Ask a physicist anything. (6)

[Chalnoth]

I really meant no nitro, C4, uranium, gun powder, etc. when I said no chemicals.

Touche on beating me with philosophy PGP.

"Chemical" is a general term that can apply to any form of normal matter that is in atomic or molecular form.

 

[Tuddrussell]

I don't know about an air bomb, but mass depression could potentially be caused through social engineering.

 

[mandyangel]

MY QUESTION: Does science ever lack truth because of the belief that everything has to be proven through the scientific method to be true?

ANOTHER Q: How can scientists ever be sure that an idea (like evolution) is true when each and every scientist only knows what they learn when AFTER they come into the world?

 

[Chalnoth]

I don't know about an air bomb, but mass depression could potentially be caused through social engineering.

Like this?
Saturday Morning Breakfast Cereal

 

[Chalnoth]

MY QUESTION: Does science ever lack truth because of the belief that everything has to be proven through the scientific method to be true?

It's not so much proven per se. It's just a recognition that the only way we can be sure we know anything is to find verifiable evidence in favor of it. If we don't have evidence, we can't assert that we know. Simple as that.

Does this mean that there are truths out there that science has not or perhaps will never access? Certainly! But there's no other way to know them. Science is the best we've got.

ANOTHER Q: How can scientists ever be sure that an idea (like evolution) is true when each and every scientist only knows what they learn when AFTER they come into the world?

In general, the way that we gain confidence that a theory is true is to gather diverse sets of independent evidence. At its core, a theory is an explanation of how things which are otherwise separate can be understood in one, single framework. That framework gives a constrained picture that demands that certain patterns, and only those patterns, exist in nature. The more we test those patterns and show that they are valid, the more confidence we gain in the theory.

The primary pattern that evolution explains is that it states that life can be grouped into one or more family trees. This statement is so powerful and explains such an incredible variety of the characteristics of life on this planet that almost nobody that has seriously investigated evolution doubts it in the least.

 

[chris4243]

Would it be possible to build an intensely concentrated PSI air bomb of unhappiness?

No chemicals. No toxins. Very low manufacturing and costs.

In today's new age of compassion, this just seems like it would be the more politically correct and nicer way of killing people.

So how close would this be theoretically possible on a large scale?

You mean, use compressed air as an explosive? It's possible, but extremely inefficient -- it would be heavy, expensive, dangerous, and the explosion would be slow rather than the rapid shockwave traveling at faster than the speed of sound that causes so much damage. It would be far more efficient to use some clean-burning chemicals instead, plus it would be easier to trigger.

 

[chris4243]

MY QUESTION: Does science ever lack truth because of the belief that everything has to be proven through the scientific method to be true?

Yes, but it is not much of a loss since it won't be anything useful. Where "useful" is defined in terms of ability to predict (aka "understand") things about the world.

ANOTHER Q: How can scientists ever be sure that an idea (like evolution) is true when each and every scientist only knows what they learn when AFTER they come into the world?

Like every other theory, because it allows us to predict things about the world we live in. Basically, the world "looks as if" all living things have descended from a single living thing via a process of randomish mutation and selection based on reproductive success. You can see patterns of migration throughout millions of years, the effects of geologic changes that cut two environments from each other resulting in the previously mixed population diverging into different species, predict the presence of proteins or DNA patterns in different species based on their classification, and many such things. (none of which, of course, would be enough to convince a dedicated creationist, who prefers to think that all scientists are stupider than they are or that God put the fossils there to trick people, or cover their ears and say lalalalalalala).

 

[Steffenfield]

You mean, use compressed air as an explosive? It's possible, but extremely inefficient -- it would be heavy, expensive, dangerous, and the explosion would be slow rather than the rapid shockwave traveling at faster than the speed of sound that causes so much damage. It would be far more efficient to use some clean-burning chemicals instead, plus it would be easier to trigger.

Okay. That makes sense. Not sure what you exactly mean by such a thing as being expensive though. It's air bro.

How about the reverse then?

A bomb with 0 PSI?

Once it explodes, well implodes actually, could this theoretically suck the air out of people's lungs within a certain radius of the detonation?

Hey, is it just me, or is it that the more I post, the dumber my questions tend to be?

 

[chris4243]

Okay. That makes sense. Not sure what you exactly mean by such a thing as being expensive though. It's air bro.

The air won't be expensive, but the container to hold all that air (enough to make a bomb that can do any damage) would have to be large and strong, and therefore expensive and heavy.

How about the reverse then?

A bomb with 0 PSI?

Once it explodes, well implodes actually, could this theoretically suck the air out of people's lungs within a certain radius of the detonation?

Hey, is it just me, or is it that the more I post, the dumber my questions tend to be?

