What would you see if you travel at the speed of light?

[ZapperZ]

If I get a $1 (or a Euro) ...

If I get a $1 everytime someone asks or says one of these, I'd be able to fund the International Linear Collider all by myself (currently estimated at US$12 billion):

1. Since E = mc^2, and photons have energy, doesn't this mean that photons have mass?

2. Why doesn't an electron crash into the nucleus (or something to that effect)?

3. What do I see when I travel at the speed of light?

4. Evolution is just a "theory".

5. What is the BEST school for physics?

I suppose it is expected that things get recycled since we get new members all the time. But sometime it feels as if we are making zero progress on any of these... <sigh>

Zz.

 

[Chi Meson]

How about :"what is energy?"

 

[dextercioby]

How about the double slit experiment...?I've been waiting for the day when someone would open a thread about the triple slit experiment,but i guess i'll have to wait,people are not that open to progress...

Daniel.

 

[marlon]

or how about QM IS WRONG !
or how much does a physicist make ?


marlon

 

[marlon]

or curvature of spacetime is NOT real because everything seems to be straight...

sighs

marlon

 

[dextercioby]

The "twin paradox" is a lot under debate...It would be perfect if everything were strainght,but,unfortunately,some of us are gay...

Daniel.

 

[Danger]

I've been waiting for the day when someone would open a thread about the triple slit experiment,

The porn site's 3 doors down on the left...

 

[dextercioby]

The porn site's 3 doors down on the left...

What would the world be like without the pervs...?


Zapper,i think you meant 1€ in the title...

Daniel.

 

[Galileo]

How'bout a sticky for these topics?
Then everytime someone asks the question, we can yell at them:
"Read the sticky, you *beep*!"

 

[marlon]

How'bout a sticky for these topics?
Then everytime someone asks the question, we can yell at them:
"Read the sticky, you *beep*!"

How about this : we write down all the questions, we solve them...and we make a sticky of that thread. Everytime somebody asks one of THE questions, we can reply by saying : read the dumb-questions-sticky...How about that ?

regards
marlon

 

[Galileo]

How about this : we write down all the questions, we solve them...and we make a sticky of that thread. Everytime somebody asks one of THE questions, we can reply by saying : read the dumb-questions-sticky...How about that ?

regards
marlon

That's a great idea. (Are you being sarcastic?)

 

[brewnog]

I know. Why don't we make a thread with all the commonly asked questions, with all their respective answers, and sticky it. When anyone asks, we just tell them to read the sticky!

 

[marlon]

That's a great idea. (Are you being sarcastic?)

i would not dare...

marlon

 

[rygar]

i think that's a good idea too

 

[franznietzsche]

If I get a $1 everytime someone asks or says one of these, I'd be able to fund the International Linear Collider all by myself (currently estimated at US$12 billion):

1. Since E = mc^2, and photons have energy, doesn't this mean that photons have mass?

2. Why doesn't an electron crash into the nucleus (or something to that effect)?

3. What do I see when I travel at the speed of light?

4. Evolution is just a "theory".

5. What is the BEST school for physics?

I suppose it is expected that things get recycled since we get new members all the time. But sometime it feels as if we are making zero progress on any of these... <sigh>

Zz.

Don't forget the classic:

"I'm an engineer, and even though i don't understand the math, i just proved einstein wrong!"

 

[quantumdude]

Don't forget the classic:

"I'm an engineer, and even though i don't understand the math, i just proved einstein wrong!"

Yep, PF has seen more engineers than I can recall come here and declare that relativity and/or qm is wrong and that classical physics can account for all known observations. It is usually electrical engineers who do this, which is astounding because SR is built into their stock-in-trade: Maxwell's equations.

Another one that makes me want to hit the Delete button when I see it is nonsense that tries to connect consciousness to quantum mechanics. We can thank Frijtof Capra for making that one popular, I think.

 

[marlon]

We can thank Frijtof Capra for making that one popular, I think.

