Total Recall: The Woman Who Can't Forget - <AUTHOR> http://www.wired.com/medtech/health/magazine/17-04/ff_perfectmemory?currentPage=1 <comment><USER2> I was a kind of quirky kid when I was younger... I sort of memorized the Hobbit without really intending to, along with every other book I ever read. Being something of a quirky kid it took me until about middle school before realizing a) this sort of thing is not normal and b) sometimes its better to keep it under your cap. (I can't do it word-for-word anymore, although I still have fairly good retention. I just stopped doing it and it stopped happening. Happy/sad about that, mostly happy. Being "scary" makes for an uncomfortable middle school experience, and being unable to forget the uncomfortable bits sucks royally. Trust me -- been there, done that.)

One of my friends from high school, also diagnosed as being LD, still remembers my drivers license number. He saw it when I showed him my photo after passing the exam, more than a decade ago. Oddly enough, I have never had a particularly good memory for numbers, even back in my freakish days. (It also took me until about age 10 to figure out the difference between left and right. My little brother, who was exasperated at that and thought I was playing, mentioned that left is always the same side as the mole I have on my left wrist. I still check my wrist to this day, out of semi-conscious habit.)

Ahh, the human brain -- it is pretty freaking weird.

<comment><USER3> I was like this for east and west when given north for the longest time. I would always ask my little brother which way east or west was.

<comment><USER4> Never Eat Soggy Waffles. Point in the four directions clockwise. It took many years of saying this alloud before I had it anywhere near down. I still ocasionally have issues. I also had problems with left/right and the months of the year.

<comment><USER3> Well the other problem was with clockwise... Couldn't do that either.

</comment></comment></comment></comment><comment><USER5> A long time ago (before Internet gambling), I remember reading in Reader's Digest about a professional card player with a photographic memory who got caught in a tragic casino fire. In the article, it said that since the fire, he'd been unable to enter any casino because his _photographic_ memory brought back the scenes of the fire vividly into the present.

I also remember the hypnotist at my college orientation who hypnotized a bunch of our class. He had a couple revert to kindergarten memories, telling him who sat where in the classroom, who their friends were. In the most memorable sequence, however, he asked a guy in childhood mode the question 'did you ever make a special sound'. The guy/kid was shy and said 'yes but I'm not sure I want to do it.' Eventually, the hypnotist coaxed and encouraged the guy/kid enough ... and the guy/kid did the most spot-on, uncanny, loud Chewbaca roar. He got the nickname Chewy around campus after that.

<comment><USER6> That's a pretty awesome story -- I've always wondered whether it was our memories or our ability to recall them that faded! Does anyone know of good reading on the subject?

</comment></comment><comment><USER7> _I soon find that except for her own personal history and certain categories like television and airplane crashes, Price's memory isn't much better than anyone else's. She struggled in school, is no good at history before 1965, and seems genuinely miffed that she was once asked when the Magna Carta was signed ("Do I look like I'm 500 years old?")._

That was the most interesting part to me out of the entire article. It raises the question of whether she consciously makes a decision to remember facts that she's interested in (herself, disasters) and exclude others or whether she just never spent any mental energy remembering these 'outside' events.

</comment><comment><USER8> I had this unusual ability to memorize entire chapters of Biology and History. And unusually I could do it only with these two subjects, as for me they were the most difficult to understand and relate to. Let me just give you an example. The tests papers would question things like: a) give any two symptoms of malaria (2 marks) b) list all symptoms of malaria (7 marks)

And I hated to lose marks and overall class rank because of this one stupid Biology, and let's say I covered malaria but this time they chose to ask about treatment for cholera.I reasoned to myself, they could ask anything. So I might memorize all symptoms/treatments of malaria AND cholera. During one such exam preparations (must've been grade 7/8) by the end of it I had an epiphany that I'd just memorized the entire chapter. I even parroted it back to my mom making her happy that here I was ready to take on the diseases of this world. The notable point is that only after that realisation, I became very good at memorizing entire chapters. I remember by 9th grade I could almost memorize the 4-5 chapters of Biology. Surprisingly it happened mostly with Biology, a subject I hated the most, Chemistry equations which our teachers never explained because even they didn't know what the fuck was going on in there with those molecules(S8+8O2=8SO2?), dates in History and exact word-for-word quotes in languages -- all things that needed memorization. I could never remember say for example the 4-digit number plate of the cars which just passed by at 60kmph even after I had summed up its digits and they came out less than 30, and done so for all the 15 cars that passed by within 30 seconds or so (try this game, its fun and it'll improve your number skills).

