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/sci/ - Science & Math

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1499437 No.1499437 [Reply] [Original]

Dear /sci/.
Would you care to explain why exactly it is impossible to reach the speed of light?
This is not intended to be a troll thread, it's just that I would like to understand the basic principles explained by the foul mouthed /sci/tard anon.

>> No.1499451

inb4 "mass grows" retarded argument

>> No.1499457

E=mc^2

look it up brah.

>> No.1499472

>>1499457
So essentially because we cannot divide by zero?

>> No.1499473

The faster you go, the more you bend space-time, the speed of light bends space at 90 degrees which is physically impossibly for an object with mass

>> No.1499477
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1499477

what is with the pics that say save as 2.hta... i hav eseen a lot of tehm

>> No.1499482

>>1499477
Oh the irony.

>> No.1499497
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1499497

>>1499473

>> No.1499509
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1499509

>>1499473
so if the earth was traveling at the speed of light it would become a cube?

>> No.1499514

>>1499473
That's not a physical argument, it's a geometrical argument from a space-time diagram, so it's not a valid answer.

>> No.1499516
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1499516

we're all math phds here

>> No.1499523

>>1499514

I also completely made it up. Was I actually somewhat correct? Holy fuck lol.

>> No.1499529

>>1499523
Doubt it bro.

>> No.1499530

>>1499516
>>1499523

Holy fuck

>> No.1499535

>>1499509

No, space would fold onto itself and form a singularity. Probably blowing the entire universe up. Most likely just creating a black hole

>> No.1499537

>>1499523
Only that you don't bend space-time. The space-time diagram "does".

>> No.1499539

<div class="math">E = \frac{1}{\sqrt{1 - v^2 / c^2}} m_0 c^2</div>

In order to reach the speed of light, you need infinite energy.

>> No.1499540

ITT: No one can explain it. Pretentious fucks.

>> No.1499542

>>1499535
NO.

>> No.1499543

NEEEEEEEEERRDSS

>> No.1499544

Because the closer to light speed you go, the more energy it takes to increase your velocity.

>> No.1499545

All observers measure the same speed for light, regardless of their relative movement.

So if you see someone moving toward you at the speed of light, and he shines a light at you, you see the light traveling right with him. But he sees the light moving ahead of him. This is an absurd situation, meaning that you can't see someone moving toward you at the speed of light.

>> No.1499553
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1499553

>>1499535
>>1499473

somewhat successful troll

>> No.1499556

Lets say you're on a bike, and you put a certain amount of energy into pedaling, and you go 5 mph. Well, let's say you put twice as much energy into it, and you'll go 10 mph. Makes sense, right? Nice and linear. If you could put three times as much energy, you'd go 15 mph, four times and 20 mph. And so on.

That's the sort of normal every day experience we have, and it's true for the speeds we travel at. But close to the speed of light, this breaks down. Speed of light is like an asymptote. If you're already going 99.9% the speed of light, and you double the amount of energy you put into your speed, you'll only be going 99.95% the speed of light.

Note: this is only a layman's analogy. I've oversimplified it, and the math is not completely correct.

>> No.1499565

>>1499539
(Not OP)
This is a reasonable answer, although it doesn't explain how does this happen. I'm also still looking for a more detailed explanation. I have some ideas on the details, but they need more development (and some review, I took the course too many years ago) and some peer review.
And I'm not telling cause it might result in a small paper. ;D

>> No.1499567

It comes from the way you add velocities together. If you have two velocities <span class="math"> u [/spoiler] and <span class="math"> v [/spoiler]. When you add them together their sum (called the relativistic sum) is actually:

<span class="math"> W=\frac{u+v}{1+\frac{uv}{c^2}} [/spoiler]

At low speeds, the <span class="math"> \frac{uv}{c^2} [/spoiler] is so smalled their added velocities looks like <span class="math"> u+v [/spoiler], but at high speeds the difference does become noticeable.

As an example. A rocket moving at 50% the speed of light shoots a rocket going 55% the speed of light, the speed of the rocket is not 105% the speed of light, but is actually:

<span class="math"> \frac{.5+.55}{1+\frac{.5\cdot.55}{1^2}}=\frac{1.05}{1.275}\approx0.82 [/spoiler]

So around 82% the speed of light.

