, I hope everyone is doing well! I’ll cut right to the chase. I have a hypothesis that I published along with simulations on wolfram cloud, that I was hoping to discuss and work out fur… --- ## [Anyone else get data from gravity from their frameworks looking like this?](https://ask.igwn.org/t/anyone-else-get-data-from-gravity-from-their-frameworks-looking-like-this/1160)
**Author:** [@Julian](https://ask.igwn.org/u/Julian)\ **Replies:** 2\ **Last updated:** [December 24, 2024, 3:21am UTC](https://ask.igwn.org/t/anyone-else-get-data-from-gravity-from-their-frameworks-looking-like-this/1160 "2024-12-24T03:21:16Z")
--- ## [Assessing team performance using logbooks](https://ask.igwn.org/t/assessing-team-performance-using-logbooks/1142)
**Author:** [@homo\_economicus](https://ask.igwn.org/u/homo_economicus)\ **Replies:** 4\ **Last updated:** [November 19, 2024, 8:56pm UTC](https://ask.igwn.org/t/assessing-team-performance-using-logbooks/1142 "2024-11-19T20:56:27Z")
Hi everyone, I come from a completely different academic background (economics) and with a different purpose than probably any other post. I am trying to feed the LIGO-Virgo-KAGRA logbook entries into an economic model … --- ## [Expressing f\_{GW} in Terms of 't' from ODE Solution](https://ask.igwn.org/t/expressing-f-gw-in-terms-of-t-from-ode-solution/931)
**Author:** [@CKS](https://ask.igwn.org/u/CKS)\ **Replies:** 3\ **Last updated:** [November 4, 2024, 6:55pm UTC](https://ask.igwn.org/t/expressing-f-gw-in-terms-of-t-from-ode-solution/931 "2024-11-04T18:55:08Z")
Hello everyone, I’ve been working on an equation describing the spin-up process of a binary system involving Primordial Black Holes (PBHs) surrounded by dark matter. The equation looks like this: \\frac{df}{dt} = C\_GW \*… --- ## [Numerical Integration of PBH Spin-Up Equation Over Extended Time Span](https://ask.igwn.org/t/numerical-integration-of-pbh-spin-up-equation-over-extended-time-span/1079)
**Author:** [@CKS](https://ask.igwn.org/u/CKS)\ **Replies:** 2\ **Last updated:** [August 4, 2024, 8:57am UTC](https://ask.igwn.org/t/numerical-integration-of-pbh-spin-up-equation-over-extended-time-span/1079 "2024-08-04T08:57:09Z")
Hello Everyone, I am trying to solve the spin-up equation for a primordial black hole (PBH) system numerically over a longer integration time. The spin-up equation is given by: fdot = C\_GWf^{11/3} + C\_DFf^{3/2} At t=0… --- ## [Which definition of ASD is the best to compare with a detector's sensitivity curve?](https://ask.igwn.org/t/which-definition-of-asd-is-the-best-to-compare-with-a-detectors-sensitivity-curve/1045)
**Author:** [@Lucy](https://ask.igwn.org/u/Lucy)\ **Replies:** 2\ **Last updated:** [May 24, 2024, 10:43pm UTC](https://ask.igwn.org/t/which-definition-of-asd-is-the-best-to-compare-with-a-detectors-sensitivity-curve/1045 "2024-05-24T22:43:22Z")
Hello! I was studying a BNS simulation (without noise) and wanted to compare its ASD with the ET sensitivity curve. For the ASD, I used the sqrt of the normalized psd (NPSD) as I have seen in one of the lectures about Da… --- ## [Cyclic\_time\_shift](https://ask.igwn.org/t/cyclic-time-shift/1009)
**Author:** [@Rao](https://ask.igwn.org/u/Rao)\ **Replies:** 1\ **Last updated:** [April 19, 2024, 12:38pm UTC](https://ask.igwn.org/t/cyclic-time-shift/1009 "2024-04-19T12:38:58Z")
Hi all, We are using cyclic\_time\_shift function in the tutorial 2.2 for shifting the wave-form(template). what is the science behind it how it calculate the approximate merger location, for calculating the SNR shifting … --- ## [Tutorial A.3 of chapter A.3 Investigation of Continuous Wave](https://ask.igwn.org/t/tutorial-a-3-of-chapter-a-3-investigation-of-continuous-wave/990)
**Author:** [@johnmora](https://ask.igwn.org/u/johnmora)\ **Replies:** 5\ **Last updated:** [April 19, 2024, 6:37am UTC](https://ask.igwn.org/t/tutorial-a-3-of-chapter-a-3-investigation-of-continuous-wave/990 "2024-04-19T06:37:27Z")
Greetings, good evening, by chance you know where I can find the tutorial A.3 of chapter A.3 Investigation of Continuous Wave, I look forward to your help, thank you very much Cordially John Mora --- ## [How do generate spectrogram](https://ask.igwn.org/t/how-do-generate-spectrogram/868)
