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Optical Tweezers and the 2018 Nobel Prize in Physics - Sixty Symbols
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- Опубликовано: 13 авг 2024
- More physics Nobel Prize videos: bit.ly/SSNobel
The 2018 Nobel Prize in chemistry: • The 2018 Nobel Prize i...
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This video features Professor Mike Merrifield from the University of Nottingham. Animation by Pete McPartlan.
The winners of the 2018 Nobel Prize in Physics were half to Arthur Ashkin “for the optical tweezers and their application to biological systems” and the other half jointly to Gérard Mourou and Donna Strickland “for their method of generating high-intensity, ultra-short optical pulses”.
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Lazer tweezers are Amazingk, just dont install them on Cats! \o7
5 mins? I'd listen to Dr. Merrifield talk for hours!
Sixty Symbols i would place a strong neodymium magnet near it to see if you can move it out of the light beam? 🤔🧲 🤷♂️
+Sixty Symbols
Do more nobel prizes please :D
This is so nice!! Keeps me up to date with new and important physics ideas quick and easy. Love it!
great animation and wonderful discussion -- thank you for sharing
*Making* such tiny spheres and lens is what impresses me the most...
Your lens could be bigger than that and the transistors in your phone are way smaller than this sphere so it is possible. But yes very impressive
Spheres are easy; controlling the exact size might be tricky, but you can just make a lot and then sort them. The lens might be harder, depending on size and shape.
this two can have great implication... in weapon industry i can imagine...so lets destroy ourselves:)
also that they can attach one end of DNA to that lens
You can buy them off the Internet for cheap. We used them for human cell dummies. Lot more sanetary and prepared use fit the real thing.
"Alright, he can keep his Nobel Prize"
You're too kind.
That part was funny!
Ohh it was his comment not your , i was going to comment ( that - Are you jealous ) you before knowing that 😃😄
11:32 later he said " i can win the Noble prize "
Dude, Donna strictland was my electromagnetism prof last year.
Which uni?
@@-_-8229 U Waterloo (Canada)
@@raintrain9921 oh cool.
Thank mr goose.
I'm in physics at u waterloo as well my man
What kinda fascinates me is how simple (on paper) this idea is, despite it's originality. It doesn't require much knowledge on the specifics to understand it, as it's literally just refraction and conservation of momentum and I'm fairly sure even a high schooler could understand the processes involved
12:04
Until you do the engineering part ...
the true is , it is difficult once you really understand what did they do. He just put it on lame terms for the average high school student to understand , but this is HARD to do.
@@The4stro same, have never taken physics, but the idea is so simple it is easy to understand
Engineering is where the real applications begin. And horrors to unveil.
I was invited to Gerard Mourou's lab once about 15 years ago. It was quite impressive. I got out of the laser business to do robotics, but it was a lot of fun back then.
These videos are the most inspiring thing in my life.
Brady was pretty challenging this time! I commend Michael Merrifield for his patience.
I love his questions tho. They teach me a lot as well.
After watching this I thought: Wow! Both of these actually Nobel-worthy ideas are so simple, yet so well explained here, that it makes one feel like any old layman could have come up with them and grabbed that prize... But of course "Understood instantly" does not mean "Able to invent". Question: How well does the glass ball suspended in a beam of light handle movement of said beam? Rotation, withdrawal, acceleration, etc. Say; If I point my laser slowly away from it, will the glass ball follow along? And what is the speed limit here? Rate of change; can it be high? As fast as light speed, perhaps? Or a non-epsilon magnitude / medium-sized fraction of it? Example: A sudden 180° will likely drop or launch the ball, losing it; but a subtle focal length adjustment or a nanometer push/pull will not. The subject will be re-centered by the various forces as shown in the animation.
Let's do a ballpark estimate. The limiting factor is how much acceleration can the beam put into the ball. The ball has known mass (m) and the laser has known power (P). Movement perpendicular to the beam is stabilized by the refraction. Let's assume the ball is perfectly transparent and that there is a position where it refracts the full beam perpendicularly. The acceleration of the ball is a=F/m. The force provided by the beam is its power divided by speed of light F=P/c. So the maximum theoretical acceleration of the ball is a ~ P/(c*m).