>> No.1499576

>>1499567

Oh yeah, to show you can never move faster than the speed of light you just show <span class="math"> c^2-W^2 [/spoiler] is always positive.

>> No.1499580
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1499580

why can't I post to diochan?

>> No.1499589
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1499589

Holy fuck

It takes energy to move an object
Heavy objects require more energy to move
The faster an object moves, the heavier it gets
Objects become so heavy once the get close to the speed of light, that the amount of energy required to move it gets closer and closer to infinity

>> No.1499590

>>1499556
>you put a certain amount of energy into pedaling, and you go 5 mph. Well, let's say you put twice as much energy into it, and you'll go 10 mph
wat

>> No.1499592

OP here, I get it, the math says so.

>> No.1499600

ITT: some legit physicsfags that still think a formula answers OP's question.

>> No.1499604

>>1499580
i think it only allows italian IPs

>> No.1499608

>>1499589
No. Einstein would slap the fuck out of you for using the "mass grows" interpretation/misconception.

>> No.1499613

I don't get it, if you approach the speed of light shouldn't you get lighter (more light-like). How come you get heavier?

>> No.1499621

>>1499604
I fucking HATE Italians.

>> No.1499625

>>1499608
Fine, cunt. You explain it

>> No.1499627

>>1499625

See >>1499567

>> No.1499632

>>1499545
THIS, goddammit.

This is the starting point: the bizarre fact that light appears to move at the same speed for everyone. No formulas, no nattering about energy and mass (which come later), just a simple experimental result, from which it is immediately obvious that no two observers can measure their relative speed as being c or greater.

And no, I am not samefag.

Wait, scratch that, I am samefag.

>> No.1499633

ITT: >>1499516

>> No.1499635

>>1499625
see >>1499565

>>1499627
see >>1499600

>> No.1499638

>>1499613
Throw a ball at low velocity at someone's head
Then chuck a ball crazy hard at someone's head
Note the difference

>> No.1499652

>>1499638
That's momentum, not mass.
Similarly, it's the relativistic momentum what grows, not the mass.

>> No.1499657

>>1499632
Light is constant
Spacetime is not

>> No.1499674
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1499674

nib4 someone postst he "don't become a scientist" paper

>> No.1499675
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1499675

YES I FUCKING LOVE YOU IT EVEN HAS THE CORRECT DEFFINITION OF PERSE OR PER SAY

WHICH FAGGOTS REGULARLY USE TO MEAN AS SUCH I HATE THEM WHEN THEY DO THAT

>> No.1499691
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1499691

>>1499657
That wasn't too far from crackpot science one liners.

>> No.1499701

It's not impossible to reach the speed of light. There is no limit to how quickly you can arrive at another place. It's just impossible to observe something else moving faster than the speed of light relative to you. This is because motion through space also affects motion through time, and observe speed is (change in space / change in time). This ratio has a limit of c for any observer.

>> No.1499705

Someone posted an equation showing that you'd need infinite energy. Now, you might, "How come that equation accurately models the relation between energy, mass and velocity?"

You might as well ask "Why does gravity diminish with the square of distance and not the cube?"

Well..it's a feature of the universe. some physics pro might be able to give you some smaller scale answer (quantum shit and whatnot) but that's just pushing it one level down.

Explanations end somewhere.

>> No.1499717

Nobody knows why, notice the lack of explanation in this thread. We only know what we have observed.

>> No.1499719
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1499719

ok, I just worked it out myself using pen and paper, velocity as a function of kinetic energy is:
<div class="math">v=c \sqrt{1-(\frac{K}{m_0 c^2} +1)^-2}</div>
which means as K (kinetic energy) gets bigger, velocity approaches c. graphed it out in mathematica too so you can see velocity clearly finds an asymptote at v=c

>> No.1499720

>>1499539
this.

>> No.1499723

>>1499701
> implying time is something more than a useful mathematical construct

>> No.1499731

It's possible to move faster than light, it would just take a lot of energy. Like say, the mass of Jupiter converted to energy.

>> No.1499735

>>1499705
The only reason you'd need infinite energy to move a massive object at the speed of light -- yes, from one perspective, the perspective outside the object, it would gain infinite mass -- but from the perspective of the object, it would mean giving it infinite speed. Accelerating it to the speed of light would mean from the perspective of the object, the rest of the universe would length-contract to zero, it it would already be wherever it was going... the opposite end of the universe. This is what life is like for the photon. From its perspective, it's already where it's going. For us, it's going at c, but for the photon it's already there.

