GeorgeOu · HackerTrans

5 yıl öncediscuss

You don't even need to complete the ring so that you can start with a lot bigger radius. The larger the radius the less the weird gyroscopic effects when people turn their heads in certain directions and the closer it replicates earth's gravity. Then you can expand the ring by increasing the arc coverage.

GeorgeOu

5 yıl öncediscuss

The best explanations I've heard is that these theores are not mutually exclusive. They can all be true at the same time and merely describe the physics from a different angle.

GeorgeOu

5 yıl öncediscuss

Yachts don't rely on solar. Sometimes they have solar but only as a small auxilary system. They primarily rely on propeller regen where the prop flips into drag mode stealing a fraction of a knot from the sail-driven ship. I've seen some yacht owners try to install a small wind turbine but it's not worth the trouble because of the noise it creates. They also tend to have at least one gas generator as an emergency backup.

GeorgeOu

5 yıl öncediscuss

I watched it in 4K on a large 43" 4K Samsung from 2 feet away and I can see a lot of problems. Some of it is compression artifacts but some is the iPhone. Honestly it doesn't look that much better than my 2014 OnePlus One phone with 4K camera.

I really hate the pitch and all these photog pros showing you how you can shoot movies or professional photos with a phone. They either use daylight which is 1000 times brighter than indoor or they use $10,000 of pro lighting. In that situation, any camera will work great. But wait till sunset or try and do some indoor shots and the tiny phone sensor and/or try and shoot some fast moving subjects that require decent shutter speeds and the phone will fail miserably.

The whole point in using a higher end $1000+ camera is that you can use it in 50% to 80% of lighting and motion conditions that a phone sucks in.

GeorgeOu

5 yıl öncediscuss

It was frustrating how my Dell XPS Laptop would frequently wake up in the laptop bag. When I open the bag, the laptop was near smoking hot. I fixed it by disabling Modern Standby but a Microsoft update killed that registry hack and I was forced to fully shut down the laptop.

Then my work Dell Precision 5530 started doing the same thing and I'm forced to shut it down. The problem was that particular laptop took several minutes to boot due to a slow BIOS post and corporate bloatware.

GeorgeOu

6 yıl öncediscuss

11 hours in a private plane with lots of room and being able to lay down flat or be in a zero gravity chair would be sheer luxury compared to many flights I've taken. My last long distance flight took 24 hours of travel to get from San Jose to Israel with 3 legs in Coach and going through multiple security gates. One time I flew 16 hours Coach from LA to Guanzhou China and that was a second leg. My tail bone was in pain for a day from sitting that long.

If an airplane like this meant being able to fly private, it's completely worth it. One other factor you have to consider is that this plane can probably use tiny airports which shaves a 4 hours of additional driving and security gates. I'd rather be in a slower flying plane for 7 hours than fly for 4 hours but spend 4 additional hours at security gates and car traffic.

GeorgeOu

10 yıl öncediscuss

It looks like this former uBeam engineer exposed Energous too. http://liesandstartuppr.blogspot.com/2016/04/those-other-guy...

He linked to this story on Energous. http://seekingalpha.com/article/3811296-energous-buy-company...

"Using the 1 watt as our transmitter power translates to 0.000507 watt (0.507 milliwatts or 507 microwatts) at the receiving end. "

But it's even worse than this! The FCC does not allow you to transmit at the full 1 watt (30 dBm) if you focus the energy with more than 6 dB gain. If you want to use a phase array to get 21 dB antenna gain, you must drop your transmit power to 25 dBm or 0.316 watts. Every 3 dBi of antenna gain must be accompanied by 1 dBm decline in transmit power.

GeorgeOu

11 yıl öncediscuss

If you read the FAQ on eevblog, 100 KHz frequency ultrasound will lose 90% of its energy at 2 meter range or just over 6 feet. That energy goes to heating the air that the sound travels through.

Then you have to contend with any orientation offset. If the receiver is off by 90 degrees or more, there is zero energy received. If your hand blocks half the surface area, that's another 50% power loss.

If you boost the power above 140 dB safety limit, you can burn your hands or cause other problems. At 140 dB at 2 meters, the theoretical best case with 100% efficiency transmitter and receiver will deliver 0.85 watts. You obviously lose even more than that.

http://www.eevblog.com/forum/projects/the-ubeam-faq/

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