And quite unsurprisingly, after my schooling, when this ability was no more required, I slowly started losing it. I always wondered if I could get that 'magic' back so to speak. Is there a name for this condition - the ability to channel immense memory powers when needed?

btw, if you guys are wondering this was an Indian school system. I also had other freakish abilities, but for now I'd leave it at that.

</comment><comment><USER9> Previously on Ms. Price:

<http://news.ycombinator.com/item?id=373529>

And similarly:

<http://news.ycombinator.com/item?id=192454>

And necessarily:

"Funes, The Memorious" by Jorge Luis Borges

<http://io.uwinnipeg.ca/~morton/bigidea/funes.txt>

<comment><USER10> I see you don't forget URLs.

<comment><USER11> The Internet never forgets. Where we once had oral retellings of epic sagas, we now have synthesis of radical new ideas. Humans are extraordinarily adaptable machines. We've now built a ubiquitous information retrieval system and it will only get better.

If you could trade memory for creativity, would you?

</comment></comment></comment><comment><USER12> I hardly ever think back.. I'm always thinking about what I am going to do or what I want to achieve.

My memory scarcely goes back further then a week. It tends to make my live a bit empty, I don't remember doing anything.

<comment><USER13> I have the strangest memory. I can remember facts, theorems, and all sorts of things that are easy to reason about, but my experiential memory is crap. I find my friends talking about things we did together and I can't participate because I don't remember very well.

However, I'm beginning to suspect it's because I spend too much time thinking to myself and not enough time paying attention to the outside world. Does anyone else have a similar experience?

<comment><USER14> I've got a pretty similar memory. Can't remember events. To remedy this I try to keep a log of event(call it a diary if you will) so that I remember some important things I don't want to forget.

<comment><USER13> Have you noticed your experiential memory improving as you keep the log? I once kept a dream diary, and I started remembering my dreams really really well.

</comment></comment></comment></comment><comment><USER15> It is interesting to note that having a very good memory used to be a tremendous advantage. I mean before ubiquitous books (never mind the web).

<comment><USER16> There is a lament by an ancient philosopher (Platon?) about the advent of writing destroying memory.

<comment><USER17> Yes, him. Generally rendered as "Plato" in English.

It is, of course, only because of writing that anyone now has even heard of Plato, never mind having available the substantial fraction of his work that we have.

</comment></comment></comment><comment><USER18> In the `Small Book about a Large Memory,' Aleksandr Luria described the case of `S.' a man with an even more astounding capability of recall. The Russian version of the monograph is even available online: <http://www.psy.msu.ru/science/public/luria/small.html>

</comment><comment><USER19> The untapped, unexplored universe that are our brains and our genes astound me every time I read a story like this! Nothing is more fascinating to me. Except for the process of human/animal evolution.

</comment><comment><USER20> I don't forget either -- I just never really remembered in the first place.

</comment><comment><USER21> Women never forget. It is unfathomable.</comment>


EC2 Instance Connect - <AUTHOR> https://aws.amazon.com/about-aws/whats-new/2019/06/introducing-amazon-ec2-instance-connect/ <comment><USER2> I made a little twitter thread here (shameless ploy for followers) (I work for AWS): [https://twitter.com/jrhunt/status/1144402767890436096](https://twitter.com/jrhunt/status/1144402767890436096)

* Works on amzn linux 2 - installed by default on newer versions

* otherwise: $ sudo yum install ec2-instance-connect

* The SSH public keys are only available for one-time use for 60 seconds in the instance metadata.

* you can send up your own SSH keys `aws ec2-instance-connect send-ssh-public-key`

* cloudtrail logs connections for auditing

* doesn't support tag based auth but it's on the roadmap

* plans to enable it in popular linux distros in addition to amzn linux 2

Install local client:

$ aws s3 cp s3://ec2-instance-connect/cli/ec2instanceconnectcli-latest.tar.gz .

$ pip install ec2instanceconnectcli-latest.tar.gz

$ mssh instanceid

<comment><USER3> Is there an easy way to integrate that with ansible style scripts (where it needs to ssh to many instances at once)? Or is it planned?

