Scientific Science
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@jinpa said in Scientific Science:
@BernieTheBernie said in Scientific Science:
and a comment on that topic in Science:
https://www.science.org/content/article/something-seriously-wrong-room-temperature-superconductivity-study-retractedIt's pay-walled, so a summary or extract would be appreciated.
It seems to be additional info for the Nature article. These seem to be the relevant bits but there is more in there:
"The retraction was unusual in that Nature editors took the step over the objection of all nine authors of the paper. “We stand by our work, and it’s been verified experimentally and theoretically,” Dias says. Ashkan Salamat, a physicist at the University of Nevada, Las Vegas, and another senior member of the collaboration, points out the retraction does not question the drop in electric resistance—the most important part of any superconductivity claim. He adds, “We’re confused and disappointed in the decision-making by the Nature editorial board.”The retraction comes even as excitement builds for the class of superconducting materials called hydrides, which includes the carbonaceous sulfur hydride (CSH) developed by Dias’s team. Under pressures greater than at the center of the Earth, hydrogen is thought to behave like a superconducting metal. Adding other elements to the hydrogen—creating a hydride structure—can increase the “chemical pressure,” reducing the need for external pressure and making superconductivity reachable in small laboratory vises called diamond anvil cells. As Lilia Boeri, a theoretical physicist at the Sapienza University of Rome, puts it, “These hydrides are a sort of realization of metallic hydrogen at slightly lower pressure.”
In 2015, Mikhail Eremets, an experimental physicist at the Max Planck Institute for Chemistry, and colleagues reported the first superconducting hydride: a mix of hydrogen and sulfur that, under enormous pressures, exhibited a sharp drop in electrical resistance at a critical temperature (Tc) of 203 K (–70°C). That was nowhere near room temperature, but warmer than the Tc for most superconducting materials. Some theorists thought adding a third element to the mix would give researchers a new variable to play with, enabling them to get closer to ambient pressures—or room temperatures. For the 2020 Nature paper, Dias and colleagues added carbon, crushed the mix in a diamond anvil cell, and heated it with a laser to create a new substance. They reported that tests showed a sharp drop in resistance at a Tc of 288 K (15°C)—roughly room temperature—and a pressure of 267 gigapascals, about 75% of the pressure at the center of the Earth.
But in a field that has seen many superconducting claims come and go, a drop in resistance alone is not considered sufficient. The gold standard is to provide evidence of another key attribute of superconductors: their ability to expel an applied magnetic field when they cross Tc and become superconducting. Measuring that effect in a diamond anvil cell is impractical, so experimentalists working with hydrides often measure a related quantity called “magnetic susceptibility.” Even then they must contend with tiny wires and samples, immense pressures, and a background magnetic signal from metallic gaskets and other experimental components. “It’s like you’re trying to see a star when the Sun is out,” Hamlin says.
The study’s magnetic susceptibility data were what led to the retraction. The team members reported that a susceptibility signal emerged after they had subtracted a background signal, but they did not include raw data. The omission frustrated critics, who also complained that the team relied on a “user-defined” background—an assumed background rather than a measured one. But Salamat says relying on a user-defined background is customary in high-pressure physics because the background is so hard to measure experimentally."
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Today in yet another “Drinking
ncups off[coffee|wine]a day[reduces|increases]your risk of heart failure byxmillion percent” study:
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@topspin I'm waiting for the study on the effect from glasses of coffeewine and/or winecoffee
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@loopback0 said in Scientific Science:
coffeewine and/or winecoffee
19 Crimes Cold Brew Red Wine: Crimes against Coffee? » CoffeeCode
Coffee and wine - are these the two best drinks in the world? Treasury Wine Estates have created 19 Crimes Cold Brew "The Deported", and done just that.
The Deported – is a red wine infused with a shot of Colombian Cold Brew Coffee
Ruh roh...
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@loopback0 said in Scientific Science:
The Deported
Sounds like an appropriate punishment for peddling this
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@loopback0 said in Scientific Science:
@loopback0 said in Scientific Science:
coffeewine and/or winecoffee
19 Crimes Cold Brew Red Wine: Crimes against Coffee? » CoffeeCode
Coffee and wine - are these the two best drinks in the world? Treasury Wine Estates have created 19 Crimes Cold Brew "The Deported", and done just that.
