I had a friend in college who's parents had a house on Chesapeake Bay. We went out boating several times and once our friend Jou decided to try wake boarding. He couldn't figure out standing, so he decided to try boogie board style. Several of us tried to tell him he'd be like the skipping stone, but he was stubborn and insisted he would do it until he figured it out. Well, he never figured it out, but he also refused to let go of the rope. He spent several minutes thwacking into the water before our friend Scott decided to turn around and pick him up. Joe's front of his body from chest down was red for a week.
Agreed with ProjectphysX. In the case of skipping stones and water skiing, it is a lift effect rather than a surface tension effects. That's fairly obvious because of the large forces involved. But more generally, it cannot be surface tension because firstly, skipping stones works when the stones are already wet. And secondly, both skipping stones and water skiing require, not simply tolerate but actually require, relative motion of the object borne up by the water and the water itself.
You, and this video, are a hoot, Professor Ruzic. I wish I could have taken classes from you even though engineering/physics was way out of my zone. Be well and keep putting up these great vids.
You've mentioned in a few of your videos the concentration of elements in seawater, so would it be possible for you to do a full video on the economics of extracting minerals from seawater? Have there been any proposals for it? Is it possible to do somewhat passively (with say, solar lenses and mirrors)?
yeah. thing is, draw an upside down toothless frown and people gonna ask 'dafuq this supposed to be?' Him explaining why the wrong shape is is supposed to be correct kinda triggerad me too. But this is entry level stuff. Whenever they show the water tension paper clip, you know you're in grade school physics.
During World War II the US Army Air Force used the skipping on water technique in a dramatic way. It was too difficult to fly over Japanese ships and bomb them. To solve this problem both B-17 and B-25 bomber crews stationed at Port Moresby practiced flying low and skipping bombs into old wrecks. The results were both accurate and devastating. Wartime skip bombing helped decide the battle of New Guinea in America's favor.
The diameter of a water drop is about 4.5 mm by measuring cave soda straws, in the current surface gravity of the Earth. In the Geologic Past, they may have been large in diameter when the Earth was smaller, and had a lower surface gravity. This would be consistent with Sauropods being up to 15 times the Volume of Male African Elephants, and going farther back in time Centipedes were up to 2 meter long, and 1 meter wide.
For the water skier, it is not the surface tension keeping him from sinking. At that scale inertial effects dominate: the water cannot be pushed down fast enough and its inert mass resists. For the skipping stone and the gecko it's also mostly inertial effects, but at this smaller scale surface tension still plays a role in the dynamics. Stone skipping should still work on ethanol for example, provided that the stone is fast enough.
@@tncorgi92 you would probably need wheels on the skies or else the friction would be too high. But you can definitely walk on a non-Newtonian fluid when you are quick enough.
You are the best commercial for you collage ... i wish i was younger i wouldn't mine taking classes from you , maybe some-day my kiddo's might take your class ,,, i had no-idea that UCI has a fusion reactor ... and a supper-computer ...
I only recently discovered this channel while researching radiation, but I could not quite make sense of channel's profile picture. (I mean you have the lecturer that is standing on top of water in the middle of a swimming pool. Quite random I'd say). But this video gave a little more context to the picture in question.
@@Mernom 66 Books, 40 authors, 3 continents. People who had no reason to lie about what they saw were murdered and testified unto death. All writing about the same thing. Historical Jesus was the most well documented event in human history. I'm an Engineer and I believe in God because when you study the sciences mainly biology you see the need for an intelligent creator. If you're a materialist you have a protein folding problem and a morality problem. Go ahead and try to prove the bible is wrong. Smarter men have tried and they have made the best apologists.
He's writing on glass and the camera is filming the image in a mirror. Looking at prof from behind the glass we see him normally but the writing is in reverse. (Note in the demo he is right handed and his wedding ring and lapel pin are left handed.) Then turn around and see that image in a mirror. The prof is in mirror-image, (left hand writing, ring on right hand) and the mirror-image of reverse writing is no longer reversed. This always perplexed me, as much at times as the topic, until I was finally able to logic it out. Which brings me to a Request... Hey Prof, could break down for us why a mirror reflects an image with only left/right reversal, but not top/bottom reversal or any other reversal. Curious minds are dying to know
Three guys are in a boat passing the time fishing and trying to solve all the world's problems. About noon the Rabbi says he is hungry but that he left his lunch in the car, but he says no problem and he gets out of the boat, walks to shore, gets his lunch, walks back to the boat, sits down and has his lunch. His friend the protestant pastor decides he wants his lunch too, so he gets up, walks to shore and back, and sits down in the boat. The priest sees all of this and gets up, steps onto the water, and sinks over his head. The Rabbi whispers to the pastor, "Should we tell him where the rocks are?"