Who the hell is that ?

marlon

 

[Chi Meson]

The Author of "The Tao of Physics." It's a staple text for "Physics for Poets" seminars at liberal arts colleges.

It's not so bad as a book, but very dangerous in the wrong hands.

 

[marlon]

It's not so bad as a book, but very dangerous in the wrong hands.

how is that ? Does it instuct how to make nuclear bombs...Then i should get me a copy

marlon

 

[ZapperZ]

The Author of "The Tao of Physics." It's a staple text for "Physics for Poets" seminars at liberal arts colleges.

It's not so bad as a book, but very dangerous in the wrong hands.

Obviously, I'm not as "forgiving" as you are, Chi Meson. :) I would categorize it as a VERY bad book, and would never recommend it to anyone, especially in light of the fact that there are other better pop-sci books available.

I actually had to read it in my philosophy of science class as an undergraduate. Even back then, when my QM understanding was still in its formative stage, I knew something wasn't kosher.

Zz.

 

[Davorak]

Yep, PF has seen more engineers than I can recall come here and declare that relativity and/or qm is wrong and that classical physics can account for all known observations. It is usually electrical engineers who do this, which is astounding because SR is built into their stock-in-trade: Maxwell's equations.

Another one that makes me want to hit the Delete button when I see it is nonsense that tries to connect consciousness to quantum mechanics. We can thank Frijtof Capra for making that one popular, I think.

EE is the largest engineering major for most universities. Usually good job market of EE majors, plus out of all the engineering disciplines EE practitioners are seen to cross over best to other disciplines in the real world.

In my opinion EE gets a wider range of caliber then other engineering disciplines do.

Maxwell's equations are not focused on much in undergrad EE from what I can tell and there SR origin is left out completely.


A sticky for all of the troubling threads sounds interesting. A list of topics could be set up for people to sign up to write a walk through for. Then edited by a mentor approved science advisor for validity.

Sounds like a considerable effort on many peoples parts. Then again with the number of knowledgeable people here you could write a books.

edit:
Or now that I think of it pull it out of post where it was already be explained well.

 

[ZapperZ]

This thread was started months and months ago. Obviously, there's a bunch of questions that keep coming up. As has been suggested in this thread, we really should have a sticky, or at least a place where we keep a "standard answer" for these questions. Obviously, it would be too tedious of a task to be done by one person.

Therefore, can I get any volunteers to write on one of these very frequently asked questions? The list of questions are below, at least from my perspective on some of THE most often asked questions around. People are welcomed to submit more suggestions, but I think we should start small. There can be more than one person writing on a topic, and hopefully I can try to edit and merge them together. You will get the credit for writing the response.

The topics are:

1. Since E = mc^2, and photons have energy, doesn't this mean that photons have mass?

2. Why doesn't an electron crash into the nucleus (or something to that effect)?

3. What do I see when I travel at the speed of light?

4. What is energy?

If you would like to volunteer, please PM me and we will make arrangements on how you can submit your article.

Thank you for your effort in advance.

Zz.

 

[rachmaninoff]

What about those basic calculus FAQ that drive everyone crazy? There are a few that show up about twice a week; Matt Grime requested a sticky for those a while back, if I recall. If you don't mind, I'll list what I perceive to be the most common, exasperating ones:

1) Is 1 = 0.9999... ?

2) What is 0/0, 1/0, 1/infinity, infinity/0, (&c.) ?

3) What is the algebraic form of \int e^{\pm x^2} dx?

Maybe I'll write a sticky for one of those? If ZapperZ doesn't mind.

 

[Pengwuino]

hahaha i didn't know this thread was old, i read the first post and I thought "haha yah zapper, I see that you got mad at 2 of the threads that are current in the forum". Then i realize the thread is 8 months old... I don't know if there could be a bigger sign as to whether or not we need a "dumb questions" category.

We also need to include "I'm still in high school and I proved Einstein wrong!" except no explanation is needed, just a "shut up, go learn english".