Vodka/Red Bull for
old peoplepretentious wankers
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Next chapter: Nobel winning image manipulations:
Dozens of papers co-authored by Nobel laureate raise concerns
Nature - Concerns about image integrity have so far led to 17 retractions, corrections or expressions of concern for papers co-authored by geneticist Gregg Semenza.
(may be pay walled)
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@BernieTheBernie There wasn't a paywall for me, and I'm not any kind of subscriber / etc. to Nature.
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Ever since I posted one video by her here, videos have been popping up in my youtube feed. :-/
This one caught my attention, though:
https://www.youtube.com/watch?v=CBLVtCYHVO8Rather ... sobering view on quantum computing. But it's in line with what I was expecting from/reading, whenever I bothered looking into the topic (mostly whenever a hype-filled colleague turns up, and I figure I should see if quantum computing is doing anything useful yet -- this happens every 2-3 years or so, and the answer has been "no" so far).
Either way, great video, because it confirmed my existing biases.</snark>
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@cvi said in Scientific Science:
Ever since I posted one video by her, videos have been popping up in my youtube feed. :-/
Same. Though I have to admit, I like how she has been getting more and more sassy. The other day I thought of posting a video (though forgot, obviously) that would've fit nicely in the "things that remind you" thread, because there was a whole bunch of trolling everybody in it.
Anyway, I haven't watched this video, but when you say it confirms your bias, I assume it's the same way I see it: Quantum Computing may turn out to be amazing in a decade or three, the same way it's been for the last decades (something something Nuclear Fusion). I fully support that we're doing fundamental research on it and build better quantum computers, but the hype I get that "ordinary" people/companies should look into it now, that doesn't make any kind of sense.
As far as I know, the best record of
breaking RSAfactoring is still on the order of factoring 21.
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@topspin said in Scientific Science:
I fully support that we're doing fundamental research on it and build better quantum computers, but the hype I get that "ordinary" people/companies should look into it now, that doesn't make any kind of sense.
More or less this.
I've yet to see a practical application for it, or even an example. Yeah, you can play around with a few qubits that represent coupled probabilities, but call me when you can do something useful and interesting with it.
As far as I know, the best record of breaking RSAfactoring is still on the order of factoring 21.
She mentions this in the video. Apparently that's not even with a general method, but one specialized for the specific problem (which I'm guessing is factoring the number 21, and not factoring arbitrary numbers). I recommend watching that part for the video, for the included burn.
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@cvi said in Scientific Science:
Apparently that's not even with a general method, but one specialized for the specific problem (which I'm guessing is factoring the number 21, and not factoring arbitrary numbers).
Not sure if that makes a difference, though. The quantum computers we're talking here are programmable, right? So loading up a different program for factoring a certain number doesn't seem that big of a deal. Sure, if you had to compile
calc.exeeach time before you perform a multiplication, that'd suck, but in the example of breaking an encryption key, I don't think having to compile once before cracking a key matters.(Of course watching the video is
)
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@cvi watched the video now. Disregard my comment about compiling, seems like I've misunderstood and generalizing it to other numbers currently doesn't work at all.
Also, I concur that she confirmed all my existing biases.
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@cvi said in Scientific Science:
I should see if quantum computing is doing anything useful yet -- this happens every 2-3 years or so, and the answer has been "no" so far
An ex-co-worker got a job working on quantum computing hardware a few years ago. According to his LinkedIn profile, he's now working on hardware for "cloud" data centers. Take from that what you will.
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@topspin said in Scientific Science:
As far as I know, the best record of
breaking RSAfactoring is still on the order of factoring 21.And as far as I recall, the amazing omega epic quantum encryption shattering algorithm requires specialised hardware for every different number. Perhaps even for every potential factor.
I will always remember when some semi-twat proclaimed [looks up the name] “Shor’s algorithm is getting pretty good” in some exchange of quantum computing-related statements. “Getting”? Is the process of multiplying two numbers getting any better too? (and never mind that this was multiple years ago yet
allmost of our cyphers are right where we left them.)Sounds like I need to plan to watch this video too…
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@topspin said in Scientific Science:
Quantum Computing may turn out to be amazing in a decade or three, the same way it's been for the last decades (something something Nuclear Fusion). I fully support that we're doing fundamental research on it and build better quantum computers, but the hype I get that "ordinary" people/companies should look into it now, that doesn't make any kind of sense.