Easy to spot a Professor that loves his job.
Love the video's, watched em all. MORE PLEASE.
Videos
Wow, the squeaky markers are back!
edit: i know that it was shot long time ago, but still, i missed those!
Wait are you telling me that i am not going to be able to get my dose of squeak in the future?
@@florianlucs7229 I`m afraid yes, they changed the markers, like a year ago th-cam.com/video/WopPVns2-fk/w-d-xo.html
I had a friend in college who's parents had a house on Chesapeake Bay. We went out boating several times and once our friend Jou decided to try wake boarding. He couldn't figure out standing, so he decided to try boogie board style. Several of us tried to tell him he'd be like the skipping stone, but he was stubborn and insisted he would do it until he figured it out.
Well, he never figured it out, but he also refused to let go of the rope. He spent several minutes thwacking into the water before our friend Scott decided to turn around and pick him up. Joe's front of his body from chest down was red for a week.
I’ve been walking on water since I was two years old. . . I wait until December. . .
Damn, this guy is good!
Agreed with ProjectphysX. In the case of skipping stones and water skiing, it is a lift effect rather than a surface tension effects. That's fairly obvious because of the large forces involved. But more generally, it cannot be surface tension because firstly, skipping stones works when the stones are already wet. And secondly, both skipping stones and water skiing require, not simply tolerate but actually require, relative motion of the object borne up by the water and the water itself.
I was waiting for him to show the effects of a surfactant and how it destroys the surface tension of water.
This is the best channel in all of youtube
You, and this video, are a hoot, Professor Ruzic. I wish I could have taken classes from you even though engineering/physics was way out of my zone. Be well and keep putting up these great vids.
If I had Illinois EnergyProf as a college teacher, I would have never flunked out of the Physics department.
You've mentioned in a few of your videos the concentration of elements in seawater, so would it be possible for you to do a full video on the economics of extracting minerals from seawater? Have there been any proposals for it? Is it possible to do somewhat passively (with say, solar lenses and mirrors)?
I really enjoy your videos, I'm glad to have new ones
Nooooo, rain doesnt look like that. It looks like a chronicaly obese bowl
yeah. thing is, draw an upside down toothless frown and people gonna ask 'dafuq this supposed to be?'
Him explaining why the wrong shape is is supposed to be correct kinda triggerad me too.
But this is entry level stuff. Whenever they show the water tension paper clip, you know you're in grade school physics.
"I know about engineers. They love to change things." -- Leonard H. McCoy, MD
During World War II the US Army Air Force used the skipping on water technique in a dramatic way. It was too difficult to fly over Japanese ships and bomb them. To solve this problem both B-17 and B-25 bomber crews stationed at Port Moresby practiced flying low and skipping bombs into old wrecks. The results were both accurate and devastating. Wartime skip bombing helped decide the battle of New Guinea in America's favor.
The diameter of a water drop is about 4.5 mm by measuring cave soda straws, in the current surface gravity of the Earth.
In the Geologic Past, they may have been large in diameter when the Earth was smaller, and had a lower surface gravity.
This would be consistent with Sauropods being up to 15 times the Volume of Male African Elephants, and going farther back in time Centipedes were up to 2 meter long, and 1 meter wide.
For the water skier, it is not the surface tension keeping him from sinking. At that scale inertial effects dominate: the water cannot be pushed down fast enough and its inert mass resists.
For the skipping stone and the gecko it's also mostly inertial effects, but at this smaller scale surface tension still plays a role in the dynamics. Stone skipping should still work on ethanol for example, provided that the stone is fast enough.
I'd like to see someone try to ski on Non-Newtonian fluid.
