Catch up on stories from the past week (and beyond) at the Slashdot story archive

 



Forgot your password?
typodupeerror
Slashdot Deals: Prep for the CompTIA A+ certification exam. Save 95% on the CompTIA IT Certification Bundle ×

Comment Re:Earth brighter than Moon - surprise? (Score 1) 77

There is actually a concept that explains this sort of thing!
It is called 'qualia'
The big idea is that no matter how much you understand an idea, no matter how detailed your mathematics, abstract understanding, or information about underlying biological processes may be the actual experience is different than be be imagined or described. These experiences are qualia.

Another way of thinking about it is a short story:
    Anne lives in a world that is monochrome. There is only shades of grey to her eyes. She has studied color, however. She understands the quantum mechanics of light emission, the wave particle duality, the idea of perception of color using cones in the eye, how that information is combined in the brain and can be distinguished. She has several PhDs on the topic of color in various disciplines.
    Anne then leaves the world without color and enters ours. She sees a blue sky for the first time.
    On that day Anne has learned something new about color.

Even though that scientist could conceive of the brightness difference the experience could still surprise him.

Comment Re: Hidden Blackholes (Score 1) 92

I'll agree that the burden of proof is on the people making the claim, but isn't that a reasonable division of labor? If a non-mainstream theory is (more) correct than other theories it may not be popular at first but it will be able to provide clear predictions and satisfy deeper mysteries than a less complete or flawed theory.
The fact that people don't tend to work on new and radical theories seems to simply be the dual onus of that theory being untested and being less known.
Theories in physics are becoming huge mathematical puzzles, so it is natural that those unfamiliar with the theory aren't keen on working with it until it has shown some merit.
In the long run anything better than what we have will win, simply by being better at what it does.
Is that so unfair?

Comment Re: Hidden Blackholes (Score 1) 92

That is a very interesting article. Note that the effect was achieved using a carefully constructed silicon crystal. Their ability to alter the light's path electrically is dependant on that changing the properties of the crystal. I tried to find a better abstract, but those are the gross details.
Regarding thinking of science as an indoctrination; I encourage you to see for yourself the level of agreement that some of these theories have with observation. They have amazing predictive power and any theory that may supplant them will have to explain at least those phenomena.

What makes you feel science is indoctrination? It does not seem to be to me. Perhaps it is a simple misunderstanding of the rigor that theories are put through? Let me know.

Comment Re: Hidden Blackholes (Score 1) 92

A magnetic field can only bend a charged particle. Photons are not charged and so are not bent.
There is a quantum effect called Delbrück scattering, but that is not bending and also the effect is weak enough to be negligible even in controlled experiments.
Further the fields Bing deflected like the tail of a comment is an interaction between the sun's magnetic field, ours, and the solar wind. It is not a "wake" in the sense that it would need to be in order to cause these effects even if magnetic fields bent light.

Comment Re:Hidden Blackholes (Score 1) 92

Time dilation effects alone cannot account for the bending of light which gravitational lensing accomplishes. Since time dilation does not change the metric of space it cannot bend light. We know that these observed effects are proper bending of light because of multiple images of the same objects as well as their distortion.

Another thing to note are that gravitational waves travel at the speed of light and so any lensing effect (and time dilation effect) that could be observed in the gravitational "wake" of a massive object would dissipate extremely rapidly relative to the motion of the object.

It is an interesting take, but it just doesn't pan out. That isn't to say that time dilation is absent, far from it, but it is not what is causing the lensing effects.

Comment Re:Hidden Blackholes (Score 4, Informative) 92

No and for two reasons.
This observation is in accordance with our models, so these aren't adding to the mass we had already inferred was there (but confirms that it is organized into massive black holes, so that is good to know)
Second, the amount of mass that is currently "dark" is about 5.4x what we can account for with all traditional forms of matter (atoms, neutrinos, light's mass-energy, etc). We know it is there based on its gravitational effects and have really good reasons to believe that it is a distinct physical phenomena (e.g. the Bullet Cluster's gravitational lensing agrees with dark matter's physical reality as opposed to a many of the proposed modifications to gravity)

Obviously dark matter is an active topic of research and so there are many areas of it that are fraught with misconceptions. Beware of simple answers which claim to be complete solutions.

I am not a researcher in this field, and this is obviously not anywhere near a complete explanation but I hope that at least clears up your question!

Comment Re:Not really missing vinyl (Score 5, Informative) 433

First I'd love to cite an extremely good video on this topic https://www.xiph.org/video/vid...

I'll try to distil down the relevant portion here.
Nyquist showed us that a bandwidth limited signal sampled by a discrete time system can be reproduced perfectly using 2n samples per unit time where n is the bandwidth of the signal in hertz.

Perfectly isn't hyperbole here. That is mathematically shown.

The other half of digital audio is the accuracy of measurement of those discrete samples. “Bit depth” or bits. While we can reproduce a signal perfectly with perfect samples there is some noise that is added by imperfect sampling of a signal. This is mathematically identical to tape hiss and can be manipulated to less noticeable frequencies using a technique called dithering.

