Are electrons, neutrons and protons visible?

[seriously disabled]

Hi everyone,

 

I asked the same question in another forum but couldn't get an answer...

 

My question is this: since the human eye can detect or see only photons or light then are electrons, neutrons and protons visible? Can electrons, neutrons and protons really be seen?

[insane_alien]

no, they are too small to be seen with visible light, the photons just pass by them and do not bounce off.

[seriously disabled]

no, they are too small to be seen with visible light, the photons just pass by them and do not bounce off.

 

So how can electrons be seen? And if we can't see them, how do we know they really exist?

[insane_alien]

we don't look at them with photons is how. what we do is we bounce particles (such as electrons) off of them or use particle detectors(usually depends on the particle reacting with something).

 

we can't see radiowaves either but we know they exist in the same way as we see their effects.

[seriously disabled]

we don't look at them with photons is how. what we do is we bounce particles (such as electrons) off of them or use particle detectors(usually depends on the particle reacting with something).

 

we can't see radiowaves either but we know they exist in the same way as we see their effects.

 

But how do we know what really bounces off the photons if we can't see it with our eyes?

 

Physics the way it is taught today looks much more like a religion or a belief system to me than a objective truth or reality. Physics looks too much theoretical to me.

 

And this is why I don't think I will go for physics but rather for other subjects like linguistics, psycholinguistics, psychology, cognitive science or computer science.

Edited June 29, 2009 by Uri

[gre]

So it seems you're inferring for something to exist you must observe it with photons?

 

If you close your eyes and throw a tennis ball as hard as you can, then it comes back and hits you in the head... Would it be safe to assume there is an object in front of you?

 

That invisible object that made the ball come back at you could be considered an electron.

[swansont]

But how do we know what really bounces off the photons if we can't see it with our eyes?

 

[Obiwan]Your eyes can deceive you. Don't trust them. [/Obiwan]

 

Instrumentation is far more reliable than eyesight.

 

Physics the way it is taught today looks much more like a religion or a belief system to me than a objective truth or reality. Physics looks too much theoretical to me.

 

I take it you're using "theoretical" to mean "guesswork" or something similar, and you couldn't be more wrong. Scientific models are tested to eliminate alternate explanations. That's why falsifiability (and if you're wrong, being verifiably wrong) is so key to the process.

 

However, science is not about searching for truth. It's about constructing models to explain how nature behaves. Much of nature is invisible to us, yet we still need to know how it works in order to exploit it. So I'll savor the irony that you used a computer — which depends on the actions of electrons — to type your statement that it's like a religion or belief system.

[Sisyphus]

Why would bouncing a photon off of something be "really there" while bouncing an electron off of something be "more like a religion?" Also, what swansont said.

[seriously disabled]

If you close your eyes and throw a tennis ball as hard as you can, then it comes back and hits you in the head... Would it be safe to assume there is an object in front of you?

 

That invisible object that made the ball come back at you could be considered an electron.

 

Yeah but it's all an assumption or a theory. A person who was born blind and has never seen a wall or a ball or any other objects for that matter cannot know whether the wall exists or not. He must rely on the sense of touch in order to make such an assumption.

 

Instrumentation is far more reliable than eyesight.

 

So what instruments do physicists use to detect particles?

 

However, science is not about searching for truth. It's about constructing models to explain how nature behaves.

 

But if science is not about searching for the higher or fundamental truth, then for what is it useful?

 

I hope that one day we will discover the truth, whether it's through science or in any other way. Many people and this includes me want to know: Is there a God which created the universe? Is there life after death (also called afterlife)? What is the meaning, purpose or goal of our lives?

 

If the above questions can be answered, then we finally got one giant step closer to the final truth.

Edited June 29, 2009 by Uri

[ydoaPs]

What makes vision more valid than touch?

[seriously disabled]

What makes vision more valid than touch?

 

With vision you can know the color of an object. Without vision it's impossible. With touch you can know the stucture and shape of an object but with vision you can infer that instantly and much more easily than with the sense of touch alone.

[Klaynos]

Colour is just the detection and interpretation of different photon energies.

 

What about optical illusions they are far far easier to create than touch illusions.

[SH3RL0CK]

You cannot tell whether something is hot or cold by looking at it. But you can by touching it.

[insane_alien]

vision isn't an option at the quantum level so we chuck things at it in various situations which allows us to determine mass, charge, stability, spin etc etc everything important about the particle and how it behaves. something is there and that something is what we call an electron(or whatever). to say it is not an electron is to be using a non standard definition of 'electron' making you wrong.

 

But if science is not about searching for the higher or fundamental truth, then for what is it useful?

 

you see all the technology more advanced than couple of rocks and sticks, that's what science is good for. we seek to know how the universe works and to model it and use that model to predict what will happen.

 

using newtonian mechanics we predicted when and where we'd need to fire rockets to reach the moon, using general relativity we predicted the frequency shift GPS would need to be as accurate as it is. and so on. everything from the bricks that make up your house(or the joints that hold the wood together) to the billions of nano-scale components in the microprocessor you are using right now to communicate with us comes from science. we also use the properties of particles you claim are just assumed to be there in all stages of that communication, we could not do this without knowing a great deal about their properties and behaviour. we found this information not by looking but by bouncing particles off each other and then seeing what that looked like.

