SporeMasterSlyth33 wrote:

Sean10M wrote:OK, so what are electrons, protons, and neutrons made of?

Quarks. Once you get to this minute a scale mass and energy are one and the same and often interchangeable, quarks themselves may not have any substructure but are rather "made of energy."

So thats what a quark is. So have people ever seen anything smaller than quarks?

Certain non-quark elementary particles have a lower rest mass than the largest of the quarks.



"Mass" in that table is given in electron-volts / the square of the speed of light, not the standard mass units you're probably used to. This is done so that the mass-energy terminology collapses to reasonable numbers when calculating masses of these particles.

The electron (not composed of quarks like the two hadrons) has a lower mass than all six quarks. A positron would also have the same mass but it is not included on that chart since it is a component of anti-matter.

My AP Chem teacher would love you.

I have two questions:

First, if we're assuming wave-particle duality (which it looks like we are), would particles (and their waves) be affected by the Doppler effect (redshift)? Of course there would be no way to observe it, but strictly theoretically speaking.

On a related note, (and this probably belongs in a physics thread), but how is light affected by the speed of what is projecting it? For example, if someone was firing laser pulses while standing still, and another was running in the same direction (or opposite), how would the light's speed be affected? Because as far as I know, speed of light is a constant, but speed is always measured in comparison to something. What would the comparison be?

Thanks, and apologies if I have completely misinterpreted both subjects

Tyhjihn wrote:I have two questions:

First, if we're assuming wave-particle duality (which it looks like we are), would particles (and their waves) be affected by the Doppler effect (redshift)? Of course there would be no way to observe it, but strictly theoretically speaking.

On a related note, (and this probably belongs in a physics thread), but how is light affected by the speed of what is projecting it? For example, if someone was firing laser pulses while standing still, and another was running in the same direction (or opposite), how would the light's speed be affected? Because as far as I know, speed of light is a constant, but speed is always measured in comparison to something. What would the comparison be?

Thanks, and apologies if I have completely misinterpreted both subjects

Here's a good paper (PDF format) about doppler shift in matter waves moving at relativistic speed

Basically, yes, there is a shift since matter wavelength is a function of momentum and relative momentum changes when the observer is moving. The rate at which the shift occurs depends on the mass of the particle, and converges to the photon doppler effect when mass approaches zero.

The speed of light is a constant independent of observer motion. If you stand perfectly still photons will appear to move at the speed of light.

If you're moving at .5c photons will still appear to move at the speed of light relative to you. If you're moving at the speed of light you no longer experience the passage of time and will cross the universe in an instant (to you anyway). Photons themselves do not experience time, they cross vast distances of space and time instantaneously.

Two objects also cannot observe the same photon due to their inherent nature. They are essentially a one dimensional "ray" with zero width. They impact a single infinitesimally small area (usually somewhere within an electron's standing matter wave, very rarely the more compact wave of a proton or neutron) and are then permanently annihilated to give energy to the other particle. You cannot observe a photon without destroying it.

Don't ask for relativistic behavior to make sense though.

SporeMasterSlyth33 wrote:
Here's a good paper (PDF format) about doppler shift in matter waves moving at relativistic speed

Basically, yes, there is a shift since matter wavelength is a function of momentum and relative momentum changes when the observer is moving. The rate at which the shift occurs depends on the mass of the particle, and converges to the photon doppler effect when mass approaches zero.

The speed of light is a constant independent of observer motion. If you stand perfectly still photons will appear to move at the speed of light.

If you're moving at .5c photons will still appear to move at the speed of light relative to you. If you're moving at the speed of light you no longer experience the passage of time and will cross the universe in an instant (to you anyway). Photons themselves do not experience time, they cross vast distances of space and time instantaneously.

Two objects also cannot observe the same photon due to their inherent nature. They are essentially a one dimensional "ray" with zero width. They impact a single infinitesimally small area (usually somewhere within an electron's standing matter wave, very rarely the more compact wave of a proton or neutron) and are then permanently annihilated to give energy to the other particle. You cannot observe a photon without destroying it.

Don't ask for relativistic behavior to make sense though.

Woah.

I just got an understanding of how far in I am over my head. That article was referencing things I'd never heard of The best I could do was skim over it... Still, I think I got the gist of it, and your condensed explanation helped.

So, particles with mass are affected by doppler shift, inversely proportionally to their mass. I wonder what that would look like...

Also, light's lack of mass makes it unaffected by time, giving it an (observationally speaking) infinite speed? This of course would give any reference points (moving or otherwise) the same speed for any given photon (even though physically observing it would be impossible).

