Journey through the Earth?

There's an awful lot of invalid assumptions in that question.

Can't type or even see the screen-have tears of laughter streaming down my face......ta great reply

Oscillations would diminish such that you would eventually by stranded at the center.

Indeed...the pendulum demonstrates this admirably.

I'm not so sure about the oscilation theory. I agree about the decay in the acceleration rate, however Gravity, which is your fuel, is sourced from the material the earth is made of not its central point, consequently as you decend further not only does the acceleration rate decrease but the material behind you is accelerating you backward. which may lead to your ship to be actually travelling at a constant velocity from a point halfway to the middle.

having said all that the crush force at the centre would is equal to the entire mass of the earth, less your billy cart and contents. consequently the hydrodynamic effects cannot be discounted

Nor can the alignment of the instantiator.

Think again, Guest#38, because you might have overlooked the mass component of gravitational acceleration. As the intrepid explorer "falls" core-ward in the tunnel, the mass in opposite directions around him (laterally) will offset, so that his weight remains constant with respect to the tunnel walls. However, the density (and with it, the mass) of earth increases core-ward, which would offset to some degree the anti-acceleration you propose; additionally, as he approaches the densest part of earth, the core, even though there is ever increasing over-head (virtual gravitational attraction), there would also be greater under-foot virtual gravitational attraction imparted by the mass beyond the core (between the core and China ). So, it would be the net of these over-head and under-foot attractions which, but for his core-ward momentum, would condemn him immediately to eternal perdition at the center of the core; but because of that momentum, which must decrease with each passage through the core, he will be granted, for a time, the boon of pondering his ultimate fate while in a state of oscillatory purgatory. It will be a very cruel purgatory at best . . . and very unkind in the end.

Guest#33

Hi Ryan

I have a better one for you. (a combination with another previous post (straw))

While tunneling the hole should be lined. After surfacing near Haiti and watching the girls go by the lining should be extended right up to space.

If one now jump into the hole one will be sucked into space on the other side.

Zim may be a better starting point - Imagine selling rides at Z$1,000,000,000 and solving some problems at the same time.

Lets do it! After reaching Haiti we could jump out, supervise the extension from the beach whilst sippling pinacoladas and enjoying the sites. But we give "old Bob" the first "first class ride" ultimatley giving him what he wants-his name in lights-we just wont tell him how far away they actually are!

I couldn't help but notice that you didn't stipulate that snacks and alcoholic beverages would be served on the trip. Frankly, I find such items to be of absolutely critical importance in relation to this journey and their omisson completely invalidates your questions.

And this is not because the trip duration would be nearly a day. Even if it only takes 10 minutes such ammenities simply must be factored into any scientific endevour. Please do more research on proper hors D'oeuvre and drink fabrication then re-post your question.

Whatever you do don't pee out of the window of the capsule 'cos you will meet it on the way back

Of course not! I would NEVER do such a thing. I can't believe you'd even for one moment entertain that I might be so foolish!

Doing so would run the unthinkable risk of accidentally extinguishing the secret sun that burns at the center of our hollow Earth. What? You didn't know about that? Of course not...it's a secret.

If it take a day to pass through the tunnel must follow a curved path to prevent hitting the sides as the earth rotates.

I suppose the tunnel could end up spiraling towards the centre.

I can't recall if it was from some SF reading or some less-than-practical 'Mechanic's Illustrated' from years ago ... but this was actually proposed. Not through the CENTER of the Earth, but through the mantle. Del is right (catty of him ) ... in an unaided environment, the mass would oscillate, finally stopping (how long would THAT take) in the center.

BUT, the premise of the less-than-practical idea was that the trip would take very little energy, because the ride is 'free' except for a little 'push' at the end.

Okay, some QUICK and BROAD BRUSH STROKE numbers (I'm no geologist ): The Earth's diameter is about 12,750 km. The upper and lower mantle is about 2900 km thick, so, assuming all that was a clear path, the tunnel would be about 10,700 km long. (I haven't checked Google Earth to see from where to where that might take you on this water-planet, but, it IS interesting, and would be one hell of a ride. The angle of entry would be nearly 60 degrees (think about it ... who needs straight down ... OMG).

SO, here is MY question within this post:

Assuming my crude numeric assumptions, assuming such a tunnel could be dug, assuming one could find a suitable place to 'start' and 'end', assuming, assuming, assuming ...

How quickly would one accelerate, what would be the maximum velocity (assume frictionless), and how long would the trip take?

You will oscillate. The tunnel need not pass thro' the centre of earth. It can be a long chord. The effect will be the same. All tunnels are parellal to the earth's surface i.e., curved. You can refer to "Physics for entertainment", a russian publication in 3 volumes. This question has been analyzed in depth

This was also dealt with on a recent Discovery TV show. As venkat points out the tunnel doesn't need to go through the center. The result is the same for a chord. But only in a world with no friction at all would you reach the surface again at the other end. With friction you will very quickly become a trog, stuck forever in the center of your tunnel. (This has been dealt with in the recent 'If you drop a stone in a deep body of water' discussion.) Bring your own girls and 'coladas.