Off course in practice it will be less. We need to take into account absorption, the fact that the refracted beam is divergent, the fact that horizontal refraction may not be possible etc. All of these are some factor ~0.001.
We now may substitute some numbers. Wavelength of the laser is l~10^-6m. Volume of the ball is V=l^3=10^-18m^3. Density of glass is ro~1000kg/m^3, so the mass of the ball is m=ro*V~10^-15kg. The power of the laser is P~1W. Speed of light is c~10^8m/s. The acceleration is a~0.001*P/(c*m) ~ 10^4m/s^2 ~ 1000g.
I probably underestimated the size of the ball significantly. But nevertheless, the force seems to be strong enough that you can probably walk around with the suspended ball, but probably not enough to shoot it out of a cannon.
I would imagine that it wouldn't have a hard speed limit, but rather a point where it's accelerating so slowly it's basically not accelerating at all anymore (then a practicality limit where the laser will refract over a long enough distance). The closer it gets to the speed of light, the more energy it's going to need to accelerate. At some point this will mean that the tiny force being exerted is still technically speeding it up, but not really in any measurable way. Objects with mass cannot reach the speed of light because the energy requirement to speed it up approaches infinity as you get closer it. Might start out kind of fast though, the fact that they can hover it means it's counteracting it's natural 9.8m/s acceleration towards Earth.
I got some pretty amazing mathy replies. Thanks guys! I really appreciate the free education you've given me this day. + Make sure you click "Show more replies" and "Read more" on each of them, to learn like I did. Especially comments by Victor Titov, KohuGaly, and psmitty840. Huge thumbs up to you all.
@@x3ICEx it should track the beam if done slow enough, but you gotta look at the scale, tiny glass beads might be finicky if you moved em by hand. tiiny adjustments, not so much movements
I'm curious what the limit is for the amount of mass you could push with a laser and how much power you would need to move large masses. This reminds me of the classic tractor beam where you have a beam of light that holds a spaceship in place and can even pull them closer.
As a young Australian aspiring to be a filmmaker, all of Brady's videos are very inspiring. Keep up the great work!
I love your interactions with all people you make videos with. It seems like you have bonded over the years.
The UFO lightcone in cartoons, picking up cows must work this way!
If the cow is round enough and doesn't get toasted on the way up...
Well, maybe they're just looking for some delicious earthly beef.
No, as both gravity and the force of the laser are pushing them down - the opposite direction.
@@PolemicContrarian 1)laser can reflect from ground might work
2)Cow have gravitational pull so if you will light not cow, but area around it then light should be get bend by gravity of the cow. So now it move under some angle, which means it lost some of its downwards momentum. And by laws of conservation cow should be accelerated up.
P.S.: i know that you just can't make this powerfull laser without destroying half a universe, but whatever
2:47 that auto correction method reminded me with the belt on crowned pulleys correction mechanism in a mechanical system.
Also similar to railway tracks.
How do you glue a molecule?
In soviet russia molecules glue YOU
Maybe with static electricity
Airfix cement
Flex tape
Elmer’s
It’s probably some kind of chemical bond
"...so simple and because of that so elegant..."
exactly the point of great science
Well, it sure _felt_ like a five-minute video ;)
I love that these nobel prizes, especially the first one, are easy enough to be understood by high school students! Props to the winners and thanks prof for the explanation :)
With all the infotainment rubbish on youtube, its a pleasure to see some gem quality offerings. Thank you!!!!
Yes, there is great ingenuity in making extraordinary material advancements starting from the obvious approach.
This second NP looks so much like a patentable invention rather than a discovery.
Yes, and I think it was patented. I would be amazed if it wasn't.
@@ronaldderooij1774 Don´t be. The guys who invented the transistor famously did not depriving IBM from controlling the world and PhDs are often considered public.
@@ronaldderooij1774 it is not patended. you can build your own cpa laser system and sell it.
It's like how the Bernoulli effect holds a ball in a airstream. Only with light.
and without the air passing through the ball...
nah not quite
Exactly like that! Nicely done.
Darik Datta exactly what I though, I use to levitate a pingpongball with a hairdryer when I was little kid
Amazing stuff and it's great that students are being rewarded as well. It's got to sting a bit for past students having been over-shadowed because it's hard to parse thoughts and effort during semi-collaborative PhD level research.
