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Can the Multiverse Be Tested Scientifically?

blincoln M-Theory and gravity (147 comments)

Ever since I read The Elegant Universe years ago, I've had a number of questions related to this (as I imagine many people have). This is the first time I've seen the topic discussed by professional scientists, though, as opposed to people like myself with a hobby interest in the subject or in science fiction (Alastair Reynolds makes use of it in one of the Revelation Space novels, for example).

For the most part, it seems like String/M-Theory is very difficult (at best) to test using technology we have access to at present. But because it includes the idea of gravity being a force which can travel between branes, it's seemed to me and a few friends of mine that this would definitely produce some interesting effects in the real world.

As the article discusses, there should be some subtle evidence of the effects of gravity from external sources on the large-scale structures of our own universe. I would think maybe even enough to at least partly explain "dark matter" and "dark energy", since those are basically the known matter in our universe behaving as if there were a lot more mass that we can't actually see (one set to hold relatively closely-spaced matter together, and the other to accelerate the expansion of the large-scale structures away from each other, if I understand correctly).

A simple flatland-style analogy for "dark energy" might be that our universe is a sheet of paper which is intersected by a universe which is wrapped around into a tube shape or a torus. The gravity of the mass in that second universe pulls objects in our universe toward it, so for the part of our universe in the "eye" of the tube, they tend to accelerate away from each other. That's a vast oversimplification, but I'm not a physicist :).

For "dark matter", the idea that's always stuck with me since reading The Elegant Universe is that maybe some/all of the most massive objects in our own universe - especially the black holes at the centers of galaxies - are caused by the same kind of cross-brane effect. If you have a bunch of matter clumping together in one brane/universe, and it exerts gravity which can cross into other branes, then it seems like it would create corresponding accretions of mass in other nearby branes. Basically, that what we perceive to be a roughly spherical/point object would effectively be the hyperdimensional equivalent of that same shape that would "pin" itself together across branes.

Where I see this as becoming testable (and I could be wrong - again, I'm not a physicist) is that if this were the case, there should be examples of anomalous astrophysical objects and events, where the mass we observe does not line up with effects we also observe. For example, a stable neutron star suddenly flashing into a black hole when it passes too close (hyperdimensionally, of course) to a large mass in another brane. Another example might be a star or planet whose mass can't be reconciled with its observed size - e.g. maybe there is a planet the size of our moon, but which exerts gravity as if it were made entirely out of a material ten times as dense as uranium.

I know that in the context of our own universe/brane, there's no way to pull matter out of a black hole (other than Hawking radiation), but assuming the "hyperdimensional singularity"-type thing I described above is accurate, would it be possible for the cross-brane components to separate (since they wouldn't actually be touching, just exerting gravity on each other)? If so, there might be even stranger observable effects, like neutron stars that "flash" into black holes, but then return to their former state when the mass in the other brane(s) is pulled too far away. IE they would "blink".

about two weeks ago

Consciousness On-Off Switch Discovered Deep In Brain

blincoln Re:Can be stimulated via sternocleidomastoid (284 comments)

Are you sure that's the mechanism at work? "pressure along the sternocleidomastoid" sounds suspiciously like "put someone in a triangle choke/'sleeper hold'", which will cause them to pass out because it cuts off the blood supply to their brain.

about three weeks ago

Researchers Create Walking, Muscle-Powered Biobots

blincoln Re:Another materials article (33 comments)

Seems like one could use this type of engineered muscle to power an electrical generator which would either recharge a battery or power an electronic device directly. Then you'd have an implanted electronic device which never needed to have its battery changed or recharged using external means.

If it burned enough calories, maybe it could even be sold for cosmetic reasons - eat all you want, and transfer the surplus charge from your implanted battery to an outside system via induction.

There isn't exactly a surplus of empty space inside the human body, but I imagine this type of system could also be used to pre-condition engineered muscle tissue or replacement hearts before they're implanted into their intended recipient's body.

about three weeks ago

Steve Jobs Defied Convention, and Perhaps the Law

blincoln Re:Simple (311 comments)

Actually, 10% above cost is the maximum that Costco will price merchandise without having something like VP-level approval. They seem to be doing well enough.

about 3 months ago

Lytro Illum Light-Field Camera Lets You Refocus Pictures Later

blincoln Re:Meh (129 comments)

So your solution to the problem is that everyone should become a Sports Illustrated-grade professional photographer and shoot hundreds or thousands of photos at every event they go to so they can pick out the 3-5 that were actually in focus and properly composed?

