I am given to understand that background radiation from the big bang has shifted wavelength into the microwave region of the EM spectrum over time due to the expansion of space. This implies that in the past, the frequency of this radiation must have been much greater and will have gradually shifted through the EM spectrum. I understand that there is nothing particularly special about the visible range of light other than the fact that human eyes are sensitive to it, but since the background radiation must have shifted through the visible portion of the spectrum, it raised the following questions:
If a human eye somehow existed when the cosmic background radiation was within the visible range, what would it see? Would space itself appear to have a colour, and if so, what exactly would it look like? This of course assumes that the intensity of radiation is great enough to be detected by the eye.
Thanks in advance :)
Hi guys,
For an experiment, we had a Strontium-90 beta source placed inside radiation housing with a Geiger detector taking the radioactive counts.
For 1 and 5 minutes respectively, we collected:
- Counts with no shield over the Strontium-90
- Counts with a 3mm Teflon shield over the Strontium-90
- Counts with a 2mm Aluminium shield over the Strontium-90
The question I have, is, is it necessary for the number of counts for each shield type to be corrected for background radiation?
I thought yes, because the shields are not perfect blockers of all radiation types, and background radiation can come in many types.
Is this rationale correct?
I understand that itβs remnant energy from the Big Bang, and that it accounts for the temperature of the universe (right?).
In chemistry class, we define temperature as the kinetic energy of particles in a system, but how can space have a temperature when there are no particles for energy to move?
Also how is CMB just everywhere? From what I understand, energy is usually in the form of electromagnetic waves, which travel infinitely in a vacuum until they are absorbed by something. What exactly is CMB if not a traveling wave?
This radiation also affects you
I have just recently bought a geiger counter and it is reading up to 60 CPM in my living room. It is not near any smoke detectors or anything else radioactive that I know of. Is this a normal reading for background radiation in a home?
As above. A solution on this sub for the Olber Paradox is that we reside in a less star dense part of the galaxy, but my question still remains. I can't seem to reconcile my above question in my head - the CMB as the "birth remnant" of the expanding universe as a delineated phenomena is further than even the furthest/earliest stars.
Someone please correct me if I'm wrong with how I'm picturing it in my head. Many thanks!
I have a Bachelor's in Bioinformatics and want to change my career into Radiation Therapy. What are the next steps for me to do? Do I need to go back in school?
Just wondered this. If it can flip a bit in a stick of RAM, can it also slowly degrade stuff like CPU's?
mmm colors
Iβve been working as a radiation therapist for a few years and was looking at advancing. I was wondering if there were any career options working for varian with a background as a radiation therapist.
It is very loud too.
Note - I am not a student of physics, just someone curious. So I've been watching physics documentaries/youtube videos lately out of curiosity in an effort to better understand the universe. I've come across this idea of microwave background radiation, from what I have gathered it is the oldest light in the universe. I have a fair (although limited) understanding of what it is/how it came to be, but I can't wrap my head around how we're still able to detect it. Since it is photons that we are measuring, it seems to me that one of two scenarios explains why we can detect it today:
-
The light that we are seeing is from an infinite source - we will always measure this radiation because the source was never "turned off" and continually emits photons
-
Somehow, our location in space traveled faster than the speed of light to its current position where we are able to continue to measure the photons emitted from the source
Both of these thoughts seem naive and absurd, I simply ask: what is it that I'm missing, and why are these ideas wrong? I suspect that the expansion of space has something to do with this but I'm not sure. If my understanding is correct, this radiation existed everywhere in the universe as it cooled to the point where hydrogen could form and photons could travel without interference. But wouldn't the radiation eventually radiate out into the expanding universe, leaving matter traveling slower than the speed of light behind? Any insights from those more knowledgeable would be much appreciated :)
Hi guys,
For an experiment, we had a Strontium-90 beta source placed inside radiation housing with a Geiger detector taking the radioactive counts.
For 1 and 5 minutes respectively, we collected:
- Counts with no shield over the Strontium-90
- Counts with a 3mm Teflon shield over the Strontium-90
- Counts with a 2mm Aluminium shield over the Strontium-90
The question I have, is, is it necessary for the number of counts for each shield type to be corrected for background radiation?
I thought yes, because the shields are not perfect blockers of all radiation types, and background radiation can come in many types.
Is this rationale correct?