My boss reckons that anything that's going to replace standard computing will probably need somewhere in the region of 10 years of massive investment (and many billions of dollars) to actually do so, just to catch up to where we've got to today with standard computing. And then it will have to catch up with where silicon+normal programs have gone in the next 10 years.
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@dkf said in Scientific Science:
@topspin said in Scientific Science:
Quantum Computing may turn out to be amazing in a decade or three, the same way it's been for the last decades (something something Nuclear Fusion). I fully support that we're doing fundamental research on it and build better quantum computers, but the hype I get that "ordinary" people/companies should look into it now, that doesn't make any kind of sense.
My boss reckons that anything that's going to replace standard computing will probably need somewhere in the region of 10 years of massive investment (and many billions of dollars) to actually do so, just to catch up to where we've got to today with standard computing. And then it will have to catch up with where silicon+normal programs have gone in the next 10 years.
Sounds like they should rebrand to Fusion Computing
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@kazitor said in Scientific Science:
Is the process of multiplying two numbers getting any better too
Last I heard, it is possible to multiply two 32-bit numbers while performing at most 16 32-bit addition operations.
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@PleegWat said in Scientific Science:
Last I heard, it is possible to multiply two 32-bit numbers while performing at most 16 32-bit addition operations.
I just use the
IMULopcode and let the hardware worry about the number of additions.
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@dkf I usually just write
c = a * b;. With whichever variable names and/or constants and/or sub-expressions are appropriate to the task at hand.
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@PleegWat said in Scientific Science:
@kazitor said in Scientific Science:
Is the process of multiplying two numbers getting any better too
Last I heard, it is possible to multiply two 32-bit numbers while performing at most 16 32-bit addition operations.
That's pretty lame. If you're talking about "multiplication getting better", you use a Fourier transform. Which is of course old news by now.
You can even do QFT, but since that's the basis of Shor's algorithm, it's not new either.So in conclusion, I think it's not been getting better in a while.
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@PleegWat said in Scientific Science:
@dkf I usually just write
c = a * b;. With whichever variable names and/or constants and/or sub-expressions are appropriate to the task at hand.I usually just use Pauli-X gates to imprint the input numbers on qbits, and then use a quantum fourier transform to create a distributed phase encoding. In this transform domain, CZ controlled phase gate quantum operators act on the distributed phases. After applying this simple QFT multiplication circuit, one can simple measure the qbits to get the result.
Sources for word salad: a and b. No, I don't know what I'm talking about.
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@cvi wild Gribnit sighting?
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@cvi said in Scientific Science:
CZ controlled phase gate
I guess if Česká zbrojovka firearms wanted to control my phase gates, I'd probably let them.
Hands up don't shoot!
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@dkf said in Scientific Science:
And then it will have to catch up with where silicon+normal programs have gone in the next 10 years.
@PleegWat said in Scientific Science:
@kazitor said in Scientific Science:
Is the process of multiplying two numbers getting any better too
Last I heard, it is possible to multiply two 32-bit numbers while performing at most 16 32-bit addition operations.
Larger calculations are still candidates for improvement:
Discovering faster matrix multiplication algorithms with reinforcement learning
Nature - A reinforcement learning approach based on AlphaZero is used to discover efficient and provably correct algorithms for matrix multiplication, finding faster algorithms for a variety of...
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@HardwareGeek said in Scientific Science:
@cvi said in Scientific Science:
CZ controlled phase gate
I guess if Česká zbrojovka firearms wanted to control my phase gates, I'd probably let them.
Hands up don't shoot!Those diacritics-ridden bastards'll have to come get my phase gate controls from my bullet-riddled hands. They're gonna find out what happens when you bring guns to a mad science party.
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@dkf said in Scientific Science:
@topspin said in Scientific Science:
Quantum Computing may turn out to be amazing in a decade or three, the same way it's been for the last decades (something something Nuclear Fusion). I fully support that we're doing fundamental research on it and build better quantum computers, but the hype I get that "ordinary" people/companies should look into it now, that doesn't make any kind of sense.