**Author:** [@Faker](https://ask.igwn.org/u/Faker)\ **Replies:** 5\ **Last updated:** [March 15, 2024, 8:19am UTC](https://ask.igwn.org/t/how-do-generate-spectrogram/868 "2024-03-15T08:19:29Z")
How do I use gwpy to plot a spectrogram similar to the gravitational wave events on the GWOSC website, and what parameters should be set. Such code is here strain = TimeSeries.read(fn,format=‘hdf5.gwosc’) center = int… --- ## [GW170817 time series txt file without noise, available?](https://ask.igwn.org/t/gw170817-time-series-txt-file-without-noise-available/884)
**Author:** [@Lucy](https://ask.igwn.org/u/Lucy)\ **Replies:** 5\ **Last updated:** [March 6, 2024, 8:15pm UTC](https://ask.igwn.org/t/gw170817-time-series-txt-file-without-noise-available/884 "2024-03-06T20:15:37Z")
Hello! Please, can you help me remember where can I get the time series (t,h) of the GW170817 from? I mean, a file without noise, only the signal, if it is available. Thank you!! --- ## [Intensity Timeseries](https://ask.igwn.org/t/intensity-timeseries/872)
**Author:** [@Gage](https://ask.igwn.org/u/Gage)\ **Replies:** 1\ **Last updated:** [January 22, 2024, 8:50pm UTC](https://ask.igwn.org/t/intensity-timeseries/872 "2024-01-22T20:50:51Z")
I want to deduce the timeseries of intensities observed at the final photodetector from the strain timeseries. It seems I cannot do this for the following reasons: All GWOSC data has been put through a high pass filter… --- ## [Attribute Error in readligo.py](https://ask.igwn.org/t/attribute-error-in-readligo-py/866)
**Author:** [@RPH001](https://ask.igwn.org/u/RPH001)\ **Replies:** 2\ **Last updated:** [December 20, 2023, 4:27pm UTC](https://ask.igwn.org/t/attribute-error-in-readligo-py/866 "2023-12-20T16:27:53Z")
In readligo.py: line 125 shortnameArray =dqInfo\['DQShortnames'\].value I am getting error: ‘Dataset’ object has no attribute ‘value’ Could anyone resolve this query? Thanks! \*\* AttributeError … --- ## [AttributeError when running google colab notebooks](https://ask.igwn.org/t/attributeerror-when-running-google-colab-notebooks/810)
**Author:** [@Lucy](https://ask.igwn.org/u/Lucy)\ **Replies:** 2\ **Last updated:** [August 17, 2023, 10:29am UTC](https://ask.igwn.org/t/attributeerror-when-running-google-colab-notebooks/810 "2023-08-17T10:29:17Z")
Hello! I wanted to use again the google colab for "notebook 1.2 open data access with GWpy and to my surprise I got the following error almost at the very beginning of the notebook: AttributeError … --- ## [How to get the fd waveform of time series in a data file?](https://ask.igwn.org/t/how-to-get-the-fd-waveform-of-time-series-in-a-data-file/796)
**Author:** [@Lucy](https://ask.igwn.org/u/Lucy)\ **Replies:** 5\ **Last updated:** [July 13, 2023, 10:38pm UTC](https://ask.igwn.org/t/how-to-get-the-fd-waveform-of-time-series-in-a-data-file/796 "2023-07-13T22:38:11Z")
Hello! I am trying to get the ASD of time series in a data file, just like in Tutorial 1.4 of GWOSC#6, where you use "hp, hc = get\_fd\_waveform(approximant=“IMRPhenomPv2\_NRTidalv2"” in order to get the fd waveform of a pa… --- ## [Introducing Skymappa: a website dedicated to gravitational wave astronomy](https://ask.igwn.org/t/introducing-skymappa-a-website-dedicated-to-gravitational-wave-astronomy/433)
**Author:** [@Lizzie](https://ask.igwn.org/u/Lizzie)\ **Replies:** 4\ **Last updated:** [June 1, 2023, 2:14pm UTC](https://ask.igwn.org/t/introducing-skymappa-a-website-dedicated-to-gravitational-wave-astronomy/433 "2023-06-01T14:14:23Z")
Hi everyone, my name is Lizzie and I created www.skymappa.co.uk as part of a research placement after completing this year’s Open Data Workshop and I thought it would be nice to share it here! If you have any thoughts/s… [Next page](https://ask.igwn.org/c/uncategorized/1.md?page=1)