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John Forbes

@redshiftless.bsky.social

Astronomer in Aotearoa/New Zealand at the University of Canterbury. Pusher of pixels, pens, arrays, and computer keys. www.johncforbes.com

1,331 Followers  |  1,515 Following  |  81 Posts  |  Joined: 25.07.2023  |  2.7859

Latest posts by redshiftless.bsky.social on Bluesky

Sharks are 2 galactic years old!

22.11.2025 02:34 โ€” ๐Ÿ‘ 13    ๐Ÿ” 1    ๐Ÿ’ฌ 2    ๐Ÿ“Œ 0
A screenshot of text, headed "Description" followed by a paragraph "XBIGSpace is an independent, fan-made channel with no official affiliation with NASA, SpaceX, or any related organizations. Our content is inspired by publicly available scientific discussions, documentaries, and space research - reimagined purely for educational and inspirational purposes." New paragraph: "All narration is delivered using AI-synthesized voice, and does not represent any real individual."

A screenshot of text, headed "Description" followed by a paragraph "XBIGSpace is an independent, fan-made channel with no official affiliation with NASA, SpaceX, or any related organizations. Our content is inspired by publicly available scientific discussions, documentaries, and space research - reimagined purely for educational and inspirational purposes." New paragraph: "All narration is delivered using AI-synthesized voice, and does not represent any real individual."

Ooh gross just discovered a bunch of youtube channels blaring about 3I/ATLAS using an AI-generated Brian Cox. The channel description says the videos are all AI, but the videos are clearly designed to make people think BC is actually saying these things..

17.11.2025 04:05 โ€” ๐Ÿ‘ 8    ๐Ÿ” 5    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

I think the "abundance agenda" is vague enough that some people could read it that way, but my read is that we need to build a lot of solar/batteries/transmission (to keep fossil fuels in the ground!), and a lot of old-school environmentalists are opposed to that because it involves building stuff.

06.11.2025 11:21 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

Ohio State astronomy is still waiting to see what happens with the federal funding landscape before deciding whether to proceed. With programs that are still TBD, I recommend waiting right now because *application fees do not get refunded if they decide to cancel after you have already paid*!!

09.10.2025 00:45 โ€” ๐Ÿ‘ 33    ๐Ÿ” 16    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 1
A printed sign on a wooden planter with grass in the foreground and long thin green leaves in the planter. The sign says โ€œRCG compost project; in progress; please leaveโ€

A printed sign on a wooden planter with grass in the foreground and long thin green leaves in the planter. The sign says โ€œRCG compost project; in progress; please leaveโ€

More hostility than I was expecting from a planter!

15.09.2025 23:29 โ€” ๐Ÿ‘ 4    ๐Ÿ” 0    ๐Ÿ’ฌ 3    ๐Ÿ“Œ 0

Re the CRs: the age might buy you a factor of 2 relative to the solar system, but there may be a larger effect (in the same direction!) - 3I's orbit sends it further above the galactic midplane -> less B field -> more CRs

(adapted from an argument made in this paper: arxiv.org/abs/2509.04165).

09.09.2025 23:55 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
A screenshot of the top of a wikipedia page for "Why We're Polarized", the book by Ezra Klein. In the screenshot, the start of the second paragraph of the article is highlighted, "Opinion on the book is polarized"

A screenshot of the top of a wikipedia page for "Why We're Polarized", the book by Ezra Klein. In the screenshot, the start of the second paragraph of the article is highlighted, "Opinion on the book is polarized"

Incredible stuff happening on wikipedia

27.08.2025 13:39 โ€” ๐Ÿ‘ 2    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

It is wild how many outdoor cats there are in NZ. Everyone loves the native birds, but the outdoor cat culture is really ingrained.

26.08.2025 08:30 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

Obviously peer reviewed vs. not can be an issue, but in this particular case the data in the paper seems to have been completely fabricated. I think it's fair to say that peer review generally operates on assumptions of good faith, so fake data will often make it through.

17.08.2025 08:25 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

They don't seem to sell many ads on these calculator-style searches, so perhaps costing google money is the most ethical choice ๐Ÿคท (if it worked lol).

But seriously, not a bad point!

04.08.2025 05:57 โ€” ๐Ÿ‘ 3    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

Yeah, could be. Google has worked well for the past decade, so it feels like the end of an era.