My boss reckons that anything that's going to replace standard computing will probably need somewhere in the region of 10 years of massive investment (and many billions of dollars) to actually do so, just to catch up to where we've got to today with standard computing. And then it will have to catch up with where silicon+normal programs have gone in the next 10 years.
The horn'll bend - but, yeah, maybe not in the next decade.
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A ton of "ifs" in this one, but the concept of 'Grabby Aliens' makes up for that. (A few fun ideas in there, even with the ifs.)
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@cvi said in Scientific Science:
Quality content, but it's very obvious she's reading a script. She has this fresh professor in their first year of giving lectures vibe. Anyway, I know what I'll be doing the rest of the evening.
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@Gustav said in Scientific Science:
@cvi said in Scientific Science:
Quality content, but it's very obvious she's reading a script.
She would probably have caught that pretty bad Germanism when she's talking about the M&Ms if she was.
She has this fresh professor in their first year of giving lectures vibe.
After like a decade of lecturing.
Anyway, I know what I'll be doing the rest of the evening.
Masturbating?
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@LaoC she's not the worst MILF, but I'm not into MILFs.
(This is fully intentional, I saw your post about RSVP.)
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@Gustav said in Scientific Science:
@LaoC she's not the worst MILF, but I'm not into MILFs.
(This is fully intentional, I saw your post about RSVP.)
MILF is a perfectly cromulent nominal acronym. To trigger me, you'd have to talk about MILFing her.
Your welcum.
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@Gustav said in Scientific Science:
She has this fresh professor in their first year of giving lectures vibe.
Not sure if it's that (and I doubt she's a fresh professor). But she does seem a bit awkwardly rooted in place now that you mention it.
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@cvi said in Scientific Science:
But she does seem a bit awkwardly rooted in place now that you mention it.
Kinky.
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@Gribnit said in Scientific Science:
@cvi said in Scientific Science:
But she does seem a bit awkwardly rooted in place now that you mention it.
Kinky.
Using the Australian meaning of "root", are we?
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@Watson said in Scientific Science:
@Gribnit said in Scientific Science:
@cvi said in Scientific Science:
But she does seem a bit awkwardly rooted in place now that you mention it.
Kinky.
Using the Australian meaning of "root", are we?
The Unix meaning is kinky enough.
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@Watson said in Scientific Science:
@Gribnit said in Scientific Science:
@cvi said in Scientific Science:
But she does seem a bit awkwardly rooted in place now that you mention it.
Kinky.
Using the Australian meaning of "root", are we?
Wombat intern under the
tableframe?
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@kazitor said in Scientific Science:
@Watson said in Scientific Science:
@Gribnit said in Scientific Science:
@cvi said in Scientific Science:
But she does seem a bit awkwardly rooted in place now that you mention it.
Kinky.
Using the Australian meaning of "root", are we?
Wombat intern under the
tableframe?No, no, wombat buggery is a crime here. 'S a sheep, is all.
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Physicists Create a Holographic Wormhole Using a Quantum Computer
The unprecedented experiment explores the possibility that space-time somehow emerges from quantum information, even as the work’s interpretation remains disputed.
Oh boy, this again.
Physicists have created a quantum entanglement of a few qbits, or something like that. Which is apparently a "simulation", previously done on a classical computer, they think maps to a mathematical model of a wormhole, even though they don't know if this mathematical model has anything to do with our physical reality. Unlike most other mathematical models of physics, this one is still completely speculative.
They have absolutely not created a wormhole. They haven't even shown anything connecting to physics. Just like Matt Groening hasn't created a perpetuum mobile because there's a Simpsons comic where Lisa does that.I've waited a week to post this because I figured, after the "Quantum Bubble" video above, Hossenfelder would make an absolutely scathing review about how the headline has basically nothing to do with the actual experiment performed. Now the video is out, and while her summary is as expected ("nothing to see here, move along"), it's more tame than I had hoped for.
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@topspin so you're saying this wormhole treats pain better than cannabis?
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@Gribnit no worse, to be sure.
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@cvi said in Scientific Science:
A ton of "ifs" in this one, but the concept of 'Grabby Aliens' makes up for that. (A few fun ideas in there, even with the ifs.)