<comment><USER4> should be a pretty simple little connection plugin: [https://docs.ansible.com/ansible/latest/dev_guide/developing...](https://docs.ansible.com/ansible/latest/dev_guide/developing_plugins.html#connection- plugins)

</comment></comment></comment><comment><USER5> About time. This is the other thing that GCP does so well and I was puzzled that AWS still couldnt do - just add more than one keys to a EC2 instance through the API ([https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-inst...](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance- connect-methods.html#ec2-instance-connect-connecting-aws-cli)).

There are tons of support questions about "how can I add multiple SSH keys to my EC2 instances".

Now if only AWS brings in "projects". That's the last usability edge that GCP has.

<comment><USER6> Note the GCP equivalent requires some permanently running crapware inside your VM, the OpenSSH hook EC2 are using is much simpler

<comment><USER5> GCP open sourced the code here - [https://github.com/GoogleCloudPlatform/compute-image- package...](https://github.com/GoogleCloudPlatform/compute-image- packages/blob/14f700ecc1adc0fa7b0e450126065f7f45347d2a/packages/python-google- compute-engine/google_compute_engine/accounts/accounts_daemon.py)

is the AWS code opensource ?

<comment><USER7> It is.

Client: [https://github.com/aws/aws-ec2-instance-connect- cli](https://github.com/aws/aws-ec2-instance-connect-cli)

Server: [https://github.com/aws/aws-ec2-instance-connect- config](https://github.com/aws/aws-ec2-instance-connect-config)

</comment></comment></comment></comment><comment><USER8> I'm puzzled. Many of the comments here seem focused on browser-based ssh which isn't new, or even the most significant thing here. Using IAM instead instead of passing around .pem files feels like a huge improvement.

<comment><USER9> that also isn't new: [https://github.com/widdix/aws- ec2-ssh](https://github.com/widdix/aws-ec2-ssh)

This will lookup your username in AWS iAM, and if it has the right permissions, it creates an account and copies the public ssh key associated with that user.

</comment></comment><comment><USER10> Google Compute Engine has had this functionality for years (at least the browser based SSH). Furthermore, Google's free Cloud Shell feature is fantastic.

Over the years, AWS has put their focus entirely on "Enterprise" customer functionality as opposed to "developer friendly" capabilities.

<comment><USER11> And that's why I'm willing to give them my money. Google's cloud offering needs to be considered a hobby like all their non-search activity

<comment><USER12> Huh? A hobby?

Transcript from Alphabet Q1 2019 Earnings Call; April 29, 2019 [1]

> Sundar Pichai, CEO Google:

> We are also deeply committed to becoming the most customer-centric cloud > provider for enterprise customers, and making it easier for companies to do > business with us thanks to new contracting, pricing, and more. Today, 9 of > the world's 10 largest media companies, 7 of the 10 largest retailers, and > more than half of the 10 largest companies in manufacturing, financial > services, communications, and software use Google Cloud.

> Some of the companies that we announced at Next included: The American > Cancer Society and McKesson in Healthcare; Media and Entertainment companies > like USA Today and Viacom; Consumer Packaged Goods brands like Unilever; > Manufacturing and Industrial companies like Samsung and UPS; and Public > Sector organizations like Australia Post.

> Finally, to support our customers' growth, we also announced the addition of > two new Cloud regions in Seoul and Salt Lake City, which we plan to open in > 2020. These new Cloud regions will build on our current footprint of 19 > Cloud regions and 58 data centers around the world.

This doesn't seem like just a hobby to Google.

[1] [https://abc.xyz/investor/static/pdf/2019_Q1_Earnings_Transcr...](https://abc.xyz/investor/static/pdf/2019_Q1_Earnings_Transcript.pdf)

<comment><USER11> Meh, I care about actions and not random words

<comment><USER13> > our current footprint of 19 Cloud regions and 58 data centers around the > world

Do you understand how expensive this action is?

<comment><USER14> How many of those data centers were already there for their advertising business?

</comment></comment></comment></comment></comment></comment><comment><USER15> This is bad news for ScaleFT, which provided this service via bastion servers (although not IAM based).

Rackspace managed AWS environments use this for high compliance systems.

The problems it solves are a) that login attempts are logged on a separate system for compliance and b) user management is handled in a centralized way. Both are handled with EC2 Instance Connect.

<comment><USER3> Another competitor to this is hashicorp vault, which does both certificate based ssh and AWS authentication. (I find the certificate based approach better though)

</comment></comment><comment><USER16> There's also SSM Session Manager [1]. Not exactly ssh, but you get mostly the same features with ssh access completely disabled and the whole session being logged to S3 bucket or some log aggregation service.

