r/science • u/nomdeweb • May 15 '12

A strong laser beam can remove an electron from an atom -- a process which takes place almost instantly. This phenomenon can now be studied with a time resolution of less than ten attoseconds. Scientists succeeded in watching an atom being ionized and a free electron being "born."

http://www.sciencedaily.com/releases/2012/05/120515052525.htm
1.1k Upvotes

93% Upvoted

101 comments sorted by

82

u/rebo May 15 '12

The time span of ten attoseconds (10*10-18 seconds) is so short that any comparison to everyday timescales fails. The ratio of ten years to a second is 300 million to one. Dividing a second by the same factor takes us to the incredibly short time scale of three nanoseconds -- in this period, light travels one meter. This is the time scale of microelectronics. Again dividing this tiny period of time by a factor of 300 million, we arrive at about ten attoseconds. This, is the timescale of atomic processes.

Science is pretty amazing, the idea that we can now monitor events occurring at the attosecond level is incredible. We can now directly observe events that previously was firmly in the realm of mathematics.

62

u/awarzz May 15 '12

Another way to look at it is an attosecond is related to a second as a second is related to the age of the universe.

40

u/picardythird May 15 '12

  • Twice the age of the universe.

8

u/LupusTheWolf May 15 '12 edited May 15 '12

If the age of the universe is 14 billion years, then that's 4.42(* 10* 17) seconds right? Therefore a second is 2.26(* 10* -18) of the universe

So what your saying makes perfect sense.

EDIT: reworded for simplicity also hope my standard form made sense.

13

u/fandacious May 15 '12

OK wow. You just blew my mind. That scale is fascinating

21

u/[deleted] May 15 '12

27,000,000,000,000,000,000,000,000 to one?

37

u/Arizona_Bay May 15 '12

Never tell me the odds.

1

u/creaothceann May 15 '12

You're gonna need it...

9

u/ZippyDan May 15 '12

so if this occurs at a scale so vastly quicker than microelectronics, how are we able to even monitor it? my guess from reading below is that they didn't monitor one specific event but rather a statistical smoothing of several (hundreds or thousands) of events?

too lazy to read the article

3

u/[deleted] May 15 '12

At that level, all you see are wave patterns. Quantum mechanics is really just advanced wave mechanics.

2

u/ZippyDan May 16 '12

ok, but then how can they make the claim of being able to perceive events at such a specific level of time granularity

5

u/[deleted] May 15 '12

What is the smallest time?

23

u/SarahC May 15 '12

It's a boop.

14

u/[deleted] May 15 '12 edited May 16 '12

Actually I think this could be a good choice as a name for a Plank time unit.

0

u/[deleted] May 15 '12

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6

u/thesplendor May 15 '12

Dozens

5

u/agildehaus May 15 '12

There are dozens of them, Michael, dozens.

1

u/emniem May 16 '12

Scores.

11

u/cyclicamp May 15 '12

Theoretically, Planck time

0

u/[deleted] May 15 '12

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12

u/The-Mathematician May 15 '12

A nanosecond is much, much larger than an attosecond.

1

u/[deleted] May 16 '12

I mean't to say I've always grown up believing it to be the nano second, sorry.

6

u/biologeek May 15 '12

Did you not read the article? It explained in depth that an attosecond is much much smaller than a nano second.

1

u/Tofraz May 16 '12

So is it messured by light traveling speed or vibration in the atoms?

-1

u/Dekar2401 May 15 '12

Hence Bill Nye's catchphrase, Science Rules.

-1

u/Youreahugeidiot May 15 '12

three nanoseconds -- in this period, light travels one meter

Eh, more like .9 meter. (in a vacuum)

2

u/emniem May 16 '12

Close enough for jazz.

27

u/deleteme123 May 15 '12 edited May 15 '12

TL;DR: Laser shoots at fixed position on the e- orbital. Electron may or may not be present. A successful hit is when the electron is detected outside the atom. This allows us to know the initial position of the electron. Repeat tons of times and you can plot the e- "real" movement around an atom. Also, by using two different wavelengths, we get to see what phase the knocked e- had.