I think I'm going to go with the light-field camera being the more realistic option.

about 3 months ago

Lytro Illum Light-Field Camera Lets You Refocus Pictures Later

blincoln Re:Meh (129 comments)

The lens on the Illum already goes up to 255mm focal length, which is a longer-distance telephoto than most people ever use. It should be plenty for capturing the player's face in your example.

about 3 months ago

Contact Lenses With Infrared Vision?

blincoln Re:You don't want to see IR (99 comments)

While that's true, most military night vision (which the article discusses repeatedly) is near-IR. Nearly all of the "bulky goggles" are of that type - including the one in the photo in the article, if I'm not mistaken.

about 4 months ago

Gabe Newell Responds: Yes, We're Looking For Cheaters Via DNS

blincoln Re:Not sending history to Valve (511 comments)

Most cheating involves modifying processes in memory, not the files on disk.

I do agree that it's really heavy-handed of Valve to ban players over DNS entries, though. What's to stop me from posting a page on some heavily-trafficked site with embedded image tags pointing to those systems (they may not load, since who knows if the cheat servers are even running web server components, but visiting machines will still cache the DNS entries), trying to get anyone who visits it banned on Steam?

about 5 months ago

Japanese SCHAFT Takes the Gold at DARPA Robot Challenge

blincoln Re:Humanoid robots are kind of dumb to me (51 comments)

I believe the idea with humanoid robots is that if you have to deploy a robot into an unforeseen and dangerous situation, having a robot with a humanoid form means it's more likely to be able to do all of the things that a human could do, and get into all of the same places.

E.g. if you have a nuclear reactor emergency - especially in an older facility - most of the controls are going to be designed for a human to operate, like the valve wheels depicted in some of the challenges in this contest, and at least some of the building is only going to be accessible through doorways, stairways, ladders, and crawlspaces designed for humans.

It's the same with operating an arbitrary vehicle (another one of the challenges). Just about any vehicle that's going to be available in an ad-hoc situation is going to be built for use by someone with at least two arms and two legs, with hands that have opposing thumbs, and which is somewhere within 20-30% of 2 meters tall (or their eyes won't be able to see anything).

Sure, you could try to build all of your critical infrastructure in ways that would allow non-humanoid robots to operate it easily as well, but that doesn't take care of all of the legacy stuff that's out there, and will be out there indefinitely.

You could also build a variety of robots that are specialized to do one or more of those things without being humanoid, but that robot probably won't do very well in the other types of situations this contest is intended to simulate.

Once they work a *lot* better, and are intuitively controllable via telepresence, I can really see some commercial applications of this too. One or two telepresence androids available for remote use sitting in a datacenter would be better in some ways than having iLO cards in every physical server. Just about anything that involves a remote, un-staffed facility becomes a lot easier if your workers can "teleport" there by android instantly when something goes wrong.

about 7 months ago

Target Has Major Credit Card Breach

blincoln Re:Inside job (191 comments)

I disagree. It's certainly possible that there was inside help, but I think it's a lot more likely someone compromised a system in Target's corporate offices and used it to pivot to capturing the data in question.

about 7 months ago

Target Has Major Credit Card Breach

blincoln Re:Chip and Pin (191 comments)

Chip-and-PIN isn't perfect, but it's about a thousand times better than the archaic mag-stripe cards that are still in use in the US.

Mag-stripe cards are a relic of 30-40 years or more ago - similar to social security numbers - where your identification is the same as your authentication. It's a "secret name"-type system where as soon as you tell someone what your account number is, they can do whatever they want with it.

Mag-stripe cards can be cloned easily with a ~$100 reader/encoder that you can order from China on eBay (I have one - it's pretty neat). All you need to do is swipe the card through it once (or through a cheap reader, which you save the data from and then write to a card using the bulkier encoder later). AFAIK with Chip-and-PIN, you would need a lot more time with the card, some expensive hardware, and some reverse-engineering skills instead of just click-the-copy-button skills.

