Thanks for pointing this out. I've obviously not gotten my head around the concept of space-time and the article fails to mention this.
Also, http://newscenter.lbl.gov/feature-stories/2011/08/25/superno... is perhaps a more official story. They too don't mention that it's discovery was a few hours after it was possible to observe the explosion, not a few hours after the actual explosion.
These conversations are useless. Everyone knows that anything we see is strictly in the past and already has happened. Yet for practical purposes, a week ago there was no supernova there. Today a supernova is there.
It may help you to look at it like this: a supernova is NOT the star exploding, it is the observation of the star exploding. In one sense, this is wrong, but in another it is really the only freaking thing a supernova can be. Therefore since it wasn't a supernova until humanity saw it being a supernova, it is currently happening.
Further, the article only says the supernova is brightening, and that the telescope saw the star early in its explosion a few hours ago. From the reference point of observability, no claim is made that something 21million light years away is being watched now, just the effects of it are being watched right now.
I don't think it's nonsensical. There is a meaningful way in which it is in the past. Even if you turn yourself into photons, match positions with the supernova remnants, then return to physical form, the supernova is going to evolve though time for quite a ways beyond the current state we observe it in before your physical form has its rendezvous, even if the trip has zero duration for you.
Putting a specific time span on how far in the past it is without further specification is dubiously meaningful, saying it is in the past is not nonsensical. Everything we see is always in the past, even if it's just on the other side of the room.
If you set a reference point, then I think it's perfectly sensical to say two events happen simultaneously or "now," but without a set reference point those notions are completely nonsensical.
Most educated people understand the principle of relativity (which states that the laws of physics behave consistent in all frames of reference) and the fact that the speed of light is constant regardless of your frame of reference, but we tend to forget the resultant phenomenon called the relativity of simultaneity. Two observers in different frames of reference can't even agree on the order of events, much less the "exact time" they occurred.
Now, you can certainly propose the semantic axiom that "everything happened in the past due to the finiteness of the speed of light," but I find that axiom to be pretty useless in scientific discussion. You can suppose that millions of years of stuff has happened to that supernova after "now," but none of those events could have any causal effects on us.
> Two observers in different frames of reference can't even agree on the order of events
Please keep in mind that we and the supernova are more or less in the same frame of reference. So all the ambiguity of simultaneity does not apply here.
I fear you don't actually undestand several core concept of special relativity, among these past, present, causality and simultaneity. Of these, only the last one is relative to the reference frame. Temporal ordering of events is absolute for events that are causally related, if event A is in the past of event B, which is defined as event B being able to observe event A or any of its consequences, then event A happens before event B in every frame of reference. Only the time difference between A and B depends on the frame of reference (for an observer at rest relative to the microwave background, there are 21 million years between the supernova and our observation of it, but a neutrino emitted by the nova passes though the earth only moments after it was created in its own reference frame, as it travels almost at the speed of light relatie to the nova and the earth). Likewise, we say that B is in the future of A if B can observe A or any of its consequences.
Only in the case that neither A can observe B nor B can observe A, which we denote by saying that the events are in their relative present, the ordering becomes relative to the frame of refrence, but that case is irrelevant in the present discussion, as we can observe the nova and so have established the fact that it (or at least its beginning) is in our past. Note that its maximum, which is predicted to be observable around next friday, is in our present (we can not influence nor observe it yet), while our observation of it is in our future (we can still make plans for where to watch it), at least until next friday, when both of these events simultaneously move into our past.
fhars is correct. I'll say that you're getting closer than most people get to these concepts, but you seem to have mistaken partial ordering for no ordering. There is still a partial ordering of events, and we can now say that the supernova is in our past without ambiguity.
> Choosing the Earth as your point of reference, the supernova is happening exactly when we see it happening.
No, that is not true. You do not say point of reference, you say frame of reference - and for a good reason. Huge areas of space can all be in the same frame of reference.
"The PTF survey uses a robotic telescope mounted on the 48-inch Samuel Oschin Telescope at Palomar Observatory in Southern California to scan the sky nightly. As soon as the observations are taken, the data travels more than 400 miles to NERSC via the National Science Foundation’s High Performance Wireless Research and Education Network and DOE’s Energy Sciences Network (ESnet). At NERSC, computers running machine learning algorithms in the Real-time Transient Detection Pipeline scan through the data and identify events to follow up on. Within hours of identifying PTF 11kly, this automated system sent the coordinates to telescopes around the world for follow-up observations."
can it look like a planet-wide intelligence to an outsider? :) . Interesting to compare to the origins of cybernetics :
It seems to me that detect-track-target feedback-looped principle was one of key in the development of intelligence of animals and humans, and it seems to continue its work in developing the intelligence beyond that.
He pointed out why that might not be possible. If an add-on is only supposed to work from version 3.6-6.0, and Firefox silently updates to 7, the user loses the add-on's functionality (and for many people, the only reason to use firefox are the add-ons)
When an add-on is disabled some sort of notification is desirable, but it doesn't have to come in the form of a modal dialog that blocks usage of the browser. There's generally nothing a user can do about it anyway. Furthermore, Mozilla could be doing a much better job of compatibility testing for the most popular extensions to ensure they don't have to be disabled every upgrade.