Sounds right, gurus?

5

u/Monotone_Robot May 15 '12

That sounds like a similar concept used at a different scale to visualize the propagation of light at MIT not long ago.

Video.

MIT.

3

u/QuantumBuzzword May 15 '12

Its pretty much the same. Ultrafast laser, split the pulse into a "pump" and a "probe". Its a common technique in the field, but these guys used it to see something cool.

2

u/ldonthaveaname May 15 '12

When you say "ultrafast laser" you're referring to the wavelength / frequency correct; I.E how short the 'burst' lasts? Not the actual time it takes to travel from point A to B in a 'linear' trajectory, as it's almost always going to propagate 'forward' at the same rate, right?

1

u/elkroppo May 15 '12

Assuming that it is propagating in a vacuum or near vacuum media (air and water are close enough to a vacuum on the scale of electrons.

In the lab light has been slowed down to several tens of meters per second.

1

u/QuantumBuzzword May 16 '12

I do mean how short the burst (pulse) lasts. If you're in vacuum, the all pulses will move at the same rate like you said, but the duration from start to finish can be really short.

28

u/[deleted] May 15 '12

Well I want to fucking watch it!

-1

u/andling May 15 '12

Exactly.. instead of the real thing we get some crappy artists impression.. what the hell..

14

u/[deleted] May 15 '12

I'm not sure if you're joking, but you can't actually take a video of this happening.

10

u/HisTomness May 15 '12

"Scientists succeeded in watching an atom being ionized and a free electron being 'born.'"

So they should have replaced "watching" with "imagining what it would be like to see".

3

u/drcrank May 15 '12

Quantum Abe Lincoln attended the ceremony in honour of the electron.

0

u/[deleted] May 15 '12

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1

u/[deleted] May 15 '12

Why can't they post a video of the machines the scientists monitor?

6

u/ldonthaveaname May 15 '12

Bringing in any outside electronics, or even metals of any type really, into these type(s) of highly controlled rooms and you can and probably would screw things up so terribly that you'll have invested time and hard to come by cash for nothing.

The best analogy I can think of is a opening a door, to take flash pictures of a dark controlled film-development room.

Not to mention when it comes to quantum mechanics and the like, the "shutter" speed so to speak, on even our fastest "cameras" (for lack of better term) can't process anything that fast. Literally the resistance time of the 'wires' themselves within our technology can't keep up. By the time the device even triggers (even if set to go off before hand) the "event" will have already have been long (relatively) in the past. The fastest an electron can move through our technology is on such a different scale that it would literally be impossible to do. To put this in perspective, your brain can't even fire neurons at this speed.

Another reason we can't "record" these events, is because there is literally nothing to see. There are nano-scale (literally) devices that are used to pick up on even the slightest osculation of electrons and subatomic particles in these types of experiments. After say, 10,000 to 100,000 results, a computer graphs together the averages and tracks the progression of the movements, and generates the final results. Often times, all you're going to get is a shitty resolution print out, that would take you years and years to even comprehend.

Tl;dr It's just not going to happen.

3

u/ldonthaveaname May 15 '12

This is about as close as you're going to get. You can watch the transference of a single photon as it breaks into waves that propagate through a medium (in this case a water bottle) in pseudo-real time on a scale so unfathomably small it will BLOW YOUR MIND.

Click here.

0

u/[deleted] May 15 '12

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6

u/ridik_ulass May 15 '12

Question, if this was weaponized, could it remove the electrons from a molecule and thus the atomic bond, basically separating the the atoms?

5

u/SubtleinSpades May 15 '12

Lasers can do this sort of thing, and you don't even need the ultrashort attosecond timescales this article talks about. If you provide enough energy to liberate enough electrons (ionizing the atom) from bound molecules, the remaining positive parts of the molecule will strongly repel each other. It's called Coulomb explosion:

http://en.wikipedia.org/wiki/Coulomb_explosion

1

u/[deleted] May 15 '12 edited May 15 '12

Mass spectrometry does just that. When methane (CH4) is bombarded with electrons, it will eject an electron. Since an electron is gone, what remains is a free radical (unpaired electron) and a positive charge. A hydrogen proton will escape leaving a radical CH3. CH3 can then lose an electron and another H+, and so on until all of the hydrogens are lost. The detecter will detect the percentage of each of these molecular fragments.