 

argue all you want, but it is evident that we are right by the very fact we are talking to each other over thousands of miles.

[iNow]

You cannot tell whether something is hot or cold by looking at it.

 

Sure you can. It's just not in the range of the spectrum which our eyes can detect.

http://en.wikipedia.org/wiki/Thermographic_camera

[SH3RL0CK]

Sure you can. It's just not in the range of the spectrum which our eyes can detect.

http://en.wikipedia.org/wiki/Thermographic_camera

 

 

Well, yes, of course. But the original poster states

how do we know...if we can't see it with our eyes?

I cannot tell the if temperature of an object is -40C or +60C by looking at it with my eyes. But I'd sure be able to tell if I touched it.

 

More to the point, I could connect a thermocouple or scan it with a thermographic camera and be able to determine the exact temperature, not just "it is hot". The point is human sensory capacity isn't nearly as good as our instruments have become.

[iNow]

Indeed. I really couldn't agree more.

[insane_alien]

the only thing we're still good for is our pattern finding ability and various wacky imaginative leaps. the actuall looking and seeing is handled far better than us. like the LHC, if we looked directly we'd be killed by the radiation and wouldn't see a damn thing except maybe some cherenkov radiation as the wave of particles impacts our eyes.

[GDG]

Hi everyone,

 

I asked the same question in another forum but couldn't get an answer...

 

My question is this: since the human eye can detect or see only photons or light then are electrons, neutrons and protons visible? Can electrons, neutrons and protons really be seen?

 

Yes. The process we call "vision" or "seeing" consists of detecting the light reflected or emitted by an object. By convention, we "see" the object, not the reflected photons; e.g., one says "I see the red balloon" and not "I see photons reflected from a red balloon". Since all matter (at least all non-dark matter that is available to us) is made of protons, neutrons, and electrons, we do indeed see protons, neutrons and electrons. Not individually, of course, but as constituents of the molecules that make up all solid matter.

 

Further, by that convention, we do not "see" photons (although photons are what our eyes respond to) because photons do not reflect other photons. You cannot shine a light on a photon to observe it.

[swansont]

A person who was born blind and has never seen a wall or a ball or any other objects for that matter cannot know whether the wall exists or not. He must rely on the sense of touch in order to make such an assumption.

 

I don't see why that makes the wall any less real.

 

 

But if science is not about searching for the higher or fundamental truth, then for what is it useful?

 

 

Because it tells how nature behaves. We can exploit that to do things, e.g. build machines, or just know how nature behaves.

---

Merged post follows:

Consecutive posts merged

Sure you can. It's just not in the range of the spectrum which our eyes can detect.

http://en.wikipedia.org/wiki/Thermographic_camera

 

The OP implies that if our eyes can't detect it it's not real. The instrument, though, has a wider dynamic range than our eyes. So, case in point.

 

The OP also implies that wavelengths outside of human vision aren't real. Yet radio waves work, and a high dose of gamma or x-rays will make you sick and/or kill you.

 

Basically, the belief/religion comment discards any notion of how the process of science works, and is a display of profound ignorance about that process. Hopefully the discussion here has/will correct that.

[mooeypoo]

Religious posts were taken off this thread. Please stay on topic and avoid religious topics, as these are against our rules of conduct and usually end up in a non-scientific discussion.

[proton]

But how do we know what really bounces off the photons if we can't see it with our eyes?

We use all of our senses to experience the world. That means that we can use electrons to interact with matter in a way that is detectable by our senses. Given a theory of electrons we can construct experiments to see if our ideas conform to reality. If the experiment works like we planned then we have more confidence in our ideas. If they don't then we modify them.

 

To explain all the reasons why physicists believe in the existance of electrons would take a lot of room in this thread. You can find that information on the internet.

no, they are too small to be seen with visible light, the photons just pass by them and do not bounce off.

Actually photons do bounce off electrons (all charged particles to be exact). The process is called Compton scattering. Edited July 1, 2009 by proton
Consecutive posts merged.

[insane_alien]

proton, i'm pretty sure you've been told this already and i'm going to repeat it.

 

when it is clear someone is struggling with a concept in physics, don't just recite off a list of phenomenon and/or the details of how they work, just keep it simple.

[swansont]

Actually photons do bounce off electrons (all charged particles to be exact). The process is called Compton scattering.

 

And will have a wavelength shift of a couple of picometers, which isn't something close to being able to be discerned by the human eye, which is the topic of the discussion.

[seriously disabled]

Don't get wrong I like physics and I'm especially fascinated by lasers, electronics and semiconductor devices and cryogenics.

 

However I have the feeling that congitive linguistics (cognitive linguistics is the study of language as a cognitive or mental process), linguistics and cognitive psychology are closer to the truth because these three fields I mention deal with cognitive processes or with the mind as opposed to physics and chemistry which deal with matter, its strucutre and energy.

 

So we basically have the mind or the cognitive versus matter and energy. Which one of them is more real is the billion dollars question.

Edited July 17, 2009 by Uri