New “Marangoni surfers” that whizz along at 10,000 body lengths per second offer new insight into active matter propelled by surface-tension gradients.
Ultrafast, Self-Propelled Particles
August 25, 2020 | Physics 13, s110
Particles that propel themselves along a fluid surface-tension gradient that they generate themselves are called Marangoni surfers. To understand the dynamics of this form of “active matter,” researchers have generally focused on how macroscopic Marangoni surfers induce surface-tension gradients by affecting either temperature or surfactant concentrations.
Now, Kilian Dietrich of the Swiss Federal Institute of Technology (ETH) in Zurich and colleagues have investigated how both of these effects combine at the microscale, deriving a more comprehensive understanding of the factors that control the particles’ speeds.
In the process, they created micrometer-scale surfers that can race along at up to a few centimeters—or about 10,000 body lengths—per second.
The Marangoni surfers that the team created are thermally activated, meaning the surface-tension gradients that drive them are created by nonuniform fluid temperatures.
Yay! Another reason to horde gold:
Each particle is a silica sphere, one-half of which is coated with a thin layer of gold.
When the researchers shone a laser onto the particle, the gold-covered side warmed more than the bare silica side.
“Shone”?
The higher temperature lowered the surface tension of the fluid on the gold side, propelling the particle in the opposite direction.
There’s no business like Joe business,
Like no business I know;
Everything about it is appalling,
Everything the media will allow.
Nowhere else to get that water-hauling
If you are the nominee for now.
There’s no people like Joe’s people,
They smile when they know he’s low.
Even with a turkey that you know will fold,
If you’re candid, in doubt and too old,
Hillary had the gall to want it all, and the gold.
Let’s go on with the show!
The FBI, the Russians, the bumblers, the clowns,
The layabouts that make the show a myth.
The music, the spotlights, the people, the towns,
The baggage that their candidate came with.
Burisma and the purses and the smell,
The trollop Junior took to the last hotel.
There’s no business like Joe business,
Like no business I know.
Everything has his lawyers appealing,
Anything to distract from gaffe or gif.
Nobody can stop the man from feeling
When he is stealing that extra sniff.
There’s no people like poll people,
They smile when they know he’s low.
Yesterday they told you you would not go far,
That night you became the nominee, and there you are!
Next day on your dressing room they’ve hung a star,
Let’s go on with the show!
The contumely, scenery, the makeup, the props,
The Wallaces that lift you when you’re down.
The head-fakes, the long breaks, the brainfarts, the flops,
The doctor who escorts you out of town!
The outrage when Trump beats you like a drum,
The rallies to which even supporters won’t come!
There’s no business like Joe business,
If he tells the media, it’s so!
Travelling through the country is so thrilling,
Or standing on your front porch is just as right.
Smiling as you watch debates beginning,
And realizing that you should be there tonight!
There’s no people like Joe people,
They smile when they are low.
Even with a turkey that you know will fold,
If you’re candid, out-and-out sold,
Hillary tried to have all that, and a sack of gold,
Let’s go on with the show!
Man, it is hard to remember who Hillary had as her running mate in 2016. That guy barely gave an impression. It was like nominating “unnamed Democrat.”
It’s weird for me because I can easily recall the VP candidate on the losing side for every election up until Dukakis (I was nine during that election).
We’re not like those primitive idiots who burned books that offended them. We’re sophisticated. We burn DVDs. Or just delete from servers.
Hopefully by summer next year we’ll have a vaccine and have finished counting the ballots.
Remember when a president being impeached would be something worth bringing up?
What is Pete from Mickey Mouse? I guess he’d be a cat since he started opposite a mouse, but there is absolutely nothing cat-like about him other than his ears. He’s the worst anthropomorphized cat ever made. Medieval painters would reject him as looking nothing like a cat.
Wow Disney has gotten popular despite being so bad at drawing animals that all you can say for certain about characters like Pete and Goofy is that they’re of the order Carnivora.
Unless Goofy is a cow.
Apparently the story for Pete is that he started out as a bear but was changed to a cat when placed opposite Mickey. And he does seem between a bear and a cat, i.e., an indistinct mammalian blob.
Pete is definitely a character that would only fly when people were all “It’s a drawing that moves! I ain’t never seen such a thing!” When people were even slightly more discriminating, he would have been rejected.
“Here’s my new character, Pete!”
“What is he supposed to be?”
“A cat.”
“Have you ever seen a cat before?”
“We had a bear drawing, so we just added pointy ears.”
“How lazy are you?”
“Extremely lazy.”
builds media empire that eventually owns and ruins Star Wars
Watched first episode of Fargo season 4. It was good, but in one scene there was a closeup of a 1911 when it was fired, and the hammer just dropped and you saw a muzzle flash and nothing else. The slide wasn’t propelled back to recock the gun. It was very distracting.
It’s baffling that the left think they’re better than the people they rage again, but I’m guessing the Nazis had a pretty high opinion of their moral superiority too.
Antifa is an anti-fascist movement by people who can neither spell nor define fascism.
Remember: Voting is just the way the government gets your fingerprints on the murder weapon.
So when they make Amy Coney Barrett a Supreme Court Justice, will they send me a red robe and bonnet for my wife, or do I have to buy it somewhere? I don’t know where to get those.