[1] [https://docs.aws.amazon.com/systems- manager/latest/userguide...](https://docs.aws.amazon.com/systems- manager/latest/userguide/session-manager.html)

</comment><comment><USER17> I'm a bit confused about this one.. we have been using SSM Session Manager for quite some time now and this looks like it does the same. We also export all logs during the session with SSM and you can see which user initiated the session. What am I missing here?

<comment><USER18> SSM session manager is basically a HTTP wrapper over a shell. You have to use browser for SSM which mostly works until it doesn't. I had trouble sometimes copy pasting to it.

This new service is basically a managed SSH so things like port forwarding etc will work. With SSM you can't do port forwarding etc because it is not SSH aware.

<comment><USER19> But this needs to expose SSH? SSM is great (although its not fast enough) because it eliminates our jumpers

<comment><USER18> Yeah but then a lot of people have use cases for SSH. The solution is targeted towards replacing jump boxes.

</comment></comment></comment></comment><comment><USER20> TBH I'm still waiting for console serial access via IAM. All my bare metal machines have that. And it's absolutely essential when you bork networking.

And as much it pains me to say it, Azure has that feature.

<comment><USER7> I really really really try to not need serial console access to my machines. I try to only rarely need SSH access.

But when you've got some sort of bug or issue that you're not getting any metrics out of, no logs recorded, no kernel crash dump, nothing sent over netconsole, nothing showing up on the instance console screenshot... Sometimes serial console is what you need.

But, for the borked networking case, I'd recommend not modifying your networking on live instances. Make your changes on a test instance, figure out what works, and add it to your configuration management ;)

</comment></comment><comment><USER21> I'm honestly a little disappointed here, I feel like there is not fully baked but it is so close.

Unlike SSM, Instance connect goes direct over SSH - so you either need to be inside of your AWS network, on a bastion host that can route to your AWS network, or use a public IP address.

It would be great if they combined this functionality with the HTTP wrapping capability so that I do not need to expose SSH/route to SSH ports in any way but can also use IAM policy to control which unix user a given IAM principal can land in the host as (Example use case would be I would only want a certain class of user to land as a user with sudo/root access).

This is still valuable to my use case, and we'll go ahead with it using the bastion approach most likely until they hopefully integrate this with their HTTP SSH wrapper.

</comment><comment><USER22> Great new feature!

But _sigh_ I just built a PKI infrastructure provisioning system using a gigantic shell script, maintenance user with sudo permissions and ssh access where a master node would command a fleet of slave nodes.

I guess all of my work was for naught since this seems to cover some my needs for user and ssh key provisioning.

Oh well, it'll work elsewhere on all other clouds. And I guess I should release it publicly, it's just not pretty enough yet. Every time I do, gremlins come out of the bushes complaining that the code isn't elegant enough for them.

<comment><USER23> This happens so often in Devops that a good rule of thumb is to really think it long and hard before doing any handrolling.

Today's dev ops stacks move so fast nobody is an expert on a single stack for longer than a week.

</comment></comment><comment><USER24> Do you still need to create users manually on each machine? There have also been many tools out there to pull the ask key from IAM and use it via authorizedkeyscommand previously, but my problem is always creating the user accounts, especially if you don't want to keep a separate list in ldap/Kerberos (or similar, like active directory).

<comment><USER25> Looks to me like this would have all users use the default ec2-user or ubuntu user accounts.

<comment><USER24> That's what I thought it was saying too. That's a mess from a compliance and best-practices point of view :(

Or am I missing something and this would follow the PCI DSS?

<comment><USER26> This is what I'm wondering as well. Does the fact that everything is logged by what an IAM user does work as compliance, or are individual user accounts on the operating system still required?

</comment></comment></comment></comment><comment><USER27> Well, it was about time...

IAM based auth was long overdue.

</comment><comment><USER28> I hope this helps all those people that somehow manage to lock themselves out of their instances.

</comment><comment><USER29> This is great! Giant step using iam over ssh keys.

</comment><comment><USER30> Not complaining, but wow that took a long time. Even Linode has had a web- based shell for many years.

Either way, this will be very nice to have.

<comment><USER31> AWS already had a web based shell via SSM. This allows native SSH connections using credentials tied to AWS IAM users.