Just got to
seeskim that, and while there are indeed a couple of fun science fiction ideas in there, it mostly reminded me of how probabilities are weird (and, in this case, how the authors may be looking a bit too hard for something that may not be there at all).(Part of) their argument is that, with a few (!!) assumptions on the likelihood of life appearing and the expected duration of the universe, there will be huge number of civilisations that appear after 13 billions (i.e. in the future). Therefore conversely, the probability of any random civilisation (say, us) to appear before 13 billions year is tiny, so extremely unlikely. I'm OK with all that, as far as all those assumptions go. It's pure speculation, but why not.
What I disagree with is the next step where they say, in essence, that since this probability is so low, there must exist another factor to increase it. That factor is the "grabby aliens" i.e. a civilisation that colonises all worlds and thus makes it impossible for further civilisations to appear. This removes a huge number of future civilisations and thus boost the probability of any random civilisation (us) appearing early.
Now, again, as far as speculation goes, why not. But the whole "we need something to increase our probability" thing just sounds wrong to me. It essentially assumes that because an event is low probability, it can't have happened. But the world is full of examples of situations where all possibilities are extremely low probability events, and yet they all do occur!
As a trivial example, take someone winning the lottery. It's extremely unlikely to get all number rights and yet some people do. And when they do, you don't go around saying "there must be some sort of hidden rule that actually made it higher probability for them to win." Or take the genetic make-up of any individual: it's extremely unlikely that you would get the specific DNA that you do, and even if just looking at your parents it's extremely unlikely that you would get this exact mix of alleles from them (something with a term in 2^23, roughly). And yet you're here, with this specific mix. Nothing special happened to give you that mix, it just happened. Call it "luck" if you want, but it would also have been "luck" if you had gotten any of the other billions of billions of... possible mix. And yet one of those happened, for no specific reason that made it more probable than the other.
So if we're an extremely unlikely early civilisation in the universe, then... so what? it would be exactly as much extraordinary to be the 1st civilisation to appear than the 42-billion-th one.
Still, "grabby aliens," so... nice one!
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@remi said in Scientific Science:
the next step where they say, in essence, that since this probability is so low, there must exist another factor to increase it.
Time-symmetry is a helluva drug.
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@remi yeah, I usually like the series, but even for a speculative theory, this one is complete bunk.
Arguing from the (theorized) abundance of civilizations in the future back to the abundance of civilizations in the presence is anti-causal nonsense. While a good application of the anthropic principle can make sense, I don't think any part of this line of thought has any merit at all. Better ignore it completely.
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@topspin said in Scientific Science:
even for a speculative theory, this one is complete bunk
The big problem is that we just don't have enough data on a number of critical parameters. Like how common is life in the universe. Or even how common planets capable of supporting earth-like conditions are (let alone how much correlation between those two things is needed); our current detection methods are far too crude and heavily slanted towards large planets in tight orbits (I suspect we couldn't even reliably detect the Earth at the distance of α-Centauri so we can't conclude much about further stars). With such a biased and partial sample, it's no wonder we've not found anything yet! The Copernican principle (that we're nowhere special and so can learn stuff about the wider universe by looking from where we are) isn't strong enough, as that doesn't require uniformity; fractal universes would also satisfy it while providing for substantially varying local conditions.
We're going to need much bigger and more accurate telescopes before we can make progress on this question.
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@remi said in Scientific Science:
So if we're an extremely unlikely early civilisation in the universe, then... so what?
Hey, that would mean that we get to be those grabby aliens! Is that cool or what?
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@remi From what I remember, I liked the concept as a sort of thought experiment. It poses an interesting problem. We have essentially one observation (ourselves) and a whole lot of nothing. What conclusions can we draw from this? Does the "nothing" count as a negative observation? What are the implications of that? But, ultimately, I also wouldn't draw too many conclusions from it. IMO it's the kind of thing you discuss with the right sort of people after a beer or five, and then have a really good discussion for the rest of the night.
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@Steve_The_Cynic said in Scientific Science:
@remi said in Scientific Science:
So if we're an extremely unlikely early civilisation in the universe, then... so what?
Hey, that would mean that we get to be those grabby aliens! Is that cool or what?
We can only be grabby once we can grab. Sadly, I don't see that happening in our lifetimes...