And if dinner isn’t ready at a reasonable hour, will there be a special hotline to report my wife or do I just call 911?
“I said she’s a ROADS scholar. She knows a lot about asphalt.”
Ignoring politics is a luxury of people with lives and perspective.
Thanks to Hamilton, we’ve had to ban the kids from taunting each other with “You don’t have the votes!”
Isn’t Melania just accurately pointing out that no one actually cares about the kids separated at the border and they’re just a sometimes convenient political prop for some people?
I don’t think anyone in politics has legitimately cared about anything since the 90s.
It’s called “virtue signaling” because they’re public displays meant to signal one has compassion and tolerance even though the rest of their behavior testifies to the opposite.
The left are now about 50/50 promoting universal health care and cheering on people’s death.
Not all blue checks are bad. I have a blue check and I’m the coolest dude you know.
Though we like to play stupid politics games, remember that we’re all one country and we’re in this together.
I have no strong feelings on candy corn.
A song from Sound of Music came on Pandora, and it really stumped me when my daughter asked what that musical is about.
“Well, a woman becomes a nanny of like seven kids. Nazis are involved somehow.”
The take industry has to hope Trump is reelected because explaining why Biden lost and Trump won would involve lots of in depth analysis while explaining why Trump lost will be pretty straightforward.
Man, we’re going to get a lot of “What happens to the Republican Party now?” pieces, though.
It’s easier for a camel to go through the eye of needle than for a rich man to enter heaven. For a poor man, it’s probably more like trying to get a camel through a wedding ring.
I’ll listen to someone about how dangerous the ACB Rose Garden ceremony was from someone who was also talking about how dangerous the mass protests are. From everyone else, their concern about COVID just seems political.
What if at the end of a campaign ad it said “I’m Donald Trump and I don’t approve this message.”? What then?!
I wonder how often refs accidentally let go of a flag and then have to quickly come up with a reason for it so they don’t get in trouble.
“Rest in Power”? Sounds like something Arnold Schwarzenegger would say if he played Electro.
Oh, I missed the last thing everyone is freaking out about. I’ll just wait a couple minutes for the next thing to freak out about.
You can’t make health care a right. You can say “I’d like to try to provide high-quality health care for everyone.” Of course, probably the best way to do that is capitalism, but everyone has decided that’s too scary.
I can think of an example of when rights were denied in regards to health care, but it’s with the NHS when with Charlie Gard the parents weren’t even allowed to pay for a treatment to try and save their son.
Are theaters going to be able to last until next year when the big movies (hopefully) screen? They’re possibly delaying things a year just to drop it on streaming because that will be the only thing left.
Star Wars Squadrons is only $40 as a new release? What’s wrong with it?
When a big studio release isn’t even the now customary $60, that just makes me think they’re planning to make their money on microtransactions or something.
The desert island analogy is that since all rights should be innate, you would also have them on a desert island. So if you think something is a right, would it make sense to assert it on a desert island?
The key is that real right can’t be given to you. It can only be infringed by another — usually through violence or threat of violence.
Oscars for this year are going to be interesting. Certainly best chance for a Bill & Ted movie to win best picture.
Hopefully we can move past Trump to get things back to the way they were before Trump when things were so bad people were like, “Eh, might as well give Trump a chance.”
Okay, having watched Disney’s Peter Pan with the “What makes the red man red song?”, the “It may contain outdated cultural depictions” warning on Disney+ might be underselling it a little.
That said, much happier with the warnings versus the memory hole as has happened with some TV show episodes.
The Song of the South kind of mystifies me. Disney seems to have recognized that was a bad idea as soon as they released it and its never hit home media in the U.S. Yet, we somehow all know “Zip-a-Dee-Doo-Dah” despite none of us having seen that movie.
And I hear they may take the characters from Song of the South out of Splash Mountain not for being racist but I guess for being accessories to something racist.
Winchester loves climbing as high as he can and then diving off head first, such as off the back of the couch. It’s very nerve-wracking.
This morning, he climbed on top of a storage bin that was in the kitchen and dived head first onto the tile floor, doing a handstand briefly before falling on his back. He cried a bit and then climbed back up to do it again.
He is a bad baby. We need to get him in that baby military school.
A mouse ran into the bathroom while I was sitting on the can and for the first time ever I thought, “Maybe we should get a cat.”
I really don’t get what Trump’s strategy is. And since I can understand up to 8D chess, he must be doing at least 9D chess.
It’s hard to believe it’s less than a month until the election. It kind of felt like this would never be over.
Oh wait. Lots of mail-in ballots. It may never be over.
“Sorry, nothing here is vegan.”
“What about water?”
“Every time we pour a glass of water, we punch a cow.”
Speaking of old Disney movies that might not be quite appropriate anymore, I’ve never heard anyone get dinged for bigotry against the English, but Dick Van Dyke’s accent in Mary Poppins kinda feels like a hate crime.
I don’t even remember why everyone hates Stephen Miller — or even who exactly he is in the administration.
So is Tenet a shoe-in to win best picture this year? It’s only competition is like Bad Boys for Life and Trolls World Tour.
What’s the 538 odds of anything significant happening in a VP debate? I can’t even imagine anything occurring tomorrow that will move the needle at all unless I dive into scifi scenarios. And would we even trust a Trump from the future who emerges from a time portal?
