Scientists don’t normally make much money.
An accelerating, expanding Universe?
Their discovery – that the Universe is expanding at an ever increasing speed – is simply profound. Although they first discovered it back in 1998, it still causes confusion amongst bespeckled star-gazers and flies in the face of the accepted notion that everything around us is simply the result of a Big Explosion.
No one has yet come up with a wholly convincing reason why stars are speeding away from each other at an increasing rate of knots. I have a little theory that’s been on my mind for a while - and I’d like to share it. Watch out, things are going to get rather theoretical…
Are we in the Dark?
Don’t get me wrong, I know I’m straying from my field of expertise; physics A-levels were over a decade ago and astrophysics didn’t feature highly at medical school. However, I feel reasonably well acquainted with science-y goings-on (for a medic and health science lecturer that is) – so here goes:
No one likes being in the dark – least of all scientists. However I have a problem with the modern explanations for heavenly mysteries: They seem to rely on ‘dark’ a lot. Dark matter – the presumed vast quantities of invisible mass lurking out there somewhere – is the accepted theory for a discrepancy between gravitational laws and astronomer’s observations. Similarly, dark energy – an unknown, unmeasured and unseen force – is apparently the thing that is spreading the Universe apart at ever increasing speeds.
Professor Hawking would have me for breakfast in a debate about this, but as far as I can see there isn’t a great deal of evidence to support these ideas and it all sounds a bit, well, mythical.
A Lighter Alternative
Just how constant is light?
What if the speed of light at the far reaches of the Universe was different to our own - and this difference is causing the illusion of an accelerating expanding universe?
To suggest that the speed of light is not constant, tramples on Einstein’s grave and risks a paramilitary uprising in the Large Hadron Collider canteen. That said, there is some evidence to suggest the sacred ‘c’ (in e = mc2) – the speed of light in a vacuum - may not be as steadfastly unchanging as we believe. Even before Italians starting saying that their Neutrinos were going faster than the speed of light, Australians last year reported that they had evidence that the speed of light may be different in different parts of the Universe.
Just supposing that the speed of light were faster in our district of the Milky Way than elsewhere – couldn’t that explain why far galaxies appear to be speeding away. Like seeing the optical illusion of a straw bend as it enters a glass of water – could the appearance of an accelerating universe just be an optical illusion?
“Is there an astrophysicist in the House?”
I know on occasion, a physicist passes by my humble blog – and I would love to be set straight by a more proficient cosmologist than I!
Failing that, would someone kindly go on and prove my theory – and could I please have a share in the Nobel Prize when you win…?
Thanks for reading - comments and feedback are warmly welcomed!
Issue Two is now out - get it here!
REFERENCES:
Riess, A., Filippenko, A., Challis, P., Clocchiatti, A., Diercks, A., Garnavich, P., Gilliland, R., Hogan, C., Jha, S., Kirshner, R., Leibundgut, B., Phillips, M., Reiss, D., Schmidt, B., Schommer, R., Smith, R., Spyromilio, J., Stubbs, C., Suntzeff, N., & Tonry, J. (1998). Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant The Astronomical Journal, 116 (3), 1009-1038 DOI: 10.1086/300499
J. K. Webb, J. A. King, M. T. Murphy, V. V. Flambaum, R. F. Carswell, & M. B. Bainbridge (2010). Evidence for spatial variation of the fine structure constant Physical Review Letters arXiv: 1008.3907v1
Love this one Stu! No matter how obscene it may make some people…
Posted by Rob Owen | October 7, 2011, 4:15 pmThis idea has been discussed in cosmology and astrophysics for decades.
Posted by seth | October 7, 2011, 6:20 pmAw shucks - there goes my dream of an honorable mention in a future Nobel Prize award…
Posted by Stuart Farrimond | October 7, 2011, 9:33 pmDr. Stu,
Hey, physical cosmologist here.
The idea that the speed of light could vary with time has been around for a long time, at least since the time of Dirac in the 1930s. A time-varying speed of light is a sometimes-discussed alternative to cosmic inflation, and under the right circumstances, I suppose it could mimic dark energy as well.
However, our observations of relics from the early Universe, in particular the cosmic microwave background (when the Universe was only 0.003% of its current age) and the abundance of the light elements (from when the Universe was less that four minutes old) place great constraints on how much the speed of light could have varied in that time.
In particular, this paper: http://cdsweb.cern.ch/record/421743/files/0001292.ps.gz shows that from the cosmic microwave background until today, the maximum allowed variation in the speed of light’s value is just 4%! So it’s a fun idea to think about, but the constraints make it rather unsuitable for explaining dark energy.
Cheers!
Posted by Ethan Siegel | October 7, 2011, 6:49 pmHi Ethan,
Thanks for commenting! That’s just the sort of info I needed…
I’ll check out that paper. I know feel more informed about the mind-bending world of astrophysics - much appreciated!
Stu
Posted by Stuart Farrimond | October 7, 2011, 9:38 pmHi Dr. Stu,
A modern discussion of inflation theory would not be complete without a reference to the “open inflation” theory that posits the presence of a scalar field know as an ‘inflaton’. While a nascent idea, it is a provocative concept that, along with ‘eternal inflation’, posits that our universe is a ‘bubble’ that’s isolated by the super-luminal expansion of the space around us- said expansion being driven by the inflaton. For more about this theory, Anthony Aguirre at the University of California at Santa Cruz is an eloquent proponent of this idea. His page is at http://scipp.ucsc.edu/~aguirre/Home.html
LiLi
Posted by LiLi Marleaux | October 7, 2011, 10:56 pmHi LiLi,
Wow - that’s heavy stuff. I know that multiple universe theory seems to be ‘in vogue’ at the moment to try to answer some of the big questions. What I find fascinating is that these ideas (like those on Aguirre’s site) seem to be unfalsifiable - they cannot be proven or disproven empirically.
Correct me please, but it appears that philosophy and science seem to be rather closely intertwined when the limits of our understanding are reached. It’s all very intriguing (for a medic and generalist) to try and get one’s head around.
I guess that should Higgs boson, fail to be found - the potential flood gates for serious ‘outside the box’ thinking will be opened?!
Thanks for your comment LiLi!
Stu
Posted by Stuart Farrimond | October 8, 2011, 8:21 amI read all that in the Beano years ago..
Posted by John McCorry | February 22, 2017, 11:57 amGreat post. I can\’t agree with you.
Posted by Backpack Vacuums | October 8, 2011, 7:03 amLove your honesty 🙂
Posted by Stuart Farrimond | October 8, 2011, 8:05 amHere comes my theory. Since Frank Zappa said that stupidity is the building block of the universe, and the humans are increasingly stupid, the universe has to expand to accommodate that.
Posted by Mihai Martoiu Ticu | October 9, 2011, 8:00 amBrilliant! Comment of the week 🙂
Posted by Stuart Farrimond | October 10, 2011, 6:42 amThe universe is expanding and accelerating
because the original bang, from the big bang,
hasn’t finished yet.
Like watching a bullet from a gun.
It has to accelerate before it starts to slow down.
Posted by D mynes | September 3, 2012, 9:53 pmThe answer you all are looking for is in a book “what causes gravity and what causes the expanding accelerating universe” by Tim G. Meloche
Posted by TGM | December 10, 2012, 7:05 pmWe know expansion is accelerating because the farther an object is’ the faster it seems to be moving away from us. Doesn’t that mean expansion is slowing down? The furthest objects are also the earliest so they’d be closer to the big bang. Faster billions of years ago means slower now doesn’t it? Sorry if this just dumb.
Posted by John McCorry | February 22, 2017, 11:31 am