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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿

@davidsheryn.bsky.social
252 followers 481 following 1.4K posts

InfoSec and aviation. Likes are bookmarks not endorsements. No DMs, please use Signal: David.7323 London, Buckinghamshire, Bristol, Wales.

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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 9h
The Graffiti Tunnel in London 🙂
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 11/10/2026
Excellent 😀 As were Pomplamoose last week 🙂
Natalie of 🎼Pomplamoose🎼 live in London.
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 20/09/2026
Nope, it looks fine 🙂
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 19/09/2026
Thanks! The bit about stucco originally being to create a sandstone effect was interesting.
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 19/09/2026
I did not know this.. I’m sure @oldenoughtosay.com does 🙂
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 18/09/2026
Not just South London, of course.
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 01/09/2026
🙂 unlike many of my school friends, I had no particular draw to London, it just kinda happened <because university> and mostly stuck, but have plenty of excuses to come back. Here’s another view of the harbour 😉
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 30/08/2026
xkcd FTW 😉 imgs.xkcd.com/comics/tech_...
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 30/08/2026
Of course, any discussion of Bristol harbour invokes the rule requiring ‘that artwork’ to be referenced 😉
Banksy’s mural of “Girl with a pearl earring”.
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 22/08/2026
Ugh, that bit of the world does seem to be stuffed at the moment 😬 Can you get to London Bridge ? It’s a short-ish hop from there.
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 21/08/2026
😉
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 21/08/2026
😉
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 21/08/2026
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 20/08/2026
Better... 🙂
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 24/06/2026
Welcome. Credit where it’s due ☺️ I have no interest in gardening, myself, but greatly appreciate other people’s work. Have some gratuitous pictures from a local property which opens as part of the National Garden Scheme.
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 08/06/2026
London’s offering in this space… 🙂
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 07/06/2026
Indeed, but I still have a soft spot for a retro L2 tower… Watched them being built across granny’s farm 🙂 (@engineerlondon.bsky.social)
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 02/05/2026
🤷🏻‍♂️ realcounties.com
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 26/04/2026
Likewise. Friends out supporting this last year. www.bowelcanceruk.org.uk/support-us/
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 20/04/2026
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 19/04/2026
First proper walk of the year… Oxford Canal.
A notice board describing part of the Oxford canal. Southern end of the Oxford canal. A footbridge over a canal. A footbridge over a canal.
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 10/04/2026
Troy Hunt suffering the same problem 🙄 x.com/troyhunt/sta...
Can anyone design us a “we’re not a US company” crest? 🤔 Extra credit for making it clear we’re Australian.
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 24/03/2026
This, I expect... (see also "cabbage patch dolls")
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 23/03/2026
“Led by a corgi…” @oldenoughtosay.com x.com/yoda4ever/st...
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 21/03/2026
Wonder how these residents feel about it? 😉
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 16/03/2026
😉
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 15/03/2026
Only if they do a better job than this! www.theregister.com/2025/08/12/u...
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 06/03/2026
The 1930s planners did with Queen’s Square in Bristol, but the 90s got it back again! 🙌
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 06/03/2026
See also x.com/bartgonnissen (Apologies it’s “the other place”)
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 24/02/2026
x.com/mathladyhaze...
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 17/02/2026
A blown plaque commemorates the place Sir Alexander Fleming discovered penicillin at St Mary’s Hospital, London.
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 12/02/2026
Body.
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 07/02/2026
A National Trust finger-post in a woodland setting, pointing the way to the Thames Path.
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 05/02/2026
AI generated summary…
AI-generated summary of the book. 

The Cuckoo's Egg does contain a section describing Cliff Stoll's PhD oral examination (what's often called a viva or thesis defense in different systems).

Multiple references, especially from physics communities and Reddit discussions of the book, point to a memorable anecdote in the book where his committee asks him to explain "Why is the sky blue?" They then repeatedly press him with "Can you be more specific?" This leads him through a detailed, step-by-step explanation—from basic scattering to molecular energies, cross-sections, optics, visible light wavelengths, and perception by the human eye—tying directly into his work as a visible-light astronomer.

This story is frequently cited as an inspiring (and exhausting but positive) example of a PhD defense in physics/astronomy contexts, contrasting with more infamous "monster" orals. It's not the main plot (the book centers on the hacker hunt), but it's included as a personal aside, likely in an early chapter where Stoll introduces his background as an astronomer who ended up in computing after his research funding dried up.
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 29/01/2026
As you have incanted the sacred rune, I am obliged to post this… 🤷🏻‍♂️
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 24/01/2026
😉
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 18/01/2026
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 18/01/2026
The original 🙂
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 12/01/2026
I see your Thames and raise you The Thames 😉
Atmospheric view of the Thames, looking upriver, with The Shard and the sun setting over Tower Bridge, reminiscent of a JWM Turner watercolour A mural, near the Thames Barrier, showing the hight above sea level of the River Thames. The stretch around Oxford is shownThe start, or end, of the original Thames Path near the Thames Barrier. A ‘fingerpost’ sign marking the route of the Thames Path.
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 03/01/2026
Not entirely comparable, because the West in general and the US in particular is still highly dependent on Taiwan for manufacturing hi-tech components.
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 26/12/2025
It’s called Leake St, and goes right under the station, hence not obvious! I see that it’s now labelled as the “Graffiti Tunnel” on Google Maps! 🙂 Easiest way to get there is to go out through the small door in into Cab Road, and then down the steps to the Lower Marsh entrance.
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 26/12/2025
There’s a tunnel under Waterloo Station in London, where street artists are allowed and encouraged to paint their work… 🙂 I’ll try and find some more pics tomorrow, if you’re interested?
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 24/12/2025
😉
Majikthise:
I mean, what's the use of our sitting around half the night arguing whether there may...

Vroomfondel:
Or may not.

Majikthise:
...be a God, if this machine only goes and gives you his phone number in the morning?

Vroomfondel:
That's right! We demand rigidly defined areas of doubt and uncertainty.
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 18/12/2025
Anna Lapwood at the RAH smashing it out of the hall, as usual 🙂
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 03/12/2025
😉
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 26/11/2025
‘Blockchain’ finished it for me… 🙄
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 12/11/2025
Have you been back recently? Wonder what you think of what they’ve done to the place (former Plumstead resident)
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 12/11/2025
And the start — or finish — of the Thames Path 🙂
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 11/11/2025
😬
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David 🏴󠁧󠁢󠁷󠁬󠁳󠁿 @davidsheryn.bsky.social · 02/11/2025
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