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Denise Case
The secret of life is two words: not always so :)
The secret of life is two words: not always so :)

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SciTech Digest by Mark Bruce. Another fascinating week of noteworthy news in science and technology. :)

Thanks +Mark Bruce​!

#robotics #ai #intelligentagents 
SciTech Digest - 16/2017.
Permalink here:

Creating negative mass, Solar water harvesting, CRISPR diagnostics, Complex 2D microchips, Complex cellular biocomputers, Cellular reprogramming for Parkinson’s, Generative adversarial networks, Prototype magnonic device, Chatbots that empathise, Adaptive robotic grasping.

1. Creating Negative Mass
An experimentally verified physical system exhibiting properties of negative mass has been achieved by cooling a Bose-Einstein condensate to a superfluid state and using a second laser to change the spin of atoms; pushing the system results in it accelerating backwards

2. Solar Powered Water Harvesting
Porous metal-organic framework materials have been configured such that any suitable heat or light source causes the material to remove and condense water from the air, even at very low humidity levels 1 kg of material would be able to provide approximately 3 liters of water from dry air with only 20% humidity.

3. CRISPR Diagnostics
A modified CRISPR enzyme that targets and cleaves RNA has been developed into the SHERLOCK diagnostics platform for rapid point-of-care testing for specific viruses, bacteria, and other relevant mutations CRISPR is also being used to mine bacterial genomes for pharmaceuticals

4. Complex 2D Microchip
The most complex two-dimensional microprocessor chip with more than 100 transistors has been demonstrated from the three-atom thick material molybdenum disulfide

5. Cellular Biocomputers with Logic Circuits
New synthetic biology tool BLADE uses DNA-recombinase enzymes to function as molecular logic gates in human cells, and currently demonstrating over 100 different Boolean logic functions for regulating gene activity based on environmental cues

6. Cellular Reprogramming for Parkinson’s
New cellular reprogramming techniques manipulate an animal’s cells in vivo and in tests in mice appear to convert one type of cell (brain support cell in this case) into a dopamine producing cell to reverse Parkinson’s symptoms

7. Generative Adversarial Networks
Generative Adversarial Networks pit two neural networks against one another in order to come up with much better and more accurate solutions than either would be able to do so on their own and might one day deliver forms of unsupervised learning

8. Prototype Magnonic Device
Competing with conventional prototype spintronics devices, a prototype magnonic device has been demonstrated that instead manipulates oscillating spin-waves that travel throughout magnetic materials without requiring electric currents

9. Chatbots that Empathise
Chatbots have been developed that assess the emotional content of a user’s text and can respond appropriately by conveying specific emotions

10. Adaptive Robotic Grasping
Soft Robotics has a new adaptive grasping system able to handle arbitrarily-shaped objects with uneven surfaces - this modular robotic gripped could benefit a range of different robotics platforms.

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Humans are amazing.

Thank you +Charles Filipponi​ for sharing!

#extraordinary #music #Rachmaninoff 
Rachmaninoff was an April Fool's baby. A day late, but one of my favorite piano pieces by him.

Yuja Wang is exhilarating to watch.

Happy Sunday, friends. :)

#musicalmelange #classicalmusic #piano #rachmaninoff #yujawang

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Explore Mount Everest in 3D. :)

Experience the harrowing trek to the summit of the Earth’s highest mountain.


Himalayan Foundation:

Discovery: Everest Rescue

Discovery: VR

#everest #mountainclimbing #3D

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Mars: virtual flight, real images. Getting ready for our manned mission. :) 
Martian Flyby Simulated

Using the static, high-resolution, but greyscale images provided by NASA's HiRise Mars-orbiting camera, Finnish filmmaker and self-confessed Space enthusiast, Jan Fröjdman, has gone to the trouble of manually selecting and interpolating more than 33,000 reference points between images, and then rendering a coloured, dynamic, 3D simulation of the view one might get if, rather being in orbit, we were to be in a futuristic spacecraft with a viewing portal, flying over the surface of Mars.

To fully appreciate the Martian landscape, one needs dimension and movement. In the video you see here, Finnish filmmaker Jan Fröjdman transformed HiRISE imagery into a dynamic, three-dimensional, overhead view of the Red Planet—no glasses required.

For Fröjdman, creating the flyover effect was like assembling a puzzle. He began by colorizing the photographs (HiRISE captures images in grayscale). He then identified distinctive features in each of the anaglyphs—craters, canyons, mountains–and matched them between image pairs. To create the panning 3-D effect, he stitched the images together along his reference points and rendered them as frames in a video. “It was a very slow process,” he says.

More here (article):

The anaglyph images of Mars taken by the HiRISE camera holds information about the topography of Mars surface. There are hundreds of high-resolution images of this type. This gives the opportunity to create different studies in 3D. In this film I have chosen some locations and processed the images into panning video clips. There is a feeling that you are flying above Mars looking down watching interesting locations on the planet. And there are really great places on Mars! I would love to see images taken by a landscape photographer on Mars, especially from the polar regions. But I'm afraid I won't see that kind of images during my lifetime.

More text and video (Vimeo ~ 5mins.):
Please watch the film in 2K if possible for greater details.

Jan Fröjdman (blog post):


Image from article.
Originally HiRise NASA/JPL/University of Arizona
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Quantum app.. Great way to explore this amazing phenomenon.