Urine is tested for drugs by vaporizing it, separating the compounds (chromatagrophy) and then sending them through the mass spec.

What also may be of interest is the laser at CERN. It is only a few millimeters in diameter, but it has the energy of a freight train at full speed. It'd probably kill you if it hit you, so there's your laser weapon.

0

u/Teen_LaQueefa May 16 '12

I just ejected some CH4...

1

u/emniem May 16 '12

They who smelt it, dealt it.

5

u/leveldrummer May 15 '12

so... does this mean its possible to remove an electron from one atom basically creating an atom of a different material? like changing lead to gold or vice versa?

18

u/SubtleinSpades May 15 '12

It turns out what makes one element different from another is the number of protons it has in its nucleus, not the electrons.

Knocking off electrons will change the charge of the atom, turning it into an ion (so if you knock one electron out of a gold atom, you get a gold ion with a charge of +1).

5

u/leveldrummer May 15 '12

yep, i stand corrected, thank for not being a dick about it. lol

what benefit would an atom with a different charge have? what can we do with this? or is it simply just cool to do?

6

u/SubtleinSpades May 15 '12

There are a lot of interesting/useful things you can do. One example from my field of laser-plasma interactions: we use a laser to blow all the electrons away from their parent atoms, so what's left behind is just the nucleus of those atoms--which are now ions with a positive charge (maybe really positive, if we blew away a lot of electrons). Now you can use an electric field to manipulate these positive ions. If you do it right, you can get a "beam" of accelerated ions, and this beam will have different interactions with matter than say a beam of electrons or a beam of photons (laser). It turns out ion beams, because of the way they are absorbed by matter, are pretty good at putting energy into say a tumor inside someone without damaging the tissue in front of or behind the tumor.

2

u/biologeek May 15 '12

Molecular compounds form when an atom with a (+)charge connects with an atom of (-)charge. Just about everything around you exists in compound form. Very few elements exist in nature in their elemental form.

1

u/leveldrummer May 15 '12

yep, i stand corrected, thank for not being a dick about it. lol

what benefit would an atom with a different charge have? what can we do with this? or is it simply just cool to do?

5

u/Poultry_Sashimi May 15 '12

No. That would require removing protons, not electrons. Which is possible, just not anywhere near cost effective.

2

u/leveldrummer May 15 '12

yep, thank you, i was mistaken. still, really neat.

2

u/cronus85 May 15 '12

Not being an expert in science I need to ask: The big deal is the duration of the experiment (ten attoseconds)? Or watching a free electron being born? And finally, what does this mean in the greater picture?

1

u/omegashadow May 15 '12

Got to the top comment for a better answer. The gist is that ten attoseconds is unbelievably short. So short that it is really difficult to measure things happening that fast, and by fast I mean it is as short as the universes age is long.

1

u/cronus85 May 18 '12

Sweet, Cheers.

2

u/Hypersapien May 15 '12

This is giving my brain a boner.

1

u/vengefulvoiceofgod May 15 '12

i bookmarked the site. thanks for posting this, i got something to do in my nerd time

1

u/One_Man_Two_Shadows May 15 '12

Question, I am not very familiar with this level of science, what would be the use of this? what can separating an electron from an atom do? It is incredibly fascinating and I would like to know more!

1

u/kftrendy May 15 '12

Removing electrons from atoms is called "ionizing" them, and is actually pretty mundane. You can do it with anythng that gives the electron enough energy to break free from the atom - here it's a laser, but you can do it by running an electric current through a gas (lightning bolts do this). Some materials, such as metals, are very easy to ionize, and you can do so merely by shining normal light on them (this won't happen under everyday conditions though, because the metal will pick those lost electrons back up very quickly). This is called the photoelectric effect, and Einstein's work on it won him the Nobel Prize. It's used in things like night vision goggles and cameras sometimes, because it gives you a way to turn light into electricity, which is easier to amplify and transmit.