Are these somewhat accurate, however simplified they are? I'm only in grade 10, so please forgive my dumbing-down of how these things work

Its actually not hard to visualize the doppler shift of a massive particle.

If you're moving towards the particle you observe an artificially short wavelength (blue shift in photons, i.e. higher energy). If you're moving away you observe an artificially low energy (red shift).

That makes sense if you think about it. If a car is moving towards you and you're moving towards it the impact will be much more violent than if you were moving away (head on collision vs rear-ended). You observe a similar effect with quantum particles, except that their relative momentum is a function of wavelength.

Light speed to an observer moving at non-relativistic speeds is a universal constant, 2.99x10^8 m/s.

As you increase your speed into the relativistic range (approaching the speed of light) your Lorentz factor begins to increase rapidly.



That factor determines the rate at which your particles experience the passage of time (among other things). A larger number corresponds to a lower rate. At zero, your factor is exactly 1. Your particles move at their universal rate. As you accelerate the factor increases very slowly. Even at thousands of kilometers per hour (the Earth is hurtling through space at an incredible speed) the factor is still essentially one. Only when you hit speeds of incredible magnitude do you begin to see major discrepancies in relative time.

When you approach light speed the Lorentz factor approaches infinity, your passage of time is infinitely small. A photon moving at light speed experiences no passage of time. Objects around it moving at much lower velocities will still observe it moving, only the photon itself is "trapped" in this state.

So the photon would observe itself crossing infinite distances in zero time, for an apparent velocity of infinity. To an observer (with a much lower time dilation factor, it's impossible to "hold still" in space) the photon will cross space at the normal speed of light.

Its not about Spore anything in here. But im gonna share about the LHC thing. Its kinda long, so i saw a video and i would like to share it with you guys:

http://www.scientificamerican.com/article.cfm?id=triple-bond-boron-joins-elite-chemical-club

Boron, now with triple bonds.

I am very intrigued by chemistry and physics, i have taken classes at the university of of Nebraska in omaha and im 12. i thought science was cool since i was born and when i was 4 i read my dads college chemistry book. an author helped me understand what all of it means in a simple way. His Name was Theodore Gray he has written many books on these subjects. another author was Yankov Perelman (check the last name).


_________________________________________________________________________________________________ 95% of teens today would die if their social network died. Copy and paste this into your sig if you're one of the 5% that would laugh like hell.

Zorqe wrote:when i was 4 i read my dads college chemistry book

what

Zorqe wrote:I am very intrigued by chemistry and physics, i have taken classes at the university of of Nebraska in omaha and im 12. i thought science was cool since i was born and when i was 4 i read my dads college chemistry book. an author helped me understand what all of it means in a simple way. His Name was Theodore Gray he has written many books on these subjects. another author was Yankov Perelman (check the last name).
*fake sig snip*

Um, that was entirely necessary.

Zorqe wrote:I am very intrigued by chemistry and physics, i have taken classes at the university of of Nebraska in omaha and im 12. i thought science was cool since i was born and when i was 4 i read my dads college chemistry book. an author helped me understand what all of it means in a simple way. His Name was Theodore Gray he has written many books on these subjects. another author was Yankov Perelman (check the last name).

*shrug* I don't entirely discount it. I was reading pretty fluently by the time I was two. I'm the only one in my family who doesn't have eidetic memory for print on pages, although that only ensures one can look at the item at will, not any special comprehension. It sure helps with faking it though

There's one huge problem with prodigies. They have expiration dates. At some point they become adults, and often not very special ones, unless their gifts were nurtured and expanded as opposed to being exploited.

[edit... I will check my spelling before hitting submit. I will check my spelling before hitting submit. I will check my spelling before hitting submit. I will check my spelling before hitting submit.]

Zorqe wrote:I am very intrigued by chemistry and physics, i have taken classes at the university of of Nebraska in omaha and im 12. i thought science was cool since i was born and when i was 4 i read my dads college chemistry book. an author helped me understand what all of it means in a simple way. His Name was Theodore Gray he has written many books on these subjects. another author was Yankov Perelman (check the last name).

Ted Gray is also one of the men behind Wolfram Research.

Yakov Perelman's information may be a bit outdated, most of it was written around the time of the first world war, Chemistry has come a long way since then, but he did a lot of work to spread the "idea" of scientific thought in the Soviet Union before the second world war.

You'll probably be getting books by Zumdahl soon, he's a favorite of the high school chemistry teachers.

If you want something more in the vein of Perelman, Neil deGrasse Tyson is something of his modern American equivalent.