</comment></comment><comment><USER32> Interesting, but I connect via ssh from Windows 10 PowerShell. I wonder why this isn't a standard use-case. I suppose I can get it to work as long as it's "openssh" or something compatible

</comment><comment><USER33> how to connect the instance from a windows machine using ec2-instance-connect? is that possible?

</comment><comment><USER34> is this also xterm.js based? the WebGL based engine will make it even better!

<comment><USER35> Not gunna lie, it makes me sad that we need some huge, fancy graphics engine just to emulate a 25 year old technology. Why are people so obsessed with their browser? No matter how much JS you layer on, it'll never be as fast as a terminal.

<comment><USER36> I had a VT102 for many years, it wasn't fast.

</comment></comment></comment><comment><USER37> I mean, this is definitely cool, but we should also try to stop using ssh so much. There's a long list of reasons why using ssh leads to bad things (but not an anti-pattern - I wish people would stop using that phrase to mean anything that _sometimes_ leads to bad things) so I just hope this functionality doesn't exacerbate its use.

<comment><USER38> Ugh, I'm a new full stack guy. Could you enlighten me about the evils of SSH?

<comment><USER37> SSH is wonderful. The problems are more what it enables, and what it lacks (or isn't designed to do).

For example, managing ssh keys for an individual is gloriously simple, but managing them for a large organization is a huge headache. You want to use ssh certificates, but even those are implemented in a weird way, and really you should use an SSO system for auth. (This makes that easier/better, so, yay?)

When people start sshing into production servers, they end up making local changes. They focus more on the "pets" aspect of managing systems rather than as "cattle". They have to install a litany of extra software to diagnose and troubleshoot bugs, rather than expose system metrics and tightly control the app environment and its operation.

Remote access to production app servers is basically a backdoor waiting to happen, and may violate corporate security policies. When you have local user access to a Linux host, it's almost guaranteed you can privesc to root.

Finally, almost everyone I have ever seen will either force-ignore/auto-accept host key changes, or just accept them blindly, because IPs and hostnames may change, and there may be multiple environments you haven't logged in to, etc). This completely defeats the purpose behind mitm protection, which is the main _intent_ of using SSH, though these days its other features may be arguably more of a reason to use it.

And for the tech hipsters out there: "it isn't serverless!!"

<comment><USER7> >They have to install a litany of extra software to diagnose and troubleshoot bugs, rather than expose system metrics and tightly control the app environment and its operation.

There's a lot of things that require more than easily exported system metrics and logs to troubleshoot.

While I've played around with using PCP's perf plugin to try and remotely do things with perf, generate flamegraphs, etc., it doesn't work nearly as well as just SSH'ing into the thing and running perf directly, especially if the perf data file is going to be large. I don't see how you could do serious performance engineering work without SSH access.

But, I think I'm nitpicking here, because I generally agree that there should be very little to no reason to login to servers via SSH day to day.

<comment><USER39> in the 'pets vs cattle' analogy, it totally makes sense that even with cattle, occasionally you bring one in for a checkup by a vet to see if you can detect any problems that might affect the herd. Ssh into a production box to check everything is working as expected and take some readings. Sure.

On the other hand, I tend to lean more towards a 'wild animals' model, where, sure, you can tranquilize one and bring it in to look over, but once it's got the smell of humans on it, it's doomed if you let it back out in the wild again.

Once you ssh into a production box, it is forever tainted. Sure, poke around in it, install some perf tools to run some diagnostics, learn what you can about its behavior. But then, rather than putting it back into the wild to serve traffic, out of mercy, you should destroy it and replace it with a clean instance.

<comment><USER7> I don't disagree with this, but, at the same time, if I haven't made any actual changes to the application, I'll generally not worry about manually taking it out of service, because autoscaling will be getting rid of it soon enough anyway.</comment></comment></comment></comment></comment></comment>


Time's Almost Reversible Arrow - <AUTHOR> https://www.quantamagazine.org/20160107-arrow-of-time-axions/ <comment><USER3> This was a great read! But I wish the article would have mentioned how tiny the microscopic time-reversal effects are, compared to macroscopic time reversal. The microscopic effects are too small to explain why we have such a clear direction of time.

Our direction of time is defined by the observation that entropy (or "chaoticness") always increases with time. If you mix orange juice with water, you will not see the result unmix itself again, even though the interactions between the individual molecules are perfectly reversible.

