Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: paul.fr on 03/09/2007 17:27:23

Title: why can't i walk through solid objects.
Post by: paul.fr on 03/09/2007 17:27:23
How could i walk through a solid object, like a brick wall?

Lets say you have a wall made of ice, if i apply heat the ice will melt and i can walk through what was a wall. Okay, im not actually walking through the ice wall, i have merely removed the wall.

But why can't i do something similar to a brick wall? It will not melt, but could we apply energy to move the move the atoms, electrons or whatever "to one side", or to pack them tighter to the side thus opening up a hole in the middle?
Title: why can't i walk through solid objects.
Post by: nothingnobody on 03/09/2007 18:05:49
Thats what they do in Harry Potter(seriously)
Title: why can't i walk through solid objects.
Post by: DoctorBeaver on 04/09/2007 08:35:11
It's all down to Pauli's Exclusion Principle. It states something to the effect of "2 particles with the same characteristics can't occupy the same point in space".

The principle applies to fermions - the particles of which matter is made - but not bosons. That is why if you shine 2 beams of light at the same spot, they will co-mingle but you can't get 2 planks of wood to do it.
Title: why can't i walk through solid objects.
Post by: Soul Surfer on 04/09/2007 08:47:34
A simpler explanation is that the electrical repulsion of the electrons prevents this from happening because it is the electrons that are attatched by electrical attraction to the nucleii of the atoms and the atoms that are bonded together by chemical bonds that make a substance solid even though in theory it is mostly empty space.
Title: why can't i walk through solid objects.
Post by: DoctorBeaver on 04/09/2007 08:51:59
Are you saying I'm not simple?  [:o]
Title: why can't i walk through solid objects.
Post by: another_someone on 04/09/2007 12:05:49
OK, say for a moment that all these reasons (Pauli's exclusion principle, or electron repulsion) did not exist, what would it mean that you are walking through a solid object?

One can walk through a fluid because one can push the fluid out of the way (that is part of the definition of what a fluid is), but one does not in any absolute sense walk through the fluid itself (i.e. at no time you you and the fluid co-exist at in the same place at the same time).

Clearly, aside from the simple case where you simply knock the solid object out of your way, one assumes that in walking through a solid object, you mean that the nature and location of the solid object has not changed, and so you are expecting that you and the solid object will coexist in the same space at the same time.

The problem is that if you try and walk through a plate glass window (without smashing the window) that at some time some or all of the molecules in your body will exist within the space occupied by the glass.  The trouble is, when this happens, how will the hydrogen, oxygen, carbon, phosphorous, etc. atoms in your body know only to react with other atoms in your body, and not with the atoms of silicon and oxygen, etc., in the glass.  The atoms cannot know, but they will simply be promiscuous, and so would disrupt the normal chemical functioning of your body, just as it will disrupt the normal chemical composition of the glass - and so destroy the integrity of both.

So I think it just as fortunate that you cannot walk through glass (or even walk through oil - except to push the oil aside), otherwise it would be very fatal to do so.
Title: why can't i walk through solid objects.
Post by: neilep on 04/09/2007 14:10:20
As a firm believer in empirical research I asked wifey to walk into a wall.

Result ?....a sore head !

Perhaps there will be a time when walking through walls will be possible !...Maybe by utilizing some kind of phase shift ?....either by adjusting yourself (except how would that stop you from just falling through the earth ?) or adjusting the item to be walked through ?
Title: why can't i walk through solid objects.
Post by: DoctorBeaver on 04/09/2007 14:12:49
Phase shift? Someone's been watching too much Star Trek  [:D]
Title: why can't i walk through solid objects.
Post by: neilep on 04/09/2007 14:29:54
Phase shift? Someone's been watching too much Star Trek  [:D]

LOL...I was going to mention it but thought I'd wait for you to.

Though......... Star Trek is a lot of fantasy...they do have scientific advisors and a lot of the principles may be based on  ' sound ' scientific conjecture..(I know that sounds oxymoronic)....with dramatic flare of course !!
Title: why can't i walk through solid objects.
Post by: lyner on 04/09/2007 15:49:15
Isn't it all a matter of definition? 'Solid' means 'you can't walk through it'.
The energy which binds the particles of a brick together is much much higher than the kinetic energy of, say, your fist. However, the  energy which binds the particles of your knuckles together is less than its KE. That means your fist gets damaged and the brick doesn't.

You could, perhaps, imagine a situation - say in deep space- where ' two visible objects'  were very diffuse - like nebulae. They would show up on a telescope as objects but  the energy binding them together is very low. So they could 'pass through' each other, at speed, without, apparently, affecting each other.
Title: why can't i walk through solid objects.
Post by: Mr Andrew on 04/09/2007 17:17:34
Phase shift is seemingly the only way to 'walk through' a solid object.  Solid objects can't be walked through by definition but fluids can (as has already been pointed out) so changing the phase would allow people to pass through a wall.