I've also seen the HUP used incorrectly in the same way many many times but i can't recall what people keep doing at the moment.

I think we also need to make that free energy device where a battery powers a generator which powers the battery into one of the dumb ideas/questions. I've seen that plenty of times on this forum... I think someone once said the government is hiding the fact that its an easy free energy machine. I'm sure the world is so stupid that we are capable of putting microprocessors on pin heads yet that device just went over the head of everyone in the scientific world.

 

[ZapperZ]

We also need to include "I'm still in high school and I proved Einstein wrong!" except no explanation is needed, just a "shut up, go learn english".

I've also seen the HUP used incorrectly in the same way many many times but i can't recall what people keep doing at the moment.

I think we also need to make that free energy device where a battery powers a generator which powers the battery into one of the dumb ideas/questions. I've seen that plenty of times on this forum... I think someone once said the government is hiding the fact that its an easy free energy machine. I'm sure the world is so stupid that we are capable of putting microprocessors on pin heads yet that device just went over the head of everyone in the scientific world.

I think we have ways to handle "crackpot" postings. So those aren't that big of a problem.

What I intended to address are really legitimate questions, but for most of us who have seen these repeatedly, we should at least be able to point to a location in PF, as has been suggested in the thread, and say "Go read that first". And these should really be questions, not "statements".

There are many other questions we could be addressing. I just wanted to start small first and see how it goes, or else it might get too daunting of a task.

Zz.

 

[Pengwuino]

Wait wait, throw in...

"Special relativity is just a theory" alongside the evolution one.

 

[ZapperZ]

What about those basic calculus FAQ that drive everyone crazy? There are a few that show up about twice a week; Matt Grime requested a sticky for those a while back, if I recall. If you don't mind, I'll list what I perceive to be the most common, exasperating ones:

1) Is 1 = 0.9999... ?

2) What is 0/0, 1/0, 1/infinity, infinity/0, (&c.) ?

3) What is the algebraic form of \int e^{\pm x^2} dx?

Maybe I'll write a sticky for one of those? If ZapperZ doesn't mind.

The Math forums certainly have their own share of annoying FAQ's. I think we need to bring in the Math Mentors to address your question. What I had in mind when I suggested this was a sticky for the physics forums. I can certainly see something similar being done in the math forums, but I can't make the decision for it.

Zz.

 

[marlon]

i have answers to

1) what is spin (not a particle rorating anout some axis)
2) what are vacuum fluctuations
3) same for virtual particles
4) misconceptions in the HUP
5) particle wave duality
6) elementary particles versus elementary fields
7) why doesn't the electron crash onto a nucleus
8) why do we need fields ?
9) difference between QM and QFT
10) what are quasi particles...
11) What is the Higgs field

These are questions i have answered many times and many students have difficulties with them...

regards
marlon

 

[ZapperZ]

Addendum: We are going to start this off very slowly and not make it too ambitious. I left out a number of more complicated questions (my most common pet peeve: optical conductivity, or how light/photons travel through transparent material). Most of the questions on my list are usually asked by people without a lot of physics background. So the explanation should be almost on that level, but must be based on solid physics. I think most of you know this.

I'm already getting volunteers! Terrific! Again, we can have more than one person writing on a particular topic. I'll try to edit them and see what happens. But don't expect these things to appear overnight (or even in a week). We'll go slow and iterate these things carefully.

Zz.

 

[ZapperZ]

Oooh.. there are a few more good suggestions on the questions to include. One is "What is a photon?", and the other, based on Marlon's list, is "Is light a wave or a particle?"

So as of now, the list of questions we are going to focus on are:

1. Since E = mc^2, and photons have energy, doesn't this mean that photons have mass?

2. Why doesn't an electron crash into the nucleus (or something to that effect)?

3. What do I see when I travel at the speed of light?

4. What is energy?

5. What is a photon?

6. Is light a wave or a particle?

OK, let's tackle these first before it grows and becomes unmanagable.

Zz.

