Tag: iPhone

Resolving the iPhone resolution

By Phil Plait | June 10, 2010 7:00 am

[Update: Some people in the comments are complaining I didn’t use metric units in this article. I’ll assume they’re new to my blog; I usually do use metric. However, note the original quote by Steve Jobs is in Imperial units, not metric, so I used those for consistency. Also, the units don’t matter, since I could have used pixels per hogshead if I felt like it. What matters is the way the numbers compare to each other, as long as the units are consistent.]

stevejobsWith much bruhaha, Steve Jobs and Apple revealed the new iPhone 4 yesterday. Among other features, Jobs said it has higher resolution than older models; the pixels are smaller, making the display look smoother. To characterize this, as quoted at Wired.com, he said,

It turns out there’s a magic number right around 300 pixels per inch, that when you hold something around to 10 to 12 inches away from your eyes, is the limit of the human retina to differentiate the pixels.

In other words, at 12 inches from the eye, Jobs claims, the pixels on the new iPhone are so small that they exceed your eye’s ability to detect them. Pictures at that resolution are smooth and continuous, and not pixellated.

eyephoneHowever, a display expert has disputed this. Raymond Soneira of DisplayMate Industries, was quoted both in that Wired article and on PC Mag (and other sites as well) saying that the claims by Jobs are something of an exaggeration: "It is reasonably close to being a perfect display, but Steve pushed it a little too far".

This prompted the Wired article editors to give it the headline "iPhone 4’s ‘Retina’ Display Claims Are False Marketing". As it happens, I know a thing or two about resolution as well, having spent a few years calibrating a camera on board Hubble. Having looked this over, I disagree with the Wired headline strongly, and mildly disagree with Soneira. Here’s why.

First, let’s look at resolution*. I’ll note there is some math here, but it’s all just multiplying and dividing, and I give the answers in the end. So don’t fret, mathophobes! If you want the answers, just skip down to the conclusion at the bottom. I won’t mind. But you’ll miss all the fun math and science.

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CATEGORIZED UNDER: Cool stuff, Debunking, Geekery

Three iPhone science apps

By Phil Plait | March 3, 2010 8:00 am

Three iPhone apps recently came out that pertain to some favorite topics on this blog, so here’s a quick roundup of them.


1) John Cook, like me, got tired of hearing the same old long-debunked claims from global warming deniers being used over and over again, so he created an app debunking these claims. Called Skeptical Science, it divides the claims into three categories: It’s not happening, It’s not us, and It’s not bad. Under each heading are quite a few claims I’ve seen made repeatedly by the deniers, and Cook includes detailed rebuttals.

Overall I like this app, and it’s bound to be handy if you find yourself in a situation where someone is using these same claims (it’s the Sun, the hockey stick graph is flawed, Al Gore is boring, and so on). I might quibble with some of the details — for example, it talks about 1934 being the warmest year on record, but doesn’t mention that 1998, the second warmest, trails behind by a statistically insignificant 0.02 degrees. There’s more like that, but this is such a small detail it really comes down to a matter of style; an "I woulda done it different" kind of thing. The content is good and links are provided for further info.

I recommend having this one handy, so here’s the direct download link.

iphoneapp_3dsun2) Next up is a NASA app called 3D Sun. And not to trick you or anything, but it’s an app that displays the Sun in 3D. Put out by the folks behind the STEREO probes, it’s a pretty cool gizmo that reports new sunspots and aurorae, lets you look at movies of solar events like plumes, filaments, and coronal mass ejections, and gives you the latest solar news.

The best thing is the 3D Sun itself. It displays the current solar disk, and you can look at it in different wavelengths (UV shows more violent activity) and from different solar observatories. You can zoom in, out, rotate the view, and pretend you’re on a spaceship roaring past our nearby star.

Now that the Sun is finally starting to show some life again, this app is pretty useful so you know what’s the latest. Here’s the direct download link.


3) The third app is called Lunar Electric Rover, and it’s also put out by NASA. Of the three, I think this is the weakest. It’s essentially a game where you command a lunar rover to traverse the Moon to get to different goals. Now, to be fair, I’m not really partial to these kinds of games, so if they’re your thing, you may love this. I found it to be a bit slow and tedious, and the narration was stilted and difficult to hear over the background sound effects. But again, I’m not a big fan of the "go over here and do this" kinds of games. I’ll note that after I took my own notes on the app, I went to the iTunes listings and the ratings are not all that great; out of 102 ratings, 130 scored it as average or below and 62 above average or great. Lots of folks thought the same things I did.

However, I do think some younger kids will enjoy this. The graphics are quite good, and there is real information displayed and used in the game that provide lots of teachable moments. Here’s the download link.

So, do you agree, disagree? All three apps are free, so I encourage readers to grab ’em, play with ’em, and leave your own comments below!

Wait, does this give you a headache or take it away?

