Would You Travel by Vacuum-Tube Train?

Is that an old Soviet era train designed to withstand EMP pulses? ;-)

The concept has been around for a while.

http://www.popsci.com/scitech/article/2004-04/trans-atlantic-maglev

The preliminary plans were a bit on the expensive side, the technology also isn't really there yet either.

In the future, who knows?

What a pile of vacuous drivel.

When Thomas Edison entered Cooper Union college, William Crookes and others had already developed the Crookes tube that demonstrated how an electron can travel in a vacuum. Now Edison did dabble in using these vacuum tubes in and shortly after school but it was John Ambrose Fleming that invented the first tube diode. [He was a paid consultant for both Marconi and Edison.] Lee De Forest is accredited with inventing the triode vacuum tube that made amplification possible.

If the author of this article gets the very first sentence so blatantly wrong is there any reason to read anything else!

"For travelers like you and me, the cost of a one-way ticket from Los Angeles to San Francisco would be an estimated $20 (USD)."

Not in a million years, unless Elon is willing to subsidize 90% of the ticket cost, or the passengers and freight are vacuum packed for transport.

The author is motivated by a desire to expand his company's market and that is fine.

If vacuum tube is underground,in case of an accident or earthquake very serious damage will occur. If it is overhead it would be more safer to attend.

Decimal points are just like darts; you can throw them anywhere.

Nice Blog entry, well laid out with a lot of links. But what is wrong with this statement? "Thomas Edison discovered that electricity could travel in a vacuum."

Yea, maybe others discovered it before him and perhaps some after. It always did travel in a vacuum. He did not make it happen, he just happened to learn about it, good for him. I am pretty sure he went on to do some pretty cool things with it when that light bulb went on in his head, LOL!

and the cost may be 20 bucks for a nice ride but we will pay a ton more just because we are willing to do it and of course our governments large and small have to suck money from somewhere all the time or else they run out of it.

It always did travel in a vacuum. He did not make it happen, he just happened to learn about it

I don't think anyone has claimed that Edison 'made it happen'. The word chosen was 'discovered'. Why belittle that achievement?

Numerous physical properties and relationships as well as geographical features have been discovered and credit is given to those who do (not always correctly as there is sometimes politics involved).

It always did travel in a vacuum. He did not make it happen, he just happened to learn about it

I don't think anyone has claimed that Edison 'made it happen'. The word chosen was 'discovered'. Why belittle that achievement?

Numerous physical properties and relationships as well as geographical features have been discovered and credit is given to those who do (not always correctly as there is sometimes politics involved).

I heard you the first time, LOL. I don't belittle the term 'discovered'. I guess the question is can someone discover something that has already been discovered by others?

Regardless, my point is that although the first line may be semantically incorrect, that should not make the rest of the post fodder for the dust bin in and of itself.

I just discovered it is possible to accidentally double post a comment. Or was that on purpose?

Sorry, my double comment was unintentional. I selected the submit comment button and got an error message, so I backed up, copied and resubmitted (highlighting a quote from your comment).

If your intent was to point out that Edison being credited with discovering something that had already been discovered, that's been pointed out and it happens from time to time. Your previous comment seemed more to criticize discovery versus creation. Or maybe I just read too much into it.

Would You Travel by Vacuum-Tube Train?

No.

It was a misunderstanding, I was referring to comment #3 about who discovered what when.

As far as the original question goes though, I would travel by Vacuum-tube train after I was satisfied that the train stays in the vacuum and the vacuum stays out of the train.

Sigh, you misunderstand my point.

When the opening sentence of an article presented to an engineering forum contains a glaring historical engineering inaccuracy the rest of the article is likely to be a puff piece. Confirmation of fluff can be found in the artistic image leading the article. An aerodynamic train design in a vacuum tunnel looks bogus to me. Add the the meaningless, eye catching buzz words of "Energy Efficient", "Mag-Lev" and Super Mass Capacity" and we quickly enter the advertising world of today's Mad Men.

Ironically any good advertising editor would tell a copyist that the first thing one should know is to know your target audience. The second thing is that if you lose that target in the opening, you will lose them completely.

A single leak in the body of the car and you're dead meat......and a slight misalignment in the tube for whatever reason, @ 4,000 MPH you go splat in a Big Way. They won't find any of your body parts, 'cause you'll be a puddle of red goo.

No thanks, I'll walk first!

That was one of the wayward decimal points.