Also, AFAIK, with Chip-and-PIN, you can't clone the card solely by intercepting network or device-to-device traffic. You have to compromise the reader itself. If you can intercept unencrypted network traffic from a mag-stripe transaction, then at a minimum you've got everything you need to use that card fraudulently online, and depending on how bad the system is that's involved, you probably have everything you need to create a full clone of the card.

about 7 months ago

Target Has Major Credit Card Breach

blincoln Re:don't connect everything to the internet! (191 comments)

Who said anything about these devices being compromised by an attack from the internet? There are all sorts of ways to attack them indirectly:

- Compromise the system that manages them, then use that management system to push out compromised firmware or OS updates (depending on the device type - the newer payment terminals are often little Linux machines).
- Compromise the POS registers and capture the data there instead of directly on the terminals.
- Compromise the centralized back-end systems that Target uses for payment authorization. PCI-compliant retailers aren't supposed to capture full track data from the cards, but it might be possible to enable some sort of legacy mode that does just that.
- Compromise the network devices (routers, etc.) that the data is transmitted over. PCI only requires network-level encryption for transmission over untrusted networks, not internal corporate networks.

Etc. etc. Magnetic-stripe cards are a security nightmare, and everything that retailers do related to them is just a band-aid. We (the US) need to move to systems that use one-time codes - like chip-and-PIN - like the entire rest of the world is either in the process of doing or has done already.

about 7 months ago

Two Years In Prison For Using Infrared Contact Lenses To Cheat At Poker

blincoln Re:Infared Contact Lenses? (320 comments)

There's a problem with the theories all of you are coming up with - IR-pass filters appear black to the human eye. Unless casino staff were unable to see that there was something unusual about the guy with pitch-black irises, I'm thinking this is not what happened. In addition, unless the casino was lit with some sort of incandescent/halogen lighting or the sun, anyone wearing long-pass (visible-light-blocking) contacts would be blind in most indoor locations. Fluorescent and LED lighting put out basically zero near-IR light.

In addition:

- Near-IR really is infrared. It is "near" as opposed to "mid" and "far", not near as in "almost". It's the kind of infrared that remote controls used until RF (e.g. Bluetooth) became common, the kind that night vision goggles use, and the kind that CD drives (but not DVD or Blu-Ray drives) use for their lasers.
- Despite the arrangement of most spectrographic data arranging it to the right of visible light, all IR is longer-wavelength (lower frequency) than visible light.

about 10 months ago

New Real Life Laser-Rifle Cuts Through Metal Like a Blowtorch

blincoln Re: of course it isn't mobile (143 comments)

What would you suggest calling it instead of a "laser rifle"? A "laser musket"? "Smoothbore laser long-gun"?

about 10 months ago

MIT Research: Encryption Less Secure Than We Thought

blincoln Re:good news for NSA (157 comments)

Actually, you're both wrong.

For certain types of encryption, you are right - a known-plaintext attack that easily reveals the key is a fatal problem for the encryption method. This is true of AES, for example. The converse is also true - currently, knowing the plaintext and encrypted values for an AES-encrypted block of data does not let an attacker determine the encryption key in a reasonable amount of time. It still requires testing every possible key to see if it produces the same encrypted block given the known plaintext.

Other types of encryption are absolutely vulnerable to known-plaintext attacks. I'm less familiar with this area, but certain common stream ciphers (like RC4) are literally just an XOR operation, and so if you know the plaintext and ciphertext, you can obtain the keystream by XORing them together.

about a year ago

Examining the Expected Effects of Dark Matter On the Solar System

blincoln Dark matter, dark energy, and M-theory (190 comments)

This is probably a dumb question, but I've been wondering about it for something like a decade, and I never see it referenced (even to debunk it) in legitimate science discussions.

A mysterious effect which looks like matter, but is invisible except for its gravitational effect. A second mysterious effect which causes the rate-of-expansion of the universe to increase.

I grow more and more skeptical of string theory and its relations every year, but the first of those definitely sounds to me like matter that's in another brane. The second one seems (to my non-physicist mind) like it could also be explained by the same thing, just a different set of matter in a different position relative to the first.