04.08.2025 04:12 โ€” ๐Ÿ‘ 6    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
A screenshot of a google search result for "2*pi*(8 kpc)/(220 km/s)" which is roughly the time it takes the Sun to go around the Galaxy. In the screenshot, google's calculator has popped up and parsed the expression correctly, but then returns the result 3 899 243.9 years, and answer which is off by 2 orders of magnitude.

A screenshot of a google search result for "2*pi*(8 kpc)/(220 km/s)" which is roughly the time it takes the Sun to go around the Galaxy. In the screenshot, google's calculator has popped up and parsed the expression correctly, but then returns the result 3 899 243.9 years, and answer which is off by 2 orders of magnitude.

PSA to scientists: Google calculator appears to no longer do basic unit conversion correctly!

n.b. the correct answer here is 223.4 Myr, a factor of about 60 larger than Google's answer.

๐Ÿ”ญ ๐Ÿงช

04.08.2025 03:08 โ€” ๐Ÿ‘ 86    ๐Ÿ” 27    ๐Ÿ’ฌ 7    ๐Ÿ“Œ 6
Video thumbnail

Crew-11 lifts off from Florida on their way to the International Space Station.

The heat signature from the launch could be seen from GOES-18.

01.08.2025 17:17 โ€” ๐Ÿ‘ 20    ๐Ÿ” 5    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 1
Video thumbnail

Cumulus clouds swirl along the Gulf Coast.

This mesmerizing view captured yesterday by GOES-19.

28.07.2025 18:42 โ€” ๐Ÿ‘ 240    ๐Ÿ” 47    ๐Ÿ’ฌ 2    ๐Ÿ“Œ 2
Preview
Are interstellar objects proof of alien life? This could finally settle the debate. The Vera Rubin telescope is poised to kick off an explosive era of discovery. "It's like old-fashioned astronomy: Find the thing, point telescopes at it, argue about it. It's going to be fun."

I wrote about Rubin again, this time about the telescope's capacity to find potentially dozens of interstellar objects.

It's going to be wild, as one astronomer put it, "like old-fashioned astronomy: Find the thing, point telescopes at it, argue about it."
www.nationalgeographic.com/science/arti...

24.07.2025 18:00 โ€” ๐Ÿ‘ 61    ๐Ÿ” 17    ๐Ÿ’ฌ 3    ๐Ÿ“Œ 0
Preview
NSF-DOE Vera C. Rubin Observatory Observations of Interstellar Comet 3I/ATLAS (C/2025 N1) We report on the observation and measurement of astrometry, photometry, morphology, and activity of the interstellar object 3I/ATLAS, also designated C/2025 N1 (ATLAS), with the NSF-DOE Vera C. Rubin ...

It's paper day! The first science paper with data from @vrubinobs.bsky.social's survey camera, the mighty LSSTCam, is a VERY quick turnaround of Rubin's observations thus far of interstellar comet 3I/ATLAS. โ˜„๏ธ
Chandler et al., submitted ๐Ÿ”ญ
A ๐Ÿงต

21.07.2025 05:28 โ€” ๐Ÿ‘ 156    ๐Ÿ” 45    ๐Ÿ’ฌ 5    ๐Ÿ“Œ 11

I don't know about "the best," but my April Fool's rant is my personal contribution to this genre. arxiv.org/abs/2003.14327

16.07.2025 01:22 โ€” ๐Ÿ‘ 3    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
Preview
From a Different Star: 3I/ATLAS in the context of the ลŒtautahi-Oxford interstellar object population model The discovery of the third interstellar object (ISO), 3I/ATLAS (`3I'), provides a rare chance to directly observe a small body from another Solar System. Studying its chemistry and dynamics will add t...

It's paper day! We use our ลŒtautahi-Oxford model of the Galaxy's interstellar object population to understand the origins of 3I/ATLAS, from only its velocity
@astrohopkins.bsky.social, Dorsey, @redshiftless.bsky.social, @astrokiwi.bsky.social, @chrislintott.bsky.social & Leicester, submitted
A ๐Ÿงต๐Ÿ”ญ

09.07.2025 03:29 โ€” ๐Ÿ‘ 106    ๐Ÿ” 34    ๐Ÿ’ฌ 4    ๐Ÿ“Œ 8

If this holds up it will be the 3rd interstellar object (comet or asteroid from another star system). Not every day we get to increase the sample by 50%!