@@tncorgi92 you would probably need wheels on the skies or else the friction would be too high. But you can definitely walk on a non-Newtonian fluid when you are quick enough.
water bug:
basilisk: "on your left!"
jesus: "hold my beer!"
How to walk on water "You must run very fast" Joel Gray in Remo Williams
am at 0:24 of the video. My guess - a plank of clear plastic
Waterbugs actually do float back up. I used to sink them to watch it happen is cool they trap air between there wing like flap and thorax.
Somebody get him a manicure :)
Would adding detergent (such as dish washing liquid) reduce the surface tension of water?
Yup. Fill cup to brim, put on a drop of liquid soap to see difference.
Walking on water? Like ice-skating?
No like Jesus Christ
Can you do a video on why ice is slippery? Thought I heard it’s also do to polarity of water?
The Prof is back!
You are the best commercial for you collage ... i wish i was younger i wouldn't mine taking classes from you , maybe some-day my kiddo's might take your class ,,, i had no-idea that UCI has a fusion reactor ... and a supper-computer ...
Love a good magic trick :)
For his next trick, he's going to make this pencil disappear ...
I only recently discovered this channel while researching radiation, but I could not quite make sense of channel's profile picture. (I mean you have the lecturer that is standing on top of water in the middle of a swimming pool. Quite random I'd say). But this video gave a little more context to the picture in question.
At the end. . That was the Jesus trick. Sea of Galilee doesn’t normally freeze. “It’s a Miracle”
Assuming you choose to believe a book written about 2k years ago who had an agenda to drive.
@@Mernom 66 Books, 40 authors, 3 continents. People who had no reason to lie about what they saw were murdered and testified unto death. All writing about the same thing. Historical Jesus was the most well documented event in human history. I'm an Engineer and I believe in God because when you study the sciences mainly biology you see the need for an intelligent creator. If you're a materialist you have a protein folding problem and a morality problem. Go ahead and try to prove the bible is wrong. Smarter men have tried and they have made the best apologists.
You forgot something really cool! Do those "indentations" made by the bugs follow Archimedes Principle?
I think I learned this when I was 8 years old, and yet my attention is maintained. HOW?
As always Thank You!!!!!
surface t e n s i o n
Anything you don't understand how it works is by definition magic. Once you understand how it works it's obviously no longer magic.
How to Play God Like an Engineer.
He's writing on glass and the camera is filming the image in a mirror.
Looking at prof from behind the glass we see him normally but the writing is in reverse.
(Note in the demo he is right handed and his wedding ring and lapel pin are left handed.)
Then turn around and see that image in a mirror. The prof is in mirror-image, (left hand writing, ring on right hand) and the mirror-image of reverse writing is no longer reversed.
This always perplexed me, as much at times as the topic, until I was finally able to logic it out.
Which brings me to a Request...
Hey Prof, could break down for us why a mirror reflects an image with only left/right reversal, but not top/bottom reversal or any other reversal.
Curious minds are dying to know
that's just a minute of physics... th-cam.com/video/1t4dOPxKgrY/w-d-xo.html :)
this was great
Three guys are in a boat passing the time fishing and trying to solve all the world's problems. About noon the Rabbi says he is hungry but that he left his lunch in the car, but he says no problem and he gets out of the boat, walks to shore, gets his lunch, walks back to the boat, sits down and has his lunch. His friend the protestant pastor decides he wants his lunch too, so he gets up, walks to shore and back, and sits down in the boat. The priest sees all of this and gets up, steps onto the water, and sinks over his head. The Rabbi whispers to the pastor, "Should we tell him where the rocks are?"
I love this one! Thank you -- an oldy but goody.
SQUEAKY MARKERS!
Back by popular demand, I hope.
❤
Criss Angel and 7 of his buddies disliked this video
Just infuse a bit of chakra to your feet.. It's basic genin stuff..
Thank you.
This was not up to his usual informative standard but I suppose the freshies have to start somewhere...
spoilers at 13.00
secret from profile pic.... Photoshop 😂
How too be gay like an Engineer...
??
Jesus Christ was never an engineer
Love the new vids, ditch the old markers.
It sounds like you need to do some research into what raindrops actually look like! (And now you've got another video topic, too!)
Most engineers are idiots when it comes to comment sense , ....I'm just saying........I know quite a few ,......WOW , IS ALL I'LL SAY