 

[FredGarvin]

How about a sticky for every section? I can think of a few for the Engineering Section's sticky:

1. How do you design a hovercraft?

2. Why do you think my perpetual motion machine won't work?

And the all time leader is

3. How does a wing create lift?

 

[Astronuc]

Reminds me of many years ago when someone tried using the expression for the fine structure constant,

\alpha\,=\,\frac{e^2/\hbar c}{4\pi\epsilon_o},

to show that the speed of light, c, was variable.

Because it was in the formula.

 

[-Job-]

Maybe for the Computer Technology forum you can do this for "why Firefox is better than IE", "Why linux/mac is better than windows", "why Openoffice is better than MS Office", or generally any of the form "why <Microsoft-competitor product> is better than <Microsoft product>". Even better, have a Microsoft bashing thread and make it a sticky because i never read stickys and this way don't have to come across this nonsense.

 

[Smurf]

What would you see if you travel at the speed of light?

 

[marlon]

What would you see if you travel at the speed of light?

i dunno

marlon

 

[marlon]

Guys,

I think this site might help our purposes too.

Smurf, the answer to your question is in there...Just give up your date and do some physics research man...:)

marlon

 

[ZapperZ]

What would you see if you travel at the speed of light?

Yup. I suppose that would be another question that is too often asked. I'll include that in the list:

1. Since E = mc^2, and photons have energy, doesn't this mean that photons have mass?

2. Why doesn't an electron crash into the nucleus (or something to that effect)?

3. What do I see when I travel at the speed of light?

4. What is energy?

5. What is a photon?

6. Is light a wave or a particle?

Again, if people can pick one of these and volunteer to write a response to such an article, please PM me. I'll try to organize them and, hopefully, after the New Year, we'll have a set of brand-new FAQ's for the physics forum.

:)

Zz.

 

[DaveC426913]

You would see the entire universe die of age in an instant (because time would have stopped for you relative to the rest of the universe). That is, inasmuch as you could see at all - considering all the light you received would be infinitely blue-shifted.

Another way of looking at it is, what if you were a photon? Well, photons do not experience time at all. The entire universe happens to them all at once.

 

[vanesch]

Well, there is of course already the usenet physics FAQ,
http://math.ucr.edu/home/baez/physics/

Maybe we shouldn't re-invent the wheel for the topics that are well-treated there ?

 

[KingNothing]

Actually this has brought up an idea I've had for some time. We all know what FAQs are - frequently asked questions...but howabout IFAQS, or Infrequently asked questions?

It would just be a huge, huge list of all the simple questions we've gotten - you know, about the speed of light, what is a photon, is the HUP real, etc.

On the other hand, although there is some redundancy, if nobody ever repeated a question, there'd be a lot less activity on the board in general.

 

[ZapperZ]

Well, there is of course already the usenet physics FAQ,
http://math.ucr.edu/home/baez/physics/
Maybe we shouldn't re-invent the wheel for the topics that are well-treated there ?

I actually do want to reinvent the wheel, but tailored-made for PF. :)

There's a chance that if we have an FAQ here, that some people might actually read that first before posting their questions. But I will admit that I am not holding out on that possibility too much. There's a notice for them to not post their homework or schoolwork type questions in the General and Classical Physics forums, and people still post their homework questions right underneath the thread that tell them not to do that.

Oy vey.

Zz.

 

[KingNothing]

You would see the entire universe die of age in an instant (because time would have stopped for you relative to the rest of the universe). That is, inasmuch as you could see at all - considering all the light you received would be infinitely blue-shifted.
Another way of looking at it is, what if you were a photon? Well, photons do not experience time at all. The entire universe happens to them all at once.

Wouldn't it be so blue-shifted that it's completely out of our visual spectrum?

 

[vanesch]

Wouldn't it be so blue-shifted that it's completely out of our visual spectrum?

You'd actually be fried like a sausage...