A vacuum bomb? That would have to be enormous to have enough of an effect, and now instead of a near-instant shockwave, you have to suck the air away for a minute or more to cause suffocation? At this point, you'd be better off lobbing such a "bomb" and hoping you flatten your target, though I have my doubts any airplane would be able to carry a vacuum bomb capable of suffocating someone -- I think it would have to be much larger than a city block. Since I don't know much about aerodynamics, it's just a guestiate -- but maybe someone else could calculate it, it may not be practical but it would be awesome.

If it is suffocation you want, you'd be better off with a bomb full of liquid nitrogen and something to provide heating. The nitrogen can displace the oxygen of the air, and since it provides pressure will remain there much longer than a vacuum would. There's still no way it would make a particularly good weapon though, since the large area that would need to be covered in case the target flees while he still has breath might result in lots of collateral deaths.

 

[mzungu]

That's science for you
BBC News - Artificial blood vessels created on a 3D printer

 

[Tuddrussell]

What is the least massive a magnet would have to be in order to overcome the repelling magnetic force of an equivalent magnet? Assuming earth standard gravity.

Also, I've noticed that if you take a standard bar magnet and break it in half it just makes two ordinary magnets. Can a unipolar magnet exist?

I've been interested lately in magnets made of amorphous materials, and how that would work. I know about ferrofluid, and I still have the stains to prove it, but still.

Preferably something that can be played with sans G&Gs.

 

[Chalnoth]

What is the least massive a magnet would have to be in order to overcome the repelling magnetic force of an equivalent magnet? Assuming earth standard gravity.

Depends upon a lot of things. The difficulty here is that if you use the same magnetic material, magnetized just as well, and just make the magnet more massive, its magnetic field gets stronger.

If you ever felt like crushing a finger from handling a large magnet then you could get this, for example:
D2000Y (Showing Fractional Measurements)

But really it all comes down to the type of magnetic material, the shape of the magnet, and how well-magnetized it is. These things vary far too much from magnet to magnet to come up with an overall answer.

Also, I've noticed that if you take a standard bar magnet and break it in half it just makes two ordinary magnets. Can a unipolar magnet exist?

There are not yet any known magnetic monopoles. So the answer appears to be no. Magnetic monopoles are predicted to exist in many theories of physics beyond the standard model, but obviously they must be very hard to produce, because we haven't yet seen a single one.

I've been interested lately in magnets made of amorphous materials, and how that would work. I know about ferrofluid, and I still have the stains to prove it, but still.

As I understand it, ferrofluid is just a bunch of microscopic iron (or other ferromagnetic) particles suspended in liquid.

 

[Tuddrussell]

Depends upon a lot of things. The difficulty here is that if you use the same magnetic material, magnetized just as well, and just make the magnet more massive, its magnetic field gets stronger.

Is there any upper limit to this? Does it just keep getting more powerful?

But really it all comes down to the type of magnetic material, the shape of the magnet, and how well-magnetized it is. These things vary far too much from magnet to magnet to come up with an overall answer.

Rare earth, cube, X A/M. (42 maybe?)

As I understand it, ferrofluid is just a bunch of microscopic iron (or other ferromagnetic) particles suspended in liquid.

It's magnetic, it's a fluid... I don't see the problem.

 

[mzungu]

The World's Strongest Magnet

 

[Chalnoth]

Is there any upper limit to this? Does it just keep getting more powerful?

I imagine that at some point, the integrity of the material will break down, and it will spontaneously flip to a lower-energy state (meaning either the material will break, or its magnetic domains will flip). But this is going to depend upon the material.

Rare earth, cube, X A/M. (42 maybe?)

What?

It's magnetic, it's a fluid... I don't see the problem.

I was just pointing out what it's made of. Ferromagnetic (probably iron) particles suspended in a fluid.

 

[Chalnoth]

The World's Strongest Magnet

That's craziness. 45T is insane.

But I should mention that's an electromagnet.

 

[mzungu]

That's craziness. 45T is insane.

But I should mention that's an electromagnet.

Its a hybrid and a beast at that too!

 

[Tuddrussell]

But really it all comes down to the type of magnetic material,

Rare earth.

the shape of the magnet,

Cube.

and how well-magnetized it is.

Let's say as powerful as the earth's average magnetic field strength.

I was just pointing out what it's made of. Ferromagnetic (probably iron) particles suspended in a fluid.

And I'm just pointing out that I don't care. Literally every single berry I think of when I hear the word berry is not actually a berry, such a distinction is pedantry at best.

As far as I'm concerned it is a magnetic fluid, because it is a fluid that happens to be magnetic. I will grant that it is not a liquid magnet, however it is close enough for my tastes.

Can there be a liquid magnet though, and how would it differ from ferrofluid?

 

[mzungu]

Rare earth.Cube. Let's say as powerful as the earth's average magnetic field strength.

You do know that Earth's magnetic field is very weak: Earth's magnetic field, 0.00005 Tesla, 0.5 Gauss

 

[AV1611VET]

According to evolution, at any time, did atom2adam evolution pass through a vermiform stage?