From an engineering standpoint, the only problem (assuming the technology for turning a solid wall into a fluid) is getting the fluid back into a solid, more specifically, the same solid.  One solution might be some sort of 'container' to keep it in the same shape...but then how do you walk through it?....  Hmmmm!
Title: why can't i walk through solid objects.
Post by: another_someone on 04/09/2007 17:55:07
Phase shift is seemingly the only way to 'walk through' a solid object.  Solid objects can't be walked through by definition but fluids can (as has already been pointed out) so changing the phase would allow people to pass through a wall.

From an engineering standpoint, the only problem (assuming the technology for turning a solid wall into a fluid) is getting the fluid back into a solid, more specifically, the same solid.  One solution might be some sort of 'container' to keep it in the same shape...but then how do you walk through it?....  Hmmmm!

To some extent magnetic fluids might have some possibilities here - but what exactly are you trying to achieve here?

If you just want a rather fancy door, we have doors that work perfectly adequately, so you would need some exceptional functionality to make it worthwhile creating such a peculiar door.

The hypothetical benefit in walking through solid matter would be to be able to pass through matter that is not of our making (e.g. to extract minerals from a minefield without having to dig a tunnel into the rock, or maybe fly through rock as one flies through the air or as one might travel beneath the sea).  It is unlikely that you could liquefy the rock and then return it to its original form.  The only hypothetical mechanism would be some sort of non-destructive compression of the rock that would then allow the rock to be pushed aside and then come back together again (as if it were fluid, but without damaging the crystal structure of the rock).  Possibly creating some massive anti-gravity field around oneself (whereas gravity will pull things in, anti-gravity would push rock away).  Possibly creating a gravitational equivalent of the microwave cloaking device that has been experimented with (ofcourse, this implies that somehow you can create a material that has a negative refractive index for solid matter in the same way that one can create negative refraction for electromagnetic waves).
Title: why can't i walk through solid objects.
Post by: syhprum on 05/09/2007 08:44:58
During a recent visit to Cochem on the Rhine I found at the railway station a Bar called gleis (track) 9 3/4,unfortunately it appeared to have recently closed so I was unable to try out the Harry Potter technique.
Title: why can't i walk through solid objects.
Post by: CliffordK on 29/11/2010 10:44:38
I know this is a little old...  but I was seeing a rash of questions on another site asking how to walk through walls...
Did Harry Potter do something crazy?  Or is it just the old railroad thing?

The phase shift/dimensional shift idea might work...  but it just means going around the wall in a round-about way.  For example, if you could change time... to a month ago... the earth wouldn't be where it is today.  And, thus, no wall...  Decompression would be a problem though. With the earth traveling at 67,000 MPH, even shifting for a second on the trailing edge of the orbit would be enough...  if one was on the leading edge...  it might not be pretty.  The sun, of course, is also traveling at 486,000 MPH.  But, there is no practical way of doing a temporary time-shift.

There is work on self-healing plastics.  I think they can recover from things like bullet holes, but probably wouldn't do well when something the size of a person tore through them.  But, it could be something in the future...  or perhaps a wall made of jello.

http://en.wikipedia.org/wiki/Self-healing_plastic


You could always get a good run at it & just charge into the wall.
Best to do with interior house walls.
And, it would be best to locate the studs before charging into the walls.
Wires could also trip you up.
And, if you are over 14.5" wide, you may prefer going at it sideways.
Also....  avoid lath&plaster walls.
If you don't like using your shoulder as a battering ram...  perhaps try a barbell.
Title: why can't i walk through solid objects.
Post by: imatfaal on 30/11/2010 10:30:03
Perhaps the reason you are seeing a slew of questions on walking through walls is that you are going back 3 years to find them! 
Title: why can't i walk through solid objects.
Post by: CPT ArkAngel on 01/12/2010 04:33:58
We have to change the fermions into bosons, pass the wall and put it back into fermions...
Title: why can't i walk through solid objects.
Post by: Soul Surfer on 01/12/2010 17:54:26
If such a thing as changing fermions to bosons was possible it would result in any structures falling apart.  To have a wall and a body with structure you need to maintain the current atomic configurations if you lost them you would not exist any more. 

The main reason you cannot walk through things that are solid even though they could be considered as mostly empty space is simply the electrostatic repulsion  of the electrons in the chemically bound (by electromagnetic forces) atoms.  So it is electromagnetic forces that prevent you.
Title: why can't i walk through solid objects.
Post by: QuantumClue on 01/12/2010 19:10:56
How could i walk through a solid object, like a brick wall?

Lets say you have a wall made of ice, if i apply heat the ice will melt and i can walk through what was a wall. Okay, im not actually walking through the ice wall, i have merely removed the wall.

But why can't i do something similar to a brick wall? It will not melt, but could we apply energy to move the move the atoms, electrons or whatever "to one side", or to pack them tighter to the side thus opening up a hole in the middle?

I have read the last response to this thread. Whilst it is trivially true, there is a more fundamental reason which stops your body from moving into the earth or your hand through a mirror. The reason lyes in the electrons in your hand and the electrons in the mirror. When you press your finger into the mirror, your finger will repel the mirror because of the electrons acting like little repelling magnets. This is also the reason why your body does not fall through other matter, because of electrostatic repulsion.
Title: why can't i walk through solid objects.
Post by: Geezer on 02/12/2010 06:32:57
I confess I'm no expert, but, as I understand QM, I think it is entirely possible to walk though a wall, it's simply a matter of probability.