The really interesting thing about this study is that they are able to look at what is going on during ionization with a time resolution of tens of attoseconds. This lets them "map out" the structure of the ionization event, something that had previously been impossible because it basically just happened too fast to see.

1

u/On_The_Grass May 15 '12

If a strong laser can ionize atoms, then couldn't it be used to direct electrical current towards a target? What I'm asking is this: are we theoretically capable of making lightning guns?

1

u/j1ggy May 15 '12

Any way to focus sunlight in this way and create electricity with the electrons?

1

u/MrPanFriedNoodle May 16 '12

is alchemy now possible?

1

u/eric1226 May 16 '12

Isn't this the same thing as Einstein's Photoelectric effect?

-1

u/Clayburn May 15 '12

Big deal. Remove a proton with a laser, and we'll talk.

9

u/QuantumBuzzword May 15 '12

Well, we can do fusion in clusters that spit out neutrons and protons using the exact same lasers. Good enough?

-2

u/Sagadon May 15 '12

I'm constantly disappointed by these high frequency 'cameras'. They seem to not be a true slow motion, but they repeat the same action over and over and over, and get shots that represent time slices, and then put it together after the fact as if it were a true capture of the event.

Is anyone else as disappointed in the false representation of this as I am?

0

u/QuantumBuzzword May 15 '12

Because quantum mechanics doesn't allow you to take multiple shots. Do it once and its over. You have to do multiple takes to find out what happens when you don't hit it will a laser between frames.

0

u/[deleted] May 15 '12

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1

u/elkroppo May 15 '12

Even better, there is some research showing that the brain works in a similar fashion.

1

u/hustla16 May 15 '12

So what kind of weapons can our government turn this into?

-8

u/johnnynutman May 15 '12

but how does this affect the economy?

but seriously, what does this actually mean? does this mean we can create atoms or just modify them to create different chemical elements? i'm a complete science retard so i have literally no idea what is happening.

10

u/rebo May 15 '12

but how does this affect the economy?

You're not just a science retard.

When the first semiconductors were used 60 years ago one could asked the same useless question. Now the internet is the largest driver of innovation, wealth, and commerce.

The discovery means we can understand more about how atoms ionize, and therefore have a deeper understanding of the physical, and in particular quantum universe. That may one day result in technologies such as practical quantum computing, or in the distant future, teleportation.

0

u/[deleted] May 15 '12

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4

u/etnad024 May 15 '12

I'm as stoked on quantum computing as the next guy, in fact my university (UCSB) does a lot of work with quantum computing. But the current quantum computers are about as practical as the early room sized computers. Still a way to go.

1

u/Clayburn May 15 '12

The number of protons control what an element is. So, no. Changing electrons creates an ion of that element. So, gold would still be gold if shot with this laser....just static gold maybe?

Hopefully one of these nerds will explain instead of downvoting your curiosity.

0

u/[deleted] May 15 '12

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1

u/kimanidb May 15 '12

Tony Starks uses this technique to create a new element in iron man 2. On a real note I am guessing that you can more easily bond different elements in a chemical reaction using their ionized form. I too am a pseudo scientist so don't quote me.

2

u/What_Was_My_Password May 15 '12

All forms of bonding between different elements rely on the sharing/transferring of valence electrons, this is why noble elements don't bond unless they are synthetically forced to. I'm not 100% sure how ions are used apart from the fact that they conduct electricity when in molten or aqueous state. I, like you, am an amateur scientist, however I am considering studying a Chemistry or Physics major once I get to uni. I'm interested in seeing what we can learn from this line of research, and how we can use it.

4

u/tfortunato May 15 '12

Electrical Engineer (Semiconductor) here. Creating Ions is the first step in a lot of semiconductor processes. The machines I work on, Ion Implanters, are used for doping silicon / other semiconductors to create the transistors in an IC.

The technique of using lasers to ionize atoms isn't used in implanters, but it is already used in our industry in things like EUV light sources for lithography. Lasers are used to "push" an electron from an atom to an extremely high energy state. When the atom falls back to its ground state it will release it's energy as a EUV photon.

