Cheap thoughts: digitally-signed images

Why aren’t cryptographic signatures wrapped around digital images in order to bolster their authenticity? Such a scheme would be strong proof that an image taken with a digital camera did in fact originate from that digital camera. Thus, if someone claims to have photographed E.T., we could at least say that the image hadn’t been digitally altered.

This would also be useful for protection against phishing. A image’s signature could include the website an image is supposed to be viewed from. Any scammer including a logo from the FBI in their email would raise flags in the recipients’ email client, which would compare the image’s source to the source encoded in the signature. If the FBI logo was intended to be served from, the email client could immediately warn the recipient that something funny is going on.

Yes, there would be ways around it but faking a legitimate image would be challenging. A scammer could always design his own, unsigned image or remove the signature through a screen capture. However, without the FBI’s cryptographic key being used to sign the image, the scammer could not fake the image’s signature as being from the FBI’s website.

It wouldn’t be a perfect solution to prevent fraud but it would be an important tool to prove a digital image’s validity.

Cheap thoughts: treadmills

I was walking on our treadmill today and wondering why it has such a big-ass motor on it. What does a motor really add to a treadmill, anyway? Besides a hundred pounds?

Shouldn’t the act of walking or running on the tread be enough to simulate a walk or a run? Do you ever see stationary bikes with motors on them? No, you don’t, because the pedaling is what makes things move.

It seems all a motor does is enforce a certain pace. When you run on the road, you don’t do that with a pace car riding right behind you, threatening to run you over if you don’t keep pace. You can speed up or slow down as it suits you. So why use a motor to set a rigid pace when on the real road this doesn’t happen?

I don’t see why a treadmill couldn’t simply have a tread on a low-friction set of rollers and perhaps an odometer to tell the user her speed. It sure would be a hell of a lot easier getting it up and down stairs!

Cheap Thoughts: Solar roads

How long do you think it will be before someone invents a way to easily coat roads with photovoltaic cells so that they generate electricity? Think of how much power that would generate!

Roads and silicon cells are both made of sand, so why not combine them?

Cheap thoughts: the nose knows

Photo by David Selby

While watching my pooch sniff his way around the neighborhood this week, I pondered how he always seemed to know when a storm is coming – often much sooner than we do. Is it the vibration of the thunder? The sound of thunder? Could it be that he is more sensitive to the electrical charges, being that he wears more fur than we do?

Then I remembered the NOVA program on dogs and how a dog’s senses are inferior or equal to humans in all aspects except one: the sense of smell. A dog’s sense of smell is its meal ticket and is a bazillion times more powerful than a human’s. What if a dog can smell an approaching storm? Of course, rain has a distinctive smell and definitely changes the way the environment smells.

But what if it went further than that? What if dogs can smell lightning? Lightning and other high-energy electric discharges ionize air, creating ozone. What if dogs can smell this ozone?

And … if my dog is at his most compliant in the midst of a storm (or the threat of a storm), could a small ozone generator attached to his collar make him safely and painlessly stop in his tracks should he decide to escape on an unauthorized jaunt through the neighborhood?

Cheap thoughts: medical care reverse auction

Joseph Ness’s recent series on profits in supposedly non-profit hospitals in the News and Observer is some great reporting. I was glad to see my neighborhood hospital, WakeMed, was holding its costs down, comparatively speaking.

On my morning walk the other day, I was still steaming about my last doctor’s visit, where my doctor basically sleepwalked through our appointment. Why does it take a medical degree to write a prescription to whatever high-priced drug-du-jour the pharmaceutical companies are pushing? Where’s the curiosity into what might really be going on? If I’m going to pay $150 to see my doctor for all of 15 minutes, what does it take to get his full attention during that time?
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Cheap Thoughts: automating appointments

After years of constant sessions spent updating our respective calendars, Kelly and I recently began to share our calendar details directly. It’s been much easier to know who’s supposed to be where, and it all happens automatically.

Why is it that coordinating appointments is still difficult if not impossible? I subscribe to a lot of mailing lists for charities and the like, and each one has important dates that they share with me. Yet, I have to manually add the information to my electronic calendar, risking typos and errors in the process.

Why hasn’t this been automated by now? An appointment has a set number of common fields, like date, time, description, participants, etc. It should be easy to standardize, yet everyone still does things the hard way. Why?

The iCalendar format was invented to solve this problem and most mail clients now support it. Still, it’s rare that I get an iCalendar invitation in my email: usually an event is described only in plain text. Why is this?

Facebook’s events are convenient for announcing events but this is only available to Facebook users. If someone came up with a easy-to-use calendaring server that put event details into an iCalendar format reached through a shortcut link, I think it would be heavily popular.

Cheap Thoughts: buoyant disposables

With a built-in air pocket, this can might have stayed at the top of Falls Lake, not the bottom.

On my greenway ride last weekend I couldn’t stop staring at the trash floating on the surface of Crabtree Creek. The trash was mostly plastic bottles: sealed but empty plastic bottles, that is, and therefore buoyant.

I thought it would be far easier to fish floating trash out of the creek as opposed to submerged trash. Empty plastic bottles are easy to fetch, but what about empty aluminum cans? Most go under as soon as they are filled with water.

What if all disposable bottles and cans were mandated to float? What if each was made with air pocket built in that would force the empty container to float? I think it would make it far easier to corral trash that floats before it fouls our seas than trash that doesn’t float. Recycling the materials would be boosted as well, since containers which might have ordinarily been flushed into the oceans could be better recovered.

I wonder if something like this could be done.

Cheap Thoughts: focused magnetic fields

Magnetic lines of force

I’ve been thinking that there must be a way to focus magnetic fields to very precise shapes. As I drove to work this week, I imagined my car driving through such a field in a way that my car’s speakers vibrated from the field’s effects, creating sound as the car moved through it. I think it would be a neat trick to get sound from a car’s speakers independent of whether or not they’re connected to anything!

For a while I’ve been thinking that perhaps magnetic fields could be used as antennas. Rather than have a big, metal dish to collect signals toward a focal point, a magnetic field could be generated that would invisibly reflect radio signals toward a focal point. By strengthening or weakening the field, the virtual dish could be expanded or contracted as needed, raising or lowering the gain.

Magnetic fields are circular in nature and the challenge would be how to create a parabolic shape with a field. I also have no idea if a magnetic field can even be made to reflect radio signals. It’s an interesting idea, nonetheless.

Update 25 March: I am reminded that a device exists that can beam sound to a remote location, only for this one the receiver isn’t just a speaker, it’s a human brain! Behold MEDUSA, which makes use of the microwave auditory effect.