Unfortunately, the probability that you actually will is fairly small, but that's no reason to stop trying. You never know. The next time could just be the one.
Title: why can't i walk through solid objects.
Post by: JP on 02/12/2010 08:07:10
The faster you run at the wall, the higher the probability is...
Title: why can't i walk through solid objects.
Post by: Geezer on 02/12/2010 08:43:15
The faster you run at the wall, the higher the probability is...

Er, I'm not sure that's quite right. Isn't it more a question of timing?
Title: why can't i walk through solid objects.
Post by: JP on 02/12/2010 09:23:20
The faster you run at the wall, the higher the probability is...

Er, I'm not sure that's quite right. Isn't it more a question of timing?

The probability of a single particle tunneling through a barrier increases as you increase its kinetic energy (i.e. speed). 

Actually, what really matters for a person and a wall is probably the force you're exerting on the wall...

I'm thinking this is a job for Kitchen Science!  [;D]

Dave: Ben, I want you to walk into that wall as hard as you can. 
Ben: That sounds easy enough. 
[Thudding sounds heard on the podcast]

[Cut to Chris]
Chris: We'll come back to them in a few trillion years to see what happens.  In the meantime, why don't you try it at home and let us know what happens?
Title: why can't i walk through solid objects.
Post by: Geezer on 02/12/2010 09:37:42
The probability of a single particle tunneling through a barrier increases as you increase its kinetic energy (i.e. speed). 

These Smartypants Physicists always have an answer! Anyway, in the grand scheme of things, is a few meters per second going to make a hill o'beans difference? I think not!
Title: why can't i walk through solid objects.
Post by: CPT ArkAngel on 04/12/2010 04:15:18
What if we could make oscillate fermions between fermion state and boson state very rapidly? Not only we could pass through walls but we could use it to move very rapidly...
Title: why can't i walk through solid objects.
Post by: Mad Mark on 06/12/2010 03:36:47
QM does not allow you to walk through a solid wall its just that there is a very small probability that as you are about to attempt that maneuver all the atoms together in the wall no longer recognise itself as being part of that wall and fall appart. And even less probability that all the atoms then would want to become a solid wall again. Either way you do not get to walk through a solid wall with QM. Of course that only applies to all known living creatures on earth if however unlike humans who only control there limbs, who,s to say what a super being is capable of doing if they have control over their atoms that they are made of?
Title: why can't i walk through solid objects.
Post by: JP on 06/12/2010 03:39:02
QM does not allow you to walk through a solid wall its just that there is a very  small probability that as you are about to attempt that maneuver all the  atoms together in the wall no longer recognise itself as being part of that wall and fall appart.

That's also true, but QM does allow you to walk through solid walls as well through a process called tunneling.
Title: why can't i walk through solid objects.
Post by: QuantumClue on 06/12/2010 04:20:33
Right - maybe in probability, but the probability is vanishing. It's beyond small.

Not only that, but quantum tunnelling is what it says on the tin - it's not a macroscopic phenomena.
Title: why can't i walk through solid objects.
Post by: JP on 06/12/2010 04:47:20
Indeed.  As is the probability of the wall disintegrating because of quantum effects.  In reality, these things won't have happened even if the wall had been around since the beginning of the universe--that's how unlikely it is.
Title: why can't i walk through solid objects.
Post by: Geezer on 06/12/2010 05:37:21
Indeed.  As is the probability of the wall disintegrating because of quantum effects.  In reality, these things won't have happened even if the wall had been around since the beginning of the universe--that's how unlikely it is.

Bummer! So you're saying the Number 10 Quantum Magician Set I bought on Ebay for Mrs G's Christmas might not live up to expectation?
Title: why can't i walk through solid objects.
Post by: techmind on 09/12/2010 23:54:23
Let's just say that somehow you could walk through a pane of glass without breaking it... somehow you could superimpose both objects...
If partway through the glass sheet was halfway across your lungs or your windpipe and you hesitated mid walk, you might suffocate. Eeek!

So it's clearly a dangerous thing to do  [;D]
Title: why can't i walk through solid objects.
Post by: QuantumClue on 10/12/2010 02:56:44
But still, I could end up on Pluto's surface because my wave function dictates so. there is almost certainly a cutoff though for the wave function, which makes this near impossible.
Title: why can't i walk through solid objects.
Post by: Bill S on 10/12/2010 17:09:25
So the thing to do is to stand by your brick wall for a few trillion years and hope to get lucky.  [;D]
Title: why can't i walk through solid objects.
Post by: Geezer on 10/12/2010 20:33:11
So the thing to do is to stand by your brick wall for a few trillion years and hope to get lucky.  [;D]

You could speed things up a lot if you try it in Amsterdam.

(I can't believe I just said that - must be some sort of quantum effect.)