By Phil Plait | February 11, 2010 1:00 pm

phil_iphoneI like my iPhone, kinda. It’s not that great as a phone, but it does have lots of fun apps. The maps hardly ever tell me to take a wrong turn at the last second, and I rather enjoy taking fuzzy red photos in low light levels.

Snark aside, there are a lot of good science and entertainment apps for the iPhone. But because I am so stubbornly reality-based, it didn’t occur to me that there would be some apps that border — if not flounce solidly into — alt-med nonsensery.

That is, until I received an email from BABLoggee Cameron Carr, who told me about an app that cures headaches.


Called, oddly enough, "Headache", it uses "… principles of Traditional Chinese Medicine [that] teach that energy imbalances in the body often contribute to headache symptoms, and these imbalances can be corrected with pressure to specific points on the body."

Energy balances! Wow, that sure sounds sciencey! Except whenever you talk to people who believe in this, they can never really tell you what energy is, or how it flows, or what precisely it does. I guess it only sounds sciencey.

So basically, this app embraces both the ancient and the modern, but with a slippery grip on both.

My favorite line in the app description is, "Selected by licensed acupuncturists, these points may bring you safe, natural, effective relief." Hmm, just "may"? And c’mon, "natural"? The app can make your phone emit sounds or vibrate, which it claims "may" relieve your headache if you hold the phone against these imagined points. How is that "natural"? Even Steve Jobs wouldn’t claim that.

Having this stuff supported by acupuncturists doesn’t exactly fill me with confidence either. Acupuncture is the idea that sticking needles at certain locations in your body can restore the balance of this energy flow. If that’s true, acupuncture can be tested to see if it works. Surprise! It has been, and it doesn’t. Or, to be more precise, it doesn’t work any better than the placebo effect.

The thing about headaches is, they can have lots of causes. Sometimes they go away by themselves, sometimes they don’t. Certainly the placebo effect will help some percentage of the time, as might a gentle vibration (just as a gentle neck massage might relieve some symptoms as well). So testing a product like this isn’t easy… and there are approximately a bajillion other products like it, so they’ll never all get tested. There are a hundred ridiculous products — no, probably ten thousand — for every person actually willing to do a proper scientific test of its efficacy. There’ll never be an end to them.

I cannot say whether this app really works, or is thinly disguised quackery. Given the description on the app’s page, I suspect it’s just another alt-med claim with little or no evidence in support of it, just as I suspect it’ll do quite well. Just as the company’s Aulterra cell phone EM neutralizer probably does quite well (and you have to read that page to believe — or disbelieve — it) despite there being no credible evidence that cell phones cause any harm… unless you’re using one while driving, or skydiving.

Science pays in the long run, but stuff you just make up pays off really well in the short run. And since it’ll never, ever, go away, nonsense pays off in the long run too.

I wish there were an app to cure that.

CATEGORIZED UNDER: Alt-Med, Antiscience, Skepticism

NASA launches an iPhone app

By Phil Plait | October 27, 2009 8:00 am

[Note: NASA is trying to launch the new ARES I-X rocket, scheduled right now for 10:54 Eastern time. As I write this weather is not so great so it may be a scrub, but follow me on my BANews feed on Twitter for the latest!]

I don’t usually talk about iPhone-specific stuff, but as it happens I own (a spiffy pink) one, and this is pretty cool.

NASA_iphoneapp_missionsNASA just released a new app for the iPhone, and I like it. It has info on missions, pictures, videos (links to YouTube), and more. It’s a pretty slick app, professionally put together.

You can filter the missions to look at using categories like Earth, Solar System, Moon and Mars, and so on. It tells you when it launched, what the mission elapsed time is (which is pretty nifty), and from there you can access images and video related to the mission. Not only that, but if you tap the Earth icon when a mission is displayed, it will show you a real-time map of the location of the spacecraft over the Earth! I checked it using the space station against the info at Heavens Above, and it matched closely.

If you start from the home page and tap the image icon at the bottom, you get a choice of pictures from NASA’s Image of the Day as well as the venerable Astronomy Picture of the Day. I checked those and they were up to date with the current day’s images, too. Nice.

Videos appear to be in reverse chronological order, which is nice. Also, if you tap the RSS symbol you get the NASA Twitter stream. Very well done.

Any complaints I have are minor. It refers to Fermi as GLAST, which was its name before launch– a year ago. Some missions are missing, and I hope they’ll put them in when they update the software. Swift would be a great candidate for this, especially if they give real-time access to when it sees gamma-ray bursts. Things like that would turn this app from something cool into something extremely handy. Also, it seemed a little slow to get started, even using 3G. I turned on my wireless connection and it zipped right up though.

Still and all, it’s worth the download. If you’re a geek like me (and c’mon, admit it: if you’re reading this blog in the first place, it’s too late to hide it) you’ll enjoy it.

CATEGORIZED UNDER: Cool stuff, Geekery, NASA, Space
MORE ABOUT: iPhone, iPhone app

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