In fact, you can build a toy-universe in your head, where all interactions are time-reversible, and you would still observe that the chaotic-ness increases with time, unless you start with a completely random initial state (in which the chaoticness stays roughly constant). This increase in chaoticness is comletely unsurprising: It's a simple consequence of the fact that there are much, much more "states" in which a system looks chaotic, than states in which it looks ordered. Therefore, a system transitioning from state to state is much more likely to be in one that looks chaotic, and very, very unlikely to ever go back to a state that is non-chaotic.

The real mystery, for me, is: Why was the initial state of our universe so completely non-chaotic? Why did the universe not start out in a state that is essentially equal to the heat-death [1]? The microscopic processes that are not time-reversible might have something to do with this, but it's not clear at all how they can solve this mystery.

[1] [https://en.wikipedia.org/wiki/Heat_death_of_the_universe](https://en.wikipedia.org/wiki/Heat_death_of_the_universe)

<comment><USER4> > Therefore, a system transitioning from state to state is much more likely to > be in one that looks chaotic, and very, very unlikely to ever go back to a > state that is non-chaotic.

This one thing I don't understand about the 2nd law of thermodynamics: given enough time won't the system go back to a more organized state simply by chance? And in that case, wouldn't the total entropy be reduced?

<comment><USER5> As others said, your understanding is fine - you just need to gain the appreciation to how much more unordered states are there for a system to be in than the ordered ones. My physics professor used to underscore it by drawing diagrams that show a line that suddenly goes from almost 0 to "the tip of this line is somewhere in the next galaxy".

Or to give you a somewhat similar problem - consider a 32x32px 8bit image (a standard Windows icon since version 3.0). The image consists of 1024 pixels, each capable of representing a different color from the set of 256 colors. How many possible pictures like this are there? Or, as you'd ask in thermodynamics, in how many states such a system can be? It's 256 states per pixel raised to 1024th power (just like 6-digit binary number has 2^6 possible values). It's 256^1024. You know how much is it?

      10907481356194159294629842447337828624482641619962326924318327861897213318491192
      95216264234525201987223957291796157025273109870820177184063610979765077554799078
      90629884219298953860982522804820515969685161359163819677188654260932456012129055
      39018863010179002525357999172000100796000265358368009052978058809523505016301954
      75653911005312364560014847426035293551245843928918752768696279344088055617515694
      34994540667782514081490061610592025643850457801332649356583604724240738244281224
      51315177575191648992263657437224322773680750276278830452065017927617009456991684
      97257879683851737049996900961120515655050115561271491492515342105748966629547032
      78632150573082843022166497032439613863525162640951616800542762343599630892169144
      61811874063953106654048857394348328774281674074953709935118687563599703901170218
      23616749458620969857006263612082706715408157066575137281027022310927564910276759
      16052087830463241104936456875492096732298245918476342738379027244843801852697776
      49410727156115804346908274593399919614142427414105991174260605564837637563145276
      11362658628383368621157993638020878537675545336789915694234433955666315070087213
      53547025567031200413072549583450835743965382893607708097855057891296790735278005
      49356215610907958451729541159729274798775277385600082041185589300047777487277618
      53813510493840581861598652211605960308356405941821189714037868726219481498727603
      65361629885617482241303348543878532402475141941718301228107820972930353737280457
      43720952287036227763639452908698062584223551485075710396193874496298668081887696
      62815778153079393179093143648340761738581819563002994422790754955061288818308430
      07964869323217915876591803556521615711540299212027615560787310793747746684152836
      29877086994501520312318625942030856938389446570613462367042340268211029589549511
      97087076546186622796294536451620756509351018906023773821539532776208676978589731
      96633030889330466516943618507835064156833694453005143749131129883436726523859540
      49042734559287239495252271846174043678547546104743770197680255766058810380772707
      07717942221977090385438585844095492116099852538903974655703943973086090930596963
      36076752996493841459818570596375456149735582781362383328890630900428801732142480
      86639626713335280092327583508730596141187237814221014601986157473868550968960891
      89180441339558524822867541113212638793675567650340362970031930023397828465318547
      23824423202801518968966041882297600081543761065225427016359565087543385114712321
      4227266605403581781469090806576468950587661997186505665475715792896

This much. (Source: [0]).

Now ask yourself, how many of those pictures represent a letter "A". Quite a lot probably, but _nowhere near that much_. In all those 256^1024 pictures, you have every possible representable letter A, as well as any other possible Unicode character. In those images are all your most cherished private photos (or at least their thumbnails), and also the photos of all things that you'd wish happened but didn't. A thumbnail of every possible photo of the universe is there as well.