While I understand that this segment of theirs was a joke, it did have a point to it. They were trying to show that it is possible to drive a Prius in such a way that you don't actually save any fuel over a non-hybrid.
I don't think anyone would dispute that a Prius is more fuel efficient than a sports car in stop-and-go traffic and having that segment on Top Gear just wouldn't be possible as it would make the show "fair" to the hybrid and actually about cars which it definitely isn't.
And I think they make these silly claims at times since they know they are so over-the-top that it's hard for anyone to take them too seriously.
Do you have any more info on how yelp.com has been running "extortion rackets"?
I don't know much about yelp, and don't use it much, but have generally been led to believe that they are a good company (admittedly, by the tech press) so it'll be interesting to hear if you have actual examples of people getting scammed.
>A federal judge...dismissed a class-action lawsuit accusing consumer review website Yelp of extortion...Judge Marilyn Hall Patel ruled last week that the original suit failed to back up small business owners' claims that Yelp was manipulating user reviews to force them to advertise on the site.
I am in India, and have a connection that is 256Kbps. This is sufficient for most things, but I cannot get Lion from Apple.
I don't mind waiting for 40 hours for ~4GB to download, but the likelihood that a connection in India is sustained for more than 10-15 minutes is rather low. The problem here isn't with the speed (it is with that as well), but with the reliability of the connection. Even at 8MBPS, this download will still take about an hour and it's rare that the connection won't be randomly dropped during that hour.
Why can't Apple download these things smartly like BitTorrent? Why this behemoth of a download? Why not break it up into smaller pieces of ~10-20MB each, with a checksum for all these pieces so that WHEN (in India it's WHEN, not if) the connection gets dropped, you're only effectively losing 10-20 MB of downloaded data, not losing an entire GB or more of downloaded material.
To me, it almost seems silly not to do this. Is Apple really this ignorant of flaky internet connections?
I have a faulty router that just this morning rebooted itself several times while Lion was downloading. Everytime the connection was lost it just resumed.
Why don't you try leaving it some hours and see how it goes?
To be very honest, I have a 3G connection with a limit of about 1.25 GB per month. Since I wanted Lion as quick as possible, I downloaded 1 GB of material using the 3G connection (took me a very, very short time - relatively). When I tried to resume the download from the App Store using my normal internet connection it didn't, and I lost about 1GB of stuff.
That's why I posted the earlier message.
In the interest of full disclosure, it was probably because the Mac App Store needed to re-authenticate me (I changed IPs remember), clicking resume resulted in me not being able to start the download, and the App Store just decided that the 1GB downloaded was useless.
The point about flaky internet connections, and "chunk"ed downloads still stands. I don't expect to be able to get through this download, and even my current issue would have been more gracefully handled with a smaller download size since only 1 chunk of data would have been lost.
Note: Interestingly, my 3G connection is more reliable than my broadband with respect to reliability. Even more interestingly, the provider is the same in both cases.
> Even more interestingly, the provider is the same in both cases.
The wired and wireless divisions of telecoms are often managed very differently. For example, AT&T's U-Verse FTTH service is great, but I wouldn't touch AT&T's cellular service with a 10' pole.
Well, India's the exception, not the rule, when it comes to exceedingly poor infrastructure. And considering Apple's upscale target demographic, India probably isn't a huge concern for them.
Is there some other reason why you think the idea I suggested is incorrect, or not worth it?
Because it seems to me that claims like India "isn't a huge concern" might hold some water, but I've read of people complaining of flaky connections even in countries with better infrastructure. Does Apple really want to waste bandwidth on re-uploading data that has already been uploaded? Lion isn't the only multi-gigabyte application available for download on the Mac App Store.
I can only comment on America and Japan, but I'm fairly sure that if it were that simple to implement resumable downloads, Apple would have already done so. Who knows - maybe they already have. After all, you admitted to actually restarting the download from a different IP, which means that the issue may be something completely different.
I'm in India too and have a 1Mbps connection and downloaded Lion overnight yesterday. MTNL isn't known to be very stable but the Lion install was there in my applications folder in the morning so it does support resuming.
That said, Apple suggested they'll let users download Lion at Apple stores and since this is India we always can do some "jugaad". Why not try talking to the friendly guys at your neighborhood Apple store and they'll install Lion for you.
Which service provider is that? I use Airtel and I've never experienced the dropping of connection in the last 5 years. Airtel is very reliable and fast too.
Yeah, that's true. We clearly told her to speak it as "wee-zee-wig" (fearing otherwise she would simply speak each letter) but she stumbled on the word (I guess). I gather from comments here that we probably need to redo the audio.
Perhaps you could test out different voices, and test which ones people skip over vs which ones people watch all the way through? Doesn't youtube offer some stats on that?
For April Fools this year, Blizzard announced the Starcraft II Patch 1.4.11 patch notes and the World of Warcraft Patch 4.1.11 patch notes. I thought that was clever, and a great way to take advantage of a coincidence in the release schedule. In fact, given Blizzard's love of April Fools it wouldn't surprise me if they shifted some patches around in order to set up that joke.
Also, http://newscenter.lbl.gov/feature-stories/2011/08/25/superno... is perhaps a more official story. They too don't mention that it's discovery was a few hours after it was possible to observe the explosion, not a few hours after the actual explosion.