Captain Feature
DgarRoses are red.
Roses are blue.
Depending on their velocity
relative to you.
Roses are blue.
Depending on their velocity
relative to you.
Georg Arne Spenden@dgar Hence "the blues".
Martin Vermeer FCD
Not with Stupid; I AM Stupid.@dgar Apparently this little ditty was via my paternal grandmother, whom I never knew:
Roses are red.
Violets are blueish.
If it wasn't for Jesus
We'd all be Jewish.
Roses are red.
Violets are blueish.
If it wasn't for Jesus
We'd all be Jewish.
Graham Lester
Spaghetti@dgar shifty
Amipfaelzer@dgar Hubble joke. Well done.
Vanessa Cobb@dgar Love this! 😁
Joan Mastodon
Stella-Luna Observatory ✨🌙@dgar Really Rapid Roses
otheorange_tag@dgar brilliant!
Wendy Nather
lagaya@dgar Hi, there. I was following you, but had to unfollow. You boost so many posts, that my timeline is almost entirely filled with your interests instead of mine. Sorry, It's too much.
@carfreesince93
No problem! I totally understand!! Thanks for letting me know.
I have so many followers now that it’s hard to keep up. I think I’m beginning to understand why people with a large following don’t interact so much with the community, but I’m still trying to connect with everybody. Maybe I should dial it down….
😊
No problem! I totally understand!! Thanks for letting me know.
I have so many followers now that it’s hard to keep up. I think I’m beginning to understand why people with a large following don’t interact so much with the community, but I’m still trying to connect with everybody. Maybe I should dial it down….
😊
Kevin RussellOr run two accounts.
Tattie (old account)@carfreesince93 hi, just a quick note: there's a "hide boosts" option hidden on the user page after you follow them, that will show you only direct posts from someone. Hope that's helpful.
@dgar
@dgar
PhDog 🇮🇪I actually unfollowed someone because I wanted it the other way around.
@Tattie thank you!
BlueShiftNZ
Jenni Tardigrade Hunter
Treble Sketch 
🚀@dgar Indeed, I've decided to nerd out a bit here...
Assuming "red" is 420 THz and "blue" is 650 THz, with the receiver standing still while *in the vacuum of space*.
The rose will be travelling to the viewer at... 106,080,408 m/s
or...
at 35.38% the speed of light!!!
Now that's a fast rose headed RIGHT at you xD
Hugo Slabbert ⚠️@TrebleSketch which now reminded me of https://what-if.xkcd.com/1/
@hugo Indeed x3
I remember reading this when it was first released, loved it!
Thanks for reminding me about this again :D
Aaron Priven
Rhinos Worry Me has movedQuick back-of-the-envelope calculation suggests it would have about 7 Hiroshima bombs of energy, too...
@RhinosWorryMe That is a lot of weapons?!?!
Andrew Werth
Digital Geenery
♦️ ereliuer eteer ♦️@dgar How does their color depend on their velocity? And how does their color depend on the velocity of the source of light?
@dgar Thanks. Yes, I understand the general idea about the redshift and the Doppler effect. I'm asking about how the velocity of the source of light (e.g. sun), and the velocity of the reflecting surface (e.g. roses) contribute to this effect. Are both of them important?
@ereliuer_eteer
The velocity of light is light speed. The velocity of the rose, as other commenters have suggested, needs to be very high indeed to appear blue.
The velocity of light is light speed. The velocity of the rose, as other commenters have suggested, needs to be very high indeed to appear blue.
@dgar No, I didn't mean the speed of light. I mean the relative velocity of the source of light (e.g. sun) to the rose and to the observer. I assume the color of the lighting is also important, not only the color of the reflective surface.
@ereliuer_eteer
…wait. You’re a theoretical physicist? Why are you asking me??! 😂
…wait. You’re a theoretical physicist? Why are you asking me??! 😂
@dgar Yes, I was 21 years ago. I asked because I always thought about the red/blueshift as depending on the relative velocity of the source of light and the observer. But you introduced a reflective surface (roses), and it created a new perspective on this phenomenon, that I never thought about before, so I invited you to a discussion about it. 🙂
@ereliuer_eteer
Ah. I’m a high school dropout. I need Brian Cox or Neil DeGrasse to explain it! ☝️😁👍
Ah. I’m a high school dropout. I need Brian Cox or Neil DeGrasse to explain it! ☝️😁👍
@dgar @ereliuer_eteer Hmmm, I'm not really sure!
WhichOne'sPink 🇫🇮
Extinction (our fate)
Vincent Wanders Aimlessly@dgar and violets are violet. Dammit
Locksmith@dgar Reminds me of Carl Sagan's Cosmos series, in the 80s, where he demonstrated that in a hypothetical universe wherein the speed of light was 80 km/h, motorcycles would be seen bluish or red depending on where the observer was.