There's also something else. Something much more frequent than all other image I've just mentioned taken together. It's the _noise_. The things we don't recognize, the things we consider uninteresting. I ask you, use your intuition - if you were to create a random Windows icon every second, how soon would you expect to get one depicting a letter "A"?

And now realize we were talking about silly icons that are probably barely visible on your screen.

There are 6.02 x 10²³ atoms in 12 grams of carbon. I.e. in a tip of your pencil. 602000000000000000000000 atoms. Those are your pixels. And if you want to compute the number of states this pile of atoms can be in, that is the number that goes _in your exponent_. The base is some combination of possible positions, orientations and velocities, and then probably something else I'm forgetting right now. And _almost all_ of those states are noise. That's how the Second Rule works.

[0] - [http://www.wolframalpha.com/input/?i=256%5E1024](http://www.wolframalpha.com/input/?i=256%5E1024)

<comment><USER6> The Digital Library of Babel ([https://libraryofbabel.info/](https://libraryofbabel.info/)) was posted here a while ago, which is a tangible way to search through this space. The library comes from a book by Jorge Luis Borges, which has all possible books, meaningful and not. The people in the book are searching for books with meaning, but the chance of finding one is really small. The digital library lets you do the search electronically. Kind of fun to play around with.

<comment><USER7> It also has a link to the Universal Slideshow. Which let's one browse every image (of a given size) that represents what TeMPOral was talking about.

Ever since I discovered that site I've been slightly obsessed with it. In the "This is really interesting" sort of way. It makes one think how _everything_ is noise. We just happen to find meaning in some of it.

</comment></comment></comment></comment></comment><comment><USER8> _The modern history of T invariance begins in 1956_.

Or 1781, when _Critique of Pure Reason_ was published. Kant proposed that time was an empirical fact based on experiencing events in time being a precondition of all human experience. The tradeoff for a well reasoned non- skeptical position was that we give up claims to "really really" know how things really are independent of human experience...i.e we give up claims to potential omniscience.

That we normally take "knowledge" to mean human knowledge, doesn't change that this is what we mean. Or to put it another way, what would time be for a computer with knowledge or as the article mentions for creatures that experience time backward?

</comment><comment><USER9> Great read on some of the history and current efforts in particle physics by a leader of the field (Frank Wilczek).

I was surprised to read such a well written article on quanta magazine (I've often been disappointed there) but it made sense when I saw who the author was. It read more like what might be published in a general audience Nature or Science article.

</comment><comment><USER10> I'm very surprised no one posted this yet:

[http://xkcd.com/1621/](http://xkcd.com/1621/)

</comment><comment><USER11> This is an honest question, how are we so certain time exists? Does anyone have a few quick references to books or articles that would explain it to the layman?

I always found the concept of time completely artificial, created by observation of cyclical systems.

<comment><USER12> "created by observation of cyclical systems". Can you elaborate on that? I'm not sure what you mean, but it sounds interesting. It seems to me we believe time "exists" because of causality; things that happen at "this moment" affect things that happen "in the future" but not things that happen "in the past". We've also predicted and measured certain weird things about time, such as how it can go faster or slower.

<comment><USER11> So, you could condense my knowledge of physics to an index card, but here we go...time seems like it's always based on the measurement of a regular thing. Say the oscillation of a quartz crystal. So we have no proof there of time, just that certain phenomena can be very regular in intervals/cycles.

I've heard things like, "if you go the speed of light, or at least really fast, time will move differently." But that seems like it would be a side effect of that local system moving at a rate that interferes with its physical interaction relative to what we consider normal.

There are probably tons of holes in that. But my point is that we tend to think of time almost as an invisible "thing", and I really have trouble wrapping my brain around that. It just feels like things happen and we call it time, but really its ordered intervals of effects.

</comment></comment></comment><comment><USER13> Wouldn't gravity have to be repulsive in a reversed time? Doesn't that mean time can't run in reverse.

Also information might be lost in black holes. Wouldn't that also prohibit it reversing time?

<comment><USER14> No.

Consider what it would look like if you ran the solar system in reverse - <USER2> the planets and moons would go backwards in their orbits, but gravity still works exactly the same. The equations of mechanics don't care about time.

And yes, information being lost in black holes would be an issue, if true - that's why that problem has been studied so much recently.

<comment><USER13> But if gravity isn't reversed how would planet formation be reversed? What would allow the matter in a planet to fly apart?