I would love a series of videos in which each professor explains his specific field of research and his current work, I think would be really interesting.
I remember seeing this in the local paper. Bell Labs in Holmdel NJ. The really old guy was once a high school teacher in Holmdel High School. Bell Labs, Holmdel no longer exists and was abandoned a while but now is in a revival as a telecom research and business office building with housing around it. If you want to read about it, look up Arthur Ashkin in the Asbury Park Press. When Bell Labs shut down, many of the employees became teachers and professors in our area. Many of my science teachers who are older worked there when I was in HS.
The invention of Laser tweezer is a great idea. Deserves the Nobel prize. Congratulations.
He was right, y'know. Each of these two concepts took on average about five minutes to explain.
can't help but notice prof Merrifield changing with time. Been watching this channel from the start,basically growing up with these people.
I love how elegant and simple the amplifier is.
I apologize - haven’t read the paper but I’ve got a hypothesis RE the question about momentum transfer: Refraction occurs due to molecular transformations in the glass altering the electric field part-way constituting the photon (collectively summarized by dielectric constant of glass). This deformation suffices to explain momentum transfer.
Brilliant brilliant work to all scientists and grad students on this project.
Glad to see you bring out that an interference pattern was needed to create the short burst, but does the initial laser pulse naturally develop the best frequencies to create this interference pattern?
This is such an amazing channel. Complex ideas explained in a way that anyone can understand. Thank you for all the amazing work.
This channel is so amazing, makes me feel like I'm still in touch with physics
My faculty advisor is a Biophysicist and was excited when this Nobel Prize was announced!
Ah, see, that's why I find it so hard to move when it's bright outside. Great info, thanks! I will stay inside now.
wow, a teacher that can actually teach. Prof Merrifield is great at distilling the concept down to an approachable morsel.
This is mindboggling, because in the same object (this ball) light behaves both as a wave and a particle. Makes me realize how little we understand what the universe is, and the great lengths we went to try to understand them.
Ok for the conservation of momemtum, but what about the conservation of energy ? If momemtum (energy)is given to the sphere then what happens to the light that passes through the sphere ? How did it lose energy ? Did the wavelength change ?
Most likely the bead was heated up slightly.
Wavelength increases. However, because the bead is so much heavier than the photon, very little energy is transfered. Imagine the photon is a small ball and the bead is a boulder: when the ball hits the boulder it bounces off with the same speed and same energy, however it did transfer double its momentum to the boulder because it changed direction.
There is no solid that can be 100% clear to a wavelength of light, therefore it will absorb some of the electromagnetic energy as it passes through. Since light has momentum, and that must be preserved, the glass bead will gain a net increase in momentum away from the light source, and grow warmer as it absorbs energy. The scientists simply used clever lenses to adjust the angle of the net momentum gain of the bead to work in their favor.
Somewhere in the Dan Simmons 'Hyperion' series they briefly describe a white laser used as a spotlight from the distance of AU
I have to give a presentation on this in a week, and the explanation here is incredibly helpful. Thanks so much!
Noble prize!!!!!!!!!!!! I always believed that understanding this would be not my piece of cake but this video is an eye-opener. The best-simplified explanation that I ever came across.
What size and mass is the sphere?
How powerful is the laser?
All scientific researches are published for everyone to read. For the technical aspects and the full explanation of the processes described above, you need to search for the original papers submitted by the authors. On the second case though, the research said it was done while Dr.Strickland was a Ph.D. student so expect a > 100-page read.
There is a video of a dude levitating diamond dust with one of his overclocked lasers, you can actually see it
Extremely well explained
I miss sixty symbols's videos, kindly upload them more frequently
Why wasn't there a 2016 & 2017 Nobel Prize video?
the interviewer doesn't seems very bright in physics but his ability to scrutinize the facts and then ask uncanny questions are commendable
When you run water over a boiled egg in the bottom of a pot, I've noticed the egg will tend to roll itself into the stream, ending up basically centered under the water. I only noticed this recently, and found it really funny that it wasn't something I'd heard about growing up as, like, some pop science tidbit from Bill Nye or something. Maybe it's common knowledge, and I just missed that episode...