To get from Montreal to Shanghai in under two hours requires an average speed of at least 3700 MPH. If one has a constant acceleration and deceleration this means that the peak velocity will be some 7400 MPH. To put this in perspective this peak velocity is about one quarter of the velocity we used to escape the Earth to get to the Moon.

This article is pure fluff and no substance.

Simpler, faster, and cheaper to use Skype.

Definitely no question for the concept, it is efficient as friction can be neglected in the transportation of car but, the main thing is how would you maintain a vacuum in a a very long tube? Also, if the car defects a pressure seal people will be definitely at an instant bloated just like in space.

I'll bite, what requirement are you speculating vacuum leakage threshold would compromise the travel of vessel in the tube?

Can't we design and build an aircraft to fly at 4000mph in an air corridor at a prescribed altitude reserved for it without sonic boom problem?.

Might be a good way to ship "product" to reduce transportation costs of goods. Then we can all stay home and use the products!

Travelling in sealed pressurised vessels experiencing potentially high acceleration and deceleration forces and traveling at fantastic speeds seems to work pretty well for the astronauts and even the general public traveling on high speed trains, perhaps you are missing some key fundamental physics principles.

The same erroneous comments were also made by some many years ago that thought motorcars couldn't travel faster than something like 40 MPH (or something, I cannot remember the exact speed sorry) because the human body couldn't take it. Just a misunderstanding of the principles and actual forces involved that the body experiences.

When one considers the ruts, mud and other poor road surfaces a horse easily navigates and the questionable suspension system of early motorcars, 40 MPH seems like a good top speed to me.

No, I read an article ages ago that some people were concerned purely with the vehicle speed and wind on open-topped vehicles causing issues with early motorists, not the bumpy road surface or crashing at speed at all. They even postulated that there was a maximum top speed people could travel without physical harm (slower than todays motorway speed limit) and hence vehicles could never go faster than this, regardless of f it had an enclosed cabin.

Might have been published in popular mechanics thinking about, post WW1 pre-WW2 possibly.

Well we do have windshields today to keep the wind, rain, insects and other muck off of our faces and eyeballs. The early windshields did become a hazard itself when they broke. This evolved into the safety glass of today. That earlier article your remembered could just be identifying what needed to be engineered for greater than 40 MPH speeds.

Yeah, there was that theory that exceeding certain speeds would harm the human body, but that is (or should be) in the past, now that we understand science and physics better, it is easy to see that as long as there are no hazards within one's inertial frame of reference, that frame can be traveling at fantastic speeds to outside reference points while the occupants are fine.

What you have to look at is the ACCELERATION⁽¹⁾ of that inertial frame, as any change to the frame's speed gets transferred to the occupants. It's all basic derivative calculus⁽²⁾:

• Taking Position as the Base function
• Velocity = change of Position / change of Time | (dP)/(dT) | 1^st derivative of Position
• Acceleration = change of Velocity / change of Time | (dV)/(dT) | (dP)/(dT²) | 2^nd derivative of Position
• Jerk = change of Acceleration / change of Time | (dA)/(dT) | (dP)/(dT³) | 3^rd derivative of Position

And as you can see, I'm already oversimplifying, since It's not the absolute acceleration we're looking for, but the rate of change of acceleration, the Jerk. That is what we feel, the Jerk, not the Acceleration. Astronauts in the ISS are in 'free fall;' their acceleration is constant, but they feel like they are not moving at all. On Earth, you can feel the effects of Jerk when in an elevator, that moment of heaviness at the bottom of your trip and moment of lightness at the top are your body reacting to the 'jerkiness' of the elevator's start and stop. Keep the Jerk low enough and you can adjust the Acceleration to obscene levels and still keep your passengers happy and healthy⁽³⁾.

Notes:

1. Or deceleration, which is just acceleration in the opposite vector.
2. So basic I use it to remember how to determine the n^th derivative⁽⁴⁾.
3. That also means insuring that the curves are a large enough radius that the centripetal force (which is just another Acceleration vector) isn't changed too fast to cause discomfort/injury.
4. I also use it when driving, keeping the factors in mind as I brake from tollway speeds down to tollbooth speeds. I've managed to freak passengers out by keeping the Jerk so low they can't feel me braking at all⁽⁵⁾.
5. I have mentioned that I'm a part-time Mad Scientist, I have to do one 'evil' thing a day to maintain my license. Fortunately, using my knowledge of science to harmlessly 'prank' others counts, on the technicality that it falls under 'demonstrating mental superiority over the fools⁽⁶⁾.'
6. I'm surprised they let that one be worded so vaguely. I could literally do a canned trick purchased from a magic shop and fulfill that requirement.