Exercise for the reader: Assuming average human eyesight, how many picoseconds away from a collision are you if you can read that size of text and the relative velocity between you and the car ahead of you is large enough that the red label is sufficiently blueshifted to look blue?
bumper sticker
Submitted 10 months ago by io@piefed.blahaj.zone to science_memes@mander.xyz
https://piefed.cdn.blahaj.zone/posts/Uk/Cl/UkClq0qiND9lCqw.jpeg
Comments
RiceMunk@sopuli.xyz 10 months ago
Zkuld@lemmy.world 10 months ago
for 800nm to 400nm, we need gamma=2. So v~.86c. At 20m this gives you ~80ns.
moriquende@lemmy.world 10 months ago
For perspective, this speed is:
- 928 157 450 kilometers per hour
- 576 730 301 miles per hour
In one second, you would travel around:
- 258 000 kilometers
- 160 000 miles
Which is around 6.43 times around the Earth’s equator.
glorkon@lemmy.world 10 months ago
The sticker should also say something like “But don’t worry, we’re going to be evaporated in a huge explosion anyway, due to the gigantic release of energy when you crash into my car in a few nanoseconds.”
janus2@lemmy.zip 10 months ago
does the observer have to be able to see the sticker with normal human eyesight? if so that constrains distance (which maybe doesn’t matter?)
jaybone@lemmy.zip 10 months ago
At that point it’s like the end of 2001: A Space Odyssey
redsand@lemmy.dbzer0.com 10 months ago
I want to know how fast you need to go to be color shifted on a traffic camera. The more I think about it the less likely getting enough light to be picked up by the camera might be an issue even with perfect placement
Tlaloc_Temporal@lemmy.ca 10 months ago
I think the problem would be getting enough reflected light and not too much radiant light from the compression and/or fusion plasma.
rizzothesmall@sh.itjust.works 10 months ago
So 75000km/s is too fast? Boooo, get off the road grandad!
Vex_Detrause@lemmy.ca 10 months ago
So is the reader fast or would it work the other way where the car with sticker is fast?
glorkon@lemmy.world 10 months ago
Even then, a BMW would tailgate and flash its headlights at you on a German autobahn.
curled@lemmy.dbzer0.com 10 months ago
Anyone would do that on an autobahn, get out of the passing lane slowpoke xD
far_university1990@reddthat.com 10 months ago
Best thing is when small car from 1990 push away large bmw or porsche because they have 900 hp engine with dual turbo and nitrous injection.
I love sleeper car.
ilinamorato@lemmy.world 10 months ago
If the sticker is blue, one or the other of you is about to cease being biology and start being physics.
Mr_Dr_Oink@lemmy.world 10 months ago
I am not sure i understand.
stray@pawb.social 10 months ago
Yup. Here’s a neat visual and more info on the page where I found it:
Mr_Dr_Oink@lemmy.world 10 months ago
Damn it. Imgur is blocked in the UK. Cant see that image.
ulterno@programming.dev 10 months ago
No, it has to do with blueshift.
Mr_Dr_Oink@lemmy.world 10 months ago
Right, thanks for the explaination…
Incidentally, my limited understanding and 5 seconds of research tells me the blueshift and redshift are directly related. One is linked to lower speeds and one to higher speeds. The sticker itself is red, so the joke is saying you must be travelling at some fraction of the speed of light to see the sticker as red and if you were going slower it would appear blue.
So it would seem to me in my very limited understanding that this is in fact, to do with redshift…
tetris11@feddit.uk 10 months ago
No, it’s just that democrats tend to drive faster than republicans because of their better cars and increased motivatiok to get out of red states
Sharlot@lemmy.world 10 months ago
Best kind of science joke: funny and educational. Bonus points for making people think about Doppler before speeding.
NaibofTabr@infosec.pub 10 months ago
If that sticker is blue, only the laws of physics can judge me.
iAmTheTot@sh.itjust.works 10 months ago
Hey I used I have one of these. Slightly different design though. Was always my favourite sticker.
FosterMolasses@leminal.space 10 months ago
This was good, had a hearty chuckle
Thedogdrinkscoffee@lemmy.ca 10 months ago
Mine was sensible.
Deceptichum@quokk.au 10 months ago
Half-Life
Devial@discuss.online 10 months ago
Make it green, and add the line “If this sticker is red, then I’m going too fast”
Bluewing@lemmy.world 10 months ago
Light speed? No! Engage Ludicrous speed!
far_university1990@reddthat.com 10 months ago
Put on f-777
ChaoticNeutralCzech@feddit.org 10 months ago
The color also depends on the ink’s near-infrared reflectivity (since the sun and halogen headlamps emit infrared, that will get shifted into the red to green parts of the visible spectrum when red becomes blue)
glorkon@lemmy.world 10 months ago
Clever, I like it. I wonder how many people read it and have no clue what it means.
three@lemmy.zip 10 months ago
Clickbait f*cebook-ass post