Digital audio can and does faithfully reproduce the original signal with levels of noise below human perception even at a meager 16 bit depth and 48KHz sampling rate (44.1 is also very popular but 48 allows easier low pass filter design).

The stair-steps don't come out of the audio jack, the signal is reproduced by the imaging circuit.
Fast attacks that fall “in-between” the samples are NOT delayed or lost since, again using Nyquist, the signal can be perfectly reproduced (and this is demonstrated directly in the video).

There is a lot of myth and misunderstanding when it comes to digital audio, and there is a lot of truth too. The loudness wars, as other posters have pointed out, has done more to damage the reputation of digital audio than anything else and there are plenty of examples of compressed (both kinds) audio sounding just terrible. One being too low a data rate combined with a terrible encoder, the other just using a small fraction of the overall dynamic range. Those are real issues but they aren't fundamental to signal reproduction.

Hope that explains some of it!

Comment Re:Gotta be a downside somewhere (Score 5, Insightful) 151

Jupiter radiates more heat than it recieves not because it is a failed star, but because of gravitational contraction and something called differentiation, which is the layering of lighter and hevier elements sorting out (like dressing separating after you shake it).

The notion that Jupiter is radiating excess heat and, therefore, is a failed star is a tempting idea, but it is far from being a star. By an order of magnitude or three.

Comment Re:bitcoin (Score 1) 241

The answer is different in theory than it is in reality, but lets start with the theory first.

The network ca never practically be slit perfectly evenly, even if it is as more computing power is added to the problem one side will "win out" and the blockchain, by definition, is officially the longest (most complex) chain yet mined. So eventually the losing side would be undone, as if it never happened (within the scope of the blockchain... goods or services would still have been exchanged).

That assumes that all of the nodes are independent and operating following a basic set of rules and weren't rational beings. What would happen in reality is that the largest mining pools would panic very quickly. Likely they would suspend mining operations in some fashion, likely keeping the workers "busy" with bogus information and throwing away the work. What this would do is drop the hashrate of the network. Assuming coordination (or at least rational action) among the vast majority of the mining effort once the split was resolved (say a treaty was signed) the major operations would resume normal operations.
In their absence the chain would, at first, flounder, not mining any new blocks until the difficulty was re-adjusted for the now lowered hashrate. Once they came back online in a coordinated way blocks would be mined very quickly, potentially fragmenting the network until, again, the hashrate was adjusted back up. At this point the algorthim takes over and the chain with the most amount of work would win and all the other chains would disapear. This would be very controlled, however, and since the largest pools would be in a position to advertise the split and warn people very little would be lost in terms of bitcoin transactions disappearing. Mostly it would damage the reputation of bitcoin.

A slightly alternative scenario to this is that the pools suspend operations only long enough to determine who is on the larger side of the split, then resume. This would be nearly seamless to everyone on the winning side and hardly harm the reputation of bitcoin since it, along with many other services, could point to the great Internet split and blame that unfathomable one time event.

Comment Re:if you're not reading science.. (Score 1) 770

Just because free will is *heavily* biased doesn't mean it does not exist.

Certainly a person deep in withdrawals from something like heroin would be desperate for relief. At the moment their free will is biased by their instinct to survive. They are in pain, they know what will take the pain away. Even if the heroin will, in the long run, kill them the acute symptoms of withdrawal tell their brain "WE ARE DYING".

That doesn't mean that the person can't seek aid, can't choose to check into rehab or be physically restrained. It simply means that free will isn't fair, it isn't weighted equally.

I don't know what your core thesis was by comparing something as nebulous as free will to a single weighted instance, and I'm not endeavoring to disagree that an addict can “simply” choose to stop, but reducing it down to a binary choice also seems incorrect.

Comment Re:Ready in 30 years (Score 1) 305

I really want fusion to happen, but this gives me pause: http://matter2energy.wordpress...

Extremely well written and by an expert in the field. Perhaps a novel approach can push past these limitations, but I'm with you on being low on enthusiasm. Still, research, test, explore!

Comment Re:CSS? (Score 1) 306

indeed! And extending the analogy even more even though we *could* write Graham's number in decimal the number of digits makes it impossible to physically realize, but we can represent it with up arrow notation with relative ease.

Granted, all of these mathematical facts don't map 1:1 back to the original debate but it does encourage thinking about programming languages not as meaningless novelties derived from one system but as a landscape of utility, each with their own merits or lack thereof.

Also +1 for citing the uncountable infinity of the reals. Learning the difference between aleph null and aleph 1 was a deeply satisfying experience for me.

Comment Re:CSS? (Score 4, Insightful) 306

I'd like to point out that you can't represent irrational numbers accurately without a new system. Let alone trancendental numbers.

Also some numbering systems are more convenient. Binary, for example. Not different numerals, but used differently.

I know, not exactly your point, but don't dismiss languages other than C, Basic, and Pascal.

Live within your income, even if you have to borrow to do so. -- Josh Billings

Working...