If our universe really is a 3D brane in a hyperdimensional space with others, isn't this exactly the sort of thing we'd expect to see? Further, wouldn't we see related effects like neutron stars unexpectedly flashing into black holes when they come into close-enough contact with dense clumps of matter in adjacent branes (IOW, when there's not enough observed mass in our own to explain the change to a black hole)?

about a year ago

Motorola Is Listening

blincoln Re:FOSS alternative(s) to Burp Suite? (287 comments)

I also linked to OWASP ZAP, which I used for most of the testing, partly because it is FOSS. Well, emphasis on the F, but the OSS is nice too.

ZAP should work fine for the kind of passive analysis I did for TFA, and if you're on a truly tight budget, you can certainly use it for more active testing. However, if you're going to do professional pen-testing, Burp is really worth shelling out for. It's the best web pen-testing tool I've seen, and I've heard the same thing from people I trust (including SANS instructors who are ZAP contributors). For professional work, it's a bargain at something like $500/year. Most professional security tools are 10+ times that expensive.

1 year,26 days

Motorola Is Listening

blincoln Re:Achievement Unlocked (287 comments)

This has nothing to do with Microsoft or ActiveSync, other than that I discovered it while testing some ActiveSync functionality that required changing my EAS configuration on the phone repeatedly. Changing the EAS settings triggered a replication of those changes to Motorola.

I tried to figure out how to sign up for a HN account to correct that, but it looks like it's invite-only?

1 year,26 days

Motorola Is Listening

blincoln Re:Achievement Unlocked (287 comments) which I mean, of course, that the whole Slashdot/Hacker News "Bifecta" solves that particular problem. I don't have any other good answers besides that :).

1 year,27 days



The Polite Thief?

blincoln blincoln writes  |  more than 5 years ago

blincoln (592401) writes "Last week I noticed four unauthorized charges on my credit card. I went through the standard process of having the card canceled and a new one issued. Oddly enough, in two of the cases the thief actually had the product shipped to my mailing address — I received flowers from FTD and five DVDs of various genres from Columbia House. Both companies told me to keep the packages even though they were refunding my money. I can only assume that this was done as a sort of "thanks for letting us use your stolen card number", but as someone with a bit of interest in criminal psychology I'd be curious to know if anyone on Slashdot has a more informed take on the situation. As a side note, I'm reasonably sure that the information was stolen from or by an online merchant (or from my bank, I suppose), given that the thief obtained my mailing address as well as the card information."



blincoln blincoln writes  |  more than 10 years ago

Scorpio's thoughts drifted to the hypometric weapon moving in its shaft, a corkscrewing, meshing, interleaving gyre of myriad silver blades. Even immobile, the weapon felt subtly wrong, a discordant presence in the ship. It was like a picture of an impossible solid, one of those warped triangles or ever-rising staircases; a thing that looked plausible enough at first glance but which on closer inspection produced the effect of a knife twisting in a particular part of the brain - an area responsible for handling representations of the external universe, an area that handled the mechanics of what did and didn't work. Moving, it was worse. Scorpio could barely look at the threshing, squirming complexity of the operational weapon. Somewhere within that locus of shining motion, there was a point or region where something sordid was being done to the basic fabric of space-time. It was being abused.

That the technology was alien had come as no surprise to Scorpio. The weapon - and the two others like it - had been assembled according to instructions passed to the Conjoiners by Aura, before Skade had stolen her from Khouri's womb. The instructions had been precise and comprehensive, a series of unambiguous mathematical prescriptions, but utterly lacking any context - no hint of how the weapon actually functioned, or which particular model of reality had to apply for it to work. The instructions simply said: just build it, calibrate it in this fashion, and it will work. But do not ask how or why, because even if you were capable of understanding the answers, you would find them upsetting.

The only other hint of context was this: the hypometric weapon represented a general class of weakly acausal technologies usually developed by pre-Inhibitor-phase Galatic cultures within the second or third million years of their starfaring history. There were layers of technology beyond this, Aura's information had implied, but they could certainly not be assembled using human tools. The weapons in that theoretical arsenal bore the same abstract relationship to the hypometric device as a sophisticated computer virus did to a stone axe. Simply grasping how such weapons were in some way disadvantageous to something loosely analogous to an enemy would have required such a comprehensive remapping of the human mind that it would be pointless calling it human anymore.

