Toysmith Euler's Disk Physics Science Desk Toy, Chrome, 3 inches

Who says anyone is too old to enjoy cool stuff like this?! I can't even believe people gave this any less than five stars! Not sure what they were expecting, and apparently some people were spinning the box it came in, I guess, or trying to spin the mirror on the disk maybe, or spinning themselves instead of the disk, ahahaha, who knows, but if you like absolutely cool gadgets that serve no other purpose than being COOL GADGETS then you will LOVE this thing! Here's a tip so to not be disappointed, thinking this was supposed to be Thor's Hammer that will make you fly or something -- just go to YouTube, look it up, watch the video, and if you say "how dumb and dull" then don't buy it -- and certainly don't buy it and then say how dull or dumb you think it is! If, on the other hand, you said, "Oh, yeah, totally cool" then TOTALLY BUY IT. It does EXACTLY what it does in the video -- put the heavy disk on the mirror, give it any kind of spin, and be amazed as, just when you think it's going to stop spinning......it doesn't stop spinning! Get even more amazed at the hypnotically cool display of colors (which can be changed in pattern, by swapping out the magnetic covering pieces you can put on the disk, and can be highlighted by shining a flashlight on it, especially in a darkened room) and then be amazed again when it still just WON'T QUIT!!! Amazement ensues even more as it finally begins the wind down stage, seeming to spin crazy fast, and faster and faster, and making an increasingly louder sound as if building up to a detonation and then amazement flies off the charts as it reaches a crescendo and suddenly, BAM, silence! You don't even have to be smart to realize you just saw something scientific and be all like, WOW, COOL!!!! Yes, I know, I just described the video, right??? Because that's what it DOES!!! So, you like the video, you say, oh I definitely want to try that, because that just can't be real, and you buy it, you spin the disk, you get the show, and you love this thing! Even more cool is every new person can't believe it -- ask anyone how long they think it will spin and nobody gets that this thing just spins SOOOOOO long and, yeah, tons of fun. Never has disappointed anyone, and it's so unassuming, just sitting there.....the curious will ask, "Hey, so what is that," and let the magic begin. I think it's so awesome when we can see something that isn't easily explained by what we normally see -- we know a spun coin will soon quit, so we don't expect this big coin looking disk to go on and on and on! Makes people feel young again, to have that taste of mystery. My office has plenty of these kinds of gadgets, but this one is the coolest and clients are always entertained, as well as my staff, haha, and all in all people love my office, which is great because you want people laid back and happy when talking to the boss, and it just makes for a relaxed and interesting space. Office gadgets rule! So, if you don't like cool scientific toys that leave people saying, "Wow, I can't believe I just saw that!" then don't buy it. But if you like those kinds of things, then, yes you'll love it -- kids and adults alike are amazed to watch it, and hey, we can all use a bit of wonder in our world, right? This is a purchase you can literally decide before buying, simply by watching it on YouTube. That's the exact product and performance you are getting, and you either like that kind of thing, or you don't, so it's a really simple purchase to make....or not! I found it more cool to own it, than just to watch the video, but then again I like stuff like this, and frankly would like to buy a lot of the other things in related videos. In this age of tech wonder, sometimes the simple old wonders are much more entertaining. As for being a "toy" I would agree with others who have said it's not really a toy, in the sense of a truck or doll or something to "play" with, but more like a science demonstration that passes as a magical trick, since it's so unusual to see, and requires no knowledge (or dull explanation, frankly) of what's happening to be impressed by what takes place. It's not something likely to entertain a child for hours on end, but such is not the point. Besides, the mirror is glass, obviously, and a wrong toss of the coin would shatter it, so not something really to give to a child and say, "Here, have fun!!!" I will say it keeps people of all ages stumped, and they always want to see it again, so it has good use as a cool gadget left out so that you can show it folks, or let them give it a try. It's something for people to experience and enjoy and if that's not worth the small asking price of twenty bucks, then people just aren't making room in life for things that have no purpose but to be awesome, which is a purpose unto itself, of tremendous value, such as having your kids, and yourself, lose the shoes and socks and step in paint and then paint with your feet, making a family footsy collage, and then just making a (controlled, ahaha" mess, for the sheer fact that it can be done, and feels cool. We have lost touch with sensory experience, much to our detriment! So put down the smart phone and tablet and enjoy this actual physical object. Definitely worth the small price of admission for this show! Watch video. Like. Buy. Be happy! Share the joy! I HIGHLY RECOMMEND!!!!

