this post was submitted on 15 Feb 2025
1273 points (98.9% liked)

Science Memes

14378 readers
2130 users here now

Welcome to c/science_memes @ Mander.xyz!

A place for majestic STEMLORD peacocking, as well as memes about the realities of working in a lab.



Rules

  1. Don't throw mud. Behave like an intellectual and remember the human.
  2. Keep it rooted (on topic).
  3. No spam.
  4. Infographics welcome, get schooled.

This is a science community. We use the Dawkins definition of meme.



Research Committee

Other Mander Communities

Science and Research

Biology and Life Sciences

Physical Sciences

Humanities and Social Sciences

Practical and Applied Sciences

Memes

Miscellaneous

founded 2 years ago
MODERATORS
 
top 50 comments
sorted by: hot top controversial new old
[–] [email protected] 117 points 2 months ago (2 children)
[–] [email protected] 88 points 2 months ago (1 children)

They'd only get a light sentence anyway.

[–] [email protected] 42 points 2 months ago (1 children)

Depending on the frequency of the offence

[–] [email protected] 6 points 2 months ago

Might have community service periodically

[–] [email protected] 5 points 2 months ago

I bet that guy feels like he gets where he's going in no time at all!

[–] troyunrau 96 points 2 months ago (6 children)

Okay, just back of the envelope math. Assuming the car is truly 550nm, so the blue car is 400nm, and the red car is 700nm... How fast is the car going?

Napkin math says 0.27c.

Δλ=λ(V/c)

Now someone else can figure out the kinetic energy of the car and why the whole continent just exploded...

[–] [email protected] 44 points 2 months ago (1 children)

OK now how fast did old man's head move

[–] troyunrau 67 points 2 months ago (2 children)

Okay, napkin math... his nose is about 20cm long, and assuming it rotated about a perfect circle. The car moved say 10m. At the speed the car is moving, it covers that distance in ~120ns. So he has to move the end of his nose around a quarter circle of radius 20cm in 120ns. Let's say 30cm total movement, for easy math. 0.25cm/ns or 0.00025m/ns. The speed of light is 0.300m/ns, so we're talking about ~0.001c at the tip of his nose. Which is incidentally very close to the speed of sound in air.

So, probably not quite a sonic boom off the end of his nose. Assuming my math is correct. Very strong neck muscles. Also, he's been vapourized.

[–] [email protected] 7 points 2 months ago

Ah this is so great. In the transonic regime (just below 1.0 Mach) the air moving over the surface of his nose will break the speed of sound as it gets out of the way.

[–] [email protected] 3 points 2 months ago (2 children)

I think you missed a factor of 1000 when comparing against the speed of sound in air. I think it should be almost 1000 times the speed of sound, so definitely sonic boom and definitely vaporised!

load more comments (2 replies)
[–] [email protected] 34 points 2 months ago (1 children)

Did you take into account that the car is not driving directly towards the viewer?

[–] troyunrau 48 points 2 months ago

I ain't doing hyperbolic equations on my napkin ;)

[–] [email protected] 13 points 2 months ago

So about 180 million MPH. I hope he doesn't get a ticket!

[–] [email protected] 9 points 2 months ago (1 children)

now calculate the Lorentz contraction

[–] troyunrau 6 points 2 months ago

Instructions unclear, car stuck in dick.

[–] [email protected] 4 points 2 months ago (2 children)

Why explode, the car didn't accelerate or interact with the continent

[–] [email protected] 19 points 2 months ago* (last edited 2 months ago) (2 children)

Even ignoring the tires interacting with the road, you have air molecules. I don't think that would be enough to destroy a continent, but it would be very destructive.

Here is a cool What If? from xkcd about throwing a baseball at 0.9c.

[–] [email protected] 8 points 2 months ago

Sound like a ton worth of mass would do a lot of damage indeed

[–] [email protected] 6 points 2 months ago

Wow, that seems to be the very first What If ever!

[–] [email protected] 3 points 2 months ago

For the same reason this baseball causes an expanding plasma-ball disintegrating everything. Fusion with air molecules that can't get out of the way fast enough https://what-if.xkcd.com/1/

load more comments (1 replies)
[–] [email protected] 78 points 2 months ago

Here's the original image. It was originally posted in 2017 and has been shared so many times it was difficult to find a good copy. I had to use wayback to get this copy.

[–] Alabaster_Mango 49 points 2 months ago* (last edited 2 months ago) (1 children)

One shift
Two shift
Red shift
Blue shift

[–] [email protected] 14 points 2 months ago (1 children)
[–] [email protected] 6 points 2 months ago (1 children)

Damn, remember when Valve made half life games? It was a better time back then.

[–] [email protected] 5 points 2 months ago (1 children)

Half life : alyx is not that old.

[–] [email protected] 4 points 2 months ago (6 children)

I’d call that half like with an asterisk.

load more comments (6 replies)
[–] [email protected] 36 points 2 months ago (1 children)

Pretty sure the sonic boom of this car passing will kill this poor man

[–] [email protected] 11 points 2 months ago

Well, when that finally happens the car will be fine, far away from Earth.

[–] [email protected] 21 points 2 months ago (1 children)

If that guy is keeping track of that car, his neck is def broken

[–] [email protected] 16 points 2 months ago

Everything around the car would be broken too, including the car

[–] [email protected] 21 points 2 months ago
[–] [email protected] 19 points 2 months ago (2 children)
[–] [email protected] 6 points 2 months ago

And one fast head turn

load more comments (1 replies)
[–] [email protected] 16 points 2 months ago

what a beatiful green car

[–] [email protected] 11 points 2 months ago (2 children)

For some reason I can never remember which causes red or blue shift, but with this I might actually remember it

[–] [email protected] 13 points 2 months ago

Blue has a smaller wavelength, so when something is approaching fast it "squishes" the light, making a smaller wavelength.

[–] [email protected] 5 points 2 months ago

Maybe it's slightly convoluted but here's how I tackle it in my head: I just think of infrared and ultraviolet, ultraviolet being greater frequencies than violet and infrared being the opposite for red. Blue is on the way from infrared to ultraviolet, so blue has a greater frequency than red.

[–] [email protected] 9 points 2 months ago

You can either know the position of the car or the momentum, but not both.

[–] [email protected] 7 points 2 months ago (3 children)

But why is the car stretched? And why doesn't it appear rotated?

[–] [email protected] 11 points 2 months ago (2 children)

It's how Doppler works.

I don't understand it enough to actually explain but Wiki does a pretty good job.

[–] [email protected] 5 points 2 months ago

The poster you are replying to is pointing out the inaccuracies that this comic didn't consider relativistic effects.

load more comments (1 replies)
load more comments (2 replies)
[–] [email protected] 4 points 2 months ago (2 children)

This is also playing on red-shift/blue-shift.

[–] [email protected] 13 points 2 months ago

what do you mean "also"?

[–] [email protected] 3 points 2 months ago

They are the same effect just using different kinds of wave.

[–] [email protected] 4 points 2 months ago

eeeeeeeeeeeeeeeeeeeyowwwwwwwwwwww

[–] [email protected] 3 points 2 months ago
[–] [email protected] 3 points 2 months ago

I know just enough about the light spectrum and the red shift to understand why this is funny (thanks Prof. Brian Cox!), but it underlines how shallow my knowledge is. So much cosmology, so little time...

[–] [email protected] 3 points 2 months ago

YEA! SCIENCE JOKES!

load more comments
view more: next ›