What exactly do you mean?
It's similar to how a strong stream of air can capture a capture a round object. If the fluid hits the round object off center, it will follow the curve and pull the object towards the center of the stream (the result is even stronger if the object can spin)
I think some demos were done with a ping-pong ball and a hair dryer
Just out of intrigue, isn't the principal of levitation mentioned in the video very much similar to acoustic levitation. But I know for sure that in acoustic levitation you need nodes of interference from different frequencies to levitate things can't see how that happens for a laser.
Someone in an earlier comment names this speaker as Prof. Merrifield, Thank You, Prof Merrifield, for explaining this so well. Very interesting. Love & Peace to All
Love these coffee-chat style talks. Super informative but super casual
For the optical tweezers, why not just shine another laser beam shining in the opposite direction? So it would also provide the same push toward the center of the beam (call it up and down) but oppose the first lazer (call that left and right.) There must be a n obvious answer, but I don't see it.
If you need to use in any practical applications, eg medically, it would be hard if not impossible to get light from the direction of the body, wouldn't it? So a solution would then have to be found anyway.
I assume it just would be tricky to balance to amplitudes of both beams so that you cancel the drift effect. The brilliance of the lens solution is that its a self correcting solution - a small drift in one direction makes for a stronger counter force to fix it. In the case of two opposite lasers, if they aren't perfectly balanced (which is hard to do) you won't get the self correction feature.
Also, if nothing else, it would be tremendously fiddly getting the laser beams aligned right, especially if the beads you are talking about are microscopic (which they generally are).
Probably the same problem as trying to balance gravity by pointing the beam upwards (i.e., hard to get it perfectly balanced, you end up with a drift). With two beams you'd have to line them up perfectly _and_ balance their intensities perfectly. This system is self-balancing.
You also get the problem that whatever machine is creating your laser beam is now having a laser beams fired directly at it.
Great video! Smarter Every Day sent me over here, and now I'm a subscriber.
Please explain an experiment on reversibility if fluid motion
9:36
I know that sine waves are the building blocks of a fourier transform, and that a perfect single sine wave goes on to infinity. However, as everyone likes to quote, you can add up numerous (infinite) sine waves to generate a tighter and tighter pulse. My question is, how do you add up infinitely repeating sine waves to generate a pulse located about a single point. I do understand how waves come together to make square waves, and triangular waves, and any other repeating structure, but how can it possibly make just a single point that never repeats all the way to infinity?
I guess, another way that I could explain my question is, what waves of the form 'A+Bsin(C+Dx)' do you need to add to the simple sine wave 'sin(x)' that starts you on the journey to a single, discrete pulse?
While watching another Sixty Symbols video (Feynman Diagrams) I followed up a passing reference to a guy called Stueckelberg. Now I'd like to suggest a video about Baron Ernst Carl Gerlach Stueckelberg von Breidenbach zu Breidenstein und Melsbach, to give him his full name.
Quoting from Wikipedia: "Stueckelberg developed the vector boson exchange model as the theoretical explanation of the strong nuclear force in 1935. Discussions with Pauli led Stueckelberg to drop the idea, however. It was rediscovered by Hideki Yukawa, who won a Nobel Prize for his work in 1949 - *the first of several Nobel Prizes awarded for work which Stueckelberg contributed to, without recognition* ".
so easy to understand!!
Best channel to underdstand every year's nobel prize
I was using optical tweezers back in college. It was used to turn and rotate cells. I was also using electricity standing waves to do the same thing. But these lasers were more troublesome than the electricity method. So just replace the glass bead with a human cell and that is what I was doing.
Hey..how come same light is deflecting in two different directions..one upwards and one downwards?
I have a few newbie questions. Why does the glass/ plastic sphere stay in place in the laser beam? Although the gaussian beam is brightest in the middle is the gradient the same downwards and upwards? if so why is the particle displaced slightly up and not down. force of gravity acting on it should keep it displaced slightly down in my newbie mind.
Brilliant all around
@5:02, does this remind anyone of Tsuna from katekyo hitman reborn, when he learns to balance himself while shooting a hard and focused flame in front, while supporting himself with a soft wide flame backwards?
Classic adventure games taught you right: combine everything with everything until you get results.