Wow! I find this "thing"...more than a toy for sure, part physics demonstration that I don't get...to be amazing and mesmerizing. An incredible example of physical laws at work. The spin duration, sound & speed, disk centering are unbelievable. The magnetic colored disks, etc., are pretty worthless, dampen the overall effect and fell off. I used a marker to put a small dot on each side so you can see the rate of disk rotation slow down vs. whatever else it's doing speeds up. As mentioned, the mirror's kinda cheap but it does the job. I've used it a bunch today and haven't noticed any scratches yet. Be kind to the steel disk tho. I tested it with a neo magnetic and that dinged the glitter band that's wrapped around the diameter making it noisy. It's a little expensive but I'm very happy with my purchase.

Ultra-cool physics toy! This spins for OVER 2 minutes normally as long as the surface is level and flat. The sound it makes is soothing for the first minute or so, then it starts speeding up and gets LOUD. It's great to show kids, their eyes light up with amazement as it keeps spinning. The ending always get their expressions going. It's great for nerdy adults like me, too!

Im 43 years old and this might possibly be the coolest purchase I've made in a long time. Everyone loves playing with it and it's one of those things that doesn't get old or boring. Even after many spins, I'm still blown away by how long the disc spins for. I gave it only 4 stars because of the price. It probably costs less than $10 to make and it took me awhile to justify spending nearly $50 on it. I don't regret my purchase, it's just a lot of money for such a simple toy.

I love playing with this. And it’s so satisfying

Stars as follows: +1 as advertised (mostly), +1 made with precision, +2 no batteries, +1 fascinating, -1 overpriced (but, I knew that when I bought it, so, I will take the minus back). With the mirror on a hard level surface, the disk will run for 3 minutes. The ad says, "Disk will spin faster and louder the longer it goes." If true, these people will be awarded a Pulitzer Prize in science as they have invented a perpetual motion machine. Alas, the laws of physics says no. What they are calling spin is actually wobble. Spin, as most commonly understood, would be a bicycle wheel set in motion, turning on a centered axis. The Euler disk is set on its edge and put into motion with a twist of the wrist. It does spin on edge, but, only briefly before friction begins to make war on energy and the spin begins to degrade (from about 50 rpm to 0. A decrease in spin rate induces wobble(one side up, the other side down). It is interesting that the further spin decreases, the more wobble increases - from 0 to a very high rate (accounting for the volume increase). I have no way to measure it, I would guess 400 cycles per second??. Thus, the disk appears to "spin up" increasing in speed. Saying, "the disk spins faster" adds a little mystery to the device which certainly helps sales. "It wobbles faster," just doesn't have the same appeal. The same effect can be demonstrated with a plate - please, not grandmothers Limoge, maybe Melmac. Set it on edge on a wood floor and give it a spin. Lotsa fun and makes lotsa racket! The best educational effect of this product would be to look up Leonhard Euler - a truly amazing mind. Or, work out the mathematics that the disk demonstrates. This is a gadget that is better left on the counter for guests to play with than as a gift.

Works as described kids like it

Who doesn't want to show friends and family a finite time singularity?? This is fun and interesting and it sings when it really gets down to business.. Toys that teach and start good conversations are the best .

I bought this to entertain and educate our grandsons. I think it will intrigue them for a few runs. After that it will be more of an occasional novelty item, but I expected that. It's fascinating to watch, particularly as it gets lower and lower. I was impressed how long it kept going, as the sound it makes keeps going up in pitch.

Very well built and it is amazingly beautiful. Looks good on the table and it really spins for a long time!

Un producto excelente de buena calidad funciona a la perfección y llegó a tiempo vale la pena tener uno ya sea para laboratorio escolar así como para el hogar donde se puede observar la ley de la conservación de la energía

見ているだけで時間が過ぎるのを忘れる。 幼少期に駒の回転等を眺めていたあの頃に戻れます。 購入後半年程度でサビ（？）の様なものがつき回転のしかたが悪くなりました。

The grandchildren love this.