>> No.1499738

Imagine space-time as a self-encompassing four dimensional grid. Not 4 dimensional as traditionally explained to you, as in xyz+time. But 4 spatial dimensions. Imagine the universe as the 3 dimensional surface of a four dimensional sphere.
Now our space-time is divided into finite pieces. You can only divide "space" to a certain amount, there's a shortest traversable unit of length. Now since my proposed space-time doesn't actually have any "time", time is and isn't really relative. If the smallest imaginable pieces of the universe move at a constant speed through 4 dimensional space (that speed being one unit of space per unit of time(time flowing constant)). Then it is impossible for anything to move faster than the speed of light since the speed of light is one unit of space per unit of time. You and i are at this very moment moving at the speed of light in 4 dimensions, but seeing as we are made out of massive particles which have four dimensional geometry we appear to have limited velocity in three dimensions

derp derp derp...

>> No.1499739

Is the speed of light the same as the speed of low fat?

>> No.1499742

>>1499731
jupiter has infinite mass? i didn't know that.

>> No.1499744

I thought you guys were smarter than this. Pointing to an equation is hardly an explanation. Am I really going to have to take you kids to school again?

>> No.1499745

>>1499717
No, it was theorized long before it was observed.

>> No.1499748

fuckin universe
how does it work

>> No.1499752

>>1499748
i lol'd. thank you.

>> No.1499755
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1499755

maybe not but you do need one if you want to earn 300,000 for start.

>> No.1499762
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1499762

>Ph. D .in Mathematics
>Any Jo bI Want
>$300,000 Starting

>> No.1499767

>>1499744
Actually it is an explanation. In physics, we use mathematics to describe physical relationships.

>> No.1499770
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1499770

where are these spammers coming from

>> No.1499771
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1499771

Not to change the subject, but with conventional methods what is the fastest we are able to propel a human being safely?

I only ask because putting someone who has an incurable illness in an orbit at near the speed of light seams like a more logical than freezing them so future generations can cure them? Could we put someone in an orbit at near the speed of light long enough for this to work?

>> No.1499772

>>1499767
Take a physics course, kid. At least university level.

>> No.1499776

There is no explanation per se. The speed of light was found to be the same in all possible reference frames which is equivalent to it being an upper speed limit if we keep causality intact.

>> No.1499781

>>1499771
>orbiting at the speed of light

OK, we're done here.

>> No.1499785

In other words what we call "moving at c" as an observer, as the object itself, that speed is called "shrinking the length of the universe to zero". Obviously shrinking the length of the universe to zero should require infinite energy.

>> No.1499795

>>1499772
Point out the necessary features of an explanation, then.

>> No.1499796

>>1499771
Only if you have a black hole to orbit.

>> No.1499803

>>1499731
>>1499735
>>1499738
0/10

OP, thesea are the only decent answers:
>>1499705
>>1499539
>>1499719

Possibly we don't have a detailed explanation of the very details of why is it this way. We might know in the future, but it's not guaranteed.

>> No.1499808
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1499808

This is all just speculation.

>> No.1499809

Besides the physical impossibility, time dilation becomes infinite at the speed of light

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

>> No.1499812

It's infinite energy + finite time OR finite energy + infinite time, so you "can" reach the speed of light with finite energy if you have an infinite amount of time to do it.

>> No.1499814

>>1499767
Actually showing that an equation requires it is no explanation, unless you also explain why the equation must be reflective of reality.

>> No.1499825

>>1499803
What are you, retarded? You think equations just fall out of the sky and we follow them?

>> No.1499833

>>1499814
There is no such thing as "must be reflective of reality". Scientific theories never achieve the status of "necessarily true".

But yeah, someone might link OP to the empirical evidence suggesting that equation indeed accurately models what's going on, or derive from some more fundamental equations and link OP to the empirical evidence that these equations are probably true.

>> No.1499840

The obligatory relativistic rocket, since the c limit doesn't mean what you think:

http://www.xs4all.nl/~johanw/PhysFAQ/Relativity/SR/rocket.html

>> No.1499846

Thought my explanation was quite elegant

If space-time has a smallest unit of length (planck length) and if space=time, then it's impossible for anything in the universe to move at any other speed than "one planck length per planck time" ergo everything is moving at the speed of light, but due to higher dimensinal properties of massive particles it doesn't appear as such.