It's not only a pair of tweezers it's also a scale or an attenuator or a pressure gauge all types of uses can be made of that how brilliant
So optical tweezers are a Piezoelectric locking or rather balancing effect.
Very clear explanation. Thanks to Destin for pointing me to this!
Great video. Explained in a very amazing and intuitive manner.
Awesome explanation and great questions
Is it possible to measure gravitational waves using this very sensitive apparatus? (incidentally, LIGO also uses light but a very different property of light)
I wonder if this could be used to measure whether ordinary matter repels antimatter
Can you do a actual double split experiment that would be the coolest thing on RUclips
Thank you this was easy to understand and helped me loads.
This is a very informative videos about this topic. Really really mind-blowing and easy to understand this clever new discovery in Physics
As with most Nobel Prize winning concepts: the solution is so elegant, I could have invented it myself
that is so cool .. darn! in those moments i seriously love physics!
if you want to get more people into stem .. show them such hands on, brilliant solutions for physical problems.
NORMALIZE THE MIC INPUT PLEASE I'M LISTENING OUT LOUD ON SPEAKERS THANK YOU
Wait, but if there is some mechanical process of the photons which get refracted hitting the sphere, mustn't the photons lose just a little momentum so they aren't moving at lightspeed anymore or am I missing something?
I know that a wave with a large amplitude is low energy (e.g. radio vs gamma), so how could it destroy the amplifier as opposed to the shorter waves?
Why is the light scattered in that pattern after entering the glass bead from being focused from the microscope lens? And why does it diverge from that specific point within the bead? Cheers.
What makes the beam combiner stronger than the amplifier, such that it doesn't melt?
the phrase in 2:45 why??? shouldnt the particle be pushed in the same direction as where the light is pushing him ??
Rudolf Mössbauer also got his Nobel prize for his PhD thesis work, actually receiving it 3 years after his defence. And that was back in 1961.
I like this Merrifield fellow. He's quite intelligent in his explanations.
heremsalillaserbeamwithstuffinnamiddle AND HERE'S OUR LITTLE SPHERE
Haven't they been using the pulse synthesis thing in radar systems for quite a long time?
I love these guys! Great questions and great explanations
How wonderfully elegant these applications of physics are! The ideas are simple enough that I could explain them to my 13 year old, but the beautiful thinking it took to invent them is stunning
What if, instead of the recombiner, they put a mirror, so light gets amplified again, and the "light splitter gizmo" works as recombiner, too? (if it's optical like in the drawing)
Fascinating to say the least!
We use it to measure protein denaturation energy, to understand the changes it needs to make to catalyze a reaction, a biochemist assembled it himself!
How does the same light passing through the same medium gets reflected in two different directions?
Force diagram would have helped us understand more easily. Thanks for the explanation though :)
He explained it in terms of momentum...
I wonder if this kind of technology if scaled up can be used to help with a space elevator 'car'. Using lasers strong enough to beam straight upwards. It may be more economically or environmentally efficient/friendly.
Energy also has to be conserved. So, no I'm not buying your explanation. Unless you are saying that the photons are losing energy to red shift as they go through the sphere. But I believe that the electron lattice resonance structure would absorb single photon energy when the resonance gets too far out of alignment creating that mystifying transfer of energy. But still, interesting stuff.
The momentum comes from the time lost in slowing the light through the sphere in order to refract it
Just how small are these spheres? Does this scale up or is there and upper limit because of gravity?
The 'tweezer' seems to have a venturi effect, around the sphere, (or maybe inverse venturi), and the sphere looks to have a positive bouyancy in the beam.
I may be reading too much into it.
i didn't understand, how the lens is manipulating momentum, i mean the mass of light refracting from the other side is same as that hitting the sphere, how can area of light emerging , change the momentum?
Everything spoken in this video is a beautiful truth.
if light has momentum, could you use a laser to propulse a spacecraft (ignoring all de ingeniering issies as the amounght of energy you need and so on). Cause, i´m thinking right now, if you could had a sistem that catches lots of energy from the sun (a super solar panel lets say) so as you have enormus amounght of energy stored into your bateries, and you use it to run a powefull laser, could you get any propulsion? it would be as de solar sail but directional.
Can't be explained more clearly than that
Full of light!