See also:

Beautiful website by the creator of the Quantum app.

#science #physics #education

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It's not family values when you don't value families. We can do better.

Bernie Sanders 'Quote Of The Day'
"The reality is that when it comes to supporting real family values like paid leave, the United States lags behind every major country on earth, and virtually all poor countries as well. Out of 188 countries, the U.S and Papa New Guinea are the only two that don’t provide some form of paid leave. Or, to put that another way: the citizens of every other major industrialized country get more protection for their families than we do here in the United States."

#StillSanders #leading #OurRevolution #MyDailyBernie


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Linux kernel creator Linus Torvalds weighs in on git and SHA1.

#computer #science #code #SHA1 #git
I thought I'd write an update on git and SHA1, since the SHA1 collision attack was so prominently in the news.

Quick overview first, with more in-depth explanation below:

(1) First off - the sky isn't falling. There's a big difference between using a cryptographic hash for things like security signing, and using one for generating a "content identifier" for a content-addressable system like git.

(2) Secondly, the nature of this particular SHA1 attack means that it's actually pretty easy to mitigate against, and there's already been two sets of patches posted for that mitigation.

(3) And finally, there's actually a reasonably straightforward transition to some other hash that won't break the world - or even old git repositories.

Anyway, that's the high-level overview, you can stop there unless you are interested in some more details (keyword: "some". If you want more, you should participate in the git mailing list discussions - I'm posting this for the casual git users that might just want to see some random comments).

Anyway, on to the "details":

(1) What's the difference between using a hash for security vs using a hash for object identifiers in source control management?

Both want to use cryptographic hashes, but they want to use them for different reasons.

A hash that is used for security is basically a statement of trust: and if you can fool somebody, you can make them trust you when they really shouldn't. The point of a cryptographic hash there is to basically be the source of trust, so in many ways the hash is supposed to fundamentally protect against people you cannot trust other ways. When such a hash is broken, the whole point of the hash basically goes away.

In contrast, in a project like git, the hash isn't used for "trust". I don't pull on peoples trees because they have a hash of a4d442663580. Our trust is in people, and then we end up having lots of technology measures in place to secure the actual data.

The reason for using a cryptographic hash in a project like git is because it pretty much guarantees that there is no accidental clashes, and it's also a really really good error detection thing. Think of it like "parity on steroids": it's not able to correct for errors, but it's really really good at detecting corrupt data.

Other SCM's have used things like CRC's for error detection, although honestly the most common error handling method in most SCM's tends to be "tough luck, maybe your data is there, maybe it isn't, I don't care".

So in git, the hash is used for de-duplication and error detection, and the "cryptographic" nature is mainly because a cryptographic hash is really good at those things.

I say "mainly", because yes, in git we also end up using the SHA1 when we use "real" cryptography for signing the resulting trees, so the hash does end up being part of a certain chain of trust. So we do take advantage of some of the actual security features of a good cryptographic hash, and so breaking SHA1 does have real downsides for us.

Which gets us to ...

(2) Why is this particular attack fairly easy to mitigate against at least within the context of using SHA1 in git?

There's two parts to this one: one is simply that the attack is not a pre-image attack, but an identical-prefix collision attach. That, in turn, has two big effects on mitigation:

(a) the attacker can't just generate any random collision, but needs to be able to control and generate both the "good" (not really) and the "bad" object.

(b) you can actually detect the signs of the attack in both sides of the collision.

In particular, (a) means that it's really hard to hide the attack in data that is transparent. What do I mean by "transparent"? I mean that you actually see and react to all of the data, rather than having some "blob" of data that acts like a black box, and you only see the end results.

In the pdf examples, the pdf format acted as the "black box", and what you see is the printout which has only a very indirect relationship to the pdf encoding.

But if you use git for source control like in the kernel, the stuff you really care about is source code, which is very much a transparent medium. If somebody inserts random odd generated crud in the middle of your source code, you will absolutely notice.

Similarly, the git internal data structures are actually very transparent too, even if most users might not consider them so. There are places you could try to hide things in (in particular, things like commits that have a NUL character that ends printout in "git log"), but "git fsck" already warns about those kinds of shenanigans.

So fundamentally, if the data you primarily care about is that kind of transparent source code, the attack is pretty limited to begin with. You'll see the attack. It's not silently switching your data under from you.

"But I track pdf files in git, and I might not notice them being replaced under me?"

That's a very valid concern, and you'd want your SCM to help you even with that kind of opaque data where you might not see how people are doing odd things to it behind your back. Which is why the second part of mitigation is that (b): it's fairly trivial to detect the fingerprints of using this attack.

So we already have patches on the git mailing list which will detect when somebody has used this attack to bring down the cost of generating SHA1 collisions. They haven't been merged yet, but the good thing about those mitigation measures is that not everybody needs to even run them: if you host your project on something like or, it's already sufficient if the hosting place runs the checks every once in a while - you'll get notified if somebody poisoned your well.

And finally, the "yes, git will eventually transition away from SHA1". There's a plan, it doesn't look all that nasty, and you don't even have to convert your repository. There's a lot of details to this, and it will take time, but because of the issues above, it's not like this is a critical "it has to happen now thing".
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