<comment><USER15> You'd see radiation hitting the planet warming the mantel, complex chemicals breaking down & releasing heat, all warming the planet significantly to the point where it was a molten ball, and finally lots of instability where large explosions were throwing pieces of it into space.

Basically take the movie and play it backwards.

<comment><USER16> I find it very hard to picture a molten ball throwing a giant chunk of cold comet deep into space.

<comment><USER17> That is what is so unsettling about T-symmetry. What you describe is merely _improbable_ , not impossible. With appropriate starting conditions, it is certain. Basically we'd require all the particles in the comet to bounce into each other in such a way that their heat motion cancels and organizes into momentum in one direction, away from the planet. This is physically permitted in either time-direction, but we only see it in one.

</comment></comment></comment></comment></comment></comment><comment><USER13> What s the current thinking on being able to run Schrödinger's cat backwards? How can time be reversed on something in an indeterminate state?

<comment><USER18> The indeterminacy may not be real. It's just that _you_ don't know the state. I don't believe there is a rule that says you get to know everything.

<comment><USER17> Are you proposing a "hidden state" which is unobservable? Such a formulation is not consistent with quantum mechanics, as proven by Bell's theorem, unless you permit instantaneous influence from arbitrarily distant parts of the universe.

<comment><USER18> I'm saying that the construction "indeterminate" is only a statement about the knowledge of the person making the statement. Are you proposing that the universe doesn't act unless _you_ are considering it?

<comment><USER17> [https://en.wikipedia.org/wiki/Bell's_theorem](https://en.wikipedia.org/wiki/Bell's_theorem)

Certain observations are probabilistic, and the correlations in them predicted by quantum mechanics cannot be reproduced by ascribing them to the traits of particles.

It means that at the lowest level, the universe is (barring faster-than-light communication, generally regarded to be false) "truly random". (No concept of an "observer" needs to be devised in order to arrive at this conclusion).

<comment><USER19> How do you know it's truly random though? Couldn't it be the result of a pseudo random process? Or universe splitting, where two universes are created, one where a coin lands head, and one where it lands tails. To the people inside, it seems random, but it's actually deterministic.

<comment><USER17> Pseudorandom means the choice is deterministically chosen by according to the state of hidden variables. Bell's theorem says there are no hidden variables that completely explain the predictions of quantum mechanics.

A many-worlds interpretation (which is consistent with QM) is basically the same as saying the result is random, because you can't predict exactly which branch any particular interaction will follow.

<comment><USER20> No _local_ hidden variables. Hugely important distinction.

<comment><USER17> Yes, see the bit in my original post and the one that follows about instantaneous communication.

</comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER13> Wouldn't the expending of space prevent particles from being able to run backwards in time? Unless you also ran the expansion backwards?

</comment><comment><USER19> There is a hypothesis that universes with reversible time can't exist. Or time travel of any kind. Such universes, the hypothesis goes, can't have any meaningful cause and effect, like we know it. Causality is an extremely important property of our universe. And it's really weird that our universe has it, if the hypothesis isn't true. The space of possible universes without causality is much larger than restricted subset that obeys that rule. This is difficult to explain, so see here: [http://lesswrong.com/lw/fok/causal_universes/](http://lesswrong.com/lw/fok/causal_universes/)

</comment><comment><USER21> With React/Redux you can reverse time! :D</comment>


Barack Obama's Year-End List 2018 - <AUTHOR> https://www.facebook.com/barackobama/posts/10156393283416749 <comment><AUTHOR> Is there away to read this without hitting facebook.com? My DNS server sends all facebook.com requests to 0.0.0.0</comment>


Product Quest II - <AUTHOR> http://productquest.andrewculver.org/post/56935035040/breaking-ground

<comment><USER2> This sounds like a cool product. I sort of wish I had heard about koudoku before deciding to use the SaaS RailsKit ([http://railskits.com/saas/](http://railskits.com/saas/)) though it has saved me a lot of time in developing our first SaaS app.

<comment><AUTHOR> Thanks so much for the feedback!

Re: Koudoku. I hear this a lot. I need to do a better job of promoting it, but until now I've been telling myself I would do it when it gets to a certain point. I need to stop procrastinating. :-)

<comment><USER2> Perhaps publish guidelines how to move from SaaS RailsKit to Koudoku. I feel like The SaaS RailsKit is a bit out of date</comment></comment></comment>