>> No.1499848

>>1499812
>you "can" reach the speed of light with finite energy if you have an infinite amount of time to do it.
Bullshit.

>> No.1499850

>>1499833
Wrong. E=mc^2 did not come from empirical evidence. It came from Einstein's reflection on what must necessarily be true, following from the ubiquity of maxwell's equations.

>> No.1499864

>>1499850
I covered this case in my post. If it follows from something else, you need to show that this something else (maxwell's equations) are accurate models of reality.

>> No.1499870

>>1499846
With all respect, that makes no sense as a theoretical construct. I used to have ideas like those before studying physics, so I understand why it seems to sound just right.

>> No.1499873

>>1499846

You're going backwards. You have to ask yourself why Planck length and time got defined the way that they did.

>> No.1499875

>>1499850
its M = c^2 now, retard

>> No.1499893

>>1499864
No, because he didn't ask why maxwell's equations were true, he asked why it is impossible to reach the speed of light, which can be explained in great detail starting at maxwell's equations, which require that regardless of the frame of reference, light is always observed as traveling at the same speed of c.

>> No.1499895
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1499895

So you reckon it's abotu time to stop calling it Atomic "Theory"? We should just recognize the definite parts ofQ unatum Mechanics for their dfeinitiveness. I mean i know we do in all means, so let's drop the term Atomic "Theory".

On a related note, we shoudl still call the Theory of Evolution theory, because i call bullshit (pic related)

So what other theories need erconsideration?

>> No.1499898
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1499898

Skeptciims thread.

>> No.1499905

>>1499850
>>1499875

You both are wrong. The equation is:

E = .00000000000000000001(m)c^2 + vibrations

>> No.1499907

>>1499873
exactly. that plank length and time are the smallest units of spacetime is nothing but speculation.

>> No.1499912

1 + 1 = 2

But why?

Why not 3? Or negative 11? Or the Belgian Congo?

>> No.1499920

>>1499895
oh, good. another retard.

>> No.1499935

>>1499893
Ok, I agree with this. (and don't get why you disagreed with me)
Also, a natural follow up question OP might then ask is "Ok so you use maxwell's equation to show why blabla. How come maxwell's equations are true models of reality?"

Since physics describes the physical world, eventually, you'll have to tell him that it is a feature of the world we established empirically.

>> No.1499938

if you gain mass as you go the speed of light... if u went the speed of dark (-c) would u have infinantly small mass?

>> No.1499945

>>1499920
its a bot.

>> No.1499957
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1499957

Ask them if they know any druids

>> No.1499979

>>1499935
Yes eventually, you get back to empiricism, if one keeps asking question. But not for the question that was asked.

Usually people will easily grasp Einstein's starting point, so you don't have to explain that any further, it's the ending point that causes confusion.

>> No.1499987

>>1499938
yes

>> No.1499989
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1499989

Save the pic at
There' syour answer.

>> No.1500017

God you people are obsessed with this

>> No.1500020
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1500020

I don't konw michigan, is that your best school? I'd apply to the top oen or two probably depending on th eadmission requirements etc.

I was kinda lucky with college applications; I had no chanec in hell of going to MIT or stanford but I was guaranteed admission to the best school in my satte on GPA and SATs alone and didn't even have to write an essay. Entire application process took about twenty minutes, all online. fuckyea.jpg

>> No.1500110

>>1499945
I think he meant "another retard downloaded the bot".

>> No.1500123

>>1500110
Actually I didn't. But thanks for assuming the best about me.

>> No.1500124
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1500124

lol

I have this bookmarked just so I can make people annoyed at will.

>> No.1500135
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1500135

At the boardwalk I always go to since I was a kid this year there were several end of the world proclaiming (its in may 2011 guys!) Creationists, they used arguments like the second law of thermodynamics (which they misunderstood) and the questionable reliablilty of carbon dating (to which I countered taht carbon dating is not the most popular proccess) we argued everything from the pope (I am agnostic but former catholic and have a deep respect for the clergy, met john paul II, good man) to the age of the earth and creationism vs evolution