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bluehawk

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How do you think the hydrogen is produced? Currently it's either a product of petroleum or produced by using electricity to split water. So your argument of electricity not inherently being clean energy applies to hydrogen as well.

Assuming you use electricity to split water to power your fuel cell, you've basically just made an even more complicated way to use electricity to power your car. So at that point, just simplify it and just use a battery and a motor.

My understanding is that it's just talking about the pumps. 95% of the energy from the battery is turned into rotational energy by a motor in the pumps. This pushes the fuel into the reaction chamber of the rocket engine. Contrast this to a gas-generator cycle that uses some of the fuel/oxidizer to run the pumps. It's not perfect combustion (you don't want it to get too hot) turbines aren't perfectly efficient, etc. so you only get 50% of the energy out of the fuel that you use in the turbo pumps.

However, batteries are heavy. I'm hesitant to believe that electric pumps will scale well to larger rockets, but I would love to be proven wrong.

Solar Roof 9 years ago

Since we are discussing Tesla solar roofs, they suggest your installation comes with a PowerWall, thereby storing power during the day to use at night. I personally don't think we are there yet, but I think the goal is that you don't need the entire national power grid just for night electricity, just a big battery.

It's a trade off. In my opinion when using rebase you don't lose history or make it inaccurate. A bug would still be introduced by the commit that made it, so tracking down bugs with bisect or other tools works the same. The main advantage is that your history is much cleaner.

The boosters were actually parachuted back down to earth and reused. Though the general consensus is that it didn't save any money, and may have been more expensive than if they had just been disposable.

Did you really? The fifth paragraph defines it:

"The chronically homeless, on the other hand, are a subset of the homeless population that is often the most vulnerable. These are people who have been living on the streets for more than a year, or four times in the past three years, and who have a "disabling condition" that might include serious mental illness, an addiction or a physical disability or illness."

I can sorta understand how he got there. Historically, making a car company is very, very hard. It's a tough industry to crack into. So when you see a startup car company with a hugely inflated stock that has a (based on historical data) very low chance of success, it makes a lot of sense to bet against it. But as it succeeds, you have to keep doubling down on the idea that it can't possibly deliver on it's promises and will fall on it's face eventually. At some point he slipped from making a reasonable bet to frothing at the mouth a bit.

Put another way, no blind person is going to sit behind the wheel of a Tesla and tell the car to take him/her to the supermarket.

That's exactly what Tesla is marketing and working on with their new self-driving features, and you can buy cars that will allegedly be capable of this today.

"All you will need to do is get in and tell your car where to go. If you don’t say anything, the car will look at your calendar and take you there as the assumed destination or just home if nothing is on the calendar. Your Tesla will figure out the optimal route, navigate urban streets (even without lane markings), manage complex intersections with traffic lights, stop signs and roundabouts, and handle densely packed freeways with cars moving at high speed. When you arrive at your destination, simply step out at the entrance and your car will enter park seek mode, automatically search for a spot and park itself. A tap on your phone summons it back to you."

From https://www.tesla.com/models/design

I liken it to the time period when Kodak had made the first digital camera, but allowed other companies to surpass them and eat their breakfast, and now Kodak is bankrupt.

The german (and american) auto companies will either need to drastically alter their composition or other companies will take their place.

I disagree completely. Sure, the change in feel is related to the accelerator, but it's the slowing down of the car that changes. In a gasoline car that would be referred to as "engine braking". Imagine if in your gas car, when the tank was full, it didn't engine brake. I can imagine people getting caught off guard when the car didn't slow down like they expect.

Muscle memory is very important, and having the car behave unexpectedly is bad.

Dang, just looked up the suicide doors. That's... interesting. The driver and passenger seatbelts look like they are attached to the rear doors, so when you pick up someone, and they get in the back, you have to unbuckle so they can open the door.

Are the major car companies even trying to make reasonable electric cars? They all look so weird and have weird design decisions that make me not want to buy them at all.

I think a couple of things will help alleviate this problem:

If you are a real estate agent with irregular driving patterns, there will be other patterns that are consistent. For example you (and your key fob) always being in the car. You would go from your home/office to several different addresses, then back to home/office.

Also, I'm sure that when tesla sent the warning the best action would be to explain the situation. If that fails, tweet Elon.

But where is the 200km of track? You also have to deal with the atmosphere. If the track is on the ground or low in the atmosphere, then when you come out of the "cannon" you would be torn apart. So that means the track (or at least the exit) needs to be above the atmosphere, which is quite a challenge in itself.

iPhone 7 10 years ago

Because it's a tiny lens with a very very short focal length. Short focal lens tend to make everything in focus, regardless of aperture.