168 hr arc = observed over a period of 1 week so far, and e~9 meaning convincingly interstellar (anything >~1 is not bound to the Sun).

02.07.2025 04:19 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
02.07.2025 03:38 โ€” ๐Ÿ‘ 3    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
A screenshot from a livestream filmed with an infrared camera in grayscale, showing a sleeping adult ferret in a container on a bed of paper squares(?) with an indeterminate number of ferret kits (turns out there are 8!)

A screenshot from a livestream filmed with an infrared camera in grayscale, showing a sleeping adult ferret in a container on a bed of paper squares(?) with an indeterminate number of ferret kits (turns out there are 8!)

It's my favorite time of the year: new black-footed ferret kits born at the National Zoo and the return of ferretcam!

nationalzoo.si.edu/webcams/blac...

05.06.2025 09:31 โ€” ๐Ÿ‘ 4    ๐Ÿ” 1    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
A screenshot from the Aurora app showing KP forecasts as a function of time:
Now: 3.0
1800: 4.0
2100: 3.67
Midnight: 7.67
0300: 7.67
0600: 7.33

A screenshot from the Aurora app showing KP forecasts as a function of time: Now: 3.0 1800: 4.0 2100: 3.67 Midnight: 7.67 0300: 7.67 0600: 7.33

Looks like a promising night for aurora chasing

01.06.2025 04:55 โ€” ๐Ÿ‘ 6    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

As far as I can tell this month is just 8 deadlines in a trenchcoat.

13.05.2025 12:59 โ€” ๐Ÿ‘ 3    ๐Ÿ” 1    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

#SaveNSF

10.05.2025 10:07 โ€” ๐Ÿ‘ 15    ๐Ÿ” 6    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

Astronomers have found thousands of planets outside the solar system. All of them are, to my knowledge, garbage. Happy Earth Day to the only good one ๐ŸŒ

22.04.2025 12:44 โ€” ๐Ÿ‘ 801    ๐Ÿ” 145    ๐Ÿ’ฌ 31    ๐Ÿ“Œ 17

Bad stats (and not a convincing biosignature in the first place) bsky.app/profile/dist...

18.04.2025 03:13 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
Artist's impression of the exoplanet K2-18b.
Credit: A. Smith, University of Cambridge.

Artist's impression of the exoplanet K2-18b. Credit: A. Smith, University of Cambridge.

๐—ก๐—ผ, ๐—ฎ ๐—ฏ๐—ถ๐—ผ๐˜€๐—ถ๐—ด๐—ป๐—ฎ๐˜๐˜‚๐—ฟ๐—ฒ ๐˜„๐—ฎ๐˜€ ๐—ป๐—ผ๐˜ ๐—ท๐˜‚๐˜€๐˜ ๐—ฑ๐—ฒ๐˜๐—ฒ๐—ฐ๐˜๐—ฒ๐—ฑ ๐—ถ๐—ป ๐—ž๐Ÿฎ-๐Ÿญ๐Ÿด๐—ฏ'๐˜€ ๐—ฎ๐˜๐—บ๐—ผ๐˜€๐—ฝ๐—ต๐—ฒ๐—ฟ๐—ฒ.

K2-18b is back in the news, now with a bold claim that biosignature molecules (DMS and/or DMDS) have been 'detected at 3ฯƒ'.

Most exoplanet astronomers are extremely sceptical about these claims, let's see why (1/n).

๐Ÿ”ญ๐Ÿงช๐Ÿช #exoplanet

17.04.2025 16:08 โ€” ๐Ÿ‘ 1131    ๐Ÿ” 368    ๐Ÿ’ฌ 37    ๐Ÿ“Œ 115

New paper!

High-order epicyclic description of orbits in spherically-symmetric potentials (plus vertical oscillations in a disk).

My love of epicycles is so notorious that the postgraduates made this meme

15.04.2025 10:34 โ€” ๐Ÿ‘ 8    ๐Ÿ” 1    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 1

"Same as yours - weird billionaire" would work surprisingly frequently as an answer here for astronomers.

10.04.2025 03:22 โ€” ๐Ÿ‘ 3    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

ลŒtautahi YIMBYโ€™s assemble!

27.03.2025 08:38 โ€” ๐Ÿ‘ 2    ๐Ÿ” 1    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

@redshiftless is following 20 prominent accounts