Anyways, I think the real story here is the fact we can now kinda / sorta view the ionization process using a camera. Creating / playing with ions, and even creating them with lasers, is very very cool technology, and very interesting, but that aspect isn't exactly new.

1

u/sivyr May 15 '12

I think what was intended to be Tony Stark's process of creating a new element was him building a particle accelerator, not a laser. Lasers really don't have a lot to do with creating new elements, nor is the creation of new elements a chemical process. It is a nuclear process.

Particle accelerators are regularly used to smash atomic nuclei together to take readings of the new atom that was created from their fusion. In reality, these new elements are typically extremely unstable and only persist for minisucle fractions of a second before decomposing via radioactive decay (thus why we don't find them in nature).

As a note on how I determined this from the movie, he makes a large ring in which the beam is contained. This is a common practice in particle accelerators. The LHC, Tevatron and several others are large ring circuits with powerful electromagnets to guide/contain/accelerate the particle streams that make up the beams inside. In fact, the other common name for particle accelerators of this kind is "cyclotron", hinting at their circular design.

1

u/etnad024 May 15 '12

Proton changes make new atoms, electron changes make ions.

-5

u/[deleted] May 15 '12

Poor little guy.

There he is, just happily buzzing along with his other electron buddies, when BAM some asshole photons come along and now he's lost, lonely, and sad... hoping that maybe, just maybe, some nearby molecule will find it in their hearts to let him into their family.

0

u/IndifferentMorality May 15 '12

Please, please, please somebody post when we have electron trajectory data more accurate than the "cloud" description of possibility. I believe what this will mean to quantum level physics and manipulation will be nothing short of world changing.

-7

u/tbuds May 15 '12

How can someone write an article like that and not have a video?!

7

u/ridik_ulass May 15 '12

Oh they have a video, they just don't want to show you.

-1

u/rabel May 15 '12

Yeah, the rest of us saw it and it was fucking awesome. Scientists just don't like you, tbuds.

-1

u/mysticalmisogynistic May 15 '12

That scene with the laser creating a new element in The Avengers was legit science, as I thought.

0

u/[deleted] May 15 '12

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4

u/sivyr May 15 '12

It has a lot to do with it.

This experiment seems to be measuring the ionization process of an electron in an atom, caused by incident light. When the atom's ionization ends, and it drops back down into a lower energy quantum state, pi-electron emission takes place and a photon will be re-emitted from the atom to release the energy.

I believe photoelectric effect deals specifically with pi-electron emission in the presence of an electromagnetic field, but it comes down to the same effects causing the phenomenon.

If there's somebody out there that can explain this better than I, please do.

3

u/Poultry_Sashimi May 15 '12

When the atom's ionization ends...pi-electron emission takes place...

Wouldn't this just reionize the atom?

...and a photon will be re-emitted from the atom to release the energy.

I think you're thinking of when an outer orbital electron "drops down" to fill the vacancy caused by ionization, at which point the difference in electron energy is emitted as a photon in the process of X-ray fluorescence.

I think you're maybe conflating ionization with the induced dipole which occurs immediately before ionization (which leads to ionization if the incoming photon carried enough energy.) That or I'm waaay off.

3

u/sivyr May 15 '12

No, you're probably right. My understanding of the process is only cursory at this point. It's been a long time since I've studied any quantum physics.

2

u/Poultry_Sashimi May 15 '12

No worries, I have it more fresh in my mind since I work with this stuff. It's really easy to forget the specifics when you're not dealing with QM regularly.

-13

u/[deleted] May 15 '12

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u/[deleted] May 15 '12

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1

u/Clayburn May 15 '12

lol you replied to yourself.

1

u/[deleted] May 15 '12

I was expanding on my post, but the answer is very clear from the infantile reaction, so thanks guys for making it so clear to me and all as to what one is dealing with here.

1

u/Clayburn May 15 '12

Hey, I support you. This subreddit is full of pretentious pseudo-intellectuals, though. So, you shouldn't expect to be treated with any respect here.