Why no one has mentioned a lava lamp?
A useless machine
I once had an hour glass that instead of sand it had some sort of slime, it was very cool to watch the bubbles slowly rise up the column.
You say it's useless, but half of internet is running on that. Hint: Cloudflare
more like stumbling, recently
potæto, potáto
I bought myself a lava lamp because yes, they're cool. Takes an hour to warm up, though. I usually lose my focus on it before that.
I love my Useless Box!
Splits a beam of white light into different colours, and shines them out diffferent orthogonal faces of a cube.
Looks cool but I had to laugh at this:

I'll do you one better, Dichroic Glass Dice
They are alluring. Agreed, those are better.
Any tips on which set is easy to read, and looks the best?
No clue, but the frosted looks easier to read to me
I think I've found my new go to secret Santa gift
Euler’s Disc, along with the most solid glass mirror you can find.
If you're wanting something that makes for a neat, mesmerising visual effect, maybe a plasma ball?
https://en.wikipedia.org/wiki/Plasma_globe


It looks like they're available on Amazon for the mid-to-low end of that price range.
I feel like the novelty of these things wears off almost immediately
X-Files Theme plays
This thread just walked me back into Sharper Image circa 2003
A desktop stirling engine makes for a fun kinetic sculpture. They're powered by temperature differential such as by setting it over your morning coffee/tea or just the warmth of the sunlight hitting it.
Little piece of bismuth was a good gift I gave, small desk ornament or such
RGB LED strip kit. Can use as backlighting for a mirror or tv, and could later be used to make an infinity mirror.
Those little parabola mirrors that make the toy seem to float above.
Newton's cradle
Good quality Rubik's cube
Prism color cube
I've always thought Galileo Thermometers were pretty cool.
Rock slings are incredibly fun, you can chuck rocks and balls so far people love to try it, especially kids
This is just a gateway drug to a trebuchet.
I bet you'd love it if we were all launching 90kg objects over 300m away.
Along a similar vein, my coworker keeps raving about a little toy salt shotgun that he uses to kill flies in his house.
Arc electric lighters
If the recipient is technically inclined, then a kit for a mini tesla coil would be cool
Gonna suggest a kinetic sand table. The tabletop is glass and underneath there's a bunch of sand and a metal ball that rolls around drawing patterns. They're pretty neat.
I built one of these (shoutout to V1Engineering) and a $20-$50 budget will get you maybe 10% of the way there.
Socks.
Awesome, and you can get them in different colors, like grey, or black, or blue, or beige. Not white though. White socks are only for playing sports.
I’ve always liked those magnetic levitating globes!
(You can also find magnetic levitating for a variety of tv shows and video games)
Magnetic sand hour glass
Ask Lemmy
A Fediverse community for open-ended, thought provoking questions
Rules: (interactive)
1) Be nice and; have fun
Doxxing, trolling, sealioning, racism, and toxicity are not welcomed in AskLemmy. Remember what your mother said: if you can't say something nice, don't say anything at all. In addition, the site-wide Lemmy.world terms of service also apply here. Please familiarize yourself with them
2) All posts must end with a '?'
This is sort of like Jeopardy. Please phrase all post titles in the form of a proper question ending with ?
3) No spam
Please do not flood the community with nonsense. Actual suspected spammers will be banned on site. No astroturfing.
4) NSFW is okay, within reason
Just remember to tag posts with either a content warning or a [NSFW] tag. Overtly sexual posts are not allowed, please direct them to either !asklemmyafterdark@lemmy.world or !asklemmynsfw@lemmynsfw.com.
NSFW comments should be restricted to posts tagged [NSFW].
5) This is not a support community.
It is not a place for 'how do I?', type questions.
If you have any questions regarding the site itself or would like to report a community, please direct them to Lemmy.world Support or email info@lemmy.world. For other questions check our partnered communities list, or use the search function.
6) No US Politics.
Please don't post about current US Politics. If you need to do this, try !politicaldiscussion@lemmy.world or !askusa@discuss.online
Reminder: The terms of service apply here too.
Partnered Communities:
Logo design credit goes to: tubbadu
