109 replies to this topic

[Russ]

Chuck Yeager!

You've probably read The Right Stuff. The book is great.

[Don Quixote]

Yeah, the book is quite a gem. I'm trying to remember when I first read it...it might have been a summer reading assignment for AP Language & Composition.

[RShack]

Chuck Yeager!

You've probably read The Right Stuff. The book is great.

 

It sure was.

 

It was one of a few things that were both a great book and a good movie... doesn't happen often... harder still to be a great book and a great movie... IMO, To Kill a Mockingbird is the all-time champ at being both...

 

ps:  Everybody probably knows this already, but just in case somebody doesn't...  in the movie they got Chuck Yeager to play the guy with the broom in the bar...

[NewMarketSean]

So, they'll just accelerate slower...   Back in the early days of the automobile, they thought going 60 mph would kill you... no kidding, they really did... I forget why, but it wasn't just some random scare... it was based on some reasonable-to-them theory...

  People used to think the sound barrier was impassible, too, because as you approach it you start getting more and more pressure from the leading edge shock wave which made it harder to accelerate and actually reach Mach.  The plot basically looked like an asymptote that died at the speed of sound until they were able to build better motors and more aerodynamic planes that could power through it.   That's also why transonic flight isn't really a popular thing.  You either need to be going subsonic to not have to deal with the shock or supersonic to be ahead of it.  Flying right around the shock wave can be really bumpy.   * Been awhile since I took Aero and learned all this, so maybe I'm misrembering some of the details.

Does the sonic boom happen in a vacuum though? Hyper loop will suck all oxygen out of tube so no air resistance.

[Mackus]

Does the sonic boom happen in a vacuum though? Hyper loop will suck all oxygen out of tube so no air resistance.

 

I didn't mean to imply that there would be shocks on the Hyperloop.  I actually know nothing about the Hyperloop.  Was mostly just pointing out how when we're at the edge of discovery, sound (pun intended) hypotheses based on currently available data can often end up looking silly in retrospect, like how many intelligent aerodynamicists thought the speed of sound was an impenetrable barrier during early flight testing and Shack's comment about people thought going 60 mph would kill a human. 

 

But, to answer your question, no there are no shockwaves in a vacuum, as those require a medium to travel through.  Does the Hyperloop intend to make a full vacuum in it's chamber?  That sounds prohibitively expensive.  It's expensive to do in small test chambers in our lab here, I can't imagine a vacuum tunnel stretching between cities.

[NewMarketSean]

That's what it said in the Forbes article I linked to.

 

The author said curves would make people sick...similar to a half hour long ride on the Top Thrill Dragster or Kingda Ka.

[Nigel Tufnel]

Hogan calls MagLev "the future of transportation" after riding a 314 MPH train in Japan.

 

http://www.washingto...64ae_story.html

 

http://www.baltimore...0604-story.html

[RShack]

Does the Hyperloop intend to make a full vacuum in it's chamber?  That sounds prohibitively expensive.  It's expensive to do in small test chambers in our lab here, I can't imagine a vacuum tunnel stretching between cities.

 

Nah, they're just sucking a lot of air out to significantly reduce air resistance, not eliminate it... so, a partial vacuum...

 

They blow some air back in underneath the vehicle to levitate the thing...

[RShack]

That's what it said in the Forbes article I linked to.

 

The author said curves would make people sick...similar to a half hour long ride on the Top Thrill Dragster or Kingda Ka.

 

Depends on how dramatic the turns are... plus, I'm guessing they'd adjust the attitude of the vehicle, to turn side-G's into down-G's, like when an airliner banks at 500+ mph...

[mweb08]

Hogan calls MagLev "the future of transportation" after riding a 314 MPH train in Japan.

 

http://www.washingto...64ae_story.html

 

http://www.baltimore...0604-story.html

This could be great for the region.

[Nigel Tufnel]

This could be great for the region.

 

No doubt, although they're estimating the price at somewhere from $10 to $40 billion, depending on how much tunneling needs to be done.

[NewMarketSean]

No doubt, although they're estimating the price at somewhere from $10 to $40 billion, depending on how much tunneling needs to be done.

The red line is currently estimated to be $2 billion, it will probably be closer to $3 so considering we could get 300 MPH trains from Baltimore to DC for 5-10 times the cost of a slow train that no one will ride, I'd consider it a bargain.

[BSLMikeLowe]

No doubt, although they're estimating the price at somewhere from $10 to $40 billion, depending on how much tunneling needs to be done.

 

And you can always assume the high end of the estimate. And since that's in today's dollars, if such a project were to ever come to fruition it'd probably be a lot more by the time it breaks ground.

[Nigel Tufnel]

The red line is currently estimated to be $2 billion, it will probably be closer to $3 so considering we could get 300 MPH trains from Baltimore to DC for 5-10 times the cost of a slow train that no one will ride, I'd consider it a bargain.

 

Yeah, I definitely agree that it's a much better idea than the red line.  And I think the Japanese train company has basically agreed to pay $5 billion of the cost, so at $10 billion that would be half of the pricetag, making almost a no-brainer.  But my guess is that the actual price would end up being at the high end, because nobody's going to want above-ground elevated tracks near their house. 

 

And I guess there's also the issue with that really narrow, 19th century tunnel in South Baltimore - that will be expensive to fix, but if they could upgrade it as part of the MagLev  process, it could mean great things for the Port of Baltimore, as well as for freight trains on the entire East Coast.

[NewMarketSean]

Hogan asks for 28M in federal funding to explore MagLev line.

 

http://www.bizjourna...p-a-maglev.html

 

Pretty awesome news. If a republican governor can get behind a project like this it may actually have legs.

[Matt_P]

Hogan asks for 28M in federal funding to explore MagLev line.

 

http://www.bizjourna...p-a-maglev.html

 

Pretty awesome news. If a republican governor can get behind a project like this it may actually have legs.

 

Eh. He'll take the $28M to say that he's working on public transport and then say we should kill the plans that are already in the work because this is better. It is better but it'll take forever to actually figure out a plan.

[RShack]

Eh. He'll take the $28M to say that he's working on public transport and then say we should kill the plans that are already in the work because this is better. It is better but it'll take forever to actually figure out a plan.

 

Maybe... but we need to get back to doing amazing shit again... it's *important* to do amazing shit.... and it's been decades since we did anything remarkable....

[BSLMikeLowe]

Maglev has itself an office now? Well that changes everything.

 

Baltimore Sun: Maglev venture opening Baltimore office

[DJ MC]

Sort-of MagLev!

 

http://www.baltimore...1005-story.html

 

Baltimore says it needs a world-class mass-transit system. A California company says it has the answer: high-speed, magnetically levitated, egg-like pods designed to ferry commuters above the rush-hour fray.

 

Has the city found a match, or does the proposal by skyTran — a NASA research partner — amount to "pod in the sky"?

[RShack]

Sort-of MagLev!

 

http://www.baltimore...1005-story.html

 

I don't get it... the thing needs tracks, just overhead ones... and if you're gonna have tracks, then the 2-person-pod idea doesn't make sense to me... rush hour is rush hour, you know when a lot of people need to go someplace...why not just have the equivalent of subway cars?