Ryan?! Cousin, Ryan?! Is that you?!!! Where the hell you been! Do you know how worried aunt Francine is! You bastard!!! And wipe that damn smile of your smug-ass face!!!

You drill the hole in a curve around the center of the earth. (distance from center might take a bit of math) The centripetal/centrifical ??? force will speed it up enough to get it back up to the surface and it can be caught when it emerges. Then you set up air locks and remove the atmosphere, provide a mag-lev type track, and use a sphere that is heavier at the bottom. This will allow it to rotate so that it will be facing right side up when it reaches the other side.

Just like doing a "slingshot" around a planet to gain speed for a deep space mission, but in this case its likely to turn into a Disney ride. Or a way to get products from China into Wal-Mart without overseas shipping costs.

Your "space-shot" slingshot analogy is inherently flawed.

"Inherently Flawed"

Nice.

Dismissal by cliche.

Strangely enough, it takes less thought to criticize than it does to create. That's like sitting down to a 50 dollar dinner paid for by somebody else and then tipping the waitress a five so you look like the big shot.

I'm pooped, and the morphine drip is kicking in. I'll explain tomorrow... With graphics.

Ok everyone, the earth is not quite round or even. Put the start point on a tall mountain say Everest I think that the highest mtn. Then you could avoid the pendulum effect if you had a way to stop from falling back in.

metalSmith's

A center that pulls you to it, needs accleeration on the other side of it. Avoiding the confusion of spherical to look at, a straight line is easier. I would find an active mass from the center for the journey back out, to pop vehicle out the other side like a ripe lava zit...on land of course. the bottom of the ocean is not a good place, no doubt. It would be dark. Unless a giant squid wants to grab you and take you to the top...crap outta luck there, more than not.

Be sure to use an 87 subaru. nothing else will survive. and be it dual range, carbed and a 5 speed.

Hello Ryan,

great idea but, you would not be doing this to save on air fairs by any chance?

And what is the best start/destination point so you will pay the least Tax? Because you know they will 'chase' you everywhere! Can I have the drinks and snack concessions? Though I would imagine you would just a little more than a snack

Don't take chocolate, it may melt..................

babybear.

Just have a guy at the other end of the hole to quickly yell, "Get out and jump now!!!"

Hello vermin,

hope you are OK?...........This is an interesting if illogical question don't you think?

I think they should pay taxes before they go 'cos' they are never coming out , from the sounds of things anyway.

What would you actually 'catch' them with? A stronger magnet than the earths mantle? I doubt you could make one. It would cost too much and take too much power.

take care

babybear

Actually, the Earth's magnetic field is rather weak with regard to area. I'm thinking a good sized neodymium magnet could drag them out or at least keep them from falling back!

It's fun to pretend, but taking all "Real World" aspects into account, I'd be much more frightened with the chain of events that would be released on the surface of the Earth just by digging the hole!!!

Some prick would stick his finger in the hole at the other end and stuff you up.

Hello Ryan

When I first looked at this thread I thought you were vermin. (not being personal, I'm sure you're a perfectly nice bloke, I mistook your avatar for Vermin's )

This one came up a couple of years back, and the ideal case (no air, no friction, non-rotating Earth etc) was discussed at length. Roger Pink and Physicist contributed, along with plenty others.

A quick calc shows that it takes ~ 42.3 minutes to reach the other side, and at centre of Earth the speed ~ 40000 km/h.

An interesting thing that came out of earlier discussion is that the vehicle sees a compressive tidal force, whereas in space between gravitating bodies tidal force is tensile.

Cheers...Codey

You could use it for exporting cooked meat products. Throw raw meat in one end and retrieve the very well cooked meat from the other.

OK...If you insist on being sensible about the whole thing...

I can counter that by saying...let's transfer the question to the Moon!

Ok it'll be a slower ride but doubtless a bit cooler...hey man it will be soooo cool!

Hmmm how hot is it in the centre of the moon? idunno...

Del

All I was trying to do was to point out that no matter HOW you cook a politician, they're still impossible to swallow! Fried, fricasseed, casseroled, boiled, broiled, grilled, baked, roasted on the spit - all inedible material! FEH!

Hello Chankley:

NICE ONE!

stay safe

babybear

And not cannibalistic!

Hello vermin

shorter words please! Can't take those long words while I am eating.........................Or should that be long worms?

babybear

http://cr4.globalspec.com/blogentry/4315/Ask-the-Experts-Would-you-fall-all-the-way-through-a-theoretical-hole-in-the-earth

ASUMING YOU COULD DRILL TO THE OTHER SIDE . THEN IT WOULD TAKE A PRETTY CRAZY PERSON TO JUMP INTO THE HOLE AND RIDE A SOAP BOX TO THE CENTER. BUT IF YOU DID DO YOU THINK THE SPACE SHIP DOWN THERE WOULD GIVE YOU A RIDE OUT? HA HA

If you couldn't make it out, do you suppose Pat Boone would serenade for an eternity? Heaven? Or hell?