The message was: make the most of what you have.

--- Alastair Reynolds, Absolution Gap


blincoln blincoln writes  |  more than 10 years ago

This is another excerpt from an Alastair Reynolds novel. He's really quite good, but almost unheard of here in North America. I had to import his latest (Absolution Gap) from England because it won't be out here for another four months. This quote and the last one are funny, but the stories as a whole are very serious and interesting. Any sci-fi fan owes it to themselves to pick up Revelation Space, and go from there.


"I'm an artist," Quirrenbach said. "Actually, a composer. I'm working on a symphony cycle; my life's work. That's what brings me here."


"Yes, Music - though that contemptible little word barely encapsulates what I have in mind. My next symphony will be a work inspired by nothing less than Chasm City." He smiled. "It was going to be a glorious, uplifting piece, celebrating the city in all its Belle Epoque splendour; a composition teeming with vitality and energy. Now, I think, it will have to be a darker piece entirely; Shostakovichian in its solemnity; a work weighed down by the crushing realisation that history's wheel has finally turned and crushed our mortal dreams to dust. A plague symphony."

"And that's what you've come all this way for? To scribble down a few notes?"

"To scribble down a few notes, yes. And why not? Someone, after all, has to do it."

"But it'll take you decades to get back home."

"A fact that has, surprisingly, impinged on my consciousness before you so kindly pointed it out. But my journey here is a mere prelude, occupying a span of time that will become inconsequential when set against the several centuries that I confidently expect to elapse before the work nears completion. I myself will probably age the better part of a century in that time - the equivalent of two or three whole working lives of any of the great composers. I shall be visiting dozens of systems, of course - and adding others to my itinerary as they become significant. There will almost certainly be more wars, more plagues, more dark ages. And times of miracle and wonder, of course. All of which will be grist to the mill of my great work. And when it is polished, and when I am not utterly disgusted and disillusioned with it, I will very probably find myself in my twilight years. I simply won't have time to keep abreast of the latest longevity techniques, you see; not while I'm pouring my energies into my work. I'll just have to take whatever's easily available and hope I live to finish my magnum opus. Then, when I have tidied up the work, and achieved some form of reconciliation between the crude scribblings I have set down now and the undoubtedly masterful and fluid work I will be producing at the end of my life, I will take a ship back to Grand Teton - assuming it still exists - where I will announce the great work's premier. The premier itself won't be for another fifty or so years afterwards, depending on the extent of human space at that time. That will give time for word to reach even the most distant colonies, and for people to begin converging on Grand Teton for the performance. I will sleep while the venue is constructed - I already have something suitably lavish in mind - and an orchestra worthy of the event is assembled, or bred, or cloned - whichever the case may be. And when that fifty years is done, I will rise from slumber, step into the limelight, conduct my work and, in what little time remains to me, bask in a fame the like of which no living composer has ever or will ever know. The names of the great composers will be reduced to mere footnote entries; barely flickering embryo stars set against the gemlike brilliance of my own stellar conflagration. My name will ring down the centuries like a single undying chord."

There was a long silence before I responded.

"Well, you've got to have something to aim for, I suppose."

--- Alastair Reynolds, Chasm City


blincoln blincoln writes  |  more than 10 years ago

He looked at the ships again. The twelve black shapes were larger, fatter versions of Nightshade, their hulls swelling out to a width of perhaps two hundred and fifty metres at the widest point. They were as fat-bellied as the old ramliner colonisation ships, which had been designed to carry many tens of thousands of frozen sleepers.

But what about the rest of humanity? What about all the old ships that are still being used?

[We've done what we can. Closed Council agents have succeeded in regaining control of a number of outlaw vessels. These ships were destroyed, of course: we can't use them either, and existing drives can't be safely converted to the stealthed design.]

They can't?

Into Clavain's mind Skade tossed the image of a small planet, perhaps a moon, with a huge bowl-shaped chunk gouged out of one hemisphere, glowing cherry-red.


--- Alastair Reynolds, Redemption Ark

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