 

[Anttech]

4. Evolution is just a "theory".

Excuse my ignorance (and as a matter of fact I believe evolution to be correct) what is Darwinism if it is not a "theory"?

 

[ZapperZ]

Excuse my ignorance (and as a matter of fact I believe evolution to be correct) what is Darwinism if it is not a "theory"?

I really did not wish that this thread goes into the actual discussion of the questions in the list. It is supposed to be producing such a list and now it is the discussion of getting people to write responses to such questions.

But since you asked, and rather than tell you to go look at my Journal Entry #12, I'll repost what I wrote there:

1. Evolution is only a THEORY.

This stems from the pedestrian usage of the word "theory", meaning to nothing more than an educated guess, if that. It implies that a scientific "theory" is nothing better, not verified, or still not accepted. Again, nothing more than an educated guess.

This argument reveals the ignorance of how the word "theory" is used in science, and especially in physics. There are two broad dichotomy of the nature of scientific studies - experimental and theoretical. Experimental involves experiment! This includes data collection, analysis, phenomenological models, etc. Theoretical, on the other hand, involves either phenomenalogical models of experiments (same as experimental), or theoretical extension of preexisting ideas via ab initio derivation. So a theory is a mathematical/logical description of an idea.

Furthermore, saying something is just a theory somehow implies that a theory can "graduate" into a law or a principle. This of course is absurd. Laws, theories, principles, etc., are all the same. Each may have varying degree of certainty or varification, but it doesn't mean one is better than the other, or that they evolve into one another.

To attack Evolution by saying it is "just a theory" is also an attack on BCS Theory of Superconductivity, Quantum Field Theory, Band Theory of Solids, etc, etc. If one is aware of how successful those physics theories are, one would never make such an idiotic argument. So this is an example of an argument made based on ignorance.

If you wish to discuss this further, I'd suggest we go to the Bio forum that already has a similar thread.

Zz.

 

[Anttech]

I was just curious, and what you stated is correct. I am not saying that it is an educated guess, but a hypothesis which has not been disproved, I was taught that science is all about uncertainty, and you should never be as naive (I know you arent) to say that something is for certain!

The definition of "theory" I was using is elequently defined here:

A comprehensive explanation of a given set of data that has been repeatedly confirmed by observation and experimentation and has gained general acceptance within the scientific community but has not yet been decisively proven. See also hypothesis and scientific law.

http://www.google.be/search?q=defin...client=firefox&rls=org.mozilla:en-US:official

 

[ZapperZ]

I was just curious, and what you stated is correct. I am not saying that it is an educated guess, but a hypothesis which has not been disproved, I was taught that science is all about uncertainty, and you should never be as naive (I know you arent) to say that something is for certain!

The definition of "theory" I was using is elequently defined here:



http://www.google.be/search?q=defin...client=firefox&rls=org.mozilla:en-US:official

But what happens when it is "decisively proven"? Does it get renamed to something else other than a theory? That has never happened! So we're stuck with playing the "name" game rather than looking at the content, which is what is more important. To say that the BCS Theory has not been "decisively proven" and that's why it has the "theory" word associated to it is absurd!

Besides, a physical theory cannot be absolutely proven. It can only be shown to be valid.

Please continue with this line of discussion elsewhere.

Zz.

 

[marlon]

Well, there is of course already the usenet physics FAQ,
http://math.ucr.edu/home/baez/physics/
Maybe we shouldn't re-invent the wheel for the topics that are well-treated there ?

You are correct but what let me answer this : many of those (great) texts are very long. I doubt if people that are not trained to much into physics will read them completely or get the point. I am sure this is not the case. Our vision should be that we make these texts shorter with more structure in them. We want short, clear answers...This is very possible.

regards
marlon

 

[Anttech]

Besides, a physical theory cannot be absolutely proven. It can only be shown to be valid.

exactly

Please continue with this line of discussion elsewhere.

Nothing further to add at my end...

 

[Pengwuino]

*comes streaking in naked* E=mc^2 is just a theory! wake up people!